Osteochondral grafting is a method of treating cartilage injuries that expose underlying bone. Osteochondral grafts replace both the articular cartilage on the surface and the underlying bone. The tissue can come from other parts of the patient’s body (called osteochondral autograft) or from a tissue donor (osteochondral allograft). These techniques are commonly used in the knee but can be used in other joints.
The injured area of cartilage is identified surgically and a core of the injured cartilage and the underlying bone is removed in a method similar to coring an apple. A replacement core, of similar size and dimension made up of cartilage and bone from another site in the knee (autograft) or a tissue donor knee (allograft), is then made to fit into the hole or defect. The replacement core is gently tapped into place until it lines up with the surrounding tissue. No screws or other devices are typically needed to hold the replacement core in place since it fits tightly. The size and geometry of the defect are critical in determining whether an autograft or allograft is necessary in treating the defect in its entirety.
Patients can usually start to bear weight within 4-6 weeks of surgery. Activity is gradually increased with return to sport typically occurring after 6-9 months.One advantage of these techniques is the ability to replace both cartilage and bone with similar tissue. While slightly more invasive than other techniques, these grafting options replace the injured area with hyaline cartilage, similar to that of the patient’s knee. There are limitations to the amount of tissue that can be taken from within a patient’s own knee so larger areas of cartilage loss may not be optimal for this approach. A potential concern with the use of donor tissue is the very low risk of disease transmission (like a blood transfusion).