Abstract
Purpose of the study: To find predictors for the clinical outcome in patients who underwent a high tibial osteotomy [HTO].
Method: Between 1984 and 1996 in 155 patients with genu varum a high tibial valgus osteotomy was performed. 133 HTOs were available for follow up at an average post-op time of 9.3 years (3,0 y). The morphology of the knee was evaluated by radiological (Kellgren) and arthroscopical classifications (Outerbridge). Survival time of HTO was estimated using Kaplan-Meier survivorship analysis. Patients outcome was evaluated using the WOMAC score. For statistical analysis Log-rank test and Wilcoxon-Mann Whitney U-Test were used.
Results: During follow up time 19.8% of patients needed a total knee arthroplasty. Survival rate of HTO was 95% after 5 years and 77% after 10 years. In the medial compartment of knee joints with a preoperative Outerbridge stage III/IV or Kellgren stage III/IV the survival rate of HTO was significantly lower when compared to stages I/II (p< 0,05).
Age, sex, dimension of the mechanical medial proximal tibial angle (mMPTA) and severity of arthrosis in the lateral compartment had no influence on survival rates. The pre-postoperative comparison of radiologically visible signs of arthrosis showed either no or only small progress. The patients who underwent a HTO had an average of 1,9 points on the WOMAC score (global index 0–10) which is a good to very good clinical outcome.
Conclusion: We identified the severity of the preoperative radiological signs of arthrosis and the extent of chondromalacia noted intraoperatively as predictors of survival rate.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
