Getting your newly replaced knee joint moving may be easier said than done. Sometimes the knee just stiffens up, frustrating both the patient and provider. It helps to know why the joint is stiff–and what can be done about it. Is it something the patient did, or did something happen during or after surgery to make the knee stiff?
Patients themselves may have something to do with it. But these factors are not always in their control. For example, some people naturally form extra scar tissue after an injury or surgery. When this occurs following knee joint replacement, the added scar tissue can cause the knee to become stiff. And a tight knee that isn’t moving fully before surgery will have a greater chance of being stiff with limited movement afterward.
Patients can control how readily they do their exercises and therapy after surgery. If they choose not to comply, their chances of having stiff knees are greater.
Loosen up. Not all problems with stiffness are due to patient factors. Errors in the way the surgery is done can also bear on stiffness in the new knee joint. An improper alignment in the parts of the new prosthesis can lead to tightness in the hinge-action of the joint. If bone spurs aren’t removed and the joint capsule is too tight in the back of the knee, tightness may occur after surgery. Likewise, an imbalance in the knee ligaments, if left untreated during surgery, can also contribute to tightness.
What about problems after surgery? Complications like infection, severe pain, or a broken or loosened prosthesis can affect knee stiffness.
Knowing when the tightness began can sometimes alert the surgeon as to the possible causes of stiffness. If the knee is stiff right after surgery, it could be from technical errors during surgery, but it could also be due to swelling and pain in the joint. If stiffness happens weeks after surgery, doctors may suspect either infection or problems with the prosthesis (loose or broken parts).
Getting the tight knee moving involves a combination of appropriate pain medication and heavy stretching in physical therapy. If the knee is still tight, patients may have to wear a special splint that helps stretch the knee. Only then does the physician recommend manipulating under anesthesia, a procedure done by forcefully stretching the knee while the patient is asleep from anesthesia.
When these efforts are unsuccessful, additional surgery may be needed. Choices include using an arthroscope to go in and remove scar tissue followed by forceful stretching of the knee. Less commonly, surgeons may need to revise or replace the parts of the prosthesis.
This author thinks prevention is the best way to avoid a stiff joint after total knee replacement. Prevention includes educating patients before surgery, avoiding technical errors during surgery, and starting a comprehensive rehabilitation program after surgery.