PROGNOSTIC FACTORS IN THE OUTCOME OF SUBCONDYLAR FEMORAL OSTEOTOMY FOR LATERAL COMPARTMENT OSTEOARTHRITIS OF THE KNEE

OBJECTIVE: To identify the demographic and operative factors that dete rmine outcome in supracondylar femoral osteotomy for lateral compartme nt osteoarthritis of the knee. DESIGN: Clinical and radiologic review of a nonrandomized, consecutive one-surgeon series. SETTING: A univers ity-affiliated, elective surgical referral centre. PATIENTS: Forty-nin e consecutive patients with unicompartmental osteoarthritis of the kne e, involving the lateral compartment, and of sufficient severity that the alternative surgical procedure would be total knee replacement. IN TERVENTION: Supracondylar varus osteotomy stabilized with a blade plat e. MAIN OUTCOME MEASURES: Knee function measured by the Knee Society S core and time to conversion to total knee replacement. RESULTS: A Knee Society Score greater than 80 was obtained in 81% of patients, but in the function portion of the measurement only 30% had a similar score. After discarding the patients who died, life-table analysis demonstra ted the predicted survival before conversion to total knee replacement to be 87% at 7 years. There was no correlation with patient age or se x, femorotibial angulation, amount of correction or time after the int ervention. Removal of the fixation device improved the clinical result . CONCLUSION: The role of supracondylar femoral osteotomy remains poor ly defined, but the procedure can delay total knee replacement for con siderable time in appropriate patients.