BACKGROUD: While the treatment of knee chondral lesions remains a challenge, mesenchymal stem cells use has spreading around the world. The allogenic human umbilical cord-derived mesenchymal stem cells (HUC-MSC) have some advantages: ease to obtaining, no ethic issue, no immune response, great plasticity, ease to expanding and cryopreserving in large amount, and ready availability for one-step surgery. Collagen matrix allows adhesion, proliferation and differentiation of these cells and associates are a promising technology for knee chondral lesions repair.

Purpose

To evaluate short-term outcomes of using HUC-MSC associated to a collagen matrix for knee focal chondral lesions repair.

Methods

In a prospective clinical study, seven patients (3 males and 4 females; mean age of 39,8 years) with knee full-thickness chondral lesion were evaluated. The mean size of focal defects was 5,1 cm2 and they were located in medial condyle (2), patella (3) and trochlea (2). All the HUC-MSC were obtained from donors with negative serology to infections. After in vitro expansion, the HUC-MSC had 97% viability; showed negative culture bacterial and/or fungi growth, absence of mycoplasma and endotoxins; flow cytometry analysis showed positive to CD90, CD105, CD29 and CD73 and negative to CD45, CD34, CD14, CD19 and HLA-DR and normal karyotype by GTG cytogenetic analysis. By knee arthrotomy, the collagen matrix Chondro-Gide? was implanted on the chondral defect with sutures and fibrin glue plus the injection of 40 x 106 of HUC-MSC under it. KOOS, VAS and MRI results were compared pre and postoperatively. Statistical significance was set at P< .05.

Results

After 12 months of follow-up, KOOS (P=.022), KOOS-QoL (P=.034), KOOS-ADL (P=.032), KOOS-pain (P=.035), KOOS-symptoms (P=.032), KOOS-Sport/Recreation (P=.022) and VAS (P=.046) scores were significantly improved postoperatively as compared to a baseline. All MRI showed signs of full-filling and smooth surface, and all repairs had complete integration to adjacent cartilage, except one. No adverse effects, rejection or complications were noted.

Conclusion

Human umbilical cord-derived mesenchymal stem cells associated to a collagen matrix is a safe one-step procedure for knee full-thickness chondral lesions repair, with good functional and MRI outcomes in a short-term.