NEOCHONDROGENESIS AND ROLE OF STEM CELLS: AN EXPERIMENTAL STUDY IN GOAT MODEL

Abstract

Purpose: A pilot study to assess whether intra-articular injections of autologous marrow-derived stem cells (MSC) and hyaluronic acid (HA) will result in a better quality of cartilage regeneration after subchondral drillings into surgically created full-thickness chondral defects.

Methods: 15 male goats were subjected to full-thickness chondral defects followed by subchondral drillings. The goats were divided into three groups: Group A, no injection (control group); Group B, a weekly intra-articular injection of HA for three consecutive weeks; Group C, a weekly intra-articular injection of autologous MSC in combination with HA for up to three consecutive weeks. The intra-articular injections were given one week after surgery. Group C goats underwent bilateral iliac crest bone marrow aspiration during surgery. The bone marrow aspirates were centrifuged and bone marrow cell suspension were then divided into vials and cryo-preserved. Prior to usage, the bone marrow cells were thawed and prepared for intra-articular injections. The repaired chondral defects were visually inspected and histologically examined at week 24.

Results: In groups A and B goats, the defects showed repair with mainly fibrous tissues. Chondral defects in Group C goats showed better repair of tissues with some specimens showing mainly hyaline cartilage as compared to the other groups.

Conclusion: Intra-articular injections of autologous MSC in combination with HA following subchondral drillings into chondral defects result in a better quality of neochondrogenesis. Preliminary results from on-going human clinical trials provide similar evidence of articular cartilage regeneration following subchondral drillings into chondral defects followed by post-operative intra-articular injections of autologous peripheral blood stem cells (PBSCs) in combination with HA.