Trochlear Osteochondral Shell Allograft Technique to Treat Trochlear Dysplasia in the Setting of Chondral Damage and Chronic Patellar Instability
The patellofemoral joint is a complex portion of knee anatomy that is composed of the end of the thigh bone and kneecap. Patients who have structural abnormalities in the surrounding ligaments and bony anatomy as well as functional factors impacting how the kneecap moves, may report acute and chronic pain. Trochlear dysplasia, which is the shallowing, flattening, or loss of concavity of this groove, is typically associated with abnormal movement of the kneecap during flexion and extension (Image 1). While the cause of trochlear dysplasia is unclear, there may be a genetic as well as environmental component, such as a breech position in utero before birth, that results in the dysplasia. Surgical intervention for patients must be based on the severity of pain and dysfunction, the severity of the dysplasia, if there are frequent dislocations of the kneecap, and whether there is arthritis underneath the kneecap.
Cartilage restoration is a broad type of surgical treatment that Dr. Chahla performs, focusing on surgical measures to restore deteriorating joint cartilage in order to prevent or delay the need for a joint replacement surgery. In this paper, we illustrate our surgical technique for correcting trochlear dysplasia, recurrent kneecap dislocations, and arthritis under the kneecap. We utilized a donor graft (cadaver) to replace the damaged bony anatomy and increased the depth of the groove (Image 2) as well as reconstructed the essential ligament (Medial Patellofemoral Ligament) needed to stabilize the kneecap during flexion (Image 3).