Introduction

The objective of this study is to report the first cases of femoral lengthening in children using Ilizarov fixator.

Background. Arthrogryposis Multiplex Congenita is a rare congenital disorder associated with multiple musculoskeletal contractures which causes substantial morbidity. Knee involvement is commonly seen among children with arthrogryposis, with flexion contracture being the most frequent. The purpose of this study was to assess the effectiveness of orthopaedic procedures, namely distal femoral supracondylar extension osteotomy and/or Ilizarov external fixator, on the ambulation status of children with knee flexion contracture and whether any functional gains are maintained at the latest follow-up. Methods. Fifteen patients were identified and their medical records reviewed. The mean age at their first surgery was 7.6 years (range, 2-16 years). The etiology for all patients was amyoplasia. The mean length of follow-up was 58 months (range, 12-117 months). Contractures were treated with femoral extension osteotomy (n=8), Ilizarov external fixator (n=2), or both (n=5). Results. Pre-operatively, 11 patients were non-ambulatory, three patients were household ambulators, and one patient walked with orthoses in the community. There was an average of 1.5 knee surgeries done per patient. At the latest follow-up, nine patients were ambulatory with technical aids, two patients were household ambulators, one patient used a wheelchair but was independent for transfers, and three patients remained non-ambulatory. The mean flexion contracture prior to the first surgery was 62.8 ± 26.7 degrees. Post-operatively, the mean flexion contracture was 13.5 ± 16.4 degrees. At the latest follow-up, the mean flexion contracture was 33.8 ± 23.6 degrees. There were complications in three patients which included infected hardware, transient neurological compromise, and pressure sores, which eventually all resolved. Conclusion. early and aggressive orthopaedic management of flexion contractures in children with arthrogryposis is supported by our findings, and may contribute to functional gains

Patient's non acceptance of a bulky external fixator, the incidence of fractures of the regenerate, muscle transfixion giving rise to contractures especially in the Tendo Achilles, increased index of consolidation and the frequency of infections has made Limb lengthening with external fixators alone unpopular. In a retrospective study, we evaluated the technique of limb lengthening over a sub muscular plate combined with Ilizarov external fixator as an alternative to external fixator alone and whether the combined procedure is successful in reducing the external fixator period. 15 patients (14 with length discrepancy in the lower limb and 1 with low stature) and a total of 16 limbs (15 tibiae and 1 femur) were lengthened over a sub muscular plate fixed on the proximal segment followed by corticotomy and application of external fixator. Lengthening was achieved at 1 mm/day followed by distal segment fixation with three or four screws on reaching the target length. The pre operative target length was successfully achieved in all patients at a mean of 4.4 cm (2.2 to 6.5 cm). The mean duration of external fixation was 59.2 days (33 to 107 days) with the mean external fixation index at 16.7 days/cm (10.95 to 23.78). Infection complicated the procedure in two patients and one patient had mild Tendo Achilles contracture. Lengthening over a plate drastically reduces the time external fixator needs to worn and is preferred by patients to limb lengthening over an external fixator alone. patient Lengthening over a plate provides an alternative method for limb lengthening, can be applied to children with open physes and to deformed bones. [Lengthening over a Plate]

Tibial fractures complicated by bone and/or soft tissue loss present a great challenge. Traditional methods of limb reconstruction are lengthy and may not yield satisfactory functional results. Despite its tremendous contribution to the management of this condition, the Ilizarov technique of bone transport has several problems and difficulties. The present study was carried out between 1997 and 2002 and included 21 patients with tibial fractures complicated by bone and soft tissue defects as a result of open fractures or surgical debridement of infected non-unions. The bone loss ranged from three to eleven cm. (average 4.7 cm.). Ages ranged from 12 to 54 years (average 28.8 years). The follow-up ranged from 24 to 75 months. The procedure included resection of all devitalised tissues, acute limb shortening to close the defect, application of the external fixator and metaphyseal osteotomy for re-lengthening. In all patients the fractures united with well aligned limbs. Acute limb shortening of up to six cm. was done in the lower third of the leg. Limb lengthening was done in all cases and ranged from 3 to 9.5 cm. (average 4 cm.). An Ilizarov external fixator was used in nine cases (41%) and a monolateral fixator in 13 cases (59%) with a total of 22 applications. Residual leg length discrepancy of more than 3cm. occurred in four cases (19%). Complications included one refracture, one transient peroneal nerve palsy and one equinus contracture of ten degrees. Satisfactory results were obtained in 93% of cases. Acute limb shortening and re-lengthening converts a complicated limb reconstruction into a relatively simpler one of linear limb lengthening, without the difficulties of traditional Ilizarov techniques and eliminated the need for soft tissue flaps. It is better instituted early in the management of these cases to ensure better functional results and shorter treatment time

Purpose. Vitamin D is a key regulator of bone homeostasis. The enzyme CYP24A1 is responsible for transforming vitamin D into 24,25(OH)2vitD. The putative biological activity of 24,25(OH)2vitD remains unclear. Previous studies showed an increase in the circulating levels of this metabolite following a fracture in chicks. Our laboratory has engineered a mouse model deficient for the Cyp24a1 gene for studying the role of 24,25(OH)2vitD. We set out to study the role of 24,25(OH)2vitD in endochondral and intramembranous bone formation in fracture repair in this mouse model based on the results of the chick fracture repair study. Method. Wild-type and mutant Cyp24a1 gene deficient mice were subjected to two different surgical procedures to simulate bone development and fracture repair. To mimic endochondral ossification, we devised a modified technique to perform intramedullary nailing of a mouse tibia followed by an induced fracture. To evaluate intramembranous ossification, we applied distraction osteogenesis to a mouse tibia using a mini Ilizarov external fixator apparatus. Histomorphometric parameters and gene expression differences in fracture repair between the mutant mice and the wild-type controls were measured using micro computed tomography, histology and reverse-transcription quantitative PCR (RT-qPCR) respectively. Results. Quantitative histomorphometric results showed a delay in endochondral fracture repair in the mutant mice calluses as compared to the wild-type mice calluses. In the same model, gene expression of type X collagen in the callus was higher in the wild-type mice. These significant differences were fully rescued by injecting the mutant mice with exogenous 24,25(OH)2vitD. In the intramembranous bone formation model, we found a trend towards reduced bone formation in the gap created by the distraction process in the mutant mice as compared to the wild-type mice. However, the differences did not reach statistical significance. Conclusion. Our results support a role for 24,25(OH)2vitD in fracture repair which is more dominant in a chondrocyte-mediated bone formation pathway like endochondral ossification. Although our results did not reach statistical significance in the intramembranous ossification model, the observed trend suggests a potential role as well. Further study of the role of 24,25(OH)2vitD in bone healing has the potential to support novel approaches in accelerating bone formation and fracture repair