Focal chondral defects are thought to contribute to the onset of degenerative changes in cartilage and therefore effective treatments of these lesions are aggressively pursued. A number of options such as bone marrow stimulation, osteochondral autograft transplantation, osteochondral allograft transplantation, and autologous chondrocyte implantation exist. Long-term data regarding efficacy and outcome for some of these approaches seem to suggest that there is still a need for a low-cost, effective treatment that leads to a sustained improvement in symptoms and the formation of hyaline cartilage.

artilage autologous implantation system (CAIS) is a surgical method in which hyaline cartilage fragments from a non-weight bearing area in the knee joint are collected and then precipitated onto an absorbable filter that is subsequently placed in the focal chondral defect. The clinical outcome of CAIS was compared with microfracture (MFX) in a pilot study. In an IRB approved protocol patients (n=29) were screened with the intention to treat, randomised (2:1, CAIS:MFX) and followed over a 24 month period. To be included in the study the patient may have up to 2 contained focal, unipolar lesions (≤ ICRS grade 3d and ≤ ICRS Grade IVa OCD lesions of femoral condyles and trochlea with a size between 1 and 10 cm². There were no differences in the demographics between the two treatment groups. We report 24 month patient-reported outcome (PRO) data using the KOOS-scale. The values (mean±SD) for the Sport&Recreation (S&R) and Quality of Life scales are shown in the figures below. We noted that at 12 months after the intervention CAIS differentiated itself from MFX in that the changes in S&R were different (p<0.05, t-test) at 12, 18, and 24 months. QoL data were different at 18 and 24 months. The other KOOS-subscales in CAIS and MFX were not significantly different at any time point. The data suggest that CAIS led to an improvement in clinical outcomes in the second year post-intervention. It is possible that the improvement of symptoms that we measured may be associated with the formation of hyaline cartilage. Study funded by ATRM and DePuyMITEK.