FLEXION GAP CONFIGURATION IN TOTAL KNEE ARTHROPLASTY FOLLOWING HIGH TIBIAL OSTEOTOMY

Introduction: Previous reports have described the potentially compromising effect of a high tibial osteotomy (HTO) on the results of a subsequent total knee arthroplasty (TKA). Although the reasons are not clear, some authors reported of problems in soft tissue balancing in TKA following a previous HTO. Method: In a prospective study 22 patients with an average interval of 5.8 years after closed wedge HTO, were operated for TKA. All surgeries were performed with the BrainLAB CT-free navigation system and measurements of the extension and flexion gap were assessed. The intraoperative data were compared to a control group of 100 consecutive computer assisted TKA without previous HTO. Results: In the study group a highly significant shift towards a medial opening of the flexion gap between the posterior condylar line and the tibial resection (study group 0.4° +/− 4.7° medial opening vs. control group 3.4° +/− 3.3° lateral opening, p Conclusion: Surgeons should be aware of difficulties in soft-tissue balance in TKA following HTO, especially for the flexion gap configuration and the axial femoral component orientation. The computer assisted technique is helpful to identify soft tissue imbalance.