Hip impingement also known as femoro-acetabular impingement (FAI) occurs when the head of femur (ball of hip) pinches against the acetabulum (cup of the hip) in abduction movement. This causes damage to the labrum (cartilaginous lip that surrounds bony acetabulum) which produces hip pain and stiffness. In the long run can lead to arthritis. This impingement happens if there is bumpy prominence at the outer edge of the superior part of femur head or the supero-outer lip of the acetabulum is prominent. Prominence at the femur head called cam and prominent acetabular lip is called pincer.

Common symptom hip impingement is pain at groin or front of thigh and stiffness. These symptoms are precipitated or can be aggravated if the hip is elevated at the level of waist like riding a bike, tying shoelaces or prolong sitting on a sofa. Diagnosis based on high level of suspicion

For minor symptoms restriction of activities which precipitates symptoms, analgesic and hip exercise can relieve the symptom. But severe symptoms usually associated with labral injury need surgical treatment in the form of labral repair and removal of cam and pincer. Target of this treatment is to relieve the symptom as well as prevent progression of arthritis. This is usually done arthroscopically.