[Proximal tibia fracture treatment with a new locking device with polyaxial screw placement: technique and early results]

BACKGROUND

Surgical treatment of tibial head fractures can be challenging due to the close anatomic relationship to the knee joint which can be affected including its intraarticular structures. Frequently, soft tissue damages are present which can have a strong impact on the planning and choice of surgical technique. An important therapeutic requirement is the anatomic reconstruction and high primary stability to allow early functional treatment. The aim of the present study was to describe a recent locking device and its surgical technique and to analyse the early results.

MATERIAL AND METHODS

The Non-Contact-Bridging Plate for the proximal tibia (NCB® PT, Zimmer Inc.) features a polyaxial locking mechanism which allows both compression and locking with the same screw. The system can be applied both minimally invasively and open. 36 patients (16 female, 20 male; average age 53 years) with three type A, 21 type B and 12 type C fractures according to the AO classification were treated. In 22 cases the system was applied open and in 14 minimally invasively. Clinical and radiological follow-up was obtained at 6 weeks, 3, 6 and 12 months.

RESULTS

The handling of the system turned out to be straightforward after an initial learning curve. Implant failure was not detected in our sample. The minimally invasive technique can be beneficial in cases of severe soft tissue damage, but must not compromise the quality of reduction. The functional result at 1-year follow-up using a knee score was good or very good and comparable to the literature. The rate of general surgical complications was 11 % (haematoma, superficial or deep wound infection). Implant-related complications were not detected. At the 3-months' follow-up 44 % and at the 12-months' 100 % of the fractures were healed on X-ray.

CONCLUSION

The NCB PT plate offers a broad variety of treatment options due to the specific locking mechanism and the fact that it can be applied both minimally invasively and open. In cases of intraarticular involvement the application of compression and locking with the same screw turned out to be very beneficial. The primary stability of the system allows early functional treatment. Clinical results and complication rates of the present study are comparable to those in the literature.

In-vivo kinematics of the cervical spine in frontal sled tests

The description of cervical spine motion and the risk to sustain a cervical spine injury in traffic accidents is mainly based on rear-end collisions. The knowledge about frontal collisions is comparable low. Therefore the objective of this exploratory study was, to describe the in-vivo cervical spine motion and acceleration during simulated frontal sled collisions and to identify sequences of motion in which the risk of injury is increased.

A frontal collision with a speed change of 10.2km/h was simulated in a sled test with ten volunteers. Cervical spine kinematics was assessed by the simultaneous analysis of the angular head motion and acceleration as well as the simultaneous analysis of the relative motion and acceleration between the head and the first thoracic vertebral body.

The motion sequence was divided into five phases. The combination of peak values of the angular head acceleration to ventral and the relative horizontal head acceleration to dorsal between the time period of 90ms and 110ms (early flexion phase) included – potential injury generating – shear forces. Although a hyperflexion (late rebound phase) as injury pattern didn’t occur, dorsal soft tissue injuries due to eccentric muscle-sprain could not be ruled out completely.

In conclusion the study showed under simulated test conditions that during the early flexion phase and the late rebound phase, acceleration and movement pattern occur that could lead to cervical spine injuries.

Image guidance shortens the learning curve for K-wire placement - an experimental study

BACKGROUND

Computer assisted systems in orthopaedic trauma depend in most cases on fixed reference markers. This work evaluated a reference-free image-based guidance system. Outcome parameters were the number of trials needed to achieve an optimal wire position, the radiation and procedure time, and the learning curve.

METHODS

Forty artificial proximal femora covered in polyurethane foam were used and randomized in two groups. Each bone was equipped with a target marker at the fovea capitis femoris. Two surgeons each inserted 20 K-wires, 10 with and 10 without assistance from the guidance system. The aim was to bring the tips of the K-wires as close as possible to the target marker. Both procedures were performed under fluoroscopic control. The new guidance system is based on 2D-C-arm images. Following the procedure the result was determined using computed tomography.

RESULTS

The same accuracy (P = 0.34) was achieved with less time (P = 0.0008) and less radiation (P = 0.0002) with the guidance system. However, use of the guidance system did shorten the learning curve of both surgeons, leading to a reduced number of trials (P <0.0001). The learning curve of both surgeons was strongly correlated. From the first trial, the performance of both surgeons while using the guidance system, improved over their performance without the guidance system.

CONCLUSIONS

The guidance system helped to achieve an optimal K-wire position with less radiation and less time. The major advantage is the ability of the guidance system to be integrated into the workflow and the short and flat learning curve.

Image guidance shortens the learning curve for K-wire placement - an experimental study

BACKGROUND

Computer assisted systems in orthopaedic trauma depend in most cases on fixed reference markers. This work evaluated a reference-free image-based guidance system. Outcome parameters were the number of trials needed to achieve an optimal wire position, the radiation and procedure time, and the learning curve.

METHODS

Forty artificial proximal femora covered in polyurethane foam were used and randomized in two groups. Each bone was equipped with a target marker at the fovea capitis femoris. Two surgeons each inserted 20 K-wires, 10 with and 10 without assistance from the guidance system. The aim was to bring the tips of the K-wires as close as possible to the target marker. Both procedures were performed under fluoroscopic control. The new guidance system is based on 2D-C-arm images. Following the procedure the result was determined using computed tomography.

RESULTS

The same accuracy (P = 0.34) was achieved with less time (P = 0.0008) and less radiation (P = 0.0002) with the guidance system. However, use of the guidance system did shorten the learning curve of both surgeons, leading to a reduced number of trials (P <0.0001). The learning curve of both surgeons was strongly correlated. From the first trial, the performance of both surgeons while using the guidance system, improved over their performance without the guidance system.

CONCLUSIONS

The guidance system helped to achieve an optimal K-wire position with less radiation and less time. The major advantage is the ability of the guidance system to be integrated into the workflow and the short and flat learning curve.

Muscle activity influence on the kinematics of the cervical spine in frontal tests

OBJECTIVE

The question of muscle activity influence on the cervical spine kinematics during rear-end and frontal crash events has been discussed. Less data are available concerning frontal collisions. Therefore, the objective of this study was to investigate the influence of the ventral and dorsal neck muscles on the cervical spine kinematics during simulated frontal sled collisions.

METHODS

A frontal collision with a velocity change (delta V) of 10.2 km/h was simulated in a sled test with 10 healthy subjects (7 female; 3 male). A high-speed camera and accelerometers recorded the motion and acceleration data. The activity of the sternocleidomastoid muscles was recorded with surface electrodes. To avoid cross-talk, an intramuscular recording of the semispinalis capitis muscles was performed with fine-wire electrodes.

RESULTS

The sequence of both muscle activities was reproducible in all subjects. The maximal force of the sternocleidomastoid muscle was observed after a median of 152 ms, with 0 defining the time of the trigger signal. With earlier onset of muscle force, maximal dorsal horizontal acceleration of the head (r = -0.600) was reached later and the ventral translation (r = -0.733) and flexion movement (r = -0.755) set in earlier. The maximal force of the semispinalis capitis muscle was observed after a median of 160 ms. If the duration of muscle force was longer, the maximal head flexion (r = 0.685) and the maximal ventral head translation (r = 0.738) were reached later.

CONCLUSIONS

The sternocleidomastoid muscle force is mainly associated with the horizontal head acceleration and influences the onset of the flexion and translation motion. To summarize, these temporal correlations allow the conclusion that the semispinalis capitis muscle force is mainly associated with the angular head acceleration and influences the duration of the flexion and translation motion.

Muscle activity influence on the kinematics of the cervical spine in rear-end sled tests in female volunteers

OBJECTIVE

Although much research has been performed to investigate the cervical spine kinematics during rear-end collisions, our understanding about the exact role of the musculature is limited. The question of the influence of muscle activity on cervical spine kinematics has been discussed.

METHODS

A rear-end collision with a speed change (ΔV) of 6.3 km/h was simulated in a sled test with 8 female subjects to investigate the influence of the ventral and dorsal cervical spine musculature on cervical spine kinematics. A high-speed camera and accelerometers recorded the motion and acceleration data. The activity of the sternocleidomastoid muscles was recorded with surface electrodes. To avoid cross talk, an intramuscular recording of the semispinalis capitis muscles was performed with fine-wire electrodes.

RESULTS

The analysis of the motion and acceleration parameters allowed the definition of 4 phases. The headrest contact began after a median of 84 ms and the sternocleidomastoid muscle force could be detected after a median of 81 ms, with 0 defining the time of the trigger signal. The maximal force of the sternocleidomastoid muscle and the maximal headrest effect began prior to the maximal ventral angular head acceleration and prior to the maximal ventral horizontal head acceleration relative to T1. The start of the semispinalis capitis muscle force was observed after a median of 159 ms and increased until a flexion of 20 to 25° was reached.

CONCLUSIONS

The headrest effect and the sternocleidomastoid muscle force firstly supported the deceleration of the head relative to T1 toward dorsal, which was followed by an accelerating effect toward ventral. The semispinalis capitis muscle force exerted a late decelerating effect on head flexion and ventral translation movement.

Image guidance can support scaphoid K-wire insertion: an experimental study and initial clinical experience

PURPOSE

In the treatment of small bone fractures, such as the scaphoid bone, conventional navigation is limited by its dependence on fixed reference arrays. We introduce a new technique based on reference markers in surgical instruments. If visible on a standard fluoroscopic image, static trajectories are overlaid in this image to guide implant insertions. Fixed markers are not required. The purpose of this study was to identify the possible advantages of the new guidance technique.

METHODS

For this study, 20 artificial hand specimens were randomized into two groups and blinded with polyurethane foam: 10 were treated conventionally and 10 were image guided. We used a clip containing radiopaque markers, which was detected by the system's workstation. A static trajectory was displayed consecutively in the fluoroscopic image to serve as an aiming device. Secondly, we included 3 patients with fractures of the scaphoid bone to test the integrability of this novel method in a clinical setting.

RESULTS

In the experimental setup, trajectory guidance reduced the duration of surgery and radiation exposure. Furthermore, it reduced the perforation rate. Accuracy was not improved by the new technique. For clinical cases, the system was integrated into the accommodated surgical workflow and rated as very helpful by users.

CONCLUSION

The system helped reduce the misplacement rate and the emission of radiation. The main limitations were that trajectories were not displayed in real time and could only be shown in a single fluoroscopic image. However, the system is simple and can be easily integrated into the surgical workflow.

Formulation of the age-education index: measuring age and education effects in neuropsychological performance

The complex interplay of education, age, and cognitive performance on various neuropsychological tests is examined in the current study. New education indices were formulated and further investigated to reveal how age and education variances work together to account for performance on neuropsychological tests. Participants were 830 English-speaking ethnic Chinese. Neuropsychological measures such as Verbal Memory, Digit Sequencing, Token Motor Task, Semantic Fluency, Symbol Coding, Tower of London, Judgment of Line Orientation, and Matrix Reasoning of the Wechsler Adult Intelligence Scale were administered. Education was measured by total years of education and adjusted years of education, as well as ratios of both measures with age. Age and education were associated with neuropsychological performance. Adjusted years of education was associated with fluency and higher cognitive processes, while the ratio between adjusted years of education and age was associated with tasks implicating working memory. Changes in education modalities implicated tasks requiring language abilities. Education and age represent key neurodevelopmental milestones. In light of our findings, special consideration should to be given when neuropsychological assessments are carried out in cross-cultural contexts and in societies where educational systems and pedagogy tend to be complex.

Navigated treatment of metatarsal V fractures using a new image based guidance system

BACKGROUND

Computer assisted imaging systems are rarely used for fracture treatment and foot surgery. We introduce a new system for image based guidance in traumatology.

METHODS

We included 20 patients with a fracture of the fifth metatarsal. They were randomized on admission into two groups. Ten patients in the metatarsal group were operated conventionally and ten were operated with the assistance of a new image guidance system. This system is based on 2D-fluoro images which are acquired with a conventional c-arm and are transferred to the system workstation. After detecting marked tools, it can be used to display trajectories for K-wire guidance in the c-arm shot.

RESULTS

The average duration of surgery in the image-guided group was 12.7 minutes. In the conventional treated group, it was 17 minutes. The average duration of radiation was 18 seconds in the image-guided group vs. 32.4 seconds in the conventional group. 1.6 trials were necessary to position the K-wire for image-guided procedures in comparison to 2.7 trials in the conventional group.

CONCLUSION

Image-based guidance systems can be used for indications, were hitherto existing navigation systems are limited due to their dependence on fixed reference devices. Image-guided systems can be integrated into existing workflows and can reduce the malpositioning of guidewires.

Therapy recommendation "act as usual" in patients with whiplash injuries QTF I°

Up to now no therapy study has used the classification system of the Quebec Task Force (QTF) to differentiate between patients with (QTF II°) and without functional disorders (QTF I°). This differentiation seems meaningful, as this difference may be relevant for the correct treatment planning. In this context the effect of the therapy recommendation “act as usual” has been evaluated in a homogeneous patient collective with whiplash injuries QTF I°.

470 patients with acute whiplash injuries had been catched in this study and classified according to the QTF. 359 patients (76.4%) with QTF I° injuries could be identified. Out of that 162 patients were enrolled to the study and received the therapy recommendation “act as usual” and the adapted pain treatment with non-steroidal anti-inflammatory drugs (NSAID). After six months the outcome was evaluated by phone.

After injury the median pain score assessed by a visual analogue scale (VAS) was 5.4 (min = 3.3; max = 8.5). After six months 5 of the 162 patients complained intermittent pain symptoms (VAS values < 2). This is consistent with a chronification rate of 3.1%. After injury, the median pain disability index (PDI) was 3.9 (min = 1.9; max = 7.7). After six months 3 of the 162 patients stated persisting disability during sporting and physical activities (VAS values < 1).

The therapy recommendation “act as usual” in combination with an adapted pain treatment is sufficient. Usually patients with whiplash injuries QTF I° do not need physical therapy. An escalation of therapy measures should be reserved to patients with complicated healing processes.

Primary tuberculous peritonitis during infliximab therapy for Crohn's disease

A 64 year old male patient suffering from Crohn's disease received infliximab therapy for a period of 5 months prior to presentation to our hospital. Due to the symptoms fever, ascites, and diffuse abdominal tenderness on palpation of unknown origin, a CT scan of the abdomen was performed and led to the suspected diagnosis of a peritoneal carcinomatosis. QuantiFERON™ test revealed a tuberculosis infection and molecular analyses of a peritoneal specimen obtained by laparoscopy clearly identified Mycobacterium tuberculosis DNA. Quadruple tuberculostatic therapy was initiated and the patient's condition continuously improved thereafter.

Transperineal omentum flap for the anatomic reconstruction of the rectovaginal space in the therapy of rectovaginal fistulas

AIM

Deep rectovaginal fistulas are a rare entity and pose a delicate challenge for the surgeon. The present study introduces different operative interventions involved in transperineal omental flap surgery.

METHOD

A retrospective analysis of all patients treated with a low or mid rectovaginal or enterovaginal fistula at the Department of Surgery of the University Hospital of Schleswig-Holstein, Campus Luebeck, was performed. Treatment results were discussed with respect to aetiology, localization, morbidity and outcome.

RESULTS

Between the years 2000 and 2010, a total of nine patients with a low or mid rectovaginal fistula were treated at our clinic. After local fistulectomy, all patients were additionally treated by a laparoscopically assisted omental flap reconstruction of the rectovaginal and perineal space. Eight of the nine patients received a protective ileostomy or colostomy. Only the patient with a history of Crohn's disease had no ileostomy raised. At a median follow-up of 22 months, no patient experienced recurrence of a rectovaginal fistula. Perioperative mortality was zero and minor complications were observed in 22%. Major complications were an anastomotic insufficiency after low anterior resection that was treated without further interventions. Another complication was a persistent fistula within the sphincter that needed re-operation and bovine plug repair combined with a mucosa flap.

CONCLUSIONS

Complete omental reconstruction of the rectovaginal space appears decisive in the operative therapy of deep rectovaginal or enterovaginal fistulas. Comparative studies on standard therapies are necessary although direct comparison of case series is difficult.

Academic interventional nephrology: a model for training, research, and patient care

Dialysis vascular access dysfunction is currently a huge clinical problem. We believe that comprehensive academic-based dialysis vascular access programs that go all the way from basic and translational science investigation to clinical research to a dedicated curriculum and opportunities in vascular access for nephrologists in training are essential for improving dialysis vascular access care. This paper reviews the fundamental concepts and requirements for us to move toward this vision.

[Expert opinion on boceprevir- and telaprevir-based triple therapies of chronic hepatitis C]

With the approval of boceprevir and telaprevir the standard treatment of chronic hepatitis C virus (HCV) genotype 1 infection will be the triple therapy of a HCV protease inhibitor together with pegylated interferon alfa and ribavirin. In clinical studies a significant increase of sustained virological response rates from 38 - 44 % to 63 - 75 % for treatment-naïve and from 17 - 21 % to 59 - 66 % in treatment-experienced patients in comparison to the dual combination therapy with pegylated interferon alfa and ribavirin alone has been demonstrated. In addition, a large number of treatment-naïve patients and relapsers benefit from shorten treatment durations to 24 - 28 weeks. However, important differences exist between the administration of boceprevir and telaprevir in terms of a pegylated interferon alfa/ribavirin lead-in phase, the duration of dosing of the protease inhibitor, the overall treatment duration, HCV RNA measurements for response guided treatment durations and stopping rules. Furthermore, triple therapies with boceprevir and telaprevir may be associated with selection of resistant viral variants, new adverse events and clinically relevant drug-drug interactions. The present review gives an overview on the results of underlying clinical studies together with a guideline for the practical management of boceprevir- and telaprevir-based triple therapies.

The effect of both a thoracic trauma and a soft-tissue trauma on fracture healing in a rat model

BACKGROUND AND PURPOSE

There is some clinical evidence that fracture healing is impaired in multiply injured patients. Nothing is known, however, about the effects of various types of injuries and their contribution to a possible disturbance of the fracture-healing process. We investigated the effect of a thoracic trauma and an additional soft-tissue trauma on fracture healing in a rat tibia model.

METHODS

3 groups of rats were operated: group A with a simple fracture of the tibia and fibula, group B with a fracture and an additional thoracic trauma, and group C with a fracture, thoracic trauma, and an additional soft-tissue trauma. The fracture and the soft-tissue injury were produced by a special guillotine-like device and the thoracic trauma by a blast wave generator. After one day, the serum level of IL-6 was quantified, and at the end of the study (28 days) the mechanical properties and the callus volume of the healed tibia were determined.

RESULTS

Increasing the severity of the injury caused IL-6 levels to more than double 1 day after injury. It halved the load to failure in mechanical tests and led to reduced callus volume after 28 days of healing.

INTERPRETATION

Fracture healing is impaired when additional thoracic trauma and soft tissue trauma occurs.