Knee replacement surgeries are performed to help people with end-stage arthritis in their knees get rid of pain and return to an active lifestyle. Knee replacements can fail; the fourth cause of failure to be discussed is stiffness.
Knee stiffness can result in a painful knee and be a source of dissatisfaction. The typical patient with a stiff knee cannot accomplish certain tasks comfortably such as climbing stairs, or rising up from a low chair as one needs at least 90 degrees of motion to perform these tasks.
There are risk factors for developing a stiff knee following knee replacement. Poor knee motion before surgery is a significant risk factor as pre-operative motion tends to predict post-operative motion. Other risk factors include post-traumatic knee arthritis, prior knee surgeries, history of stiffness, and poor pain control.
The treatment for a stiff knee usually begins with physical therapy. Acutely stiff knees following surgery will often respond to physical therapy. Some knees will not respond to this measure. If no improvement with a few weeks of physical therapy, manipulation of the knee under anesthesia becomes necessary. This is performed before 3 months to decrease the risk of complications from the procedure and to maximize gains. After 3 months, knee arthroscopy surgery to break up scar tissue in the knee might be more appropriate.
For chronically stiff knees not responsive to non-surgical measures, revision surgery can be indicated. An infection will need to be ruled out as an infection can be present even in the setting of knee stiffness. Revision surgery can range from removing the scar tissue in the knee to removing all the components and implanting a new knee replacement.
One must understand the goals of the patient before performing revision surgery. Some patients might be satisfied, and well-functioning with a stiff knee. These patients do not necessarily need revision surgery. The goal of revision surgery for stiffness is to restore range of motion and decrease pain (if present). This usually results in improvement in functioning.
Dr. Oluwaseun Akinbo M.D. is an orthopedic surgeon at HaysMed. For more information, https://www.haysmed.com/oluwaseun-akinbo/.