The knee is made of two joints - the patellofemoral and tibiofemoral joints. The patellofemoral joint comprised the kneecap (patella) and the top groove at the end of the thigh bone (femoral trochlea).
Pain in this joint often is felt in the front of the knee which is often made worse when sitting for prolong periods, going up stairs or crouching down. Sports or heavy lifting can exacerbate the pain.
What Causes Patellofemoral Pain?
Pain from this joint is usually caused by overload - where more force goes through the joint than it can manage. When the muscles that control this joint become weak, even normal day to day activities can stress this joint to the point of pain. In up to 50% of cases of “patellofemoral syndrome”, this pain is due to long standing overuse.
Pure pain from this joint is not well understood. Small cartilage damage under the kneecap is common and usually not painful. Alteration to the normal cartilage that prevents the cartilage to protect the bone from the constant joint forces is the most likely cause of pain.
There are some anatomic features that may predispose development of this condition such as knock knees, lax ligaments, a shallow (dysplastic) groove for the kneecap to glide in. These and other features may cause the kneecap to maltrack or even dislocate from time to time.
Most cases of patellofemoral pain can be treated without surgery, focusing on preventing further overload. Treatment often includes working on quadriceps strengthening with a focus on VMO (vastus medialis obliquus), balance and correct kinematics between the quadriceps and hamstring muscles and proprioceptive control of the joint.
In a majority of cases, the kneecap comes out of the trochlear groove as a result of injury. The MPFL (medial patellofemoral ligament) is usually damaged when the kneecap comes out of joint and can predispose to further dislocations or patellar instability.
After a first time traumatic dislocation and assessment to exclude fracture or other knee injuries most cases do not require surgical treatment. Prevention of further dislocations can be achieved by physiotherapy designed to improve muscle strength, muscle control and proprioceptive control of the kneecap.
In cases where further dislocation or subluxation (partial dislocation) occurs, surgery may be indicated. Surgical correction often involves MPFL reconstruction, sometimes in conjunction with bony realignments allow the kneecap to track more normally.
Contact Dr J Tsung
|1300 399 223|
|(07) 3041 5087|
Suite 6C Fred McKay House
42 Inland Dr, Tugun Qld 4224