[Cost-effectiveness of a local bone bank based on thermodisinfection according to § 20 b and c AMG and alternatives]

INTRODUCTION

The German tissue law creates a different and more difficult situation for German musculoskeletal tissue banks. The objective aim of the new regulations was an increased safety and a reduction of viral and non-viral disease transmissions. In the authors' case, the government officials demanded a thermodisinfection for human femur heads. As a consequence of the requirements we aimed at an analysis of the cost-effectiveness of an admission according to § 20 b and c "Arzneimittelgesetz" (AMG) and implementation of the "lobator bonebank system™".

METHOD

We calculated the working hour requirements for all medical staff involved in the tissue procedure. Additional costs were the current consumptions of two freezers (cooling power - 80 °C) for one year, the current consumption of one thermodisinfection process, the material cost of one disinfection and documentation set, expenses for laboratory examinations and the non-recurrent expenses for the admission according to § 20 b and c AMG and the "lobator bonebank system". Non-recurrent expenses were calculated for five years according to 610 tissue donations. We compared the overall costs for one processed femur head with the charges of an industrial chemical treating and irradiation.

RESULTS

Expenses for medical doctors were 14.13 € and for nurses 3.71 €. Energy costs were 15.20 € for each stored femur head. Costs for the disinfection and documentation sets were 105.15 €, laboratory expenses were 107.25 €. The non-recurring fee for the admission according to § 20 b and c AMG was 2650 €, the cost for the lobator-sd2 was 12 495 €. The overall expenses for one disinfected femur head were 274.82 € compared to 535.23 € in a tissue service.

CONCLUSION

To comply with legal requirements, operating expenses of the new tissue act increased. Nevertheless we could still prove the cost-effectiveness of a local bone bank in Germany.

Changes in dialysis treatment modalities during institution of flat rate reimbursement and quality assurance programs

Dialysis procedure rates in Germany were changed in 2002 from per-session to weekly flat rate payments, and quality assurance was introduced in 2009 with defined treatment targets for spKt/V, dialysis frequency, treatment time, and hemoglobin. In order to understand trends in treatment parameters before and after the introduction of these changes, we analyzed data from 407 to 618 prevalent patients each year (hemodialysis over 90 days) in 14-21 centers in cross-sections of the Dialysis Outcomes and Practice Patterns Study (phases 1-4, 1998-2011). Descriptive statistics were used to report differences over time in the four quality assurance parameters along with erythropoietin-stimulating agent (ESA) and intravenous iron doses. Time trends were analyzed using linear mixed models adjusted for patient demographics and comorbidities. The proportion of patients with short treatment times (less than 4 h) and low spKt/V (below 1.2) improved throughout the study and was lowest after implementation of quality assurance. Hemoglobin levels have increased since 1998 and remained consistent since 2005, with only 8-10% of patients below 10 g/dl. About 90% of patients were prescribed ESAs, with the dose declining since peaking in 2006. Intravenous iron use was highest in 2011. Hence, trends to improve quality metrics for hemodialysis have been established in Germany even after introduction of flat rate reimbursement. Thus, analysis of facility practice patterns is needed to maintain quality of care in a cost-containment environment.

[Does the body mass index influence the results of revision total knee arthroplasty?]

BACKGROUND

Revision total knee arthroplasty (TKA) is one of the most demanding as well as increasing orthopaedic operations. The influence of a higher body weight or body mass index (BMI) on the results of revision TKA is not evident so far. We therefore hypothesised that obesity as well as a high body weight could influence the results of revision TKA.

PATIENTS

75 consecutive revision TKA in 75 patients were included and stratified according to a BMI greater or smaller than 30 kg/m2 and a body weight greater or smaller than 90 kg. The Knee Society score (KSS), the function and the knee subscales were analysed pre- and postoperatively as well as the pre- to postoperative improvement. The duration of the procedure, the occurrence of complications, the blood loss and the length of hospital stay were collected.

RESULTS

All patients showed a significant improvement of the KSS and function score (p < 0.05). There was a tendency to superior results in patients with a smaller BMI and a lower body weight. This tendency was most pronounced in the function subscale which depicted significant differences in favour of a BMI smaller 30 kg/m2. No significant differences were observed in the other analysed factors.

CONCLUSION

BMI greater than 30 kg/m2 as well as a higher body weight seem to negatively influence the function of revision TKA. However, all patients significantly improved after revision TKA and no differences were found according to the occurrence of complications. Therefore, revision TKA should not be refused to obese or heavy patients.

[Imaging-guided injection techniques of the lumbar spine]

Spinal injections are an important treatment option in the conservative management of many spinal disorders. A large number of imaging techniques are available to achieve a precise and safe needle placement in interventional procedures. Fluoroscopy-guided injections are safe, cost effective and available in most institutions. The following article presents an overview of common fluoroscopy-guided spinal injection therapy of the lumbar spine.

Alternative technique of cement augmentation of loosened pedicle screws -- technical note and presentation of two cases

An alternative cement augmentation technique for pedicle screws is described, which was applied in two patients with mono- and bisegmental non-union after preceding multisegmental lumbar fusion. The correctly placed pedicle screws in S1 with diameters of 6 and 8.5 mm had severely enlarged the screw cavities due to segmental instability. Revision screws with 10 mm diameter demonstrated sufficient purchase only on the left side. Therefore, cement augmentation was performed for the right sided screws. After verification of intact pedicle borders, the cavity was filled up with PMMA bone cement. Afterwards, a Kirschner wire was positioned centrally, the hardening of the cement was awaited, the cement was gradually drilled and the screw was placed. In both patients, sufficient purchase of the cemented pedicle screws was documented. Screw insertion after awaiting the hardening of the bone cement in pedicles and vertebral bodies with huge defect situations seems to be an alternative to previous cement augmentation techniques of pedicle screws with the advantage, that the screws could be more easily unscrewed, if necessary.

Anatomical reconstruction of the medial patellofemoral ligament in children with open growth-plates

Recurrent lateral patellar dislocation is a common knee injury in the skeletally immature adolescent. In adults, anatomical reconstruction of the medial patellofemoral ligament (MPFL) is recommended, but due to the open physis, operative therapy in children is more challenging. We present a minimal invasive technique for anatomical reconstruction of the MPFL in children respecting the distal femoral physis. This technical note considers the important fact that the femoral insertion is distal to the femoral physis. Since the importance of an anatomical reconstruction respecting the femoral insertion of the ligament has been proven an insertion proximal of the physis has to be strictly avoided.

[Spinal epidural lipomatosis]

Spinal epidural lipomatosis (SEL) is a rare condition affecting the thoracic and lumbar spine, characterized by a hypertrophy and hyperplasia of the rich vascularized fat tissue inside the spinal canal. The etiology of SEL is unknown. A high number of cases are associated with obesity, corticosteroid intake and a dysbalance in adrenocorticotropic hormone (ACTH)-cortisone metabolism. It can be an incidental radiographic finding or present with symptoms, such as low back pain, weakness of the lower limbs, dysesthesia, radiculopathy, claudication or even cauda equina syndrome. The interdisciplinary treatment consists of weight reduction, weaning from corticosteroids and in persisting cases or neurologic alterations in surgical decompression of the spinal canal. The following article presents a current review and a case report of this rare entity.

[Validity of digital templating in total hip arthroplasty: impact of stem design and planner's experience]

INTRODUCTION

Preoperative planning in total hip arthroplasty decreases the risk of implant oversizing and facilitates intraoperative orientation. The size of the acetabular and femural components can be estimated. The aim of the present study was to determine the validitiy of digital templating. Furthermore, we compared the accuracy of three planners with different clinical experience and the effect of two different femoral component designs on planning accuracy.

METHODS

On 60 a. p. pelvis radiographs, 60 unilateral, non-cemented total hip arthroplasties using the planning tool "AGFA-Orthopaedic-Tools Version V2.10®" (Fa. Agfa Health Care, Mertsel, Belgium) were repeatedly planned by three orthopaedic surgeons (planner A fifth year, planner B third year, planner C second year of training). All 60 patients received pressfit acetabular components, a straight stem was implanted in 28 (CLS-Spotorno™, Fa. Zimmer) and a short stem (Fitmore™, Fa. Zimmer) in 32 patients. The planned sizes of the components and the offset-variations were compared to the implanted sizes.

RESULTS

The percental accuracy and ICC planning for the straight stem were 42.9 %/0.906 for planner A, 39.3 %/0.833 for planner B, and 28.6 %/0.836 for planner C. Planning the short stem, the percental accuracy and ICC were 34.4 %/0,886 for planner A, 21.9 %/0.708 for planner B, and 12.5 %/0.681 for planner C. The accuracy and ICC of templating the acetabular components were 35 %/0.796 for planner A, 30 %/0.725 for planner B, and 26.8 %/0.511 for planner C. Planning the sizes of both femoral components showed significant differences between planner A and C and planner B and C in Wilcoxon's signed-rank test.

CONCLUSION

A lower level of experience showed no effect on the planning results of the acetabular components, but there were considerable and significant differences on planning the femoral components. Furthermore, the design of the femoral component had an impact on planning accuracy.

[Radial MRI of the hip joint for evaluation of degenerative changes in the young adult: a comparison of different sequences]

AIM

Femoroacetabular impingement has been shown to be an important cause for the development of osteoarthritis of the hip joint. Radial MRI of the hip has proven to be the diagnostic procedure of choice to differentiate which patient to operate. While examinations after instillation of contrast agents have been described, new papers have shown high accuracy without contrast medium. Since instillation of contrast medium is considered painful and poses the risk of infection, it is not performed for MRI evaluation of the hip at our institution. However, the question as to which sequence to use has not been settled yet. Therefore, four frequently used sequences using the same resolution were compared.

MATERIALS AND METHODS

A retrospective analysis of T (1)-weighted (T (1)), T (2)-weighted (T (2)) and proton density sequences (the latter with and without fat saturation [PDfs and PD]) of 50 hips in 48 patients with femoro-acetabular impingement and developmental dysplasia of the hip was performed by two raters blinded to the clinical information. The different sequences were rated separately. Evaluated criteria were subjective imaging quality, power to differentiate acetabular from femoral cartilage as well as the labrum from the joint capsule, and localisation and characterisation of pathological changes in joint cartilage, the labrum and at the femoral head-neck junction.

RESULTS

Subjective imaging quality was assessed to be similar for T (1), PDfs and PD, whereas it was significantly worse for T (2). In discriminating specific intraarticular structures, however, only PDfs and PD were superior. The differentiation of acetabular from femoral cartilage was possible in only 44% and 40% of T (1) and T (2) images, but in 79% and 76% of PDfs and PD images. Similar results were found for the differentiation of the acetabular labrum from its vicinity, especially the joint capsule (36%, 35%, 77% and 74%, respectively). Intralabral pathology was seen in a comparable extent in all sequences. An intramedullary oedema at the head-neck junction, however, was significantly more frequent in PDfs only (67% vs. 0%, 17% and 10% for PDfs vs. T (1), T (2) and PD).

CONCLUSION

Despite their good subjective quality, T (1)- and T (2-)weighted sequences could not depict the acetabular labrum as efficiently as PD-weighted sequences. Concluding from our data, a PDfs sequence (possibly combined with a conventional PD sequence) is advantageous over T (1) and T (2) sequences. Intraarticular administration of contrast medium seems to be superfluous.

[German observational trial on secondary hyperparathyroidism therapy with cinacalcet (EARLY)]

BACKGROUND AND OBJECTIVES

The calcimimetic cinacalcet (Mimpara) was approved in the European Union in 2004 for treatment of secondary hyperparathyroidism (sHPT). This observational trial was conducted to investigate efficacy of cinacalcet and practices of sHPT treatment under routine clinical conditions.

PATIENTS AND METHODS

913 patients on maintenance hemodialysis were recruited from 136 German kidney centers. 662 patients who fulfilled the entry criteria of moderate to severe sHPT (intact parathyroid hormone, iPTH: 300 - 800 pg/mL or 32 - 85 pmol/l) were included in the trial. Primary objective was to investigate efficacy of cinacalcet in patients treated for at least 160 days (efficacy collective, N = 555). The primary endpoint was defined as the percentage of patients with a iPTH within 150 - 300 pg/ml and a calcium-phosphate product (CaxP) ≤ 4.44 mmol (2)/l (2) (55 mg (2)/dl (2)) after 6 months of treatment. Further objectives were the course of calcium (Ca) and phosphate (P) as well as the use of phosphate binders and vitamin D in treatment of bone metabolism disorders.

RESULTS

According to the predefined entry criteria none of the patients reached the combined target criterion for iPTH and CaxP at baseline. The mean initial iPTH and CaxP were 530.0 ± 134.3 pg/mL and 4.82 mmol (2)/L (2) (mean ± SD) respectively. In spite of the unfavorable prognostic factors 25 % of the recruited patients met the combined target at the end of the trial. The mean reduction per patient for iPTH was 203.6 pg/mL [95 % confidence interval (CI) 183.3 - 224.0] and 0.69 mmol (2)/L (2) [95 %-CI 0.57 - 0.79] for CaxP. Ca and P were reduced by 5.3 % [95 %-CI 4.3 - 6.3] and 5.5 % [95 %-CI 3.4 - 7.7], respectively. The mean daily dose of cinacalcet at trial end was 44.9 ± 25.0 mg (mean ± SD). At baseline, 90 % of patients who were analyzed for efficacy (n = 500/555) were treated with phosphate binders, 57 % were treated with a calcium-based phosphate binder (n = 317/555). The use of active Vitamin D (all active Vitamin D compounds) was recorded for 59 % of the patients (n = 328/555). No relevant changes of these treatments were observed in the course of the trial. Tolerability of cinacalcet was good, 94 adverse drug reactions were recorded in 57 of the 913 enrolled patients (6 %).

CONCLUSIONS

One out of four patients reached the combined target of iPTH and CaxP with relatively low dose cinacalcet after 6 months of treatment. iPTH, Ca and P were reduced. The results confirm the high efficacy of cinacalcet in treatment of sHPT and underline the role of cinacalcet in the control of Ca and P.

[Perioperative morbidity in lumbar disc replacement]

AIM

For several years now interbody fusion has been the gold standard procedure for treating degenerative disc disease. The problem of adjacent disc degeneration after interbody arthrodesis led to the development of non-fusion techniques. The device which best represents the philosophy of spine arthroplasty is the total lumbar disc replacement (TDR). An analysis of the perioperative morbidity of lumbar disc replacement was carried out in the current study.

METHOD

66 patients underwent lumbar disc replacement between 2001 and 2007. 78 protheses were implanted. Retrospectively patient-related variables (comorbidity, prior surgeries), perioperative blood loss, number and levels operated on, operation duration and technical and general complications were analysed.

RESULTS

54 patients had mono- and 12 patients bisegmental TDR. The mean operation time was 112 minutes with an average blood loss of 560 mL. Neither the type of comorbidity, prior surgery, operation duration, nor level operated on had an influence on the occurrence of perioperative morbidity. A significant influence could be shown for the number of levels operated on and the intraoperative blood loss. General complications were seen in 6 persons (9%) with urinary tract infection, technical complications occurred in 4 persons (6%) with severe blood loss (> 1500 mL) and erythrocyte/plasma substitution, 1 person (1.5%) with an injury of the iliac vein, 1 person (1.5%) with retrograde ejaculation and 1 person (1.5%) with dural tear and consecutive epidural infection.

CONCLUSION

In our study the perioperative morbidity of lumbar disc replacement was similar to the data published so far and seems to be comparable with the perioperative morbidity of lumbar interbody fusion.

The impact of implantation technique on frontal and sagittal alignment in total lumbar disc replacement: a comparison of anterior versus oblique implantation

The concept of total lumbar disc replacement (TDR) is gaining acceptance due to good clinical short-term outcome. Standard implantation is strict anterior, which poses especially above the segment L5/S1 sometimes difficulties due to the vessel configuration. Therefore, oblique implantable TDR have been invented. In oblique implantation the anterior longitudinal ligament (ALL) is only partially resected, with additional partial resection of lateral annulus fibers. This could have an impact on biomechanical properties, which has not been evaluated until now. We therefore compared the standing ap and lateral X-rays pre- and postoperative after anterior and oblique implantation of TDR in segment L4/5. Significant differences between the groups were not found. In both the anterior and oblique group, segmental lordosis showed a significant increase, whereas total lordosis as well as ap balance were unchanged. The absolute segmental lordosis increase was nearly double in the anterior group. In conclusion, both anterior and oblique implanted TDR significantly increase segmental lordosis while retaining total lordosis and ap balance. The segmental increase is lower in the oblique implanted group which is probably due to the remaining ALL. Further studies should evaluate whether this finding has any implication for the long-term outcome.

Screw loosening after posterior dynamic stabilization--review of the literature

PURPOSE OF THE STUDY

The malposition of pedicle screws in the lumbar spine is associated with a potential risk of iatrogenic injury of neurological structures but also with a decrease of biomechanical stability. The correct position of the pedicle screws of a dynamic stabilization device, as a long-term implant, seems to be of great importance. A high incidence of screw loosening could influence both the rate of revision surgeries and the clinical results.We compared screw loosening in our own patients with published data after navigated and non-navigated implantation of Dynesys.

MATERIAL AND METHODS

Posterior instrumentation with the Dynesys system was performed in 19 patients after improvement of facet joint infiltrations. Seven (37%) patients underwent conventional surgery (group I), five (26%) were operated on using a CT-based navigation (group II) and seven (37%) using a fluoroscopic-based navigation (group III). Pre-operatively, the "Oswestry Low Back Pain Disability Questionnaire (OQ)" and the "Short Form 36 Health Survey Questionnaire (SF-36)" were used to obtain pain and functional scores. Furthermore, radiographs, MRI and CT examinations were performed before surgery. Screw position was analyzed on post-operative CT scans. At a minimum follow-up of twelve months, clinical examination, plain and dynamic X-rays were performed, and pain and functional scores (OQ, SF-36) were obtained.

RESULTS

Pedicle perforation of minimum 2 mm was detected in two group I patients, in one group II and in two group III patients. Regarding OQ and SF-36, an improvement was observed in all patients, except for one column of SF-36. One patient (group I) underwent revision surgery due to symptomatic screw loosening and another patient (group III) due to persistent pain without signs of screw loosening.

DISCUSSION

In former publications the majority of patients improved after Dynesys implantation with or without the use of navigation methods.Malposition of screws was not always followed by screw loosening. Revision surgery due to screw loosening, but without clinical symptoms, was not necessary in the majority of cases.

CONCLUSIONS

It still remains unclear if screw loosening after Dynesys implantation influences the clinical results or the rate of revision surgery and if malposition of screws will be followed by a higher rate of screw loosening.

[Tarsal coalitions: a rare differential diagnosis of congenital clubfoot]

The Ponseti method has proven to be successful in the treatment of idiopathic congenital talipes equinovarus (clubfoot). In particular, if plaster cast treatment as recommended by Ponseti does not show the desired correction of the foot, tarsal coalitions as a rare cause for a secondary clubfoot deformity have to be ruled out. In these cases a surgical release of the coalition in addition to the tenotomy has to be performed to achieve a satisfactory correction.

[Transfixation in slipped capital femoral epiphysis: long-term evidence for femoro-acetabular impingement]

AIM

It was the aim of this study to reveal whether and to what extent femoro-acetabular impingement (FAI) was present 10 to 20 years after transfixation of the gliding epiphysis in patients treated for unilateral slipped capital femoral epiphysis (SCFE).

METHOD

Clinical and radiological evaluations were undertaken of 20 patients who were treated with a bilateral transfixation of the epiphysis with screws or Kirschner wires because of mild unilateral SCFE. The Harris hip score, the activity level according to Tegner and Lysholm and the range of motion of both hip joints were noted. An impingement provocation test was performed on both sides. The femoral head-neck junction was qualitatively and quantitatively assessed in anteroposterior radiographs of the pelvis and "cross table" lateral radiographs of both hip joints. Quantitative assessment was achieved by measuring the alpha angle according to Nötzli et al.

RESULTS

All except one patient showed excellent results in the Harris hip score. The activity levels of the majority of patients, however, were mediocre. There was no difference for flexion, whereas internal rotation and abduction significantly differed between affected and non-affected hips (p = 0.135, p = 0.002 and p = 0.007, respectively). The impingement provocation test was found positive in eight affected and five non-affected hips (p = 0.004). The alpha angle was significantly different between affected and non-affected hips in the anteroposterior radiographs of the pelvis (86 vs. 61 degrees; p < 0.001), but not so, however, in the "cross table" lateral radiographs (52 vs. 46 degrees; p = 0.145).

CONCLUSION

Clinical evaluation of 20 patients at a mean of 14.9 years after transfixation of the epiphysis revealed some evidence for the presence of FAI in affected hip joints. Radiological evaluation suggests that its localisation is more lateral and less anterior.

[Surgery of the cervical spine in rheumatoid arthritis. Diagnostics and indication]

The cervical spine is often affected in rheumatoid arthritis. Beside destructive changes, instabilities can occur, mainly in the upper cervical spine. Typical symptoms are missing so that routine x-ray examinations are needed to prevent severe consequences up to death. AP/lateral cervical spine x-rays and lateral functional x-rays are the standard diagnostic tool. Depending on the findings, further neurological examination and MRI must be initiated. Aim is the early recognition, respectively prevention of myelopathy. Therapy includes stage dependent conservative and surgical measures.

[Embolisation of aneurysmal bone cysts as a minimally invasive treatment option - presentation of two cases]

AIM

The aim of this study was to evaluate embolisation as a therapy option for aneurysmal bone cysts of the trunk.

METHOD

Case reports about two males with intermittent pseudo-radicular lumboischialgia and coxalgia are discussed.

RESULTS

The diagnostic work-up and biopsies verified an aneurysmal bone cyst in both males. In one patient the tumour-like lesion was localised in the fifth lumbar vertebral body, in the other in the left ischium and pubis. Arterial embolisation was performed in both cases. Follow-up at 6 and 24 months after embolisation showed a significant increase of sclerosis and a reduced volume of the cysts.

CONCLUSION

In accord with literature data, arterial embolisation seems to be a sufficient and minimally invasive therapy option in aneurysmal bone cysts of the spine and the pubis.

Radiological evidence of femoroacetabular impingement in mild slipped capital femoral epiphysis: a mean follow-up of 14.4 years after pinning in situ

Conventional treatment of mild slipped capital femoral epiphysis consists of fixation in situ with wires or screws. Recent contributions to the literature suggest that even a mild slip may lead to early damage of the acetabular labrum and adjacent cartilage by abutment of a prominent femoral metaphysis. It has been suggested that the appropriate treatment in mild slipped capital femoral epiphysis should not only prevent further slipping of the epiphysis, but also address potential femoroacetabular impingement by restoring the anatomy of the proximal femur. Between October 1984 and December 1995 we treated 16 patients for unilateral mild slipped capital femoral epiphysis by fixation in situ with Kirschner wires. In this study we have reviewed these patients for clinical and radiological evidence of femoroacetabular impingement. There was little clinical indication of impingement but radiological evaluation assessing the femoral head-neck ratio and measuring the Nötzli alpha angle on the anteroposterior and cross-table radiographs showed significant alterations in the proximal femur. None of the affected hips had a normal head-neck ratio and the mean alpha angle was 86 degrees (55 degrees to 99 degrees ) and 55 degrees (40 degrees to 94 degrees ) on the anteroposterior and lateral cross-table radiographs, respectively. While our clinical data favours conventional treatment, our radiological findings are in support of restoring the anatomy of the proximal femur to avoid or delay the development of femoroacetabular impingement following mild slipped capital femoral epiphysis.