Medial open wedge high tibial osteotomy is a viable option in young patients with advanced arthritis in a long-term follow-up.

PURPOSE This study aimed to evaluate the long-term outcomes of medial open wedge high tibial osteotomy (MOWHTO) as a treatment option for advanced medial compartment knee osteoarthritis (OA) Kellgren-Lawrence (K-L) III and IV. METHODS Patients with severe medial compartment arthritis, who underwent MOWHTO with locking plate between 2003 and 2015, were retrospectively reviewed. A locking plate for the osteotomy was utilized. Preoperative and postoperative patients' evaluation was performed using the International Knee Documentation Committee Score (IKDC), the Oxford Knee Score (OKS), the Knee Injury Osteoarthritis Outcome Score (KOOS) and the Short Form-12 Score (SF-12). Standardized standing whole-limb X-rays were taken to evaluate the mechanical tibiofemoral angle (mTFA) and proximal medial tibial angle (PMTA), and the severity of OA. RESULTS A total of 32 patients, 35 knees (27 males, five females) of which 21 were classified as K-L Grade III and 14 as K-L Grade IV, and mean age 47.1 ± 9.17 years old, who were followed for 13.6 years (range 7-20 years), were included in the study. During the follow-up period, three knees required conversion to total knee replacement (91.5% survival rate). All clinical outcome scores (KOOS, OKS, IKDC and SF-12) showed a significant improvement compared to preoperative status (p < 0.05). Preoperative mTFA and PMTA were significantly corrected immediately after surgery and retained this improvement at the last follow-up. CONCLUSION MOWHTO with a locking plate is an effective method to treat severe medial compartments. Clinical and radiological results are satisfactory and the survival rate is 91.5%, at a mean follow-up of 13.6 years after the procedure. LEVEL OF EVIDENCE Level IV.