[Modified acetabuloplasty using bioresorbable screws and lyophilised allogenic bone]. / Modifizierte Azetabuloplastik unter Verwendung von bioresorbierbaren Schrauben und lyophilisiertem allogenem Knochen.

AIM: Various pericapsular procedures are available to surgically improve the acetabular coverage of the femoral head prior to closure of the triradiate cartilage. In this study the acetabuloplasty with the modification according to Westin (Pember-Sal) was applied. Indications for surgery were congenital hip dysplasia or luxation as well as Perthes' disease. To date, the standard procedures for acetabuloplasty include the transplantation of an autologous iliac crest bone graft and the fixation with K-wires. The aim of this study was to investigate if a modification of the operative procedure with the use of resorbable screws and allogenic bone transplants can minimise the operative trauma, avoid a second procedure, and permit MRI follow-ups without increasing the risk of the operation. METHOD: 15 patients with a mean age of 6.7 years were included in this case series and treated with a modified acetabuloplasty for the indication hip dysplasia or Perthes' disease. The modification of the standard procedure included the transplantation of allogenic bone wedges customised from lyophilised femoral grafts. The fixation was performed with bioresorbable polylactide screws. Clinical and radiographical follow-ups were conducted. RESULTS: Procedure-related complications occurred neither in the intra- nor the postoperative period. The allogenic bone graft was remodelled successively as seen on radiographic controls. Dislocations of the bone wedges were not detectable. Subsiding of the allograft did not occur to a noticeable extent as the acetabular index showed no increase during follow-up. CONCLUSION: This study presents a gentle method of acetabuloplasty which avoids iliac crest bone harvesting with its known complications as well as a second procedure under anaesthesia for the removal of implants.

[Sonography for evaluation of containment in perthes disease: a comparison with magnetic resonance imaging]. / Wertigkeit der Ultraschalluntersuchung in der Containmentdiagnostik des M. Perthes im Vergleich zur Magnetresonanztomografie.

PURPOSE: The objective of the present study was to investigate whether the sonographic visualization of lateralization of the femoral head is comparable to magnetic resonance imaging (MRI) and would therefore be able to contribute to the diagnosis of containment in patients with Perthes disease. MATERIALS AND METHODS: 46 patients with unilateral Perthes disease (age: 5.9 +/- 2.3 years) of Catterall group III/IV were evaluated at first presentation by means of ultrasound (US) and MRI of both hip joints to evaluate the morphology of the acetabular lip (LA) and the epiphysis (EP). The diagnosis of containment was performed in MRI as well as in US by the protrusion and deformity of the epiphysis of the femoral head with cranialization of the labrum. The evaluation of the sonographic and MRI findings was carried out independently by three observers (high experience: 1, 2, low experience: 3). Statistical analysis was performed using Cohen's non-weighted kappa kappa (kappa > 0.75 very high level of correlation). The study was conducted in accordance with the recommendations of the local ethics committee that approved our study. RESULTS: There was a high to very high agreement of the morphology of the LA and EP between observers 1 and 2 (MRI: LA: kappa = 0.87; EP: kappa = 0.90; US: LA kappa = 1.0; EP: kappa = 0.57). The comparison of observers 1 and 2 with observer 3 showed only a poor to acceptable level of agreement. US agreed well with MRI in the evaluation of the containment of the femoral head (1: kappa = 0.79; 2: kappa = 0.70, 3: kappa = 0.72). CONCLUSION: The results of our study suggest that US is a reliable examination method for monitoring the containment of the femoral head in Perthes disease. The evaluation of both methods depends on the experience of the observer.

The fixation strength of hydroxyapatite-coated Schanz screws and standard stainless steel Schanz screws in lower extremity lengthening : a comparison based on a new torque value index: the fixation index.

INTRODUCTION: Lengthening procedures are often complicated by loosening of pins. It has been reported that coating with hydroxyapatite improves fixation and reduces the rate of pin-track infection. MATERIALS AND METHODS: We compared 47 hydroxyapatite-coated Schanz screws (HA screws) in 12 monolateral fixators mounted at the University Hospital Hamburg-Eppendorf with 45 standard stainless steel screws in 9 monolateral fixators mounted at the St Josefs-Hospital Wiesbaden by measuring the insertion and extraction torque values. The average implantation period was 7 months for the hydroxyapatite-coated screws and 5.4 months for the uncoated screws. We established the quotient of the maximum extraction torque over insertion torque which shows the change in the fixation strength with respect to time, the fixation index. It eliminates the influence of the varying pin-bone contact. RESULTS: There was no significant difference in the rate of infection. In the Schanz screws without signs of infection the index was 1.92 for the HA screws and 0.76 for the stainless steel screws (P = 0.0002) giving evidence of the improvement of the fixation by the coating. CONCLUSION: HA coating resulted in improved fixation of Schanz screws in bone and may be useful in prolonged external fixation of the lower leg. The fixation index proved to be a simple tool for the evaluation of the fixation strength of Schanz screws.

Evaluation of hip containment in legg-calvé-perthes disease: a comparison of ultrasound and magnetic resonance imaging.

BACKGROUND: To compare the performance of magnetic resonance imaging (MRI) and ultrasound (US) in the determination of head containment in hips with Legg-Calvé-Perthes disease (LCPD). METHODS: In 26 children (22males, 4 females; age range 2.75 - 11.5 years; median 5.7 years) with LCPD classified as Catterall group III/IV, MRI and US were compared to assess the containment of the femoral head. A total of 63 individual examinations of LCPD and the healthy contralateral hip were evaluated and analyzed objectively by two independent observers. The containment was quantified by MRI with the "cartilage acetabulum-head-index" (CAHI) and by sonography with the "lateral cartilage distance" (LCD). For analyzing MRI and US data, the Pearson correlation coefficient was used and a probability value of less than 0.05 was assigned to indicate statistical significance. RESULTS: US correlated well with MRI in the objective evaluation of the lateralization of the femoral head (CAHI: p = 0.01; LCD: p = 0.01). All hips showed a high agreement between the observers for the width of the femoral head/roof (Pearson: > 0.70) and for the LCD (Pearson: > 0.70). In comparison with the unaffected side, the loss of containment should be considered if CAHI is less than 73 % and LCD higher than 6.5 mm. CONCLUSION: Hip sonography seems to be a reliable method for monitoring the containment of the femoral head in LCPD.

[Therapy for chronic radial epicondylitis with botulinum toxin A]. / Therapie der chronischen Epicondylopathia humeri radialis mit Botulinumtoxin A -- eine Therapiestudie mit 2 Jahren Nachuntersuchungszeitraum.

AIM: Chronic radial epicondylitis (tennis elbow) is not a serious disease but patients may suffer greatly. If standard conservative and possibly operative treatment modalities have not been effective, patients need further therapy. First trials with injection of Botulinum toxin A (Btx A) have shown promising results. The purpose of the study was to clarify if a single injection of Btx A could be an efficient therapy for chronic radial epicondylitis. METHODS: In this study 16 patients received injections into the forearm extensors. The site of injection was determined by local tenderness and pain provocation on finger and wrist extension. RESULTS: A significant clinical improvement was already seen at 2 weeks following injection. The effect was noted up to the last follow-up at 2 years. Continuous and maximal pain during the last 48 h, as self-assessed on a visual analogue scale, was also significantly reduced. In a few cases a significant decrease of muscle strength was seen for the third finger two weeks after injection. It slowly returned thereafter. CONCLUSION: A single injection of Btx A was effective as therapy for chronic tennis elbow. It can be carried out in an out-patient setting, and allows the patient to continue working.

Treatment of lateralisation and subluxation of the hip in cerebral palsy with Botulinum toxin A: preliminary results based on the analysis of migration percentage data.

It has been reported that cerebral palsy patients with adductor spasm and lateralisation/subluxation of the hip can be treated with Botulinum toxin A, but statistical evaluation is lacking. We present the radiological results in 5 patients. The follow-up ranged from 18 (5 patients) to 24 months (4 patients). Reimers' migration percentage was chosen as parameter for lateralisation/subluxation. Statistical analysis was performed by the Wilcoxon test. The migration percentage improved from 51% to 44% at 9 months, 37% at 18 months, and 34% at 24 months. The improvement was significant from the 9th to the 18th month (p=0.04).

Primary subacute epiphyseal and metaepiphyseal osteomyelitis in children. diagnosis and treatment guided by MRI.

We present three children with primary subacute epiphyseal and metaepiphyseal osteomyelitis. The diagnosis was delayed because of subtle radiological findings and mild general symptoms. Primary epiphyseal osteomyelitis is extremely rare. We believe that this is the first time that the MRI findings have been presented. In the first case they revealed a perforation into the knee and therefore an intra-articular epiphyseal approach was used for debridement. In the second and third cases the metaepiphyseal lesions showed considerable physical involvement and a metaphyseal approach was chosen. We believe that in this condition MRI is essential both for diagnosis and in the planning of surgical treatment.

[Tensile strength of bone fixation of hydroxyapatite coated Schanz screws of the Heidelberg External Fixation System (HEFS)--comparative torque measurements in clinical use and in cadaver tibia]. / Zur knöchernen Verankerungsfestigkeit hydroxylapatitbeschichteter Schanz-Schrauben des Heidelberg External Fixation Systems (HEFS)--Vergleichende Drehmomentmessungen im klinischen Einsatz und an der Leichentibia.

It is claimed in the literature that hydroxyapatite(HA)-coated screws of external fixators have superior fixation strength in bone, which is postulated to lead to a substantial decrease in loosening and infection rates. We report on a study of the maximum torque values developed while inserting and removing 30 HA-coated Schanz screws of 8 Heidelberg external fixation systems applied to the tibia to correct leg length differences and axial deformities. The infection rate was determined in accordance with defined criteria, and was found to be about 20% for the HA-coated screws. Screws without infection showed an extraction torque above insertion torque, screws with infection an extraction torque below. A significant correlation (p = 0.05) was seen between infection and decrease in fixation strength (quotient: loosening torque/tightening torque). To exclude the impact of such biological processes as osteointegration and bone remodelling, the clinical results were compared with the torques measured for coated and uncoated Schanz screws in a human cadaveric tibia. A significantly higher fixation strength in bone was found for HA-coated screws in comparison with uncoated screws (p = 0.002). These data warrant a clinical study directly comparing HA-coated and uncoated Schanz screws.

[Evaluation of hydroxyapatite-coated Schanz screws in the Heidelberg external fixation system (HEFS)]. / Evaluation hydroxylapatitbeschichteter Schanz-Schrauben bei Verwendung des Heidelberg External Fixation System (HEFS).

The use of monolateral external fixation systems for the correction of limb length and/or axial anomalies involves the implantation of Schanz screws in the long bones for periods of weeks or months. The loosening rate, which increases with duration of implantation, is a problem. In animal experiments/superior fixation and a reduced infection rate have been reported for hydroxyapatite-coated screws in comparison with conventional screws. We report on the clinical application of 59 hydroxyapatite-coated Schanz screws in 15 external fixation mountings. The performance of the screws was evaluated by clinical and radiological criteria. Infection was seen in 15 screws, necessitating the early removal of 6 of them. In patients with a second fixation system/the infection rate was lower, with infection developing in only 1 of 12 screws.

The effect of extracorporeal shock waves on joint cartilage--an in vivo study in rabbits.

The application of extracorporeal shock waves has become a new mode of treatment for affections of the locomotor apparatus such as calcifying tendinitis, epicondylitis humeri radialis, calcaneodynia and pseudarthrosis. The treatment often takes place in the vicinity of joints. Up to now no systematic data have been published about possible side-effects on joint cartilage. In an in vivo study the effect of extracorporeal shock waves on joint cartilage was evaluated in 24 immature New Zealand White rabbits. The left lateral femoral condyle of each animal was treated with 2000 shock waves of 1.2 mJ/mm2; the right condyle served as control. Macroscopical, radiological and histological analysis at 0, 3, 12 and 24 weeks after treatment showed no pathological changes in the joint cartilage. We conclude that extracorporeal shock wave treatment does not cause damage to the joint cartilage of growing rabbits.