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

Abstract

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.