132 – LONG-TERM SURVIVAL OF HIGH TIBIAL OSTEOTOMY FOR MEDIAL OSTEOARTHRITIS OF THE KNEE

Abstract

Purpose: The management of degenerative arthritis of the knee in the younger, active patient often presents a challenge to the orthopaedic surgeon. Surgical treatment options include: high tibial osteotomy (HTO), uni-compartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). The purpose of this study was to examine the long-term survival of closing wedge HTO in a large series of patients 8–19 years after surgery.

Method: The results of 458 consecutive patients undergoing lateral closing wedge HTO for medial compartment osteoarthritis (MCOA) between 1990 and 2001 were reviewed. Between 2008–2009, patients were contacted via telephone and assessment included: incidence of further surgery, Oxford Knee Score, and British Orthopaedic Association (BOA) Patient Satisfaction Scale. Failure was defined as the need for revision HTO or conversion to UKA or TKA. Survival analysis was completed using the Kaplan-Meier method.

Results: We were able to contact 400/458 (87%) patients for follow-up via telephone interview. Five patients (1%) who declined participation were excluded. Fifty-eight patients (13%) were lost to follow-up. Of the 395 patients, 12 (3%) had died of unrelated causes and 124 (31%) required further knee surgery. The remaining 259 (66%) completed the BOA patient satisfaction score and Oxford Knee Score. The probability of survival for HTO at 5, 10 and 15 years was 95%, 79% and 55% respectively. Multivariate regression analysis showed that only age < 50 years (p< 0.001) was associated with significantly longer survival. Mean Oxford Knee Score was 40/48 (range 17–60). Ninety-two percent (239/259 patients) were enthusiastic or satisfied and 90% (234/259 patients) would undergo HTO again at mean 11 years follow-up. Complications included: 5 pulmonary embolisms, 8 deep vein thromboses, 1 non-union, 1 post-operative subarachnoid hemorrhage and 1 transient peroneal nerve palsy.

Conclusion: To our knowledge, we have reported the long-term follow-up of lateral closing wedge HTO in the largest group of patients in the literature. We found that the results of HTO do deteriorate over time but that HTO can be effective for as long as 19 years. In appropriately selected patients and circumstances, HTO gives high patient satisfaction and affords patients unrestricted activity for many years.