In vivo functional brain mapping using ultra-high-field fMRI in awake common marmosets

The common marmoset (Callithrix jacchus) is gaining attention in the field of cognitive neuroscience. The development of an effective protocol for fMRI data acquisition in awake marmosets is a key factor in developing reliable comparative studies. Here, we describe a protocol to obtain fMRI data in awake marmosets using auditory and visual stimulation. We describe steps for surgical and anesthesia procedures, MRI training, and positioning the marmosets within an MRI-compatible body restraint. We then detail fMRI scanning and preprocessing of functional images. For complete details on the use and execution of this protocol, please refer to Jafari et al. (2023).1.

A radiofrequency coil to facilitate task-based fMRI of awake marmosets

BACKGROUND

The small common marmoset (Callithrix jacchus) is an ideal nonhuman primate for awake fMRI in ultra-high field small animal MRI scanners. However, it can often be challenging in task-based fMRI experiments to provide a robust stimulus within the MRI environment while using hardware (an RF coil and restraint system) that is compatible with awake imaging.

NEW METHOD

Here we present an RF coil and restraint system that permits unimpeded access to an awake marmoset's head subsequent to immobilization, thereby permitting the setup of peripheral devices and stimuli proximal to the head.

RESULTS

As an example application, an fMRI experiment probing whole-brain activation in response to marmoset vocalizations was conducted-this paradigm showed significant bilateral activation in the inferior colliculus, medial lateral geniculate nucleus, and auditory cortex.

COMPARISON WITH EXISTING METHOD(S)

The coil performance was evaluated and compared to a previously published restraint system with integrated RF coil. The image and temporal SNR were improved by up to 58 % and 27 %, respectively, in the peripheral cortex and by 30 % and 3 % in the centre of the brain. The restraint-system topology limited head motion to less than 100 µm of translation and 0.30° of rotation when measured over a 15-minute acquisition.

CONCLUSIONS

The proposed hardware solution provides a versatile approach to awake-marmoset imaging and, as demonstrated, can facilitate task-based fMRI.

[Instabilities of the Thumb Carpometacarpal Joint: Our Surgical Outcomes]

PURPOSE OF THE STUDY Carpometacarpal (CMC) instabilities of the thumb joint occur after injuries or due to joint overload in patients with congenital joint hypermobility. They are often undiagnosed and, if left untreated, are the basis for the development of rhizarthrosis in young individuals. The authors present the results of the Eaton-Littler technique. MATERIAL AND METHODS The authors present a set of 53 CMC joints of patients with an average age of 26.8 years (15-43 years) operated on in the years 2005-2017. Post-traumatic conditions were found in 10 patients and in 43 cases instability was caused by hyperlaxity, also demonstrated in other joints. The operation was performed from the Wagner's modified anteroradial approach. After the operation, a plaster splint was applied for 6 weeks, after which rehabilitation (magnetotherapy, warm-up) began. Patients were evaluated using the VAS (pain at rest and during exercise), DASH score in the work module, and subjective evaluation (no difficulties, difficulties not limiting normal activities, and difficulties limiting normal activities) before surgery and 36 months after surgery. RESULTS During the preoperative assessment, the average VAS value was 5.6 at rest and 8.3 during exercise. During the VAS assessment at rest, the values at 6, 12, 24 and 36 months after surgery were 5.6, 2.9, 0.9, 1, 2 and 1.1. When evaluated in the given intervals under load, the detected values were 4.1, 2, 2.2 and 2.4. The DASH score in the work module was 81.2 before surgery, 46.3 at 6 months, 15.2 at 12 months, 17.3 at 24 months, and 18.4 at 36 months after surgery. In the subjective self-assessment made at 36 months after surgery, 39 patients (74%) assessed their condition as having no difficulties, ten patients (19%) reported difficulties that did not limit normal activities, and four patients (7%) reported difficulties limiting normal activities. DISCUSSION Most authors present the results of their surgeries in patients with post-traumatic joint instability, and they report excellent results at two to six years after surgery. There is a negligible number of studies addressing instabilities in patients with instability caused by hypermobility. When using the conventional method described by the authors in 1973, our results of the evaluation performed at 36 months after surgery are comparable to those reported by other authors. We are well aware of the fact that this is a short-term follow-up and that this method does not prevent developing degenerative changes in the case of long-term follow-up, but reduces clinical difficulties and may delay the development of severe rhizarthrosis in young individuals. CONCLUSIONS CMC instability of the thumb joint is a relatively common disorder, although not all individuals experience clinical difficulties. In the case of difficulties, the instability needs to be diagnosed and treated as this is how the development of early rhizarthrosis in the predisposed individuals can be prevented. Our conclusions suggest a possibility of a surgical solution with good results. Key words: carpometacarpal thumb joint, thumb CMC joint, carpometacarpal thumb instability, joint laxity, rhizarthrosis.

[Arthroscopic Excision of Osteoid Osteoma of the Femoral Head]

Osteoid osteoma is a primary benign bone tumor with rare intra-articular occurrence. Our case report describes a rare case of a 21-year-old man with long-term severe pain in the right hip region caused by osteoid osteoma managed by arthroscopic excision. The clinical finding of pains and a limited range of motion did not correlate with the normal plain X-ray finding. The osteoid osteoma was suspected based on the CT scan. In literature, several methods of resection of intraarticular osteoid osteoma of the hip are described. Since our department has long specialised in arthroscopic hip surgery and based on the available examinations the tumor appeared to be located within the arthroscopic reach, we decided for arthroscopic resection of the tumor. Our study comprises a detailed description of the entire surgical procedure, the used arthroscopic approaches and the arthroscopic technique of tumor excision. The histological examination of samples taken from the mass confirmed the suspected osteoid osteoma. The success of arthroscopic excision of the tumor was later confirmed also by very positive postoperative recovery when the patient very soon experienced a considerable reduction of pain observed during our five-year follow-up of the patient (Day 13, Week 2 and 6, Year 1, 2 and 5). During the follow-up period, an increase of the Harris Hip Score (13.5 preoperatively vs 76.6/91/94/96/96 postoperatively) and a decrease in VAS (9 preoperatively vs. 3/1/1/1/1) were reported. The follow-up CT and MRI performed at 2 or 5 years after surgery did not show tumor recurrence. The case report includes also illustrations consisting of X-rays, CT and MRI scans before and after surgery as well as multiple scans taken intraoperatively. It has to be emphasized that this is a rare case and an evaluation of a larger group of patients would be necessary to verify the successful outcomes of arthroscopic technique in treatment of the hip joint osteoid osteoma.

[Clinical Outcomes of the Application of Platelet-Rich Fibrin during Anatomic Anterior Cruciate Ligament Reconstruction: Results of Prospective Randomised Study]

PURPOSE OF THE STUDY It was a prospective, randomised, unblinded study. Effects of the application of platelet-rich fibrin (PRF) on the anatomic anterior ligament reconstruction were examined. MATERIAL AND METHODS A total of 40 patients who underwent a surgery between 2012 and 2014 were enrolled in the study. The patients were randomised into two groups: the group with PRF application (n=20) and the group without PRF application (n=20, control group). The study included 11 women and 29 men, with the mean age at the time of inclusion into the study 29.1 years. Vivostat ® PRF was obtained perioperatively from the patient s blood and applied intraoperatively to the hamstring tendon graft. The ACL graft healing was assessed through magnetic resonance (MRI) at 6 and 12 months postoperatively. The clinical outcomes (the Lysholm score and the IKDC Subjective score, return to pre-injury sport levels, Pivot-shift test, graft failure) as well as standardised laxity measurements using GenouRob arthrometer were performed preoperatively and 12 months after surgery. RESULTS The study was completed by thirty-three (33) patients (17 in the PRF group and 16 in the control group). In two cases, postoperative graft failure was reported (both cases in the control group). No significant differences were found in the process of graft ligamentization evaluated through MRI (p=0.07). No significant difference between the groups was identified with respect to return to pre-injury sport levels (p=0.232), or the Lysholm score and IKDC Subjective score (p=0.259, and p=0.364 respectively). The postoperative knee laxity measurement using Genourob arthrometer did not reveal any significant differences between the PRF group and the control group. DISCUSSION Results similar to those arrived at by our study have recently been published also by other authors worldwide. We can therefore assume that the application of PRF can be of benefit, especially at the early stage of healing. The results still need to be verified on a larger study group, the study design should focus on the development in the early postoperative period. CONCLUSIONS In our study group, no significant difference was observed in the evaluated subjective and objective clinical parameters. Only the parameter regarding the ACL graft failure fell just short of statistical significance, namely to the disadvantage of the group without the PRF application. Key words: anterior cruciate ligament, arthroscopy, anatomic ACL reconstruction, magnetic resonance imaging of the graft, platelet-rich fibrin, graft healing, MRI signal intensity of the graft.

Radiofrequency coil for routine ultra-high-field imaging with an unobstructed visual field

Many neuroscience applications have adopted functional MRI as a tool to investigate the healthy and diseased brain during the completion of a task. While ultra-high-field MRI has allowed for improved contrast and signal-to-noise ratios during functional MRI studies, it remains a challenge to create local radiofrequency coils that can accommodate an unobstructed visual field and be suitable for routine use, while at the same time not compromise performance. Performance (both during transmission and reception) can be improved by using close-fitting coils; however, maintaining sensitivity over the whole brain often requires the introduction of coil elements proximal to the eyes, thereby partially occluding the subject's visual field. This study presents a 7 T head coil, with eight transmit dipoles and 32 receive loops, that is designed to remove visual obstructions from the subject's line of sight, allowing for an unencumbered view of visual stimuli, the reduction of anxiety induced from small enclosures, and the potential for eye-tracking measurements. The coil provides a practical solution for routine imaging, including a split design (anterior and posterior halves) that facilitates subject positioning, including those with impaired mobility, and the placement of devices required for patient comfort and motion reduction. The transmit and receive coils displayed no degradation of performance due to adaptions to the design topology (both mechanical and electrical) required to create an unobstructed visual field. All computer-aided design files, electromagnetic simulation models, transmit field maps and local specific absorption rate matrices are provided to promote reproduction.

[Unstable RAMP Lesions of the Medial Meniscus in ACL-Deficient Knee: Comparing the Outcomes of Outside-in versus All-inside Surgical Repair - a Retrospective Study]

PURPOSE OF THE STUDY We present the results of the retrospective study comparing the clinical outcomes of outside-in versus all-inside suture techniques of unstable RAMP lesions (RL) of the medial meniscus in patients with simultaneous ACL lesion with a minimum two-year follow-up. MATERIAL AND METHODS The retrospective evaluation covered two groups of patients who underwent the arthroscopic repair of unstable RL in combination with anterior cruciate ligament reconstruction (ACLR). Group 1 included 42 patients (28 men/24 women). Group 2 consisted of 36 patients (21 men/15 women). In Group 1, RL suture repair using the outside-in technique by posteromedial approach with absorbable PDS suture was performed, while in Group 2 the all-inside technique of RL suture via the standard anteromedial portal was applied using the Fast-Fix system (Smith Nephew, USA). The evaluation was done preoperatively and postoperatively with the mean follow-up of 27.9 months in Group 1 and 30.1 months in Group 2. The patients were assessed using the subjective IKDC score and the side-to-side difference (SSD) in ventral laxity was measured by Genourob (GNRB) laximeter at the applied pressure of 134 N and 250 N. Moreover, the failure rate of RAMP lesion repair, ACL graft, necessity of secondary partial meniscectomy and return to pre-injury level of sport were analysed. RESULTS The median IKDC score increased in Group 1 from 56 points preoperatively to 92 points postoperatively and in Group 2 from 58 points preoperatively to 90 points postoperatively (p>0.05). The median value of SSD in ventral laxity of the knee measured by the GNRB laximeter at the applied pressure of 134 N in Group 1 was 5.6 mm preoperatively and 1.9 mm postoperatively and in Group 2 it was 5.9 mm preoperatively and 2.3 mm postoperatively. At the pressure of 250 N, the median value in Group 1 was 7.9 mm preoperatively and 2.7 mm postoperatively and in Group 2 it was 8.1 mm preoperatively and 3.2 mm postoperatively. When comparing the SSD of the groups postoperatively, no statistically significant difference was found (p>0.05). Revision arthroscopy was performed in 8 patients. In 1 patient (2.4 %) in Group 1 and in 4 patients (11.1%) in Group 2 a rerupture of the RL of the meniscus occurred and partial meniscectomy was performed. In Group 2, statistically significant higher occurrence of the RL suture failure (p<0.05) was reported and there was a need to perform partial medial meniscectomy (p<0.05). The ACL graft failure was observed in 2 patients (4.7%) in Group 1 and in 3 patients (8.3%) in Group 2 (p>0.05). 31 evaluated patients (73.8%) from Group 1 and 24 patients (66.7%) from Group 2 (p>0.05) returned to the pre-injury level of sports activities. DISCUSSION When comparing the outcomes of individual techniques of the RL repair published in recent literature with our conclusions, we may state that the results of subjective as well as objective criteria achieved were similar to those reported by other authors worldwide. No study has so far been published which would compare the outcomes of the by us presented two surgical techniques of the RL suture in an ACL-deficient knee with a minimum follow-up of 24 months. CONCLUSIONS Both the surgical techniques of unstable RL repair in combination with the ACLR using a tendon graft result in a statistically significant improvement of clinical outcomes postoperatively. In Group 2, with the all-inside RL repair, a statistically significant higher failure rate of RL repair was confirmed as well as the need to perform secondary partial meniscectomy compared to Group 1. Key words: RAMP lesion, ACL-deficient knee, unstable medial meniscus lesion, repair of meniscus, all-inside technique, posteromedial technique, ACL reconstruction.

[Effect of a Single Dose of Tranexamic Acid Administered during Anterior Cruciate Ligament Reconstruction Using Hamstrings: a Randomized Clinical Study]

PURPOSE OF THE STUDY Anterior cruciate ligament reconstruction is one of the most common reconstruction surgeries. The unintended consequences of the surgery are hemarthrosis, blood loss, knee swelling and postoperative pain. The purpose of the study was to evaluate the effect of a single dose of intravenous tranexamic acid (TXA) on the postoperative parameters and functional status of the knee joint 3 months after surgery. MATERIAL AND METHODS It is a prospective randomised clinical study. An intravenous injection of TXA equivalent to 15 mg/kg in 100 ml of saline solution was administered to the test group during the surgery (20 minutes before the end of the surgery). The control group was administered 100 ml of saline solution without TXA. In both groups, the following parameters were evaluated preoperatively and postoperatively (on Day 1 and Day 10 and at 1 month and 3 months): thigh circumference at 1 cm above the patella, Coupens and Yates (CY) score for swelling, and pain score (VAS). At 24 hours after the surgery, the blood loss (secretion into the drain) and decrease in hemoglobin (Hb) and hematocrit (HCT) levels compared to the preoperative levels were assessed. The functional status of the knee joint was assessed based on the Lysholm knee scoring scale and the IKDC subjective knee evaluation form preoperatively, or at 1 and 3 months postoperatively. RESULTS In the test group, a significantly lower blood loss was detected 24 hours after the surgery. The mean difference of 128 ml compared to the control group was both statistically and practically significant (p < 0.001, d =1.42). The test group showed a lower decrease in Hb and HCT levels postoperatively compared to the control group, although with no statistical significance. On the first postoperative day, slightly better results of the thigh circumference at 1 cm above the patella and of the CY score were observed in the test group. However, during the follow-up check performed postoperatively on Day 10, the differences in the thigh circumference at 1 cm above the patella, CY score and pain VAS score were negligible. The differences in the functional status of the knee joint between the two groups ascertained during the check performed 1 month and 3 months after the surgery were insignificant. DISCUSSION Our study, just like other studies, confirms a significant effect of a single dose of intravenous TXA on the volume of blood loss and early postoperative swelling, which are the parameters affecting the early postoperative course. Even though the intervention does not affect the subsequent result of surgery, it can undoubtedly be of benefit perioperatively. There is a fairly limited number of randomised clinical studies on this topic in literature, with most of them published in the last 7 years. Further research should, among other things, optimise the protocol and identify a suitable candidate for TXA administration in patients undergoing an ACL reconstruction. CONCLUSIONS Our study confirmed the positive effect of a single dose of intravenous TXA during the reconstruction of anterior cruciate ligament using hamstrings on early postoperative blood loss and early postoperative swelling, which can have a positive effect on wound healing and prevent postoperative complications. Therefore, in agreement with available literature, we recom mend administering a single dose of intravenous TXA in ACL reconstruction, unless there is a contraindication to this therapy. Key words: anterior cruciate ligament reconstruction, hamstrings tranexamic acid, single intravenous administration, clinical evaluation.

[Benefits of the Acetabular Microfracture Technique in Arthroscopic Treatment of Chondral Defects in Femoroacetabular Impingement Syndrome: Two-Year Results of a Multicenter Prospective Randomized Study]

PURPOSE OF THE STUDY Two-year clinical results of a multicenter prospective randomized study in patients with arthroscopically treated Femoro - acetabular Impingement syndrome and concurrently performed microfracture for grade IV chondral lesions of the acetabulum. MATERIAL AND METHODS The study evaluated a group of 55 patients of the originally enrolled 92 patients with the underlying diagnosis of FAI syndrome with intraoperatively confirmed grade IV acetabular chondropathy of up to 4 cm2 in size, who had undergone a comprehensive hip arthroscopy (correction of structural cam-type and/or pincer-type deformity, labral refixation or partial labral resection etc.) performed by two experienced surgeons. The patients were randomized intraoperatively using a closed envelope method into two groups. In Group 1 (31 patients), microfractures for chondral defects was performed, while in Group 2 the patients underwent a defect debridement procedure only. The studied group included a total of 7 professional and 48 recreational athletes (33 men and 22 women), with the mean age of 34.4 in Group 1 and 31.1 in Group 2. Preoperatively and 6, 12 and 24 months postoperatively the modified Harris Hip Score (mHHS) parameters and VAS score were evaluated and also revision surgeries, conversion to endoprosthesis, and occurrence of complications were recorded. RESULTS Preoperatively, no statistical difference between the two groups was found in the studied parameters (mHHS and VAS). Postoperatively (after 6, 12 and 24 months), in both groups a statistically significant increase in mHHS and VAS score was reported. When comparing the mHHS parameter at individual evaluated times in Group 1 and Group 2, a statistically significant difference was confirmed at 12 and 24 months after surgery (P < 0.001), namely in favour of Group 1. At 6 months postoperatively, no statistically significant difference in this parameter between the two groups was confirmed (P = 0.068). When comparing the VAS score parameter in these two groups at individual times, no statistically significant difference was confirmed at 6 and 12 months after surgery (P= 0.83 / P= 0.39). A statistically significant difference in the VAS score parameter was observed only at 24 months after surgery, namely in favour of Group 1 (P< 0.037). In the course of the follow-up period, altogether 3 patients (2 patients from Group 1) were indicated for revision hip arthroscopy and in 1 female patient an endoprosthesis was implanted. No severe intraoperative or postoperative complications were observed. DISCUSSION In agreement with other authors worldwide, the arthroscopic treatment of FAI syndrome, if indicated and performed correctly, was confirmed to improve the clinical condition of patients postoperatively, regardless of the technique used in treating the chondral defect. Based on our results as well as conclusions of other world authors, in treating the grade IV defects of smaller size it is appropriate, in treating the cartilage, to prefer the microfracture surgery, which is less demanding both technically and financially and contrary to mere debridement allows to fill the original defect by fibrocartilage tissue. CONCLUSIONS The benefits of the acetabular microfracture in patients with the FAI syndrome treated arthroscopically were confirmed. A statistically significant difference between the two studied groups was reported in the mHHS parameter at 12 and 24 months after surgery and also in the VAS parameter at 24 months in favour of the group with performed microfracture. In both the studied groups, the arthroscopy resulted in a statistically significant improvement of the assessed quality of life parameters. Key words: hip arthroscopy, femoroacetabular impingement syndrome, chondral defect, microfracture, abrasive chondroplasty.

Reproducibility of Neurite Orientation Dispersion and Density Imaging (NODDI) in rats at 9.4 Tesla

PURPOSE

Neurite Orientation Dispersion and Density Imaging (NODDI) is a diffusion MRI (dMRI) technique used to characterize tissue microstructure by compartmental modelling of neural water fractions. Intra-neurite, extra-neurite, and cerebral spinal fluid volume fractions are measured. The purpose of this study was to determine the reproducibility of NODDI in the rat brain at 9.4 Tesla.

METHODS

Eight data sets were successfully acquired on adult male Sprague Dawley rats. Each rat was scanned twice on a 9.4T Agilent MRI with a 7 ± 1 day separation between scans. A multi-shell diffusion protocol was implemented consisting of 108 total directions varied over two shells (b-values of 1000 s/mm2 and 2000 s/mm2). Three techniques were used to analyze the NODDI scalar maps: mean region of interest (ROI) analysis, whole brain voxel-wise analysis, and targeted ROI analyses (voxel-wise within a given ROI). The coefficient of variation (CV) was used to assess the reproducibility of NODDI and provide insight into necessary sample sizes and minimum detectable effect size.

RESULTS

CV maps for orientation dispersion index (ODI) and neurite density index (NDI) showed high reproducibility both between and within subjects. Furthermore, it was found that small biological changes (<5%) may be detected with feasible sample sizes (n < 6-10). In contrast, isotropic volume fraction (IsoVF) was found to have low reproducibility, requiring very large sample sizes (n > 50) for biological changes to be detected.

CONCLUSIONS

The ODI and NDI measured by NODDI in the rat brain at 9.4T are highly reproducible and may be sensitive to subtle changes in tissue microstructure.

[Combined Symptomatic Treatment of Groin Pain Syndrome in Professional Football Players - Prospective Study Results]

PURPOSE OF THE STUDY The results of the prospective study evaluating the outcomes of a combined therapeutic approach of non-operative therapy of Groin Pain Syndrome (GPS) in professional football players are presented. MATERIAL AND METHODS The evaluated cohort consisted of a total of 31 football players of a professional football club divided into two groups. The Group 1 included 10 symptomatic patients suffering from GPS for at least 4 weeks, the Control Group 2 included 21 healthy football players not suffering from GPS. The symptomatic patients with GPS who had undergone any surgery or had sustained any major injury to their low back, groins, hip or knee joints were excluded from the study. It was a prospective non-randomized study. The results were evaluated using the HAGOS (Copenhagen Hip and Groin Outcome Score) questionnaire, which in Group 1 compared the results before the initiation of the new combined therapeutic approach of non-operative therapy developed by us and the results after the end of this treatment, i.e. after 6 weeks. Moreover, the HAGOS was used to compare the results of the Group 1 after the treatment and the Control Group 2, i.e. the healthy football players. The HAGOS evaluated six separate areas: Pain, Symptoms, Physical function in daily living, Physical function in sport and recreation, Participation in physical activities, and hip and/or groin-related Quality of Life. The resulting score for each domain ranges from 0 to 100 (100 = no problems, 0 = extreme problems). The results were statistically evaluated by an independent statistician. RESULTS In Group 1, after the end of the treatment a statistically significant improvement was observed in all the parameters assessed by HAGOS. Pain (70 before the treatment, 95 after the treatment), Symptoms (58.9 before/85.7 after), Physical function in daily living (70 before/100 after), Physical function in sport (46.9 before/90.6 after), Participation in physical activities (43.8 before/100 after), Quality of Life (66.3 before/95 after). When comparing the two groups, before the treatment a statistically significant difference was found in all the six parameters assessed by HAGOS, while after the treatment no significant difference between Group 1 and Group 2 was detected. DISCUSSION The most important result of our study is that by applying the new combined therapeutic approach of the GPS nonoperative therapy developed by us better HAGOS score were achieved in our cohort than those achieved by other types of non-operative therapy presented in recent literature. The approach proposed by us is more successful in terms of the speed of return to sport (6 weeks) than the multimodal therapy programme (12 weeks) and Training programme (18 weeks). CONCLUSIONS The results of this prospective study confirm that the Group 1 having undergone the 6-weeek long combined symptomatic non-operative therapy of GPS proposed by us showed a statistically significant improvement in all the parameters assessed by HAGOS and these values showed no statistically significant difference from those of the Control Group of healthy individuals. Key words: Groin Pain Syndrome (GPS), professional football player, HAGOS (Copenhagen Hip and Groin Outcome), symptomatic therapy.

[Outcomes of Treatment of Calcaneal Fractures Using Locking Compression Plate with or without Augmentation]

PURPOSE OF THE STUDY The retrospective study aims to compare the outcomes of augmentation of neutral triangle formed after the calcaneal fracture reduction with osteosynthesis using the locking compression plate with the outcomes of osteosynthesis without augmentation. MATERIAL AND METHODS In the period from 2005 to January 2011, 98 patients with 114 calcaneal fractures were treated by open reduction and internal fixation (ORIF) method with the use of calcaneal plate. The group included 15 women (15.3%) and 83 men (84.7%), with the mean age of 39.2 years (12-62 years). There were 16 cases of bilateral calcaneal fractures, of which 2 in women (12.5%) and 14 in men (87.5%). The fractures were classified based on the Sanders classification as Type I -IV. The patients with Type II and III fracture according to the Sanders classification were indicated for surgical treatment with ORIF using the calcaneal LCP. The defect in the region of neutral triangle of the calcaneus was filled with the injectable hydroxyapatite cement. The cohort of operated patients was evaluated based on the AOFAS (American Orthopaedic Foot and Ankle Society) Clinical Rating System. The bilateral fractures were not evaluated. This group shows a substantially higher occurrence of associated injuries, which causes strong distortion of results. RESULTS The cohort of 82 operated patients with Sanders Type II and III fractures were evaluated. In 20 fractures (24.4%) the defect in the calcaneus body was filled with hydroxyapatite cement. In osteosynthesis without defect augmentation an excellent result was achieved in 21 patients (33.9%). A good result was reported in 24 patients (38.7%), a satisfactory result in 12 patients (19.4%) and a poor result in 5 patients (8.0%). In patients with osteosynthesis of the calcaneus with augmentation, an excellent result was achieved in 6 cases (30%), a good result in 5 cases (25%), a satisfactory result in 7 cases (35%) and a poor result in 2 cases (10%). Early postoperative complications were observed in a total of 13 patients (15.8%). In osteosynthesis without defect augmentation, there were 2 cases of wound dehiscence (3.2%), 3 cases of marginal skin necrosis (4.8%), 4 cases of superficial wound infection (6.4%) and 1 case of deep wound infection (1.6%). In patients with performed augmentation, wound dehiscence was seen in 1 case (5%), superficial wound infection in 1 case (5%) and superficial marginal skin necrosis in 1 case (5%). Deep wound infection was not reported in this group. DISCUSSION A question frequently discussed is the filling of defect in the diaphysis of calcaneus. Brodt et al. state a statistically higher stability of the calcaneus in osteosynthesis with augmentation, but he does not use the locking plate. Longino in his study compares the results of calcaneal osteosynthesis with spongioplasty with a graft from pelvis and without it and does not observe any major differences in the final outcome in his cohort. Elsner evaluates the results in 18 patients, in whom calcium phosphate cement augmentation was used for osteosynthesis. Over the period of three years he did not observe a higher rate of complications. Schildhauer assesses the early load of the calcaneus with tricalcium phosphate cement augmentation. After three weeks of full loading no loss of reduction was found. Thordarson evaluates 11 operated patients with Sanders type II and III calcaneal fracture. The defect of the calcaneus was filled by calcium phosphate cement. In this small group 1 case of serious infection complication and 1 loss of reduction with full load at six weeks after the surgery were observed. In our group no differences were observed between the outcomes of patients with performed or not performed defect augmentation in the neutral triangle site. A higher percentage of complications in patients with filled defect of the calcaneus was not observed either. CONCLUSIONS The operative treatment of displaced intra-articular fractures consisting of open reduction from extended lateral approach and internal calcaneal LCP fixation brings good results. We concluded that there is no statistically significant difference in the results of osteosynthesis with a locking plate alone and combined with augmentation of diaphyseal defect of the calcaneus. Filling of the diaphyseal defect in the calcaneus is not necessary, it neither accelerates the healing, nor brings better treatment outcomes Key words: calcaneal fracture, cement augmentation of defect, locking plate, extended lateral approach.

Concentric radiofrequency arrays to increase the statistical power of resting-state maps in monkeys

The close homology of monkeys and humans has increased the prevalence of non-human-primate models in functional MRI studies of brain connectivity. To improve upon the attainable resolution in functional MRI studies, a commensurate increase in the sensitivity of the radiofrequency receiver coil is required to avoid a reduction in the statistical power of the analysis. Most receive coils are comprised of multiple loops distributed equidistantly over a surface to produce spatially independent sensitivity profiles. A larger number of smaller elements will in turn provide a higher signal-to-noise ratio (SNR) over the same field of view. As the loops become physically smaller, noise originating from the sample is reduced relative to noise originating from the coil. In this coil-noise-dominated regime, coil elements can have overlapping sensitivity profiles, yet still possess only mildly correlated noise. In this manuscript, we demonstrate that inductively decoupled, concentric coil arrays can improve temporal SNR when operating in the coil-noise-dominated regime-in contrast to what is expected for the more ubiquitous sample-noise-dominated array. A small, thin, 7-channel flexible coil is developed and operated in conjunction with an existing whole-head monkey coil. The mean and maximum noise correlation between the two arrays was 5% and 23%, respectively. When the flex coil was placed over the sensorimotor cortex, the temporal SNR improved by up to 2.3-fold in the peripheral cortex and up to 1.3-fold at a 2- to 3-cm depth within the brain. When the flex coil was placed over the frontal eye fields, resting-state maps showed substantially elevated sensitivity to correlations in the prefrontal cortex (54%), supplementary eye fields (39%), and anterior cingulate cortex (41%). The concentric-coil topology provided a pragmatic and robust means to significantly improve local temporal SNR and the statistical power of functional connectivity maps.

[Evaluation of the MRI Findings on a Tendon Graft after the Anatomic Anterior Cruciate Ligament Reconstruction in Patients with Versus without the Application of Platelet-Rich Fibrin - Results of the Prospective Randomised Study]

PURPOSE OF THE STUDY The purpose of the prospective randomised study was to assess the benefits of the platelet-rich fibrin (PRF) application during the anatomic anterior cruciate ligament reconstruction (ACLR) for tendon graft healing. MATERIAL AND METHODS The study included 40 patients with an isolated rupture of the anterior cruciate ligament in the knee. The MRI findings on the tendon graft were evaluated at 6 months and 12 months after the surgery in a total of 33 patients, namely in 10 women/23 men (21 right knee/12 left knee), with the mean age of 29.1 years and at the mean follow-up of 15.9 weeks after the injury. The randomisation using envelopes was carried out at the beginning of arthroscopy either in the group with the PRF application (Group 1) (17 patients) or in the group without the PRF application (Group 2) (16 patients). The followed-up patients underwent the ACLR with targeting the femoral tunnel through anteromedial portal using the autografts of m. semitendinosusand m. graciliswith Tightrope femoral fixation and Inion implant in tibia. In Group 1, during the surgery PRF was applied both in the drilled tunnels (intraosseously) and directly to the surface of the tendon graft itself (intraarticular part). The Group 2 was a control group in which the same intervention was performed, however without the PRF application. In the 6 th and 12 th month after the surgery, the signal intensity of the knee and occurrence of the ACL graft failure, bone (marrow) oedema rate near the tunnels were assessed by an independent radiologist using a 3 Tesla MRI. RESULTS In the 6 th and also in the 12 th postoperative month, neither a complete, nor a partial graft failure was found in the group with PRF, whereas in Group 2 a complete or a partial graft failure was observed in 12.5% (p = 0.23). In the 6th month, a bone marrow oedema near the intraosseous parts of the graft was reported in 94.1% of patients in Group 1 and in 81.3% of patients in Group 2, while in the 12 th month it was 23.5% of evaluated patients in Group 1 and 37.5% patients in Group 2. The differences between the two groups were not statistically significant in the 6 th (p = 0.096) or in the 12 th month (p = 0.43). In the 6 th month, a fully ligamentised graft was found in 52.9% of patients in Group 1 and in 37.5% of patients in Group 2 (p = 0.061), a partially ligamentised graft was present in 47.1% of patients in Group 1 and in 50% of patients in Group 2. In the 12 th month, a fully ligamentised graft was seen in 94.1% of patients in Group 1 and in 75% of patients in Group 2 (p = 0.26) and a partially ligamentised graft was present in 5.9% of patients in Group 1 and in 12.5% of patients in Group 2. In the remaining 12.5% of patients in Group 2, the finding was assessed as a graft with no signs of ligamentisation. DISCUSSION We have not encountered a paper in the Czech or world literature which would present results of a similar study, i.e. which would evaluate the potential benefits of the platelet-rich fibrin application in the course of the anatomic anterior cruciate ligament reconstruction. Majority of studies evaluate the benefits of the application of platelet-rich plasma aimed to achieve a positive effect on the LCA graft healing. CONCLUSIONS Our study proved a higher percentage of ligamentisation and healed grafts into the bone as well as a lower occurrence of graft failure in the group with PRF compared to the group without the PRF application, namely both in the 6 th and in the 12 th month. Nonetheless, the differences between the two groups assessed at the same time were not statistically significant. Key words: anterior cruciate ligament, arthroscopy, anatomic ACL reconstruction, magnetic resonance imaging of the graft, platelet-rich fibrin, graft healing, MRI signal intensity of the graft.

[Anatomical All-Inside Anterior Cruciate Ligament Reconstruction Using Quadrupled Semitendinosus Tendon Graft with Posteromedial Harvest - Clinical Results of Prospective Study at a Minimum 12-Months Follow-up]

PURPOSE OF THE STUDY This original paper aims to present the conclusions of the prospective study evaluating the clinical results of anatomical all-inside ACL reconstruction using quadrupled semitendinosustendon graft with posteromedial harvest using suspensory fixation by Tightrope implants at the follow-up of at least 12 months. MATERIAL AND METHODS The prospective study included a total of 119 patients (74 men/39 women) with the mean age of 28.3 (18-52) years, in whom demographic data was collected and a clinical examination was performed. The patients satisfying the "inclusion" and "exclusion" criteria were enrolled in the study and subsequently underwent the same, aforementioned surgical procedure performed by a single surgeon. Preoperatively and at a minimum 12-month follow-up the following subjective criteria were evaluated using the Lysholm and IKDC subjective scores and the Visual Analogue Scale (VAS) (0-10). The objective parameters comprised the side-to-side difference in anterior knee laxity assessed by Genourob arthrometer with an applied pressure of 134 and 250 N, anterior drawer test, and the pivot shift test. The occurrence of graft failure, complications and return to pre-injury sport levels were monitored. The obtained data was statistically evaluated at the statistical significance level of 0.05. RESULTS A total of 89 patients were assessed at the follow-up of at least 12 months after the surgery. The median Lysholm score increased over time from 58.7 preoperatively to 94.2 postoperatively (p < 0.05) and the IKDC subjective score went up from 46.3 to 91.4 (p < 0.05). The median postoperative VAS kept decreasing from 7.3 (Day 2), 5.1 (Day 14), 3.1 (Week 6), 1.2 (Month 6) to 0.3 at 12 months after the surgical procedure. Preoperatively, the results were significantly positive (i.e. C, D) in 52.8% (C) and 21.4% (D), whereas postoperatively the results of the PST were significantly positive only in 4%. Therefore, the surgical procedure was conducive to a statistically significant decrease in rotational knee laxity over time (p < 0.05). The median side-to-side difference in anterior laxity of the operated knee objectively assessed by GNRB arthrometer with the applied pressure of 134 N was 4.2 mm (3.1-6.8) as against the postoperative 1.2 mm (0.4-2.1) and with the applied pressure of 250 N it was 6.2 mm (4.6-8.7) prior to the surgical procedure versus 2.4 mm (1.6-3.5) postoperatively. That concerned a statistically significant decrease of postoperative side-to-side difference in anterior laxity of the operated knee at both the measured pressures (p < 0.05). The graft failed in 3 patients only (3.4%), no major complications associated with the surgical procedure were observed and 62 of the evaluated patients (69.6%) were able to return to the pre-injury level of sport within one year after the surgery. DISCUSSION When comparing the results obtained by our study with the conclusions of clinical studies carried out by other authors and evaluating similar clinical parameters with the identical surgical technique applied, it is obvious that in our group of patients we achieved similar clinical results as the other authors from abroad. CONCLUSIONS The results of our study showed that the all-inside ACL anatomical reconstruction using quadrupled semitendinosus tendon graft with posteromedial harvest with suspensory fixation by Tightrope implants at one year after the surgery bring very good subjective as well as objective clinical results and minimum complications. Key words:anterior cruciate ligament tear, anatomical ACL reconstruction, all-inside technique, posteromedial harvest, quadrupled semitendinosustendon graft, retrograde drilling, suspensory graft fixation.

[Evaluation of Clinical Outcomes of Arthroscopical Treatment of Femoroacetabular Impingement Hip Syndrome - 2-Year Outcomes]

PURPOSE OF THE STUDY Hip arthroscopy is a widely used method of treatment of hip pathology. It is a technically demanding procedure for which accurate indication is critical. The indication criteria, however, are not yet fully supported by long term results of large patient groups in recent literature. The purpose of our study is to present the 2-year outcomes after hip arthroscopy. MATERIAL AND METHODS In our study 203 patients (110 women, 93 men) with the mean age of 34 years (17-67 years) were evaluated. The mean NAHS score was 87/100 at 24 months after the surgery, which represents a statistically significant improvement compared to the preoperative values (p < 0.02). RESULTS The patients were divided into four groups based on their clinical results. Group 1 with NAHS score of 90-100 included 84 patients, Group 2 with NAHS 80-90 had 86 patients, Group 3 with NAHS 70-80 had 17 patients, and Group 4 with NAHS below 70 consisted of 10 patients. The rate of serious complications was 6% (12/197 patients). CONCLUSIONS Hip arthroscopy is an effective and safe method of treatment of hip pathology. It is a technically demanding procedure that requires exact indication criteria in order to reach excellent clinical results. Key words: hip arthroscopy, femoroacetabular impingement, labral lesion, hip pain.

[Correlation between the Arthroscopic and MRI Findings in Patients Active in Sports with Clinically Suspected Acetabular Labral Tear - Prospective Study Results]

PURPOSE OF THE STUDY The aim of our prospective study was to establish correlation between the arthro-MRI and arthroscopic findings in patients active in sports clinically suspected of having a hip labral tear. We sought to identify the benefits of arthro-MRI for clinical practice prior to the considered hip arthroscopy. MATERIAL AND METHODS The prospective study included 34 patients with hip pain and clinically suspected of having a labral tear. The group consisted of 19 men (55.9%) and 15 women (44.1%) of the mean age of 32.2 years (18 to 50 years). All our patients were active athletes, either professional (12; 35.3%) or recreational (22; 64.7%). Included in the study were exclusively patients aged 18-50 with hip pain lasting longer than 3 months, not responding to conservative therapy, with normal X-ray findings, or FAI syndrome. The patients underwent arthro-MRI and subsequently also hip arthroscopy, namely within no more than 3 months. The description of findings was translated into simple numerical scales, assessed using Spearman s rank correlation coefficient. We also examined the specificity, sensitivity, positive and negative predictive values and the odds ratio at various cut-off values of the scale for arthro-MRI. The statistical significance was set at the alpha level = 5%. The quality of tests was also evaluated using the ROC curve. RESULTS In hips assessed by the radiologist as reliably with no pathological finding (MRI type 1) the negative predictive value achieves 83.3% and the positive predictive value of 85.7%, with 96.0% sensitivity and 55.6% specificity. When evaluating the reliably negative finding together with the likely negative finding (MRI type 2) as against the pathological and certainly pathological findings (MRI type 3 and 4), the negative predictive value is 57.1%, the positive predictive value 95.0%, the specificity 88.9% and the sensitivity 76.0%. DISCUSSION In our study, the values achieved were comparable to or better than those reported by foreign authors in their studies establishing correlations between the arthro-MRI and intraoperative findings. Significantly higher was primarily the negative predictive value. CONCLUSIONS The results of our study indicate that the arthro-MRI performed as a part of preoperative examination prior to hip arthroscopy has adequate specificity and sensitivity in patients with suspected labral tear. Based on this examination a decision can be made as to whether to perform arthroscopy. Our study also shows that it is essential to have a highly competent radiologist to evaluate the arthro-MRI results. Key words: hip arthroscopy, labral tears, arthro-MRI, hip joint, predictive value of tests, sensitivity and specificity, minimally invasive surgical procedures/methods.

[Clinical Results of Endoscopic Treatment of Greater Trochanteric Pain Syndrome]

PURPOSE OF THE STUDY This retrospective study aims to present short-term clinical outcomes of endoscopic treatment of patients with greater trochanteric pain syndrome (GTPS). MATERIAL AND METHODS The evaluated study population was composed of a total of 19 patients (16 women, 3 men) with the mean age of 47 years (19-63 years). In twelve cases the right hip joint was affected, in the remaining seven cases it was the left side. The retrospective evaluation was carried out only in patients with greater trochanteric pain syndrome caused by independent chronic trochanteric bursitis without the presence of m. gluteus medius tear not responding to at least 3 months of conservative treatment. In patients from the followed-up study population, endoscopic trochanteric bursectomy was performed alone or in combination with iliotibial band release. The clinical results were evaluated preoperatively and with a minimum follow-up period of 1 year after the surgery (mean 16 months). The Visual Analogue Scale (VAS) for assessment of pain and WOMAC (Western Ontario MacMaster) score were used. In both the evaluated criteria (VAS and WOMAC score) preoperative and postoperative results were compared. Moreover, duration of surgery and presence of postoperative complications were assessed. Statistical evaluation of clinical results was carried out by an independent statistician. In order to compare the parameter of WOMAC score and VAS pre- and post-operatively the Mann-Whitney Exact Test was used. The statistical significance was set at 0.05. RESULTS The preoperative VAS score ranged 5-9 (mean 7.6) and the postoperative VAS ranged 0-5 (mean 2.3). The WOMAC score ranged 56.3-69.7 (mean 64.2) preoperatively and 79.8-98.3 (mean 89.7) postoperatively. When both the evaluated parameters of VAS and WOMAC score were compared in time, a statistically significant improvement (p<0.05) was achieved postoperatively. The mean duration of surgical procedure was 68 minutes. Moreover, in peritrochanteric space apart from chronic bursitis also another pathology was found in a total of 14 cases (74%). In six cases (32%) it was a mild degeneration of m. gluteus medius (treated only with debridement) and in eight patients who underwent surgery (42%) the dorsal third of tractus iliotibialis was hypertrophic and protruding into bursa (treated with an incision of the hypertrophied part of the band). No serious neurovascular or thromboembolic complications were recorded. Only minor postoperative complications in a total of 7 patients who underwent surgery (37%) occurred. DISCUSSION There are lots of studies in literature presenting the results of endoscopic treatment of GTPS either using an independent trochanteric bursectomy or its combination with iliotibial band release. In our study we succeeded in achieving similar clinical results as those achieved by the other authors engaged in this area. CONCLUSIONS It has been proven in this retrospective study that the technique of endoscopic trochanteric bursectomy in patients with greater trochanteric pain syndrome yields statistically significant improvement of clinical results with the concurrent minimum incidence of postoperative complications. Key words: greater trochanteric pain syndrome, peritrochanteric space, recalcitrant trochanteric bursitis, hip arthroscopy, endoscopic trochanteric bursectomy, iliotibial band release.

[Augmentation of the Anterior Cruciate Ligament in Patients with Symptomatic Isolated Tear of Anteromedial or Posterolateral Bundle: Evaluation of Two-Year Clinical Results]

PURPOSE OF THE STUDY

We present the results of a prospective study of patients with symptomatic partial ACL tears comparing the pre-operative findings with the clinical results at two years after anterior cruciate ligament (ACL) augmentation.

MATERIAL AND METHODS

A total of 29 patients (7 women, 22 men; average age, 27.8 years) who were diagnosed with an isolated tear of the posterolateral (PL) bundle (18 patients) or the anteromedial (AM) bundle (11 patients) at 9 to 24 weeks after injury, and underwent ACL augmentation by isolated PL or AM bundle replacement, were evaluated. The characteristics assessed before surgery and at two years after it included the Lysholm and subjective IKDC scores and knee laxity measurement with a GNRB arthrometer (at 134 N and 250 N) and its assessment by the Lachman, anterior drawer and pivot shift tests. In addition, the presence of cyclop syndrome, graft failure and post-operative complications were evaluated.

RESULTS

The patients with isolated reconstruction of the PL bundle showed post-operatively statistically significant improvement in the degree of rotational knee laxity (p < 0.05) and the ventral knee laxity assessed by the Lachman test (p < 0.05). Postoperative improvement in the anterior drawer test results was not statistically significant (p = 0.07). The median value of side-to-side difference in knee laxity measured with the GNRB arthrometer decreased at 134 N from 1.7 mm pre-operatively to 0.8 mm at two years post-operatively (p < 0.05) and, at 250 N, from 2.8 mm to 1.5 mm (p < 0.05). The median Lysholm score increased from 74 to 91 points at two post-operative years and the median IKDC score improved from 76 to 92 points (p < 0.05). Graft failure was reported in one patient (5.6%) and 14 subjects (77.8%) reported return to pre-injury sports activities. The patients undergoing isolated reconstruction of the AM bundle achieved, at two years after surgery, a statistically significant decrease in positivity of the Lachman and anterior drawer tests (p < 0.05), while the results of the pivot shift test did not improve significantly (p = 0.09). The decrease in median values of side-to-side difference in knee laxity measured with the GNRB arthrometer was from pre-operative 3.1 mm to 1.2 mm at 134 N (p < 0.05) and from 6.2 mm to 1.9 mm at 250N (p < 0.05). The median Lysholm and IKDC scores increased from 68 to 92 points and from 70 to 94 points, respectively (p < 0.05). Nine patients (81.9%) reported return to pre-injury participation in sports. Apart from early wound bleeding in one patient, no complications were recorded.

DISCUSSION

By permitting maintenance of a healthy bundle and replacement of only a torn one, ACL augmentation provides several benefits. It allows for accelerated revascularization and re-innervation of the graft through mechanoreceptors of the healthy portion; it enables the surgeon to get a good anatomical orientation and achieve precise tunnel reaming; in addition the healthy bundle provides protection for the graft in the early post-operative period. Thus rehabilitation can be faster and also return to sports activities.

CONCLUSIONS

Our results show that ACL augmentation using isolated replacement of either the AM or the PL bundle brings about statistically significant improvement of all subjective and most of the objective criteria by two years after surgery.

[Anatomical ACL reconstruction by a double- versus a single-bundle technique. Prospective randomised study of short-term clinical results]

PURPOSE OF THE STUDY

The aim of the study is to present a comparison of short-term results of double- versus single-bundle anatomical reconstruction of the anterior cruciate ligament (ACL) using hamstring endons and their fixation with absorbable interference screws.

MATERIAL AND METHODS

A total of 110 patients with an isolated ACL lesion and the healthy contralateral knee who met the indication criteria for ACL double bundle reconstruction (TISL, 14 mm; ICNW, 12 mm) were intra-operatively allocated at random to either double-bundle group (DB, n=55) or single-bundle group (SB, n=55). At 12 months after surgery, 97 patients (DB group, n=49; SB group, n=48), comprising 68 men and 29 women, were evaluated; the average age was 29.1 years and the injury-to-surgery interval was 15.9 weeks. Pre- and post-operative subjective criteria involved the IKDC and Lysholm score. Objectively, the occurrence of graft failure, range of motion deficit, return to pre-injury sports activity, side-to-side difference in anterior laxity of both knees in 20° flexion on a GNRB laximeter at an applied pressure of 124 N and 250 N, and pivot shift phenomenon were assessed.

RESULTS

No statistically significant difference was found in pre-operative values between the two groups. Post-operatively, there were no significant differences in the occurrence of complete graft failure (p=0.0755; DB group, n=0; SB group, n=3), range-of-motion deficit (p=0.2277-0.9788) or return to pre-operative sports activity (p=0.2322). In the DB group, side-to-side anterior tibial shifts at a pressure of 124 N (medians=1.3 mm and 2.1 mm for DB and SB groups, respectively; p=0.0007) and at a pressure of 250 N (DB group =2.1 mm; SB group = 3.1 mm; p<0.0001) were significantly different from the corresponding values in the SB group. Positive results for the pivot shift test (PST) were significantly less frequent in the DB than the SB group (Chi-square test =0.0112). The SB group patients had a 2.9-times (odds ratio, 2.8704) higher risk of positive postoperative PST results than the DB group patients. In both groups, a comparison of pre- and post-operative criteria showed significant improvement in both the subjective and the objective results.

DISCUSSION

The results of this study, in accordance with other authors' conclusions, suggest that the double-bundle technique provides better control over rotational and anterior knee laxity and therefore restores knee biomechanics better. However, other literature data do not confirm any significantly better outcomes of this method. Since only short-term results have been obtained so far, the study will continue because only the long-term results can provide conclusive evidence of an advantage of one technique over the other.

CONCLUSIONS

Our study showed significantly better restoration of knee rotational and anterior laxity in the patients undergoing anatomical reconstruction of the ACL by the double-bundle technique. The other evaluated criteria did not differ in relation to the technique used.

[Type AO/ASIF B3 fractures of the thoracic and lumbar spine]

PURPOSE OF THE STUDY

Type B3 thoracic and lumbar fractures are often found in spines with previous hyperossification processes such as ankylosing spondylarthritis (AS) or diffuse idiopathic skeletal hyperostosis (DISH). They occur most frequently due to high-energy trauma in a healthy spine and as fall-related domestic injury in a spine affected by hyperossification. Generally, they are less frequent than type B3 cervical spine fractures. In this retrospective study involving two centres, the incidence of these fractures, their characterisation, therapy and complications associated with them were investigated.

MATERIAL AND METHODS

Between March 2003 and March 2012, 21 patients with type B3 injuries (Magerl classification) were treated in our centres. The thoracic spine was involved in 14 and the lumbar spine in seven patients. The patients' average age was 61.8 years, with a range of 33 to 87 years. There were three women and 18 men. Six fractures occurred in previously healthy spines, five and 10 were in AS- and DISH-affected spines, respectively. The evaluation included the mechanism of injury, patient's weight and height, neurological findings, type of treatment and its result, outcome after treatment termination, complications and associated diseases and injuries.

RESULTS

The mechanism of injury differed between the healthy and disease-affected spines. All five AS patients suffered low-energy fractures while patients with previously healthy spines had high-energy injuries. The DISH patients had both low- and high-energy fractures. Type B3.1.1 fractures were diagnosed in two AS patients and six DISH patients, and in no previously healthy patient. Type B3.1.2 fractures were found in one AS patient, two DISH patients and one previously healthy patient. Type B3.2 fracture occurred in one patient with a previously healthy spine, in two AS and two DISH patients. Type B3.3 fractures were in four patients with previously healthy spines. Neurological deficit was found in five injured patients, four of whom had complete paraplegia (Frankel grade A) which did not improve. One AS patient in whom the spinal fracture was associated with Frankel grade C injury improved to Frankel D after surgery. All patients had an elevated BMI, ranging from 25.1 to 41.9; the average value was 32.2, which is within grade 1 obesity. Associated injuries were found in 11 patients, mostly in those with high-energy trauma. Seventeen patients were treated surgically, four conservatively. Posterior stabilisation was carried out in 10 patients who had either AS or DISH conditions; seven patients had a short spinal stabilisation. Complications included early infection in two patients, cerebrospinal fluid fistula in one, urinary tract infection in one and confused state of mind in two patients. All patients healed well but for one patient who died at 4 months after injury due to multiple complications.

DISCUSSION

In the majority of relevant publications these injuries are reported in patients suffering from hyperossification disorders such as AS or DISH. In patients with healthy spines they occur less frequently and the traumatic hyperextension mechanism must have great intensity. Fractures of a hyperossified spine are related to obesity and this was also confirmed by our study in which all patients were overweight or obese. This factor plays an important role in the hyperextension mechanism that produces a sudden overcoming of the resistance of a spinal segment to force, resulting in a type B3 fracture.

CONCLUSION

A different approach to these fractures is required in comparison with other spinal fractures. Type B3 fractures have some features common with type C fractures and are frequent in spines affected by spinal disease. In hyperossification disorders, paradoxically associated with advanced osteoporosis, fracture treatment requires long instrumentation. In healthy spines, fractures are treated with short instrumentation. In AS and DISH patients, the diagnosis may be delayed because these patients suffer from chronic spine pain and the pain due to fracture may be attributed to an accelerated chronic condition.

[Open reduction and plate fixation (ORIF LCP) for treatment of bilateral calcaneal fractures]

PURPOSE OF THE STUDY

Calcaneal fractures are frequent injuries which may interfere with the patient's daily activities for a long time. They usually occur as the result of an axial load causing impaction of the talus into the calcaneus. They can also be bilateral. Falls and jumps from height are the most frequent causes.

MATERIAL AND METHODS

Between August 2005 and December 2011, the method of open reduction and internal fixation (ORIF) with a calcaneal locking compression plate (LCP) was used to treat 98 patients with 114 calcaneal fractures. Of these, 16 were bilateral fractures found in two women and 14 men. In each patient, plain lateral and axial X-ray films of the calcaneus were taken on the day of injury. Computer tomography (CT) scans in the sagittal, transverse and coronary planes were obtained. Based on these, the fractures were classified as type I to type IV according to the Sanders system. The patients with type II and type III calcaneal fractures were indicated for ORIF treatment. The results were evaluated using the Rowe score.

RESULTS

The most frequent cause of fracture was a fall or a jump from height, which was recorded in 81 patients. Bilateral fractures were found in 16 patients. Of the 98 patients, excellent results were in 31, good in 39, satisfactory in 20 and poor in eight patients, as assessed with the Rowe score. Unilateral fractures achieved excellent results in 28, good in 35, satisfactory in 15 and poor in four patients. The results in bilateral fractures were excellent in three, good in four, satisfactory in five and poor in four patients. Early post-operative complications were recorded in a total of 24 patients, of whom 13 had unilateral and 11 had bilateral fractures.

DISCUSSION

The Sanders classification based on CT examination is used as an indication scheme in our department. Type II and type III fractures are indicated for ORIF treatment. A calcaneal LCP and an extended lateral approach are preferred. This allows for an almost perfect view of the fracture, an accurate reduction of the subtalar and calcaneocuboid joints and a stable internal fixation. In the patients with bilateral fractures, the occurrence of complications, multiple trauma and associated injuries was significantly higher. Also, they had less satisfactory results than the patients with unilateral fractures.

CONCLUSIONS

The surgical treatment of intra-articular fractures using open reduction from the extended lateral approach and internal fixation with a calcaneal LCP has achieved good results. CT scans are necessary for the diagnosis, fracture classification and indication for a surgical procedure. The timing of surgery plays a decisive role. Open fractures and fractures associated with severe soft tissue injury are treated urgently, other fractures at an appropriate time. Our results showed a significantly higher rate of complications in the patients with bilateral calcaneal fractures, as compared with the patients with unilateral fractures, as well as less satisfactory outcomes. High-energy trauma resulting in bilateral fractures predisposes to comminuted fractures with dislocation, which leads to more serious damage to subtalar joint function.

[Arthroscopic transcapsular iliopsoas tenotomy from the peripheral versus the central compartment in internal snapping hip syndrome. Short-term results of a prospective randomised study]

PURPOSE OF THE STUDY

In this prospective randomised study, the short-term results of arthroscopic transcapsular iliopsoas tenotomy approached from the peripheral versus the central compartment for internal snapping hip syndrome are presented.

MATERIAL AND METHODS

A group of 19 patients (15 women and four men; mean age, 24.3 years) who underwent arthroscopic transcapsular iliopsoas tenotomy for internal snapping hip syndrome in the period between September 2010 and December 2011 were prospectively evaluated. No injury, hip surgery or feeling of hip instability was recorded in their personal histories. Radiographs did not show any dysplasia, retroversion of the acetabulum or cam lesions. The patients were allocated to two groups using sealed envelope randomisation: Group 1 patients (n=10) were treated by tenotomy from the peripheral compartment and group 2 patients (n=9) underwent tenotomy from the central compartment during traction of the lower extremity. The evaluation included pre-operative 3T MRI findings, arthroscopically detected intra-articular lesions, duration of traction and post-operative complications. The pre-operative WOMAC scores were compared with those at one-year follow-up. In comparison of the two groups, the Mann-Whitney exact test was used for WOMAC scores and Fisher's exact test for post-operative complications. Statistical significance was set at a 0.05 level.

RESULTS

In comparing post-operative complications, a significant difference (p=0.0468) between the groups was found only for genital paresthesia, which did not occur in group 1. The other differences were not statistically significant. The pre-operative WOMAC scores did not differ significantly between the groups (p=0.79). The post-operative WOMAC scores were significantly higher in group 1 (p=0.02). In each group the change in WOMAC scores was different and was statistically significant in group 1 (p=0.0014). Associated intra-articular hip pathologies, most frequently synovitis of the peripheral compartment, acetabular chondropathy, or labral lesions, were diagnosed in 90% of group 1 patients and in 66.7% of group 2 patients.

DISCUSSION

Most of the authors comparing the results of two different ilioproas tenotomy techniques at one-year follow-up did not report any statistically significant differences in WOMAC scores between them. In accordance with the data reported, an increase in the post-operative WOMAC score, i.e., improvement of clinical outcome, was achieved in all our patients and, in group 1, it was significantly higher (p=0.0015), as compared with a similar study by Ilizaliturri. However, further follow-up of the patients and evaluation of long-term results will be necessary.

CONCLUSIONS

The technique of arthroscopic ilioproas tenotomy approached from the peripheral compartment resulted in significantly fewer cases of genital paresthesia and provided significantly better clinical outcomes in comparison with tenotomy from the central compartment.

[Evaluation of the clinical results in patients with symptomatic partial tears of the anterior cruciate ligament diagnosed arthroscopically]

PURPOSE OF THE STUDY

The study presents a retrospective evaluation of clinical data and arthroscopic findings in a group of our patients with symptomatic knee instability due to a partial tear of the anterior cruciate ligament (ACL).

MATERIAL AND METHODS

The group included 31 patients diagnosed with symptomatic partial ACL tears, i.e. an isolated tear of the posterolateral (PL) or the anteromedial (AM) bundle. The patients' average age was 26.5 years. A side-to-side difference in ventral knee laxity was assessed using the anterior drawer test and the Lachman test under general anaesthesia before arthroscopy was commenced; rotational knee laxity was evaluated by the pivot shift test. An objective evaluation of side-to-side ventral laxity differences in both knees was performed on the GNRB® arthrometer with an applied pressure of 134 N and 250 N in the conscious patient. During arthroscopic examination, findings on the two ACL bundles were recorded.

RESULTS

All 31 patients were diagnosed with symptomatic partial ACL tears, of them 22 had a PL bundle lesion and nine had an AM bundle tear. All patients with PL bundle lesions only reported problems in association with pivot sports, and all patients with AM bundle tears had problems regardless of any sports activities. In all patients with isolated AM bundle tears, the lesion was located close to its femoral attachment. In the patients with PL bundle tears, femoral location was found in 68% and tibial location in 32% of the patients. In the patients with partial PL bundle lesions, + and ++ results in the pivot shift test were recorded in 32% and 68% of the treated patients, respectively. The Lachman test showed + and ++ results in 71% and 9% of the patients, respectively. The anterior drawer test had negative results in 87% and positive + results in 13% of the patients. The side-to-side difference on the GNRB arthrometer ranged from 0.4 to 2.3 mm at a pressure of 134 N and from 1.2 to 4.2 mm at 250 N in the patients with isolated PL bundle lesions. In the patients with AM bundle lesions, the results were as follows: pivot shift test, 89% negative. 11% positive +; Lachman test, 56% negative, 44% positive +; anterior drawer test, 89% +, 11% ++; GNRB test, 2.2 to 4.4 mm at 134 N, and 4.3 to 7.1 at 250 N.

DISCUSSION

The diagnosis of partial ACL lesions, i.e., isolated tears of the AM or the PL bundle, requires accurate knowledge of knee anatomy and its biomechanics. In accordance with other authors our results showed that an arthroscopic examination of both bundles of the ligament as well as knee laxity evaluation under general anaesthesia are most essential for making the definite diagnosis in partial ACL tears. They also confirmed that, in isolated AM bundle lesions, ventral laxity is present more often particularly at a higher degree of knee flexion while, in PL bundle lesions, rotational laxity is more frequent and ranges from 0 to 30 degrees of knee flexion.

CONCLUSIONS

To make the definite diagnosis of partial ACL tears, patient medical history, clinical knee examination including instability type and degree assessment under general anaesthesia and, most importantly, arthroscopic findings on both ACL bundles are necessary.

[Anatomical double-bundle anterior cruciate ligament reconstruction - transtibial versus anteromedial reaming of femoral tunnels]

PURPOSE OF THE STUDY

The aim of the study was to compare two options of how to get the correct anatomical position of both femoral tunnels, using the transtibial or the anteromedial portal technique, during anatomical double-bundle anterior cruciate ligament (ACL) reconstruction.

MATERIAL AND METHODS

A total of 36 patients, 29 men and seven women, underwent double-bundle ACL reconstruction between October 2009 and December 2010. Their average age was 26.5 years. The average interval between ACL injury and reconstruction was 7.4 months. A diagnostic arthroscopy for the treatment of cartilage and meniscal lesions was performed in 21 patients and one-stage ACL reconstruction with diagnostic arthroscopy was carried out in the remaining 15 patients. In all 36 patients, the position of the tip of the guide wire in relation to the anatomical insertion sites of both the anteromedial (AM) and posterolateral (PL) bundles was assessed intra-operatively. Three guide wire positions were found: the tip was in the centre of the native insertion site, the tip was within the insertion site but not in its centre, and the tip was outside the insertion site.

RESULTS

Using the transtibial technique through the AM tunnels, the tip of the guide wire was centred within the femoral AM insertion site only in one patient (2.8%), out of the centre but within the AM insertion site in four patients (11.1%) and outside the insertion site in the remaining 31 patients (86.1%). With this technique, the position of the femoral PL tunnels was outside the native PL insertion site in all 36 patients. With the transtibial technique using the PL tunnels, the tip of the guide wire was centred within the femoral AM native insertion in 11 patients (30.5%), out of the centre but still within the AM insertion site in 16 (44.5%) and outside the AM insertion site in nine patients (25%). Aiming for the femoral PL tunnel resulted in the tip of the guide wire being outside the native femoral PL insertion site in all cases. Using the technique of guide wire insertion through an accessory AM portal it was possible to achieve the centres of both the AM and PL native anatomical insertion sites in all 36 patients (100%).

DISCUSSION

We agree with the many authors who recommend the reaming of PL femoral tunnels through an accessory AM portal because the transtibial technique does not allow for the placement of their precise native anatomical positions. Our intraoperative findings showed that the transtibial technique was effective to get the correct anatomical position of AM femoral tunnels just in 30.5% of the patients. In view of the fact that the same results can be achieved with the AM transportal technique in 100% of the patients, we prefer this technique in accordance with the majority of other authors.

CONCLUSIONS

In anatomical double-bundle ACL reconstruction, the native anatomical position of PL tunnels was achieved in all patients and the native AM tunnels in most of them using the accessory AM portal technique. The transtibial technique proved to be unsatisfactory.

[Arthroscopically-assisted procedures on the hip joint]

PURPOSE OF THE STUDY

Since 2000 arthroscopically-assisted surgery on hip joints has become more widely used. The technique is relatively demanding and should be used only after arthroscopic procedures on other large joints are mastered to perfection. A thorough study on cadaverous specimens should be a prerequisite for adopting it as a routine method. The aim of this study was to evaluate indications for hip arthroscopy as, from the year 2006, this was gradually introduced and more widely used at our department.

MATERIAL AND METHODS

Forty-two hip joints were assessed out of the 83 hips which had been treated by arthroscopic surgery before the date of evaluation and which had been followed up for at least 2 years. The patient group evaluated consisted of 25 men and 17 women, with an average age of 40.3 years and a range of 21 to 65 years. Patients with a follow-up shorter than 2 years and those subsequently undergoing total hip arthroplasty were not evaluated. Indications for arthroscopic surgery included the presence of intra-articular bodies, labro-cartilaginous lesions and impingement syndromes. Neurovascular disorder affecting the limb and a higher degree of osteoporosis were considered contraindications. The outcome of surgery and its indications were evaluated on the basis of the questionnaire which recorded the patient's objective findings and subjective feelings at 3 and 6 months and then at 1 and 2 years after surgery.

RESULTS

The average VAS score was 7.83 points before surgery, and 3.87 points at 3 months and 2.01 points at 2 years after surgery. Nearly all patients (98%) reported their willingness to undergo the surgery again. The complications included transient hyperesthesia in the perineal region completely resolved within 4 weeks of surgery in three cases and subcutaneous extravasation after extensive capsulotomy in one patient. It subsided within 48 hours without compartment syndrome development.

DISCUSSION

A good view allowing for comprehensive exploration of the central as well as peripheral compartments enables us to treat all pathologies, which are manageable by arthroscopic intervention, in one procedure. Patient recovery is faster and the risk of intra- and post-operative complications is lower that in open surgery. The avoidance of extensive capsulotomy and the possibility of leaving the femoral head in place with only minimum distractions and without injury to the ligamentum capitis are the most important advantages of this method. Complications were found in 8.4% of the cases, which is in agreement with the literature data. The method can be applied in both the diagnosis and therapy of chronic conditions such as femoroacetabular impingement, as well as in the treatment of post-traumatic conditions ranging from traumatic labral lesions to the correction of incongruence of articular surfaces in acetabular fractures.

CONCLUSIONS

Arthroscopically-assisted surgery enables us to achieve very good results, but requires appropriate, high-standard facilities and a well-mastered operative technique. It should be adopted as the method of choice for young adults still free of arthritic changes including hip impingement syndrome. Similarly to arthroscopic procedures on shoulders and knees, it is associated with low risk factors, and rapid recovery allows the patient to return soon to normal daily activities.

[Arthroscopic stabilisation of post-traumatic ventral instability of the shoulder by use of bioknotless anchors]

PURPOSE OF THE STUDY

Post-traumatic ventral shoulder instability is a frequent disorder resulting from ventral and caudal dislocation of the humeral head. The aim of this retrospective study is to evaluate the long-term results of arthroscopy-assisted reinsertion of the ventral labrum using absorbable bioknotless suture anchors.

MATERIAL AND METHODS

A group of 129 patients with unidirectional ventral instability of the shoulder was evaluated for the results of treatment involving labrum reinsertion with use of absorbable bioknotless anchors. This arthroscopy-assisted method is performed from two minimal incisions, with the patient in a beach-chair position. The shoulder rating scale of Rowe and Zarins was used to compare the pre-operative status with the treatment outcomes during follow-up ranging from 12 months to 5 years.

RESULTS

Return to the pre-injury level of activities was recorded in 93.8 % of the patients. The methods failed and dislocation recurred in 4.6 % of the patients. These underwent repeat surgery with the same technique and implants.

DISCUSSION

Arthroscopy-assisted stabilisation of the shoulder is a minimally invasive technique allowing for anatomically exact and complete treatment of traumatic injury to the intra-articular structures. It results in faster convalescence and provides better results than open methods. It requires short hospital stay and is performed as one-day surgery in our department; consequently, the costs of care for one patient are reduced. The use of absorbable suture anchors permits reimplantation of other anchors, either when suture material at primary stabilisation fails or at a potential repeat operation. The cosmetic effect of only two minimal incisions also plays a role. CONCLUSIONS Arthroscopic labrum repair with absorbable knotless anchors is, after a perfect mastering of the surgical technique, an effective treatment and, based on the results achieved, also the method of choice used at our department for managing labral lesions caused by traumatic unidirectional instability of the glenohumeral joint.

[Long-term results of calcaneal fracture treatment by open reduction and internal fixation using a calcaneal locking compression plate from an extended lateral approach]

PURPOSE OF THE STUDY

To report on the surgical treatment of intra-articular calcaneal fractures by open reduction and internal fixation with a calcaneal locking compression plate (LCP) from an extended lateral approach, and to retrospectively analyze the mid-term results in a group of patients treated by this technique.

MATERIAL

In the period from August 2005 till March 2007, a total of 49 patients with 61 calcaneal fractures were treated. Of these, 11 (18 %) were treated conservatively. Reduction combined with Kirschner-wire fixation was used in four fractures (6.6 %). Open reduction with internal calcaneal LCP fixation (ORIF- calcaneal LCP) from an extended lateral approach was carried out to treat 46 fractures (75.4 %) in 38 patients. The group evaluated here comprised 29 patients with 33 calcaneal fractures treated by ORIF-calcaneal LCP at a follow-up longer than 6 months. The fractures were classified on the basis of computer tomography (CT) findings as Sanders types I to IV. The group had two woman (6.9 %) and 27 men (93.1 %) with an average age of 34.2 years (range, 19-55 years). In 11 fractures (33.3 %), the primary treatment included filling a central cancellous bone defect area. Calcium phosphate bone substitute material (resorbable ChronOS) was used in nine cases (27.3 %), a self-solidifying hydroxyapatite implant was injected in two (6.1 %) cases (X3 Wright and Norian SRS, respectively), and a bone allograft was implanted in one case (3 %).

METHODS

Indicated for surgery were patients with an intra-articular calcaneal fracture, Sanders type II or type III, with articular surface displacement by more than 1 mm. Contraindications included age over sixty years, poor cooperation, smoking habits, peripheral vascular disease or skin infection. Surgery was performed only after oedema had resolved. The aim of our treatment was to achieve anatomical reconstruction of all articular surfaces, to restore the height, length, width and axis of the heel bone, to carry out primary stable osteosynthesis, and to enable the patient to begin rehabilitation with early mobilization. A passive rehabilitation usually started on the first post-operative day, and full weight-bearing of the extremity was allowed not earlier than 3 months post-operatively. Regular check-ups were at 6 weeks, 3, 6 and 12 months and then every year. The mid-term results were evaluated by the system of Rowe et al., scoring rest pain, possibility of return to preinjury jobs, use of walking aids, restriction of physical activity and limping. RESULTS The most frequent cause of injury was a fall or jump from height; this was recorded in 27 patients (93.1 %). An open fracture was diagnosed on two occasions (6.9 %). Bilateral calcaneal fractures were found in six patients (20.7 %); four (13.8 %) were treated by bilateral ORIF-calcaneal LPC and two (6.9 %) underwent closed reduction on one and Kirschnerwire transfixation on the other extremity. A combined injury to the musculoskeletal system was diagnosed in 11 patients (38 %), in whom four (13.8 %) had a tibial pylon fracture of the contralateral limb and four (13.8 %) had a thoracolumbar spine fracture. The surgical procedure was performed on average within 11.7 days of injury, and the average hospital stay was 18.2 days (range, 6 to 18 days). Early post-operative complications were recorded in six patients (20.7 %). Wound dehiscence was found in two (6.9 %), necrosis of wound edges in two (6.9 %), and early superficial infection responding to antibiotic therapy also in two patients (6.9 %). Deep infection, non-union or post-operative compartment syndrome were not recorded. Excellent Rowe scores were achieved in 10 patients (34.5 %), good in 15 (51.7 %) and satisfactory in two (6.9 %). Only two patients (6.9 %) reported poor outcome.

DISCUSSION

The methods of classification and treatment of calcaneal fractures continue to be a frequently discussed topic. The technique of ORIF-calcaneal LCP from an extended lateral approach has recently been preferred for patients with displaced Sanders type II or III calcaneal fractures. In agreement with other literature references, this approach allowed us to observe the fracture, to reduce both the subtalar and calcaneocuboid articulations, to stabilize the fracture by internal fixation and to begin early rehabilitation. Because of the risk of early complications, the timing of surgery and a thorough consideration of indications and contraindications are of principal importance.We agree with other authors that filling calcaneal bone defects is not necessary. Pre- and post-operative CT scans are necessary. In accordance with literature data, fractures developing compartment syndrome are indicated for urgent fasciotomy and ORIF-calcaneal LCP should be postponed. In patients with multiple trauma and also in those with open calcaneal fractures, a temporary stabilization with an external fixator medially is performed first, and then converted to a second-stage, ORIF-LCP procedure.

CONCLUSIONS

The surgical treatment of displaced intra-articular fractures that involves open reduction from an extended lateral approach and internal fixation with a calcaneal LCP shows very good preliminary results. A CT examination is required for the diagnosis and classification of fractures and a correct indication for surgery. Good timing is of principal importance. An urgent surgical intervention is necessary in open fractures or in those in which soft tissues are squashed by bone fragments. In the other fractures, surgery is carried out after oedema subsidence. Foot compartment syndrome is a serious complication of calcaneal fractures and urgent fasciotomy is the only adequate therapy. Full weight-bearing of the operated extremity depends on the rate of bone healing; it is usually allowed at 3 months after surgery.

Internet supported standardized patient information for selfcare

BACKGROUND

An informed patient is a better partner for the physician than an uninformed one. Such a patient will be more likely to practice effective selfcare, appropriately utilize the health care system, and be prepared to seek and obtain health care services that meet his needs. Objectives. To develop a system of presenting standardized medical information for the general population based on guidelines developed for general practitioners (GPs).

METHODS

Guidelines are instruments to be used by GPs to assure comprehensive and consistent enhancement of the quality of care. At the same time, guidelines describe the actions which could be expected by patients in various clinical situations. These materials establish a good basis for the patient's understanding of health care procedures and when and how to utilize health services. These materials will have to be adapted in form, content, and nomenclature in order to be understandable with the background knowledge of the average "citizen". This information for patients is currently being developed in various forms of presentations and applications. The use of web-oriented tools is a priority, because web content offers the patient a very simple and easy way of browsing and searching for the latest relevant information on both basic and advanced/detailed levels, including supporting pictures and animations. Materials are also being developed in other formats such as printed leaflets, audio presentations and videoclips.

RESULTS

Web content and printed materials based on clinical guidelines have been created. Focus groups of health professionals and non-professionals were used for evaluation of the materials. General practitioners have tested written materials in practices.

CONCLUSIONS

The development and preparation of information and materials for patients has become an integral part of the GP practical guideline development cycle.

GIS tools for tick and tick-borne disease occurrence

Geographic information systems (GIS), their fundamental components and technologies are described. GIS is a computer-based system enabling the storage, integration, query, display and analysis of data using information on data location. Further, remote sensing (RS) methods and their application in landscape characterization are described. Landscape pattern analysis, combined with statistical analysis, allows the determination of landscape predictors of disease risk. This makes RS/GIS a powerful set of tools for disease surveillance, enabling the prediction of potential disease outbreaks and targeting intervention programs. The 'pre-GIS era' is briefly described including the early mapping of tick distribution, analyses and the display of biogeographical and medical data. The theory of natural focality of diseases (NFD) is explained and its significance in tick-borne diseases (TBD) research is discussed. Many problems of tick ecology and TBD epidemiology and epizootology have been addressed by means of GIS and examples of these studies are presented and discussed.

[Antibodies against mosquito-born viruses in human population of an area of Central Bohemia affected by the flood of 2002]

In the Central-Bohemian area affected by the flood of 2002, 497 residents were screened for antibodies against the mosquito-borne viruses Tahyna (TAHV), West Nile (WNV), Sindbis (SINV) and Batai (BATV; syn. Calovo) using the haemagglutination-inhibition (HIT) and plaque-reduction neutralization (PRNT) tests. Blood samples were collected in September 2002 when the mosquito populations showed the maximum density following the flood. Antibodies against TAHV (16.5% persons in PRNT, 14.9% in HIT), SINV (1.4% in HIT) and BATV (1.4% in HIT, 0.2% in PRNT) were detected. Although 6.8% and 1.2% of the subjects tested reactive with WNV in HIT and PRNT, respectively, the results were interpreted as cross-reactivity with tick-borne encephalitis virus. The seroprevalence of TAHV (both in PRNT and HIT) showed no association with gender (15.8% of males, 16.9% of females), increased with age (1.4% of persons younger than 20 years, 11.2% of persons aged between 20 and 50 years, and 26.2% of persons older than 50 years were positive), and correlated with the mosquito peri-residential challenge (5.0% residents seropositive in a mosquito-free control zone D--mostly Prague, 14.7% in a mild-risk zone C, 20.5% in a moderate-risk zone B, and 28.0% in the most heavily mosquito-infested risk zone A). The highest TAHV seropositivity rate (> 25%) was found amongst the inhabitants of the villages Obríství, Kozly, Tuhan, Chrást, Chlumín and Hostín. Paired blood samples were obtained from 150 of the persons at a 6-month interval: an infection episode with TAHV during or after the flood was clearly evidenced in one person living in Obríství, and less convincing findings of recent TAHV infections were found in other three residents of Chlumín and Obríství (seroconversion and/or significant antibody titres increase detected in HIT only). This serosurvey indicated the existence of an active natural focus of Valtice fever (TAHV infection) stretched along the river Labe nearby Neratovice (Obríství, Chlumín, Tuhan; Kozly, Tisice, Chrást), and a low TAHV activity area along the lower reaches of the river Vltava between Zloncice and Bukol/Zálezlice. An increased population density of mosquitoes after the flood may have boosted the incidence of mosquito-borne virus diseases, particularly Valtice fever, in Central Bohemia. An optimum prophylactic strategy to control these diseases would be epidemiological surveillance (including monitoring of both the density of mosquitoes and their rate of infection with viruses in natural foci) on the basis of which antiepidemic measures such as integrated mosquito control can be taken.

[Comparison of extraction methods for detection of Ehrlichia DNA in whole blood using PCR]

The author compared nine methods for isolation of specific DNA of the etiological agent of human granulocytic ehrlichiosis from human blood for examination of the PCR. To full blood of healthy donors a laboratory culture of the agent was added and the effectiveness of isolation an stability of the template was tested under conditions when the blood was fresh or frozen. For universal use QIAamp (QIAGEN) was most suitable, frozen blood was extracted best using NucleoSpin Tissue (Macherey-Nagel).

[Antibodies to granulocytic Ehrlichiae in the population of the western and central part of the Czech Republic]

A total of 963 subjects in four groups from western and central Bohemia were examined in 1998-2000 for the presence of antibodies against granulocytic ehrlichiae. In the indirect fluorescence assay, a specific antigen from ehrlichiae (HGE) cultivated in-vitro and commercial anti-IgG and anti-IgM secondary antibodies were used. An overall prevalence of HGE antibodies of the class IgG corresponding to titres < or = 1/80 and 1/160 was found to be 21.0 and 13.5%, respectively, with a predominance during the warm season (May-October). The seasonal seroprevalence was discriminated best from an all-year background by titres 1/80-1/160. Elevated antibodies were found more frequently in older subjects; no effect of gender was observed. Antibodies of the class IgM were detected only exceptionally and did not exceed the titre of 1/40. Only minor differences were observed in the prevalence of HGE antibodies between groups differing geographically or by the presence of Borrelia antibodies. The seasonal incidence of HGE antibodies did not differ significantly from that of Borrelia antibodies.

Differential effects of pentaerythritol tetranitrate and nitroglycerin on the development of tolerance and evidence of lipid peroxidation: a human in vivo study

OBJECTIVES

We investigated the development of nitrate tolerance after continuous exposure to nitroglycerin (GTN) as compared with pentaerythritol tetranitrate (PETN) in humans.

BACKGROUND

Sustained therapy with GTN causes tolerance and has been associated with increased production of free oxygen radicals by the endothelium. Pentaerythritol tetranitrate is an organic nitrate that has been used in the therapy of angina. There have been no investigations concerning the development of tolerance to PETN in humans. Animal investigations suggested that continuous therapy with PETN does not cause increased free radical production or hemodynamic tolerance.

METHODS

We randomized 30 healthy volunteers to continuous GTN (0.6 mg/h/24 h), long-acting PETN (60 mg orally three times a day) or no treatment (control group) for seven days. We studied systemic blood pressure responses and venous volume responses to GTN with strain-gauge plethysmography. The levels of cytotoxic aldehydes and isoprostanes were measured as markers of free radical-mediated lipid peroxidation.

RESULTS

Tolerance, as demonstrated by blood pressure and forearm plethysmography, developed in the GTN group and was absent in the PETN group (p < 0.05). Therapy with GTN was associated with a significant increase in plasma markers of lipid peroxidation. This response was not observed in those treated with PETN (isoprostanes: control: 38 +/- 5; GTN: 59 +/- 6; PETN: 38 +/- 3 microg/ml; p < 0.005).

CONCLUSIONS

Treatment with PETN does not cause tolerance and is not associated with evidence of increased free radical production.

Epizootiologic background of dissimilar distribution of human cases of Lyme borreliosis and tick-borne encephalitis in a joint endemic area

Lyme borreliosis (LB) and tick-borne encephalitis (TBE) are co-endemic in some parts of Europe, however, their distribution differs despite a common tick vector and comparable animal hosts. A serosurvey of game and small mammals was made in a highly endemic area and compared with historical data in human cases; the epidemiologic risk and the population density of game were modelled using a geographic information system. While LB-risk corresponded with an overall population density of game (red deer, roe deer, mouflon, wild boar) regardless of mouse abundance, TBE-risk suggested a dependence on the abundance of mice on the one hand, and game, particularly roe deer, on the other. While the prevalence of TBE-antibodies generally grew with the game's age, it was virtually constant at about 65% in LB irrespective of species. It implies a cumulation of scarce TBE-infection histories during the game's lifetime, and thus a limited size of TBE-foci relative to the living space of these animals, as well as omnipresent LB-foci, in which the animals became continuously re-infected. More ecological prerequisites seem necessary to keep TBE circulating in nature which may be responsible for its confined distribution.

Mosaic pattern of Borrelia infection in a continuous population of the tick Ixodes ricinus (Acari: Ixodidae)

An array of 12 20 x 20 m quadrats in a mixed forest near Poteply, Central Bohemia, Czech Republic, was investigated for the abundance and spatial distribution of host-questing Ixodes ricinus nymphs and their infection with borreliae. Tick densities were estimated by flagging and their borrelia infection status was determined by direct immunofluorescence. While the tick population appeared to be continuous and homogeneous based on quadrat counts, their infection with borreliae evinced a mosaic pattern. The nymphal infection rates ranged between 1.6 and 10.5% (mean = 6.0%) with significant differences between adjacent quadrats. Home ranging of small rodents (Apodemus flavicollis and Clethrionomys glareolus) inhabiting the forest seems to be responsible for the spatial pattern of borrelial infection.

Tick-borne encephalitis and Lyme borreliosis: comparison of habitat risk assessments using satellite data (an experience from the Central Bohemian region of the Czech Republic)

The vegetation types have been used as the indicators of an ecosystem suitable for high incidence of Ixodes ricinus ticks and their hosts, for the circulation of tick-borne diseases pathogens and, accordingly, for the existence of natural foci of these infections, namely tick-borne encephalitis (TBE) and Lyme borreliosis (LB). The method of remote sensing offers a suitable solution to this problem. We attempted to prepare the habitat risk assessment maps on the territory (11,500 km2) of Central Bohemia (Czech Republic) using Landsat 5 TM imagery. Nine forest classes have been recognized in the satellite data and further identified in a field checking botanical survey. Beside the conclusions dealing with the importance of different plant types for I. ricinus occurrence, also the epidemiological TBE and LB maps based on human cases contracted in the territory under study were exploited for the evaluation of particular forest classes significance, and for the comparison of results achieved. Apart from a general pattern of risk gradation from coniferous to deciduous wood types, both TBE and LB data suggest a specific position of the heterogeneous deciduous wood class (including mainly young deciduous stands and stand ecotones with highly heterogeneous structure). Epidemiological significance of the other particular forest classes was assessed by the degrees of positive class-to-risk associations (see Table 1 and 2).

Borrelia-infection rates in tick and insect vectors accompanying human risk of acquiring Lyme borreliosis in a highly endemic region in Central Europe

The methods of spatial statistics were applied to assess the geographical pattern of risk of Lyme borreliosis in Central Bohemia, the Czech Republic, based on retrospective data on disease contractions. The statistical risk was then compared at 15 selected localities with the infection challenge presented by ticks and insects carrying borreliae. Over 5,000 Ixodes ricinus (L.) ticks and 390 haematophagous dipterans were screened by direct immunofluorescence method, and the spatial and seasonal variance of infection rates were studied. Infected ticks were found at each locality throughout the warm season; in nymphs, sample infection rates ranged from 4.9% to 23.1% with a mean of 14.5% in spring, from 7.7% to 28.7% with a mean of 16.1% in summer, and from 7% to 20.6% with a mean of 13.6% in autumn. The statistical risk was found to correlate well with an average nymphal infection challenge, i.e. I. ricinus nymphal abundance x infection rate, at a given locality. Statistically significant cumulation of insect-history recalling patients into several, generally wetland, areas was ascertained; borreliae were revealed in 0.5% of the dipterans examined.

A conserved region of the R domain of cystic fibrosis transmembrane conductance regulator is important in processing and function

The R domain of cystic fibrosis transmembrane conductance regulator (CFTR) connects the two halves of the protein, each of which possess a transmembrane-spanning domain and a nucleotide binding domain. Phosphorylation of serine residues, which reside mostly within the C-terminal two-thirds of the R domain, is required for nucleotide-dependent activation of CFTR chloride channel activity. The N terminus of the R domain is also likely to be important in CFTR function, since this region is highly conserved among CFTRs of different species and exhibits sequence similarity with the "linker region" of the related protein, P-glycoprotein. To date, however, the role of this region in CFTR channel function remains unknown. In this paper, we report the effects of five disease-causing mutations within the N terminus of the CFTR-R domain. All five mutants exhibit defective protein processing in mammalian HEK-293 cells, suggesting that they are mislocalized and fail to reach the cell surface. However, in the Xenopus oocyte, three mutants reached the plasma membrane. One of these mutants, L619S, exhibits no detectable function, whereas the other two, D614G and I618T, exhibit partial activity as chloride channels. Single channel analysis of these latter two mutants revealed that they possess defective rates of channel opening, consistent with the hypothesis that the N terminus of the R domain participates in ATP-dependent channel gating. These findings support recent structural models that include this region within extended boundaries of the first nucleotide binding domain.

[Social work with the elderly--current orientation and strategies]

Social work for the elderly in a demographical ageing society is not justified per se, but has to prove its utility under the altering social conditions of the changing age-structure. In the field of practice, this has led to an increasing need for professional orientation and to searching for profiles of performance with greater attraction. As manifold as the target groups are the spectra of social work for the elderly is also manifold in its content and methods. Nevertheless, we are able to recognize some general orientations and strategies, which are conceptual adaptions from social work in general, cultural work and educational work--combined with fundamental supplies of social gerontological knowledge. In this sense, social work, for the elderly--in its most advanced realms--should be integrated into an ageing-policy concept, which is of relevance for the society as a whole.

Predictive map of Ixodes ricinus high-incidence habitats and a tick-borne encephalitis risk assessment using satellite data

The main objective of this project was to predict Ixodes ricinus abundant habitats reliably as a means of tick-borne encephalitis (TBE) risk assessment for the prevention of this disease. The vegetation types were used as the indicators of an ecosystem suitable for tick occurrence, for TBE virus circulation and, accordingly, for the existence of natural foci of this infection. Remote sensing methods were used to determine the indicative plant cover. Satellite data covering an experimental area of 70 x 70 km in Central Bohemia, the Czech Republic, was acquired by the Landsat 5 TM scanner. Nine forest classes were recognized in the experimental area by successive supervised and unsupervised classifications and identified in a field-checking botanical survey. An epidemiological TBE map based on human cases contracted in the territory under study was exploited for the evaluation of risk in particular forest classes. Predictive maps are expressed both in digital and in printed forms at a scale of 1:300,000 for an overall risk evaluation and at a scale of 1:25,000 for a detailed local orientation.

Lyme borreliosis habitat assessment

Tick ecologists throughout Europe provided descriptions of Lyme borreliosis habitats according to a standardised format and data for 105 habitats in 16 countries were received. The data showed that high risk situations, as defined by the presence of large numbers of B. burgdorferi sensu lato-infected nymphal I. ricinus, occur in heterogeneous deciduous woodland, usually with a recreational function and with a diverse fauna, usually including deer. Large numbers of ticks occurred in some other habitats, but infection prevalence was usually low. The situation for adult I. ricinus was similar but less clearly defined. Tick infection rates were found to be lower in western Europe than in the east, and the infection rate in I. persulcatus, the most easterly vector species, was markedly higher than in I. ricinus. In the vast majority of habitats the infection rate in adult I. ricinus was greater than in nymphs. Larvae were rarely found to be infected.

[Prediction of sites with an increased risk of infestation with Ixodes ricinus and tick-borne encephalitis infection in the Central Bohemia Region based satellite data]

Based on elaboration of a prediction map of sites of increased incidence of Ixodes ricinus associated with an increased risk of attack on humans and activation of the virus of tick-borne encephalitis it was assumed that different types of vegetation can serve this purpose as suitable indicators. For assessment of these sites and their location on the territory of the Central Bohemian region (on an area of 11,508 sq.km) data from spectral analysis of reflected light recorded by a scanner, Thematic Mapper, working on satellite LANDSAT 5 with a spatial resolution of 30 m, obtained in six bands of the visible and near infrared spectrum resp. was used. Digital satellite data were processed in station IBM RISC 6000 using the professional software EASI/PACE of PCI Co. Inc. Canada. First by supervised classification seven main classes describing the position of the whole area were differentiated and then by a combination of unsupervised and subsequently supervised classification the forest areas were divided into nine classes of forests (with a different structure and different composition as to species), which have a different incidence of ticks. These classes were then compared by statistical methods with the epidemiological map of risk of acquisition of the tick-borne encephalitis virus. This resulted in the finding that coniferous tree forests ("1" and "2") are practically devoid of risk, while mixed and deciduous forests ("3" to "9") involve a varying degree of risk. The maximum risk was found in class 6 which comprises very heterogeneous young deciduous growth and ecotones. The results are presented graphically on the specimen of the prediction map (part of the classified picture supplemented by topographic signs at scale 1:25,000) and on classified satellite picture of the whole area (scale of the original computer printout 1:300,000). In the legend the grade of risk of different classes is expressed verbally, corresponding to values of the Spearman coefficient of rank correlation (Table 1). The laboratory tests were verified and characterized from the botanical aspect during the field investigation.

Objective assessment of risk maps of tick-borne encephalitis and Lyme borreliosis based on spatial patterns of located cases

BACKGROUND

Clusters of infection can indicate the underlying risk pattern of an endemic disease. Retrospective epidemiological data have been used to map the risk of tick-borne encephalitis (TBE) and Lyme borreliosis (LB) in the Central Bohemian region of the Czech Republic.

METHODS

Both reported places of infection and patients' residences were entered in a geographical information system; their distance distribution and census data were used to model density of the population at risk. Point-pattern analysis and non-parametric kernel smoothing of points of infection were applied to compute the risk maps. Tick flagging and direct immunofluorescence assay were used to probe true LB-risk in the field.

RESULTS

Tick-borne encephalitis infections proved to be more clustered than those of LB which was widespread; however, the most prominent clusters of both diseases largely correspond to each other. The estimated LB risk correlated well with tangible disease challenge as assessed from the tick abundance and Borrelia infection rates at 15 selected localities surveyed annually.

CONCLUSION

The risk of LB is widely and smoothly distributed over the area studied, apparently following tick habitats wherever they occur, while TBE is confined to a subset of these locations.

[Possibilities of dialysis therapy in irreversible renal failure in rheumatoid arthritis with secondary amyloidosis]

The authors discuss their initial experience with the treatment of secondary amyloidosis in rheumatoid arthritis with irreversible renal failure in patients included in a regular dialyzation programme. The hitherto assembled 15-month experience justifies the inclusion of patients with this cause of irreversible renal failure in a dialyzation programme. The reverse is not only wrong from the medical aspect but is inhuman and interferes with the life of families of these patients. Although the procedure during a regular dialyzation programme of these patients with rheumatoid arthritis with secondary amyloidosis is more complicated, more pretentious and more responsible, it is our medical duty to carry this burden together with the patient.

Tolerance and cross-tolerance to stress-induced increases in plasma Met-enkephalin in rats with adaptively increased resting secretion

Plasma concentrations of both native (pentapeptide plus its sulfoxide) and peptidase-derivable (trypsin followed by carboxypeptidase-B) Met-enkephalin showed brisk increases in response to the stresses of immobilization, hemorrhage, and electric footshock in conscious, freely moving, adult male rats. Daily exposure to 150-min periods of immobilization resulted in a maintained increase in baseline plasma concentrations of native Met-enkephalin 21.5 h after the sixth day and a further increase after 39 days. The plasma native Met-enkephalin response to acute immobilization was attenuated on day 7 and completely absent on day 40. Unstressed rats showed a plasma native Met-enkephalin response to hemorrhage of 15% blood volume and a further increase in response to 25% hemorrhage. Immediately after initial acute immobilization or 6 days of daily immobilization when plasma native Met-enkephalin was elevated but the response to acute immobilization was attenuated, plasma native Met-enkephalin responses to hemorrhage were also attenuated. Rats that had been immobilized daily for 40 days and showed no plasma native Met-enkephalin response to acute immobilization also showed no responses to hemorrhage. After 39 days of immobilization when there was no plasma native Met-enkephalin response to acute immobilization, there was also no response to footshock. Thus, development of tolerance or adaptive loss of plasma native Met-enkephalin response to immobilization with repeated exposure to this stressor is associated with cross-tolerance or adaptive loss of the responses to the stresses of hemorrhage or electric footshock. Development of tolerance and cross-tolerance of plasma responses of peptidase-derivable Met-enkephalin paralleled that of native Met-enkephalin. Thus, adaptation of plasma Met-enkephalin responses to repeated exposure to a stressor included both increased resting secretion and decreased acute responses to homotypic or novel stressors.

[Simultaneous occurrence of tick-borne encephalitis and Lyme borreliosis in the Central Bohemian Region]

An analysis of joint occurrence of tick-borne encephalitis and Lyme borreliosis in the Central Bohemian region of Czechoslovakia, based on clinical cases, showed a divergency in the dispersion patterns of the diseases. Whilst tick-borne encephalitis infections occurred in a few limited areas and its clinical cases tended to aggregate into well defined clusters, apparently following its natural focality, the cases of Lyme borreliosis were scattered +/- randomly over nearly all the region without forming such marked clusters and having little topographical correlation with tick-borne encephalitis. A computer model was applied to substantiate the observations.