A histological comparison of the repair tissue formed when using either Chondrogide® or periosteum during autologous chondrocyte implantation

Objective: In this study, we compare the clinical and histological outcome between periosteum and Chondrogide (R) during autologous chondrocyte implantation (ACI). Method: This study consisted of 88 patients having received ACI in the knee; 33 treated with Chondrogide (R) (ACI-C) and 55 with periosteum (ACI-P). Post-operative biopsies were taken at a mean of 16.6 +/- 8 months (range 7-37 months) and 19 +/- 18.4 months (range 4-114) for ACI-C and ACI-P respectively. Histological assessment was performed using the ICRS II and OsScore scoring systems. The immunolocalisation of elastin and collagen types I and II was analysed using specific antibodies. Lysholm scores, a measure of knee function, were obtained pre- and post-operatively at the time of biopsy and annually thereafter. Results: Compared with ACI-P, the repair tissue formed from patients treated with AdI-C demonstrated a significantly higher score for cellular morphology (ICRS II score), significantly better surface morphology from medial femoral condyle treated defects (ICRS II score) and a significantly higher proportion of hyaline cartilage formation (OsScore). Elastin fibres were present in both ACI-C and AC!-P samples, although their presence was very variable in quantity, distribution, orientation, thickness and length. Patients treated with ACI-C demonstrated significantly more collagen type II immunolocalisation compared with ACI-P. Both groups exhibited a significant increase in Lysholm score post-ACI. Conclusions: This study demonstrates a significantly better quality of repair tissue formed with ACI-C compared with ACI-P. Hence Chondrogide (R) is perhaps a better alternative to periosteum during ACI. (C) 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.