Dislocation of the patella occurs when the kneecap is pulled out of the groove on the end of the thigh bone. The kneecap is typically pulled to the outside of the groove. Once a patella dislocation occurs, it is much more likely to occur again in the future.
Understanding why the kneecap dislocation occurred is key to determining the appropriate treatment. In some people, the bone alignment or anatomy may be an issue; in others, there may be a torn ligament. If it is decided that surgery is the best treatment option, then determining the specific surgery is the most important step to prevent future dislocations.
Traditionally, after a first-time patella dislocation, non-surgical treatment is recommended. Non-surgical treatment usually consists of physical therapy to strengthen the muscles around the knee as well as the use of a brace to help hold the kneecap in a proper position. How effective non-surgical treatment is at preventing future dislocations is debatable, but many doctors feel that it is important to determine if this was a one-time event, or if it is likely to be a recurrent problem. Immediate surgery after a first-time dislocation has not been proven to be beneficial, except in cases where an additional injury in the knee warrants urgent surgical treatment.
Most surgeons agree that if the kneecap dislocates multiple times, surgery should be considered.
When the kneecap dislocates, it is possible to damage the cartilage in the knee, leading to an increased risk of knee arthritis. When multiple dislocations occur despite treatment, patellar stabilization surgery should be considered.
A medial imbrication is a procedure that tightens the structures on the inner side of the knee. The most common method of tightening the medial side of the knee is advancing the attachment of the quadriceps muscles on the kneecap on the inner knee.
The most common procedure performed for patellar dislocation addresses an important ligament called the medial patellofemoral ligament, or MPFL. The MPFL is the restraint between the end of the thigh bone (femur) and the inner side of the kneecap (patella). When the kneecap dislocates, the MPFL is always torn.
In acute injuries, it may be possible to repair the MPFL. This is only true in first-time dislocations that are addressed with immediate surgery. Therefore, some surgeons advocate immediate surgery after an initial patella dislocation to repair the MPFL, despite the fact that this has not been shown to decrease repeat dislocation.
After repeat dislocations, in order to fix the MPFL, a new ligament must be made. This can be done using a ligament or tendon from elsewhere in your body, or from a donor (cadaver). The new MPFL ligament is created and attached to the thighbone and kneecap. This newly reconstructed MPFL then prevents the kneecap from dislocating again.
Bone Realignment/Fulkerson Procedure
In some patients, their anatomy is abnormal and contributes to the kneecap coming out of joint. The problem may be a shallow groove on the end of the thigh bone or abnormal alignment of the lower extremity.
In some situations, surgery is performed to align the extremity by positioning the tibial tubercle on the shin bone. The tibial tubercle, the bump at the top of the shin bone, attaches to the patellar tendon. By positioning the tibial tubercle, the patella is pulled more to the inner side of the knee and becomes less likely to dislocate.
There are numerous variations of surgery that accomplish this task. The Fulkerson procedure is the most common and is named after the physician who described this technique. There are a number of other, similar procedures that also reposition the tibial tubercle, as well as other types of procedures that can correct the alignment of the knee.
Rehab After Surgery
Rehab after surgery to realign the patella varies. The longest rehab is typically after a bone realignment procedure, to allow time for the bone to heal. No matter what procedure is performed, one of the more common complications after surgery is stiffness of the knee. Getting normal strength and mobility recovered after surgery can take months or even longer.
While dislocations of the patella can occur after surgery, they are much less common. Most patients can resume their pre-injury level of activity without having the risk of re-dislocating their kneecap.
A Word From Get Meds Info
If you have a kneecap dislocation, the most important step is to determine the best surgery to perform based on your situation. Not all kneecap dislocations occur for the same reason, and therefore not all treatments are the same. Seeing a surgeon who is familiar with the causes and treatments for kneecap dislocations is very important.