To report the long-term outcomes of medial open wedge high tibial osteotomy (MOWHTO) for the treatment of medial compartment knee osteoarthritis in patients younger than 45 years old. It was hypothesized that the correction of knee alignment would result in preservation of knee function in a long-term follow-up.
Patients under 45 years old, who underwent MOWHTO for symptomatic medial compartment knee osteoarthritis between 2001 and 2005 were retrospectively reviewed after a minimum of 10 years. The osteotomy was performed utilizing a locking plate without the use of bone graft. Patients were evaluated pre- and postoperatively using the International Knee Documentation Committee Score, the Oxford Knee Score, the Knee injury Osteoarthritis Outcome Score and the Short Form-12 Score. Standardized standing whole-limb radiographs were also obtained to assess mechanical tibiofemoral angle (mTFA) and the grade of osteoarthritis.
A total of 20 patients (18 males, 2 females, mean age 35.4 years) with a mean follow-up of 12.3 years were included in the study. During the follow-up period, one patient required conversion to total knee replacement (95% survival rate). All clinical outcome scores (IKDC, KOOS, OKS, and SF-12) significantly improved postoperatively (p < 0.05), with no significant deterioration over time. Preoperative varus alignment with an mTFA of - 5.8 ± 2.4° was corrected to 2.5 ± 1.9° immediately after surgery (p < 0.05), and remained 2.2 ± 1.7° at the last follow-up. Furthermore, no significant radiographic progression of osteoarthritis was observed.
Level IV therapeutic, retrospective, cohort study.
MWOHTO with a locking plate is an effective joint preservation method to treat medial compartment OA in active patients less than 45 years. Clinical and radiological results are satisfactory and the survival rate is 95%, 12 years after the procedure.