Arthroscopic implantation of a matrix to cover large chondral defect during microfracture.

Microfracturing techniques have been reported to be successful cartilage-restoring treatment options in defects of smaller sizes. The success may be limited by the size of the defect and the shoulder of the intact surrounding cartilage. We report a new technique using a 3-dimensional matrix to cover large cartilage defects during microfracture healing. In contrast to autologous chondrocyte implantation techniques, this technique is a 1-stage procedure. The defect cover consists of a resorbable polymer felt and sodium hyaluronan to induce hemostasis and to protect the underlying tissue. After conventional microfracture, the defect size is determined with an intra-articular measuring device, and the matrix is sized and introduced with an arthroscopic grasp. Depending on the size of the defect, the 3-dimensional matrix is fixed with 1 or 2 biodegradable pins perpendicular to the surface. The combination of the common microfracture technique with the implantation of the matrix leads to complete defect filling with cartilaginous repair tissue and therefore improves cartilage regeneration in the defect. We conclude that the introduced technique may be helpful in large cartilage defects combining the benefit of microfracturing and avoidance of the increased morbidity of matrix-associated autologous chondrocyte implantation.