Cost-Effectiveness Analysis of Unicompartmental Knee Arthroplasty and High Tibial Osteotomy for Treatment of Medial Compartmental Osteoarthritis

ABSTRACT Background Interest in unicompartmental knee arthroplasty (UKA) has recently increased in the United States concomitantly with an increase in the prevalence of physiologically active patients presenting with medial compartment osteoarthritis. This study examined the cost-effectiveness of UKA compared with high tibial osteotomy (HTO) in patients with medial compartment osteoarthritis. Methods A Markov decision model was constructed with review of literature to conduct a cost-utility analysis of UKA as compared to HTO in a patient population aged 40 years at the time of surgical intervention. Utility values were assigned to health states annually based on the commonly accepted reference values of 1 being “full health” and 0 being “death”. These values are used to estimate quality-adjusted life years (QALYs). The Markov decision model was used to evaluate the total accumulated costs and effectiveness, measured in QALYs. Results The average cost of the UKA was cheaper by $842 and resulted in a significant incremental effectiveness gain compared to HTO (+ 0.96 QALY). UKA gained 20.05 QALY at a cost-effectiveness (C/E) ratio of $1048/QALY, whereas HTO gained 19.09 QALY at a C/E ratio of $1145/QALY. Conclusion Both UKA and HTO are cost-effective procedures but patients treated with UKA may experience an increased net health benefit over their lifetime. Level of evidence Economic and decision analysis level II.