Results of forty two computer-assisted double level osteotomies for severe genu varum deformity

Abstract

Purpose The goal of this article was to present the clinical and radiological results of 42 severe genu varum operated on between August 2001 and June 2010 using computer navigation. Methods All the osteotomies were navigated using the Orthopilot® device (B-Braun-Aesculap, Tuttlingen, Germany). The procedure was performed such that after inserting the rigid bodies and calibrating the lower leg, we first made the femoral closing wedge osteotomy (from four to seven mm) which was fixed by an AO T-Plate, and then, after checking the residual varus, the tibial opening wedge osteotomy was made using a Biosorb® wedge (Tricalcium phosphate, SBM, Lourdes, France) and a plate (AO T-plate or C-plate). Results All the patients were assessed at a mean followup of 46 ± 27 months (range, 12-108). The mean Lyshölm-Tegner score was 83.3± 7.5 points (62-91) and the mean KOOS score was 95.1±3.2 points (89-100). Forty patients were satisfied (22) or very satisfied (18) with the result. Regarding the radiological results, the goal was reached in 92.7% of cases and the mean HKA angle was 181.83°±1.80°(177-185°). At that mid-term follow-up no patient had revision to a total knee arthroplasty. Conclusion Computer-assisted double level osteotomy in severe genu varum is a reliable, reproducible, and accurate technique. This procedure, which is very delicate, especially in reaching pre-operative objectives, is simplified by computer-assistance.

The use of navigation in medial opening wedge high tibial osteotomy can improve tibial slope maintenance and reduce radiation exposure

“…Most of the previous studies that compared the results of navigated HTO with those after the conventional method reported that the navigated group achieved more accurate coronal alignment with less frequent outliers than the conventional group [10][11][12][13][14][15][16]. However, a concerning incidence of outliers is still reported even in navigated HTO, with a wide range, from 0 to 35 % [7,10,12,[14][15][16][17]. Whether the use of navigation improves sagittal alignment is still controversial [11][12][13]18].…”

Concept of Combined Femoral and Tibial Osteotomies

“…In our series based on 42 computer-assisted cases, 20 we had no complication but one case of recurrence of the deformity related to an impaction of the femoral osteotomy on the medial side (high body mass index patient). Two patients were lost to follow-up after removing of the plates (24 months) but were included in the results because the file was complete at that date.…”

“…One from Babis et al in 2002 13 and one from our group. 20 In their article, Babis et al 13 reported on 24 patients (29 knees) operated up on using a conventional technique (two closing wedge osteotomies). The mean preoperative HKA angle was 193.3 degrees (i.e., 13.3 degrees of varus), and they used a computer-aided analysis of the mechanical axes of the knee for preoperative planning.…”

“…This procedure, in case of an HTO, allows to reach the preoperative goal in more than 70% of the cases, 11,17 but it is much less accurate than navigation. 20,21…”

Applications of computer navigation in sports medicine knee surgery: an evidence-based review

“…Further prospective studies are needed to confirm that the use of CAS is justified, since it increases surgical duration and navigation equipment comes at significant additional cost. Computer navigation may also have a role in aiding more complex osteotomies, such as following femoral malunion [82] or combined femoral and tibial osteotomies for severe genu varum [83].…”