Aims:Short-term results of lateral closing wedge high tibial osteotomy (CWO) is satisfactory in 80–90% of patients but the results of CWO shows steady decline over time. We evaluated results of osteotomies to determine survivorship and to identify risk factors associated with survival of the osteotomies.

Methods:Between 01.01.1986. and 31.12.1991. 113 patients have undergone CWO. We could evaluated 54 patients (31 men and 23 women) with 58 operations. The average age at operation was 57.6 (31–69) years and the mean follow-up was 12.2 (10–15) years.

The probability of failure was estimated as a function of time, with use of the Life-table survivorship method.

The linear correlation, uni and multivariate Stepwise regression method were used for statistical analysis. Results:Using the Life-table survivorship estimate of failure, the probability of survival for CWO was 91.3% at 5 years and 72.5% at 10 years.

An age, preoperative varus deformity and range of movement have not inßuenced long term survivorship (linear correlation).

Uni and multivariate Stepwise regression showed, that overweight, grade III chondromalacia in medial compartment, previous menisectomy and insufþcient valgus correction (FTA< 170¡) were signiþcantly associated with early failure.

Conclusions:Analysis of risk factors suggests that careful patient selection can improve long term survivorship of CWO.