OBJECTIVES: Characterized Chondrocytes Implantation (CCI), a knee cartilage repair technique using an autologous cell therapy product (ChondroCelect®), results in better structural repair than microfracture as demonstrated in a prospective randomized clinical trial (Saris, Vanlauwe et al. 2008). The SF-36 questionnaire collected along the trial allowed the calculation of utility scores. This analysis aims to quantify the gap in utility levels by surgery outcome. METHODS: Patients were split by response status to the self-reported Knee injury and Osteoarthritis Outcome Score (KOOS) and pain Visual Analog Scale (VAS) regardless of the treatment received. Utility scores were derived from the SF-36 via a validated algorithm and compared between responders (overall KOOS increase >=10%, VAS decrease >=20% vs. baseline) and non-responders at Months 24, 30 and 36 post-surgery using the Mann-Whitney test. Pearson correlation coefficients were calculated between utility scores and the KOOS overall, KOOS quality of life and VAS scores at each time-point. RESULTS: Significantly higher utility scores were observed in KOOS responders compared to non-responders at Months 30 (0.817 vs. 0.691, n=25/14, p=0.004) and 36 (0.775 vs. 0.618, n=19/6, p=0.006) and in VAS responders compared to non-responders at Months 24 (0.827 vs. 0.701, n=17/9, p=0.038) and 36 (0.764 vs. 0.600, n=21/4, p=0.015). A similar trend of borderline significance was measured at Months 24 (using KOOS, 0.818 vs. 0.728, n=16/10, p=0.136) and 30 (using VAS, 0.800 vs. 704, n=21/4, p=0.053). Utility scores correlated best with the KOOS overall (Pearson coefficients ranged from 0.579 to 0.721, p-values<0.01) and VAS scores (-0.514 to -0.671, p-values<0.01). CONCLUSIONS: Gaps in utility scores between responders (=successful surgery) and non-responders ranged from 0.091 to 0.164. This finding validates the assumption made in a previous Health Technology Assessment on Autologous Chondrocytes Implantation. Consistent gaps and significant correlations with validated tools provide valuable information for future economic modeling of CCI.