1. Anatomy and Function: The patella is a small, flat, round bone that articulates with the femur in front of the knee joint. The under surface has articular cartilage on it to allow it to glide smoothly over the femoral groove(trochlea) as the knee is flexed. The quadriceps muscle uses the patella as a fulcrum to increase it’s power when extending the knee.

2. Injury: The patella is commonly injured when it’s position in the femoral trochlea is not in the center. This condition is called Patella Malalignment or Subluxation. These problems typically become painful in young, active patients as the uneven stress on their articular cartilage causes softening(Chondromalacia) of the tissue. Left untreated, this abnormal wear can lead to gradual deterioration of the articular cartilage under the patella. Further, a severely malaligned patella is at risk for patella dislocation, which can inflict permanent cartilage damage as well.

3. Treatment: The goal of treatment in painful patella malalignment is to improve the balance and position of the patella tracking mechanism. This is divided into three phases of treatment:

a) Isometric quadriceps strengthening, patella-stabilizer brace and anti-inflammatory medication for 8 weeks.
b) Phase "a" plus intra-articular injection of Cortisone for 4 weeks.
c) Surgery: mild cases of subluxation as determined by exam and X-ray are treated by arthroscopic repositioning of the patella and smoothing of the articular surface.

Normal

MILD SUBLUXATION

Open Soft Tissue Realignment