The patella (kneecap) is a protective bone attached to the quadriceps muscles of the thigh by the quadriceps tendon. The patella interacts with the trochlea of the femur bone and forms the patellofemoral joint. The patella is stabilized by the bony anatomy as well as soft-tissue structures such as the medial patellofemoral ligament (MPFL), which secures the kneecap and prevents it from gliding out of alignment.
Dislocation of the patella occurs when the patella moves out of the patellofemoral groove, (called the trochlea) onto the bony head of the femur. If the kneecap partially comes out of the groove, it is called a subluxation and if the kneecap completely comes out, it is called a dislocation (luxation). Patella dislocation is commonly observed in young athletes between 15 and 20 years of age and commonly affects women because the wider pelvis in females creates a lateral pull on the patella.
Some of the causes for patellar dislocation include a direct blow or trauma, twisting of the knee while changing direction, muscle contractions, and congenital defects. Dislocation also occurs when the MPFL is torn. The common symptoms include pain, tenderness, swelling around the knee joint, restricted movement of the knee, numbness below the knee, and discoloration of the area where the injury has occurred.
Dr. Patel will examine your knee and suggest diagnostic tests such as X-rays, CT scan, and MRI scan to confirm the condition and determine the approach to treatment.
Medial patellofemoral ligament reconstruction – In this procedure, the torn MPF ligament is imbricated and then a new ligament is reconstructed using a donor tendon graft. The grafts are either taken from the same individual (autograft) or from a donor (allograft). This procedure may be performed minimally invasive using an arthroscope; however, typically other procedures such as a lateral lengthening, tibial tubercle osteotomy or cartilage procedure may need to be done concurrently and an open technique is performed
Anatomic MPFL reconstruction is very important as any misplacement of the graft can lead to recurrent dislocations, articular cartilage damage and loss of motion.
After the surgery, Dr. Patel will suggest you use crutches for a few weeks, prescribe medications to control pain and swelling, and recommend physical therapy which will help you to return to your sports activities at the earliest.