The trochlea is a groove in the femur bone underneath the kneecap (patella). The walls of the trochlea stabilize the patella and allow it to glide down the center of the trochlea as the knee bends. It is important for the patella to glide down the middle of the trochlea because a centralized patella increases the strength and efficiency of the quadriceps of the thigh (knee extensor mechanism).
In some individuals, the trochlea does not develop normally. Instead of a groove, some patients have a flat or a dome-shaped trochlea. This condition is called trochlear dysplasia. When an individual has a flat or dome-shaped trochlea, the patella loses stability and can track to the outside of the knee as the knee bends. Individuals with trochlear dysplasia are much more likely to dislocate the patella compared to individuals with a normal trochlea.
- Achy pain in the front of the knee with squatting and stairs
- Sense of kneecap slipping or moving out of place
Diagnosis And Treatment
Dr. Keller considers each patient’s symptoms, as well as a detailed physical examination, x-rays, and sometimes an MRI of the knee to make the diagnosis of trochlear dysplasia. Dr. Keller recommends non-surgical management for most patients with trochlear dysplasia. A dedicated physical therapy program is a very important part of the treatment plan. Physical therapy focuses on strengthening of the core muscles, hip muscles, as well as the quadriceps to help stabilize the patella. Other non-surgical treatment options include a stabilizing brace and oral anti-inflammatory medication. In those patients who do not improve with non-surgical management, Dr. Keller may recommend surgical intervention.