The Cartilage Autograft Implantation System (CAIS) is being investigated as a potential alternative surgical treatment to provide chondrocyte-based repair in a single procedure for articular cartilage lesion(s) of the knee. CAIS involves preparation and delivery of mechanically morselized, autologous cartilage fragments uniformly dispersed on a 3-dimensional, bio-absorbable scaffold and fixated in the lesion with bio-absorbable staples. CAIS maintains chondrocyte viability and creates increased surface area, which facilitates the outgrowth of embedded chondrocytes onto the scaffold. A proprietary disposable arthroscopic device for harvesting precisely morselized cartilage tissue is used.
In an EU pilot clinical study involving 5 countries 25 patients were randomized and treated using a 2:1 schema of CAIS:microfracture (MFX). Subjects returned for follow-up visits at 1 and 3 weeks and then 2, 3, 6, 9, 12, 18 and 24 months and were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS). Outcomes at each time point were analyzed with Students t-test.
This study showed that CAIS is safe to use. During the first year, the clinical outcome data in both groups were similar. However, at 18 and 24 months we noted that selected outcome measures were different. At 18 months the Sports & Recreation values were 50.6 ± 22.70 and 21.3 ± 33.25 (p=0.016) for CAIS and MFX respectively and at 24 months 52.1 ± 27.9 and 26.7 ± 26.2 (p=0.061) for CAIS and MFX respectively. At these same time points the Quality of Life data were 43.0 ± 27.14 and 27.2 ± 29.11 (p=0.2) for CAIS and MFX respectively (18 months) and 45.1 ± 28.07 and 20.5 ± 21.47 (p=0.062) for CAIS and MFX respectively (24 months).
While some of the data are not significantly different in this pilot study, taken together they do provide evidence to support the initiation of a more robust clinical trial to investigate efficacy.