[Avascular necrosis of the femoral head in the patients with posterior wall acetabular fractures associated with dislocations of the hip].

INTRODUCTION: Acetabular fractures are severe injuries, mostly occured in young patients after traffic accident or fall from heights. Of the all acetabular fractures, posterior wall acetabular fractures are the most often observed. Regarding to mechanism of the injury, about 30% of these fractures are associated with posterior hip dislocation. MATERIAL AND METHODS: The incidence of AVN in 18 patients with posterior wall acetabular fractures associated with dislocations of the hip is presented. Thompson-Epstein Scale (type I-V) was used as the classification of the injury. Kocher-Langenbeck surgical approach was achieved in all patients. RESULTS: Average following time after surgery was 22, 66 months (8-36 months). After that period the incidence of femoral head AVN was observed in 33.3%. Femoral head AVN was observed in 5.55% of patient who was treated by the reduction of hip dislocation in first 24 hours after injury, while in patients with later reduction, femoral head AVN were observed in 27.77%. CONCLUSION: Posterior wall acetabular fractures associated with hip dislocation are severe injuries. Urgent, closed reduction of the hip, early definitive stable osteosynthesis of acetabulum and the experience of surgical team are factors that greatly decrease the possibility for AVN occurence. Later reduction, comminution of posterior wall of the acetabulum (Thompson- Epstein III et IV), impaction, chondral lesion of the femoral head and associated fractures of femoral head, increase the possibility for AVN occurence.

[Knee angular deformity correction using unicorticotomy and callus distraction by external fixation method and presentation of new external fixation device for varus correction of proximal tibia].

The main goal of this paper is to present clinical results of surgical correction of angular (varus and valgus) deformities of knee area. Goal is also to present new external fixation device for surgical treatment of varus deformity of proximal tibia. As material it has been used series of 70 patients treated during the period of 6.5 years in University Orthopaedic and traumatology clinic. Biomechanical investigation of 80% cut bone model fixed by new external fixation device was performed in the measurement laboratory of Mechanical Faculty University of Nis. Clinical results of treatment of 58 high tibial surgeries (49 varus and 9 valgus) and 12 distal femur surgeries (2 varus and 10 valgus) showed that unicorticotomy and callus distraction by the use of Mitkovic external fixation device leaded to correction and bone union. Superficial pin tract infection happened in 9 patients and has been successfully treated without pins removal. Biomechanical investigation of new device showed that during axial loading of bone model by 690 N (70 kg) movement of medial distal end of bone model was 0.30 mm while posterior distal end of bone model was 0.26 mm. From results obtained in can be concluded that unicorticotomy and gradual callus distraction by the use of external fixation is one reliable method. Biomechanical testing of new external fixation device showed that it is more stable in control of varus and posterior position of proximal tibial fragment.

[Open wedge osteotomy and callus distraction by means of the external fixator in distal femur and proximal tibia in knee arthrosis with valgus and varus deformity]. / Open wedge osteotomija i kalusna distrakcija spoljnim fiksatorom na distalnom femuru i proksimalnoj tibiji kod artroze kolena sa valgus i varus deformitetom.

Various methods can be applied for treatment of knee deformity. One of them is open wedge osteotomy and callus distraction by means of the external fixator. This paper presents the results of treatment of 16 patients with knee arthrosis associated with varus and valgus deformities (10 varus and 6 valgus deformities). Open wedge osteotomy of the varus deformity was performed in the proximal tibia, and in case of the valgus deformity in the distal part of the femur. The patients who were operated on had a knee varus larger than 10 degrees and a knee valgus larger than 12 degrees. Prior to open wedge osteotomy and application of the external fixator, knee arthroscopy was performed (meniscectomy, cartilage drilling and shaving, debridement, the extraction of loose bodies). After one-year follow-up, the final outcome of the treatment was positive in all patients. The treatment alleviated the pain in these patients. The method is minimally invasive and relatively easily applied. Mitkovic's external fixator type M20-CD-V allows for continuous callus distraction with simultaneous correction of the varus or valgus knee deformity.