Treatment of Extension Knee Contractures with Ilizarov Apparatus Versus Orthopedic Hexapod Ortho-SUV Frame

Abstract

Background. In case if it is impossible to eliminate the knee contracture by soft tissue release, external fixation is additionally used. Most often, the Ilizarov apparatus with a uniaxial hinge is used for this purpose. Orthopedic hexapods, unlike the Ilizarov frame, are able to reproduce the kinematics of movements in the knee joint. Aim of the study to evaluate the effectiveness of orthopedic hexapod for the treatment of patients with knee extension contractures in comparison with the Ilizarov apparatus. Methods. We analyzed 64 cases of combined treatment of extension knee contractures, which were divided into two groups. In the 1st group (31 patients) in addition to the soft tissue release, the orthopedic hexapod Ortho-SUV Frame (OSF) was used. In the 2nd group (33 patients) the Ilizarov apparatus with an uniaxial hinge was used. In a comparative analysis between groups, the number of flexion-extension cycles, the time required to complete them, and the time needed for complete knee range of motion (ROM) restoration were evaluated. Functional results were assessed using specialized scales-questionnaires KSS, Lysholm, LEFS in 2 days, 6 and 12 mon. after frame dismantling. Results. Comparing the total external fixation period, as well as the time needed for ROM restoration, no significant difference between groups was found (р0.05). When using the orthopedic hexapod, in comparison with the Ilizarov apparatus, fewer flexion-extension cycles were required. When assessing the amplitude of movements in 12 mon. in the first group, excellent results were found in 27 patients and good results in 4. In the second group, in all 33 patients good ROM was evaluated. On average, the ROM in the 1st group was 20 more than in the 2nd group. The knee function in 12 mon. was 16 points higher on the KSS in the 1st group, 5 points higher on the Lysholm scale, and 15 points higher on the LEFS scale than in the 2nd group. When analyzing the frequency of complications, no significant differences were found (р0.05). Conclusions. The results obtained indicate the effectiveness of the orthopedic hexapod in the treatment of patients with knee extension contractures.