Patellofemoral Pain (Kneecap)

The number one cause of pain in the young, healthy athlete is patellofemoral pain. Patellofemoral pain syndromes are referred to by many different names, some of which include; anterior knee pain, patellofemoral malalignment, chondromalacia patellae, patellar hypermobility, lateral pressure phenomenon, and patellar tilt.

Causes

The primary cause of patellofemoral malalignment is an unbalanced set of forces across the patellofemoral joint causing the patella to not be centered within the trochlear groove, which is a part of the thigh or femur. The abnormal forces that act on the patella to cause this problem can be as simple as a muscular weakness of the quadriceps muscles (thigh muscles) or an imbalance between the various portions of the quadriceps muscles, tight ligaments either on the outside or the inside (lateral and medial, respectively), having flatfeet, being knock-kneed, and having significant ligamentous laxity.

Although it is possible, traumatic causes of patellofemoral pain are not common. In a traumatic situation, pre-existing malalignment often exists and it is harder, but not impossible, to treat the pain and discomfort conservatively. When traumatic injuries do occur and a cartilage lesion is caused, treatment by any means is more involved and full recovery harder to achieve. In fact, it is not uncommon in these situations, for surgical intervention to be suggested and/or required to return athletes to their full potential.

Symptoms

  • Aching around the patella.
  • No specific area of point tenderness.
  • Pain worsens with stairs – up or down.
  • Pain worsens with long periods of sitting – Theatre Goers’ Sign.
  • Clicks or pops (though some clicking and grinding under the patella is normal).

Treatment

The type and duration of treatment is dependent on the severity the condition. A period of non-operative treatment is normally the initial step taken to correct the problem.

Non-operative
The treatment of patellofemoral malalignment centers on the factors which predispose it to occur. The most common of these is lateral (outside) tightness especially of the ilio-tibial band (ITB). Stretching of the lateral retinaculum and ITB, though difficult, is very beneficial. Significant knock-kneed (genu valgum) position of the knees can also lead to and cause patellofemoral malalignment. This is quite common in females, as they have broader hips for giving birth. In these situations, reversing this knock-kneed condition is possible but is a large undertaking, and is usually not necessary. Flatfoot deformity (pes planus) also can contribute to patellofemoral malalignment symptoms. In situations where flat footedness exists, a medial arch support and sometimes some medial posting in an orthotic will dynamically help the patellofemoral joint. Placing an arch support is a common first step taken during the conservative treatment of patellofemoral malalignment.

Overall, non-operative treatment of patellofemoral problems is successful 85% of the time. Patience and diligence increase the success rate with several courses of therapy and activity modification often necessary.

Alternative Treatment Options

Glucosamine

Hyaluronic Acid

Non-steroidal Anti-inflammatory Medications (NSAIDs)

Operative

Though not common, operative management of patellofemoral problems is sometimes necessary. Long standing malalignment problems that are resistant to non-operative care as well as traumatically induced patellofemoral problems which cause surface damage can be treated surgically.

Operative treatment begins with an arthroscopic procedure to remove loose fragments from within the knee and to smooth out rough and/or irregular edges when they exist. Re-alignment procedures are then performed to correct abnormal forces as is appropriate. A lateral release is commonly performed and will treat tilted knee caps well when this is the sole problem within the patellofemoral joint. Re-aligning the forces within the joint, however, when subluxations, dislocations, and/or significant ligamentous laxity exist requires more extensive procedures. These procedures include tightening of medial or lateral ligaments, advancement of muscular attachments on the proximal pole of the patella, and sometimes osteotomies of the patellar tendon attachment to the tibia via an open procedure (i.e., tibial tubercle osteotomies).