Can Autologous Matrix-Induced Chondrogenesis (AMIC) provide positive outcomes in the treatment of retropatellar chondral lesions?

Abstract

Abstract Background The patellofemoral joint is a challenging environment for treating chondral defects. Among the surgical options for the treatment of chondral defects, the single-stage AMIC procedure uses a collagen I/III membrane to enhance bone-marrow stimulation. However, longer term outcomes data are rare for this specific indication. In order to provide real-world information, an ongoing registry has been established in order to record patient data and outcomes when AMIC is used to treat chondral and osteochondral lesions, which for this study were those of the patella.Methods Patient data were retrieved from an ongoing, prospective, multisite registry of patients who had undergone surgical repair of chondral defects via AMIC. We identified 65 patients, all of whom had been treated by one of the authors and for whom pre-operative and at least 1 post-operative score was available. Outcomes were assessed via the KOOS and the Lysholm scores. Outcomes at the post-operative time-points were analysed using a factorial ANOVA with post-hoc testing while linear regression was used to assess associations between the change in the Lysholm score and lesion size.Results The mean lesion size was 3.1 ± 1.4 cm2. The most common surgical approach was mini-open, the most common fixation was via fibrin glue and the mean length of follow-up of 5.8 years (range 1–10 years). There was a significant improvement in the KOOS scores from pre-operative to the 1st year post-operative (p < 0.001), which was maintained during the follow-up. Likewise, a significant improvement in the sports-recreation score (p > 0.001) as well as in ADL and QOL (p > 0.001 for both) were maintained throughout the follow-up.Conclusions The forces exerted on the patellofemoral joint make this a challenging scenario for chondral repair. Our data demonstrates that the AMIC procedure is an effective treatment for retropatellar cartilage lesions, and provides reliable results, with decreased pain and improved function. Importantly, these improvements were maintained through the follow-up period.