Condition guide
Hip impingement (femoroacetabular impingement, FAI) happens when the ball at the top of the thigh bone or its socket in the pelvis has a different shape, so the hip cannot glide smoothly as it moves and the surrounding tissues become irritated. It most often causes groin pain that gets worse with movement. This bone shape is also seen in many people with no pain, so the diagnosis is made by looking at symptoms, examination and imaging together. Treatment usually starts with physiotherapy and cutting down on movements that aggravate the hip.
There are two main shape differences: extra bone where the head of the thigh bone meets its neck (cam type, more common in men) and the socket covering the head of the thigh bone too much (pincer type, more common in women). The shape may be present from birth or develop over time, and it is more common in teenagers who play sport. Work and sport, a previous hip injury and control of the muscles around the hip also play a part.
According to an international expert consensus, three things are needed together for the diagnosis: movement-related hip or groin pain, that pain being reproduced on examination, and a difference in bone shape on imaging. Familiar pain when the hip is bent and turned inwards during the examination supports the diagnosis, but is not enough on its own.
The first imaging is a plain X-ray; if surgery is being considered, an MRI or CT scan may be requested.
In a study at 23 hospitals in the UK, 348 people were assigned to either hip arthroscopy (keyhole surgery) or personalised physiotherapy. After 12 months both groups had improved; the quality of life score rose by 6.8 points more in the arthroscopy group. However, there was no sham surgery group, the benefit was seen mainly in the cam type, and long-term results are not yet known.
Surgery is usually considered when symptoms do not settle with other treatments; not everyone needs an operation.
Regular movement reduces pain and stiffness and strengthens your muscles. You can try exercise that puts less strain on the hip, such as swimming.
Deep squats, lunges, leg press, deadlifts, high box jumps and the rowing machine can make the pain worse. You can take a break from these until the pain settles.
Sitting cross-legged and bending the hip deeply can be uncomfortable. You can try putting on socks or getting into a car without bending your hip too far.
Heat or cold, paracetamol or a painkilling gel can bring relief. You can ask your pharmacist or doctor which one suits you.
For pain on the outer side of the hip, see the lateral hip pain guide; for groin pain in later life, see the hip osteoarthritis guide.
Exercises at home
Some mild discomfort is normal, but pain should not rise noticeably during exercise and should return to its usual level within 24–48 hours. The repetitions are a guide; you can adjust them to a level that feels comfortable.
Lie on your back with your knees bent and your feet flat on the floor. Gently tighten your stomach and press the hollow of your lower back down towards the floor; hold for 5 seconds, then relax. Do not hold your breath.
10 reps, twice a dayLie on your back with your legs straight. Gently tighten your tummy muscles; slide one heel along the floor towards your buttock, keeping your knee pointing at the ceiling. Stop before you feel a pinch in the groin, then slowly slide it back and repeat with the other leg.
10 reps on each legLie on your back with your knees bent and feet flat on the floor. Squeeze your buttocks and lift your back off the floor so that your shoulders, hips and knees form a straight line. Hold for 3–5 seconds, then lower slowly.
10–15 reps, 1–2 times a dayLie on your side with the bottom knee slightly bent. Lift the top leg with the knee straight and toes pointing forwards. Your hip muscles help keep the knee stable.
10–15 reps on each sideLie on your side, facing forwards, with your elbow directly under your shoulder, your forearm on the floor and your knees bent. Lift your hips off the floor so that your body forms a straight line from your head to your knees. You can reach your top arm up towards the ceiling or rest your hand on your waist. Lower slowly, then turn onto your other side.
10–20 seconds, 3 times on each sideStand upright in front of the kitchen counter, holding on lightly with one or both hands. Lift one foot off the floor by bending the knee back, and keep your balance. As it gets easier, hold on with one hand, then with just your fingertips.
10–15 seconds, 3–5 times on each footThis is not yet clear. According to international expert consensus, there is no evidence that surgically correcting this bone shape in people without pain changes their risk of osteoarthritis. For more on osteoarthritis, see our hip osteoarthritis guide.
Not everyone needs an operation. Treatment usually starts with physiotherapy, cutting down on aggravating movements and painkillers; if symptoms do not settle with these, surgery may be considered. You can make the decision together with your surgeon, after talking through the possible benefits and risks.
Most of the time you do not need to stop completely. You can cut down for a while on movements that make the pain worse, such as deep squats, lunges and jumping, and turn to sports that put less strain on the hip, such as swimming.
This bone shape is also seen in many people with no pain. According to international expert consensus, surgery is rarely offered to people without pain; you can carry on staying active with regular exercise.
Sources
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