Acute chondral injuries of the patellofemoral joint

Rehabilitation following microfracture for chondral injury in the knee

Full-thickness chondral defects in the knee are common, and these articular cartilage lesions may present in various clinical settings and at different ages. Articular cartilage defects that extend full thickness to subchondral bone rarely - by providing a suitable environment for new tissue formation and takes advantage of the body's own healing potential. Proper surgical technique and rehabilitation improve the success rate of the microfracture procedure. The goals are to alleviate the pain and disability that can result from chondral lesions and restore joint conformity, thereby preventing late degenerative changes in the joint.

Microfracture: surgical technique and rehabilitation to treat chondral defects

Full-thickness articular cartilage defects rarely heal spontaneously. Some patients may not have clinically significant problems from chondral defects, but most eventually have degenerative changes. Techniques to treat chondral defects include abrasion, drilling, autografts, allografts, and cell transplantation. The senior author (JRS) developed the microfracture technique to enhance chondral resurfacing by providing a suitable environment for new tissue formation and taking advantage of the body's own healing potential. Microfracture has been done in more than 1800 patients. Specially designed awls are used to make multiple perforations, or microfractures, into the subchondral bone plate. Perforations are made as close together as possible, but not so close that one breaks into another. They usually are approximately 3 to 4 mm apart. The integrity of the subchondral bone plate must be maintained. The released marrow elements (including mesenchymal stem cells, growth factors, and other healing proteins) form a surgically induced super clot that provides an enriched environment for new tissue formation. The rehabilitation program is crucial to optimize the results of the surgery. It promotes the ideal physical environment for the marrow mesenchymal stem cells to differentiate into articular cartilagelike cells, ultimately leading to development of a durable repair cartilage that fills the original defect.