Q: What kind of rehab program should I expect to follow after reconstruction surgery for a chronically dislocating kneecap? I'm prepared for just about anything but thought I'd ask around a bit to see what the standard programs might be.

A: Your postoperative rehabilitation program will be highly dependent on the surgical technique used to reconstruct the soft tissue structures. The patella or kneecap is a very complex structure. Anatomists are still exploring and learning how the patellar tracking mechanism really works (i.e., how the kneecap moves up and down over the knee joint).

Understanding normal patellar anatomy and kinematics (movement) will help surgeons repair and restore this part of the knee when injury leads to the type of chronic, painful patellar dislocations you may be experiencing.

Many times, the medial patellofemoral ligament (MPFL) is torn and becomes the focus of repair or reconstruction. This soft tissue structure provides passive restraint (holds the patella in place) as the kneecap moves during the first 30 degrees of knee flexion. There are different ways to reattach (repair) this soft tissue structure. After so many recurrent dislocations, the tissue may be too damaged to repair. That's when graft tissue is used to reconstruct the tissue.

So, once again, rehab will be determined based on the procedure performed and surgeon preferences. Most likely, you will begin with isometric exercises of the quadriceps muscle (large muscle along the front of the thigh that attaches around the kneecap). Isometrics means the leg won't actually move while you contract the muscle.

You will be instructed by a physical therapist in how to perform isometrics, especially including straight-leg raises (lifting the straight leg up). You will be doing these exercises throughout the first hours and days following surgery.

You may be allowed to put partial weight on that leg while wearing a splint or brace holding the knee in full extension. This will protect the healing soft tissue structures. The therapist will show you how to use a pair of crutches safely, efficiently, and effectively while walking.

In a few days after surgery, you may be allowed to start range-of-motion exercises. Gradually each component of rehab will be progressed. Around three months postop, you will be allowed to exercise (e.g., fast walking, jogging). When you have sufficient motion, strength, and stability, then full activities are once again allowed. If you are an athlete (especially one who is hoping to return to full sports participation), then an additional rehab focus will be added to prepare you for your specific sport requirements.

Again, all of these things are variable depending on multiple factors. These can include the type of surgery you have, any complications or problems that might develop, surgeon preference, and your own personal goals, attitudes, and approach to recovery.

Reference: Huijun Kang, MD, et al. Comparison of 2 Different Techniques for Anatomic Reconstruction of the Medial Patellofemoral Ligament. In The American Journal of Sports Medicine. May 2013. Vol. 41. No. 5. Pp. 1013-1021.