Osteochondral autograft transplantation or autologous chondrocyte implantation for large cartilage defects of the knee: a meta-analysis

Autologous chondrocyte implantation (ACI) and osteochondral autograft transplantation (OAT or mosaicplasty) are two effective surgeries for the treatment of large cartilage defects for more than two decades. But there are always some controversies about which one has the better outcomes for the patients. The purpose of this meta-analysis is to compare the outcomes of these two surgeries and give an advice to the clinical practices. The literature search was performed on multiple electronic databases with specific included criteria. After the assessments, five Randomized controlled trials (level II) were included and two of them were in the same cohort. The continuous data of outcomes were categorized into ranked ones (excellent, good, fair and poor) for comparisons. In the six comparisons of excellent or good results and poor results, the outcomes of ACI were significantly better than OAT in only one comparison (RR 2.57, 95 % CI 1.09–6.07, P = 0.03) while others had no significant differences. We may reach a primary conclusion that there is no significant different outcome between ACI and OAT in a short-term follow-up but it may indicate that the patients with OAT may be more likely to have worse condition than that with ACI for a long-term period.