Patellofemoral Syndrome

Patellar Maltracking (Patellofemoral syndrome) can be due to the anatomy of the patient’s body or specific activities. It is essential to understand the anatomy to better understand the underlying cause. The knee is composed of bones, ligaments, muscles, and cartilage. The three significant bones are the thigh bone (femur), the shin bone (tibia), and the knee cap (patella). The kneecap lies in a small groove in the femur called the trochlear groove. It is held in place by the quadriceps tendon on top and the patella tendon on the bottom.

There are variations in anatomy that causes some patients to be more prone to dislocation. If the trochlea is too shallow, the patella is more likely to dislocate. If a person has anatomy with a wider placement of the hip bones, they may also experience instability. This is often the case in young individuals, particularly women. Lastly, people with connective tissue disorders, such as Ehlers Danlos or Marfan’s Syndrome, have lax ligaments that allow instability.

Certain activities can also cause patellar maltracking. Damaging the stabilizing ligaments on the medial side of the patella, called the medial patellofemoral ligament (MPFL) is associated with 70-100% of cases of lateral patellar dislocation. Additionally, injuries that cause cartilage damage and inflammation can cause bony growth that creates an irregular surface between the patella and the trochlea. Activities that cause such injuries include trauma caused by motor vehicle collisions, sports that require quick changes in direction, such as soccer or basketball, and running.

Patellar Maltracking can be treated conservatively or with surgery, depending on the details of their conditions.

Non-operative treatment is generally reserved for people who have pain with no dislocations, or first-time dislocations without evidence of bone or cartilage damage. Initially, ice improves the swelling in the area. Non-steroidal anti-inflammatory medications, such as ibuprofen, help reduce the pain. Occasionally an injection can help with the pain. If the patella was dislocated, a physician typically recommends immobilization of the joint for 3-6 weeks. Physical therapy is beneficial and helps patients gain range of motion, strength, and stabilization. If the pain is associated with specific activities, patients should cease those activities for the time being. Strengthening the muscles of the legs can help realign the kneecap into a more appropriate position.

Surgical treatment depends on the cause of the instability. Over 100 different procedures have been used for patellar instability. Therefore, the approach should be individualized to each patient. Patients who choose surgery may have fractures or loose bodies after dislocation, injury to the MPFL, recurrent dislocations, or failure to improve with conservative management.

Generally, surgery for patellar instability is thought of in two categories: soft tissue procedures and bony procedures. Soft tissue procedures provide stability to the region by tightening lax soft tissues. For patients with a torn MPFL, the MPFL can be reconstructed with a ligament. Bone procedures are ideal for people whose instability is caused by bone involvement, such as a shallow trochlea or loose bodies. Trochleoplasty is a bone procedure in which the shape is the groove is changed to allow for better tracking. Surgeons may also do a surgery called tibial tubercle transfer in which they shift a bump of bone to a better position to allow for better tracking.

Patellar maltracking is a condition that causes pain, swelling, and instability in the knee. Over time, it can cause severe damage to the joint. Fortunately, many treatment options ranging from conservative management to surgery. Ask Dr. Morton about which choice is right for you.