Your surgeon is the best one to answer this question. He or she will probably have a specific protocol that you will follow after surgery. Some of this depends on the surgery you have done (e.g., repair versus reconstruction) and how it’s done.
There isn’t one specific surgical procedure that can be used for everyone with patellar instability (that’s the medical term for a kneecap that repeatedly dislocates). The surgeon takes into consideration the age of the patient, activity level, anatomical factors, and the overall condition of the patellofemoral joint (where the kneecap moves up and down over the leg). If there is generalized joint laxity or congenital changes (present at birth) in the shape of the patella, further reconstruction may be necessary before patellar stability is fully restored.
Usually the first step is to restore the natural movement of the patellar as it moves up and down the trochlear groove (anatomical track that holds the patella in place). Then everything necessary to keep the patella tracking normally must be done. The surgeon does whatever is necessary to restore the soft tissue restraints needed to prevent a lateral pull on the patella. It may be necessary to perform a tendon graft or shave off some of the bone that is preventing normal trochlear tracking.
The surgeon will also check the Q-angle and correct it if necessary. The Q-angle is the angle of pull placed on the patella by the quadriceps muscle. An increased Q-angle pulls the patella laterally (toward the outside of the joint away from the other knee). With enough pull and not enough restraint, the patella can be pulled so far over that it pops out of the groove and dislocates. Exactly how the Q-angle is corrected depends on the underlying pathologic (abnormal) anatomy and altered biomechanics.
No matter what kind of surgery is done, a hinge-brace is worn for about six weeks after surgery. This protective brace limits motion and weight-bearing. You’ll probably be allowed to put about half your weight on that leg at first. Motion is usually restricted to 30-degrees of flexion. The physical therapist directing your rehab program will advance the motion allowed by 30-degree increments every couple of weeks.
Quadriceps strengthening is the main focus of rehab but the physical therapist will also make sure the patient’s posture, joint proprioception (joint sense of its own position), and kinesthetic awareness (leg sense of movement) are fully restored as well. Sports specific exercises enable the athlete to return to sports approximately 12 weeks after surgery. For those who are less athletically inclined, recovery may take slightly longer. The therapist will provide a home program of exercises that will help you progress along at the pace you are most comfortable until you reach the goals you have determined for yourself in conjunction with the surgeon and therapist.