Microfracture procedures are becoming more popular as a means of attempting to salvage a severely arthritic knee. The concept behind microfracturing is relatively simple: a surgeon uses a small needle to make tiny punctures in the surfaces of the femur, tibia, or patella (all of which make up the joint surfaces of the knee). This puncturing action causes the body to lay down a cushioned layer of scar tissue where normal joint cartilage used to lie. The end result is a “cartilage like” layer of scar tissue that provides some protection in the joint from the stresses of walking and other activities.
The rehabilitation protocol for microfracture surgery differs from that of many other types of knee surgery. Most orthopedic surgeons will recommend that the patient be “non weight bearing” for a significant amount of time following the surgery. Using crutches for up to a month or more may be necessary to allow the body to adequately rebuild scar tissue, especially when the tibia and femur joint surfaces are involved. If the patella is the only bone involved in the procedure, it is common to see patients who are allowed to bear weight immediately after surgery, given that the patella does not bear much weight when the knee is kept in a straightened position.
Here are a few important guidelines in managing recovery from a microfracture procedure to the knee:
1. A transition to full weight bearing should be gradual one. When you are given permission to begin placing weight through the knee, start by gently placing weight through the foot while using the crutches to take most of your body weight. Walk very slowly at first with the crutches and gradually (over the course of several days) build up the amount of weight that you allow the knee to take.
2. Do not forget to maintain strength in your hip, lower back, and ankle during the time that you are non-weight bearing. Although these muscles were not directly involved with the surgery, they become weak very quickly when they are not used during normal walking. There are many exercises that can be done that are “open kinetic chain,” meaning that no weight is placed directly through the leg.
3. Swelling is an inevitability following any knee surgery. Icing and elevation will help to lessen swelling during the early portion of rehabilitation. It is also extremely important to work on strengthening the VMO portion of the quadriceps (see picture), as this muscle plays a vital role in stabilizing the gliding of the patella. Quad sets (video below) and straight leg raises (video below) are great exercises that address VMO strength.