Open-Wedge High Tibial Osteotomy and Combined Abrasion/Microfracture in Severe Medial Osteoarthritis and Varus Malalignment: 5-Year Results and Arthroscopic Findings After 2 Years

Purpose: To determine survivorship and functional results of medial open-wedge high tibial osteotomy (HTO) combined with a chondral resurfacing procedure (abrasion/microfracture) in patients with Kellgren-Lawrence grade 3 and 4 osteoarthritis with full-thickness cartilage defects and varus malalignment. Methods: From September 2005 to December 2008, all cases of HTO (fixation with an angular-stable internal fixator) combined with a chondral resurfacing procedure performed at our institution were prospectively surveyed, with a minimum follow-up of 5 years, regarding survival (not requiring arthroplasty), functional outcome (subjective International Knee Documentation Committee [IKDC] score), and subjective satisfaction (whether patients would undergo the operation again). Clinical evaluation (according to objective IKDC parameters), radiologic evaluation, and revision arthroscopy for evaluation of regenerated cartilage were performed between 1 and 2 years. Results: A total of 91 knees (85 patients; mean age, 50.4 +/- 8.0 years; age range, 28.3 to 67.7 years) were included. The survival rate was 95.2% (95% confidence interval, 90.7% to 99.7%) at 5 years, with 4 conversions to arthroplasty (3 unicondylar and 1 total knee arthroplasty; follow-up rate, 87.9%). Subjective IKDC scores significantly improved from 45.1 +/- 11.6 points preoperatively to 69.1 +/- 14.2 points after 1 year, 66.4 +/- 14.5 points after 3 years, and 67.2 +/- 14.4 points after 5 years (P < .001). In 94.9% of the cases patients were satisfied with the result after 5 years, including those with arthroplasty. Revision arthroscopy was performed in 80 cases (87.9%) at 1.5 +/- 0.8 years: Cartilage regeneration was graded good in 50.0% and excellent in 25.8% on the tibial side compared with 48.1% and 39.0%, respectively, on the femoral side (P < .001). The overall complication rate was 6.6%. Conclusions: HTO in combination with a chondral resurfacing procedure is effective in the treatment of severe medial osteoarthritis and varus malalignment. The effect of the chondral resurfacing in this combined approach remains unclear.