A preference-based single-item measure of quality of life following medial opening wedge high tibial osteotomy: Large improvements similar to arthroplasty

BACKGROUND: Improvements in generic and disease specific scores have been reported with medial opening wedge high tibial osteotomy (MOW HTO). However, meaningful comparisons between competing surgical interventions have been hampered by the lack of a preference based single index of health related quality of life (HRQoL). The primary aim of this study was to derive and report a single index measure of HRQoL for patients undergoing MOW HTO, preoperatively and at 12 and 24 postoperatively. Secondary aims were to evaluate changes in various additional measures of quality of life at these time points. METHODS: The impact of MOW HTO was evaluated using generic and disease specific instruments. One hundred thirty eight patients completed the Medical Outcomes Study short form health survey (SF-12) and Knee Osteoarthritis Outcomes Score (KOOS) before, 12 and 24 months after surgery. A preference-based single index measure of HRQoL was calculated and changes were evaluated. RESULTS: The mean change in the HRQoL suggested large, clinically significant improvements from 0.69 preoperatively to 0.82 (p<0.001) and 0.8 at 12 and 24 months postoperatively respectively. All dimensions of the SF-12, except role mental health, and all dimensions of the KOOS also demonstrated statistically significant improvements between pre and postoperative measurements. CONCLUSIONS: The preoperative HRQoL of young patients with mechanical varus alignment and medial compartment knee osteoarthritis is similar to older patients with knee osteoarthritis. Medial opening wedge high tibial osteomoty results in significant improvements in HRQoL, the magnitude of which is comparable to other surgical interventions for knee osteoarthristis.