Deformity Correction about Knee with Ilizarov Technique: Accuracy of Correction and Effectiveness of Gradual Distraction after Conventional Straight Cut Osteotomy.

BACKGROUND The aim of the study was to retrospectively analyse the long term clinical outcome, accuracy of correction, and the complication rate in patients treated for deformities around the knee with gradual distraction with or without additional limb lengthening using Ilizarov technique. MATERIAL AND METHODS The study presents a retrospective analysis of 26 patients treated for deformities about the knee by gradual distraction with Ilizarov technique with an average follow-up of 6.1 yrs (2-13 yrs). Preoperative and post-operative radiographs of all patients were assessed for the deformities. Deformity involved the tibia in 16 patients and the femur in 9 patients and one patient had both components. The deformity comprised of varus in 15 patients and valgus in 11 patients, and deformity in two planes (oblique plane) in 2 patients, while 8 patients had either deformity with associated average shortening of 4.75 cms (2-7 cm).The mean angle of deformity in the frontal plane was 30 degrees (15-60 degrees) and 48 deg on sagital plane. The CORA (centre of rotation of angulation) was located in the juxtaepiphyseal region in 15 patients, metaphysis in 6 patients and at the metadiaphyseal junction in 5 patients. RESULTS All except two adult patients achieved exact correction with gradual distraction at an average correction of 30 degrees. Exact limb lengthening was achieved in all 8 patients with shortening. Complications involved mild procurvatum in three patients, mild mismatch of the mechanical and anatomical axes in two patients with tibial deformities, pin tract infection in two patients and one incidence of pin breakage, however, with no true complications. CONCLUSION Gradual distraction after conventional corticotomy provides excellent results with deformities around the knee with or without additional limb lengthening.