Knee Joint Cartilage Defects: Medium Cartilage Defect Replacement Animation

Knee Joint Cartilage Defects: Medium Cartilage Defect Replacement Animation

This animation demonstrates an osteochondral allograft transplantation, or OATS procedure, used to treat a medium-sized cartilage defect in the knee. In this procedure, a cartilage and bone graft is obtained from a cadaver donor and transplanted to the area of cartilage damage in the patient’s knee.

Here, we see a right knee with the inner side of the knee shown on the right side of the screen. The knee is bent to expose the end of the femur, or thigh bone, where a medium-sized cartilage defect is visible along the inner portion of the femur.

A sizing instrument is first used to measure the cartilage defect. The same instrument is then applied to donor cartilage from a cadaver femur to outline the exact size of the graft needed to fill the defect.

The sizing instrument is repositioned over the defect, and a drill pin is inserted into the thigh bone. The surrounding cartilage is marked, and a scoring instrument of the same size is used to create a circular cut through the cartilage down to the bone. A reamer is then placed over the drill pin to remove the damaged cartilage and underlying bone, creating a socket that will precisely accept the graft.

A dilator is tapped into the socket to finalize its shape, and a depth gauge is used to measure the socket depth to ensure proper graft sizing. The donor femur is secured in a workstation, and a drill and saw are used to harvest a matching cartilage and bone graft, which is then measured and shaped to fit the prepared socket.

The graft may be soaked in a solution derived from the patient’s own blood to promote healing, and bone gel is applied to the exposed bone in the socket. The graft is then positioned and gently tapped into place until it sits flush with the surrounding cartilage. Once the graft is secured, the procedure is complete.