Flexion Contractures & Physical Therapy

Arthritic and non-arthritic joints may develop “arthrofibrosis.” In this condition the knee fails to straighten fully. This is called a flexion contracture. Persons with this condition walk with the knee bent to varying degrees. The photo below shows a patient with a large flexion contracture in the right leg. Although they can straighten out their left leg so that it lies flat on the table, this is a straight as the right leg can get. The angle that the knee makes can be measured and is labeled as the degrees of the flexion contracture. The higher the number, the more bent the knee is.

Patient with a large flexion contractureWalking with a bent knee is an abnormal stance. It causes increased pressure and “wear and tear” on the knee while walking, especially on the knee cap. The end result is pain and disability. The worse the flexion contracture, the more rapidly the symptoms appear. But even mild flexion contractures can cause disability if they are left untreated. One study by Riddle found that over three years, for every degree of flexion contracture present, the risk of having a knee replacement increased 6%.

Treatment of Flexion Contractures

Physical therapy can usually diminish and often eliminate these flexion contractures. This improved motion decreases pain in the overwhelming majority of patients to some degree. At times it can allow a patient who needed surgery to function adequately without it. It takes hard work on the part of the patient and therapist but our expert physical therapists are quite experienced in using and teaching the needed techniques.

The main goal of physical therapy is to get the knee straight by stretching it out. Patients can work on this at home with the help of a family member. The patient needs to sit or lie on a hard, flat surface and have the family member press firmly on the knee to straighten it out. This is hard work and can be uncomfortable, but it needs to be done for 10 to 20 minutes daily until the knee is completely straght, and then occasionally afterward to keep it that way.

Image of extensionator alone and in useAnother method that can help to straighten a knee is use of a device called an extensionator. The image on the left shows the extensionator frame above and the extensionator in use below. The leg with the flexion contracture is fastened into the framework and then compression is used to slowly pull the knee straight. This is simple to use and a very effective way to straighten a bent knee.

See These Published Papers for Additional Information:

Factors associated with rapid progression to knee arthroplasty: Complete analysis of three-year data from the osteoarthritis initiateve. Riddle, et al, 2012.


  • American Academy of Regenerative Medicine
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