Lateral Retinacular Release

What is the retinaculum?

            The patella (kneecap) is balanced in the front of the knee on the femur (thigh bone). In order to keep the patella centered in the middle of the knee, there are tissues on the inside and outside of the patella which are supposed to pull the patella equally each way. These tissues are call the medial (inside) and the lateral (outside) retinaculum.


What causes the pain?

            In the painful knee there is a tendency for the patella to tilt toward the outside of the knee. This occurs because of the chronic pull of the knee cap to the outside by the thigh muscles, creating a strain on the medical or inside tissues (the retinaculum). Over time if the strain is great enough, the medial tissues resisting the lateral pull of the muscles become painful. The pain comes from the tissue on the inside of the kneecap (the medial retinaculum).


What is a lateral retinacular release?

            It is a surgical release of the outside or lateral retinaculum.


Why should this help?

            The nonsurgical interventions which have been tried, such as physical therapy, bracing, icing, painful medications, and activity modification, were aimed at decreasing the strain on the medial retinaculum. If these measures fail to relieve symptoms, surgically decreasing strain by releasing the lateral retinaculum may help. In addition, this will allow the leg strengthening exercises to work better.


How is a lateral retinacular release done?

            This is an arthroscopic surgery ( a knee “scope” which is performed through 3 small incisions ( about ½ inch each) around the knee. From the inside of the knee the lateral retinaculum is incised, from the inside, allowing the kneecap to untilit itself. Releasing the tight lateral tissues takes the strain off the medial tissues which are causing pain.


What is recovery after surgery?

            Postoperatively, the knee will initially be in a knee brace locked at 30 degrees of knee flexion. Partial weightbearing, with crutches, is recommended to minimize pain and swelling. The first office visit after surgery is between 7 and 14 days after surgery. At the office visit the timing of physical will be determined. After initiating physical therapy, the discontinuation of the knee brace and resumption of full weightbearing on the surgical knee will be guided by the physical therapist.


Do I have to do physical therapy or the exercises?

            Yes the arthroscopic lateral release is done to make the physical therapy work more efficiently. Failing to perform physical therapy will delay, and possibly prevent the eventual improvement from the surgery. This means more knee pain, fatigue, weakness and swelling for a longer time period.


When can sports be restarted?

After surgery the physical therapist will assist in making the determination. In general most individuals are able to reinitiate most activities by 3 months after surgery. Some discomfort may still occur at this time, but should get better each subsequent month.

When will maximal recovery after surgery be reached?

            Typically it takes up to 3 months for most of the improvement to occur, however it will take approximately 1 year after recovery to reach maximal recovery.


Important Numbers:


Office Appointments- (314)454-2500


Debbie Krenning, M.A.- (314)454-4191        krenningd@


Kim Cordia, BSN, RN, ONC- (314)454-5221         [email protected]

Request an Appointment