Purpose: To assess costs and health status outcomes following ACI and mosaicplasty used to treat chondral knee defects (1).

Methods: Patients received ACI or mosaicplasty at the Royal National Orthopaedic Hospital between 1997 and 2001, or, were on a waiting list for ACI. Resource use per patient was collected to two years post-operatively. A postal questionnaire collected sociodemographic characteristics, knee-related (Modified Cincinnati Knee Rating System) and general health status (EQ-5D).

Results: 53 ACI, 20 mosaicplasty and 22 patients waiting for ACI participated in this study. The average cost per patient was higher for ACI (£10,600: 95%CI £10,036-£11,214) than for mosaicplasty (£7,948: 95%CI £6,957-£9,243). Estimated average EQ-5D social tariff improvements for QALYs (quality adjusted life years) were 0.23 for ACI and 0.06 for mosaicplasty. Average costs per QALY were: £23,043 for ACI and £66,233 for mosaicplasty. The ICER (incremental cost effectiveness ratio) for providing ACI over mosaicplasty was £16,349. Post-operatively, ACI and mosaicplasty patients (combined) experienced better health status than patients waiting for ACI. ACI patients tended to have better health status outcomes than mosaicplasty patients, although this was not statistically significant.

Conclusions: Average costs were higher for ACI than for mosaicplasty. However, both the estimated cost per QALY and ICER fell beneath an implicit English funding threshold of £30,000 per QALY. To our knowledge this is the first study to compare the costs and utility of ACI with alternative ‘best’ treatments for people with chondral knee problems. Prospective studies are required to confirm these results.