Survival and functional outcome of high tibial osteotomy for medial knee osteoarthritis: a 10-20-year cohort study.

BACKGROUND

The primary aim of this study was to identify independent predictors of long-term survivorship after high tibial osteotomy (HTO). The secondary aims were to describe the functional outcome of surviving HTO 10-20 years after surgery.

METHODS

A retrospective cohort of 223 HTO that were performed for the treatment of medial osteoarthritis was identified. Details were recorded from the patient notes. All surviving patients were contacted and asked to complete a Tegner Activity Scale, Lysholm Knee Score and rate pain using the Visual Analogue Scale (VAS). Survival analysis was performed, using conversion to arthroplasty as the definition of failure.

RESULTS

The mean age was 54 years (24-80 years). There were 123 (55.2%) in males and 100 (44.8%) in females. The mean BMI was 27.2 (SD 3.9). Twenty (9%) patients were lost to follow-up. The mean follow-up was 12 (SD 4) years. Survival at 10 years was 75 and 55% at 15 years and less than 40% at 20 years. Cox regression analysis demonstrated age of 50 years or more, female gender and surgical technique to be significant independent predictors of failure. The median Tegner score was 3 (inter-quartile range (IQR) 1-3). The mean Lysholm score was 75.5 (SD 18.4). The median VAS was 5 (IQR 0-6).

CONCLUSIONS

The medium- to long-term survival and functional outcome after HTO was good to excellent at 10-20 years of follow-up. Age, gender, surgeon and surgical technique were identified as independent predictors of failure.