Patellofemoral knee pain, or anterior knee pain, is the most common cause of knee pain, especially in females. It usually causes a deep pain in the front area of the knee, which often is worse with climbing stairs, squatting, running, and sitting with the knees bent. There is usually no swelling, catching or locking, but the knee may feel like it is going to buckle.
The kneecap—or patellofemoral—area is prone to pain for a number of reasons. The kneecap is a small bone but bears a great deal of load. During certain activities, 3 to 6 times a person’s body weight may be placed across the patellofemoral joint. Certain anatomic factors predispose some people to patellofemoral pain and overload. Dynamic factors, like tightness in the iliotibial band or weakness in the quadriceps and hip can also contribute to patellofemoral knee pain.
Patellofemoral knee pain is treated initially with activity modification and physical therapy. This is successful for most patients. If these measures are unsuccessful or if there is cartilage damage surgical treatment may be considered. Surgical procedures used to treat patellofemoral knee pain include: tibial tubercle osteotomy, lateral release, and cartilage replacement surgeries when appropriate.
Tibial Tubercle Osteotomy
The tibial tubercle is the bony prominence right below the knee joint where the patellar tendon attaches. Some patients are predisposed to patellofemoral problems because of the angle the quadriceps and patellar tendon make as they cross the knee and attach onto the tibial tubercle. Patients with severe patellofemoral knee pain, that is not resolved with physical therapy, may be candidates for tibial tubercle osteotomy. Tibial tubercle osteotomy can also be used to treat patellofemoral arthritis in selected patients, patella instability and can also be used in combination with other procedures such as cartilage replacement surgery.
Tibial tubercle osteotomy involves cutting the bone where the patella tendon attaches and moving it slightly. The tendon is usually moved toward the inside of the knee to decrease the angle of the quadriceps. It can also be moved forward to decrease the force across the kneecap.
Lateral Reticular Release
The lateral retinaculum is the soft tissue along the outside of the knee. It is often tight in patients with patellofemoral knee problems. A lateral release involves releasing this soft tissue along the outside of the knee. This is done arthroscopically. The procedure is most often done in combination with other patellofemoral procedures such as tibial tubercle osteotomy or MPFL reconstruction. Selected patients with patellofemoral knee pain and a tight lateral retinaculum may be candidates for isolated lateral release as a minimally invasive way to treat their pain.