Cost Effectiveness of Characterised Chondrocyte Implantation for Treatment of Cartilage Defects of the Knee in the UK.

Abstract

Until recently, treatment options for damage to cartilage in the knee were limited to the use of microfracture or, occasionally, mosaicplasty. The developments of autologous and characterised chondrocyte implantation have provided new treatment options but have large upfront costs. The objective of this study was to estimate the cost effectiveness of characterised chondrocyte implantation in the UK National Health Service. An economic model was constructed in Microsoft Excel®, with patients undergoing either microfracture or chondrocyte implantation. Following treatment failure, patients can undergo a series of interventions, ultimately ending in knee replacement. Effectiveness and utility were modelled using clinical trial data, which were supplemented with synthesised registry data, and costs were taken from published sources. Results were expressed in clinical events, quality-adjusted life-years (QALYs) and British pounds. Both costs and outcomes were discounted at 3.5% per year. Chondrocyte implantation is estimated to reduce the lifetime probability of knee replacement by 50% in comparison with microfracture, and to increase QALYs by 0.72 (16.57 vs. 15.85). Costs were estimated to be £23,307 for chondrocyte implantation, and £8008 for microfracture, with the incremental cost of £15,299 for chondrocyte implantation reflecting reduced resource use offsetting some of the procedure cost. These values gave a cost per QALY gained of £21,245. Chondrocyte implantation is estimated to provide substantial patient benefits over a lifetime horizon, with a considerable increase in QALYs. Despite the increase in costs, the procedure is cost effective at standard thresholds used in the UK.