KNEECAP INSTABILITY: A TROUBLESOME ISSUE FOR GIRLS

Key Points:

  • Kneecap instability can be a frustrating source of pain and limited function for the young female athlete
  • A combination of anatomic and sport-specific factors is involved in creating the instability
  • Kneecap instability can often be treated successfully without surgery but surgery may be needed for recurring instability
  • Recovery can be very long, sometimes taking six to 10 weeks without surgery and four to nine months with surgery

The kneecap can be a source of trouble for young athletes, especially girls. There are some features in a growing young girl’s anatomy that place her at risk for kneecap instability. When combined with some sports in which a high amount of twisting torque is involved we have a recipe for problems such as the kneecap partially shifting (“subluxation”) or completely shifting out of place (“dislocation”).A00707F02

In a growing girl there are changes in the shape and length of the pelvis and legs that are normal, such as a widening of the pelvis and an increase in the angle the legs form at the knees. These changes tend to cause an increase in the angle of pull on the kneecap, resulting in the kneecap sitting towards the outside of the knee.

The changes in the angles are normal but when combined with sports that require twisting of the body around the knee, it can create a situation where the normal motion of the kneecap is overwhelmed by the outward pull. The result can be kneecap instability. A classic situation that we start to see in springtime is instability of the right knee in a right-handed softball batter. Other sports where we’ll often see kneecap instability are basketball, soccer, and lacrosse.

What the athlete feels with patellar instability depends on how far out of place the patella has moved and how much damage occurred when it happened.

Some general symptoms the athlete may experience include:

  • Pain, usually in the front of the knee near the kneecap
  • Feeling the kneecap shift or slide out of the groove
  • Feeling the knee buckle or give way
  • Hearing a popping sound when the patella dislocates
  • Swelling
  • A change in the knee’s appearance — the knee may appear misshapen or deformed
  • Apprehension or fear when running or changing direction.

Treatment for kneecap instability has improved substantially over the last 30 to 40 years. Gone are the days of placing the knee in a cast, with total immobilization for perhaps 6 weeks. A recent scientific publication in the journal Sports Health outlines the changes in our treatment process for this common problem.

Nonsurgical treatment usually works for first-time patellar dislocations, but surgical treatment is recommended for first-time dislocations accompanied by cartilage injuries. Nonsurgical rehabilitation takes some time, and six to 10 weeks is common before full sports are allowed. Surgery is sometimes needed to stabilize a kneecap that repeatedly becomes unstable. The surgery can be very successful but the rehabilitation can take quite a long time. I have seen a four to nine month timeline to return fully to sprinting, twisting, and jumping sports after surgery.

By Dev Mishra, M.D., President, Sideline Sports Doc, Clinical Assistant Professor of Orthopedic Surgery, Stanford University

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