Femoroacetabular Impingement (FAI), also known as hip impingement, is a condition in which the hip joint does not have the usual shape. The structure is altered, and the joint space is constricted. This causes the bones to rub together painfully. This can “pinch” and eventually damage the labrum.
A hip impingement is not painful at first.
It becomes a syndrome when the following symptoms occur:
- Pain in the groin especially when flexing the hip
- Decreased range of motion of the hip.
Pain that occurs at night or when walking on level ground suggests that the cartilage that cushions the impact of the hip has begun to break down and wear away, a condition known as osteoarthritis. The labrum, the fibrous cartilage that lines the outer edge of the acetabulum, may also be damaged.
Symptoms
- There may be no symptoms.
- Pain or soreness
- A locking, or catching, sensation in the joint
- Pain when sitting for long periods of time (Car)
- Difficulty putting on socks or shoes
- Difficulty climbing a hill
- Low back pain
- Sacroiliac pain
Cause
There are three possible presentations of hip joint surface irregularities:
- Tenaille: Calcium deposition forming a lump on the edge of the acetabulum, which can damage the labrium.
- Cam: The femoral head is not round and cannot rotate freely inside the acetabulum.
- Mixed: Both the pincer and the cam are present.
Radiography
