One-step osteochondral repair with cartilage fragments in a composite scaffold

This study proposes a single-step therapeutic approach for osteochondral defects using autologous cartilage fragments loaded onto a scaffold composed of a hyaluronic acid (HA) derivative, human fibrin glue (FG) and autologous platelet-rich-plasma (PRP), in a rabbit model. The aim is to demonstrate the in vitro outgrowth of chondrocytes from cartilage fragments and the in vivo formation of a functional repair tissue.

In vitro: minced articular cartilage was loaded onto two different types of scaffold (paste or membrane) according to two different HA preparations (injectable HA-derivative or HA-derivative felt). In vivo: trochlear osteochondral defects were created in 50 adult rabbits, which were then assigned to 5 different treatment groups: cartilage fragments loaded onto membrane scaffolds with FG (Group 1) or without FG (Group 2); membrane scaffolds alone with FG (Group 3) or without FG (Group 4); empty defects (Group 5). Membrane scaffolds were used "in vivo" for simpler preparation and better adhesive properties. Repair processes were evaluated histologically and by immunohistochemistry at 1, 3, and 6 months.

An in vitro time-dependent cell outgrowth from cartilage fragments was observed with both types of scaffolds. At 6 months, in vivo, cartilage fragment-loaded scaffolds induced significantly better repair tissue than the scaffold alone using histological scoring. Repair in Group 2 was superior to that in any of the control groups (p < 0.05).

Autologous cartilage fragments loaded onto an HA felt/FG/PRP-scaffold provided an efficient cell source, and allowed for an improvement of the repair process of ostechondral defects in a rabbit model. Human FG, however, hampered the rabbit healing process. These results may have clinical relevance as they show the potential of a novel one-stage repair technique for osteochondral defects.