Probably half of them are because of trauma alone, the others might have lax ligaments, a flattened grove the kneecap tracks along, intoeing gait, long patella tendon, knock knees, or any combination. These are not easy cases to sort out. Typically with a first time dislocation, an arthroscopy & washout might be undertaken to speed up the recovery process especially if the knee is still very swollen and loose fragments are suspected. Physiotherapy and taping are then usually instituted. If there is a significant concern the dislocation might become recurring, corrective surgery might be undertaken.
The most common operation is to reconstruct the damaged ligament from the inner aspect of the femur to the kneecap.
In this case, drill holes through the kneecap hold the hamstring graft at one end, the screw in the femur holds the graft in a tunnel.
Some surgeons use screws that cannot be seen on XR, either way, the screw is usually left permanently.
2. Faulkerson Procedure.
This operation can be applied to many cases including cases where the patella tendon doesn’t line up well, those with kneecap pain, patients with a combination of problems even ligamentous laxity. In this operation, the boney prominence that the patella tendon connects to the tibia through is surgically moved and screwed into its new position, some soft tissue surgery is also undertaken.
3. 8-Plate Correction of Knock Knees
This operation using “8-plates” is performed to gradually correct knock knees, in doing so the direction of pull of the patella tendon is corrected. Some might still need a ligament reconstruction, but this surgery on growth plates is quite time critical, before the growth plates close. The typical girl would need this by 13 years of age, and perhaps 15 for boys. The surgery is done through a 1cm cut for each of the four plates, sometimes only one leg, or only one growth plate per knee needs to be corrected.
4. Other operations
Other operations include deepening the groove the patella tracks in, rotating the femur either near the hip or knee joint. In some acute cases, it might be possible to repair the damaged MPFL (ligament) but often much of the ligament has been stretched as well as the obvious injury.
Mr David Mitchell