Femoroacetabular impingement (FAI) has become a frequently used term over the past few years. It is defined as a morphological variant of the hip joint. FAI in itself is not a pathology but a pathological mechanical process that can affect the ball-and-socket function of the joint.
FAI is divided into three categories including cam deformity, pincer deformity or mixed.
- Cam deformity: Additional bone arising on the head-neck of the femur creating a “bump“ on the femoral surface
- Pincer deformity: Additional bone spur on the acetabular surface
These deformities may interfere with the normal positioning and dynamic interplay of the femur relative to the acetabulum especially when the hip does extreme or repetitive motion. This could lead to damage of the labrum and labral tears which could develop into chondropathy and early osteoarthritis of the hip.
Femoroacetabular impingement may always remain asymptomatic in some patients, but may be a key element in understanding the cause of degenerative hip pathologies and pain in other patients.
Article: What is femoroacetabular impingement? (R Agricola et al. British journal of Sports Medicine; bjsports-2015-094914; published online June 30, 2015)
Written by: Genevieve Rochette Gratton, MD, CCFP