Abstract
Purpose: Characterized chondrocyte implantation (CCI) uses an autologous cartilage cell population capable of making stable cartilage in vivo. Despite comparable short-term improvement after intervention, clinical follow-up was to determine long-term clinical benefit of CCI in the repair of full-thickness knee cartilage lesions.
Methods: In a randomized controlled clinical trial comparing CCI to microfracture, patients with single ICRS grade III/IV symptomatic defects of the femoral condyles were randomized to receive either treatment (n=57 vs. n=61, respectively). Clinical improvement was measured up to 36 months using the KOOS, Visual Analogue Scale for knee pain (VAS) and Activity Rating Scale (ARS). Treatment failures and safety were monitored throughout.
Results: At baseline, KOOS was comparable between treatment groups (Mean ± SD: CCI, 56.30 ± 13.61; microfracture, 59.53 ± 14.95); improvement from baseline in adjusted mean ± SE of the overall KOOS at 36 months was 21.25 ± 3.60 for the CCI group and 15.83 ± 3.48 for the microfracture group. In a mixed linear model (with LOCF imputation), significantly greater improvements were shown for CCI vs. microfracture in change from baseline in all KOOS domains (p-value for the Overall KOOS = 0.0007) except for ‘Sports’. Between-group improvements from baseline to month 36 in VAS and ARS scores were similar. For CCI and micro-fracture groups, the percentages of treatment responders (improvement of 10 percentage points or more) were 83% (n = 34 of 41) vs. 62% (n = 31 of 50) on the KOOS and 83% vs. 66% on the VAS. Time to treatment failure was not statistically significant between the groups (n CCI/MF = 7/9). There was no change in safety profiles in comparison to the previous recorded data.
Conclusions: The initial superior structural outcome with CCI after 12 months post-surgery was substantiated by superior clinical benefit at 36 months compared to microfracture.
Correspondence should be addressed to: BASK c/o BOA, at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London, WC2A 3PE, England.
