A runner’s guide to hip impingement

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What is hip impingement?

Hip impingement - also known as femoral acetabular impingement (FAI) - is caused when the thigh bone (femur) and the hip socket (acetabulum) produce too much friction in the hip joint. 

This causes hip pain and reduced mobility in one or both hips, and can damage surrounding cartilage. Running can lead to pinching of the surrounding tissues, which can also provide labral tears (damage in the labrum, the strong cartilage around the hip socket).

What types are there?

·      Cam: a bony overgrowth on the head of the femur

·      Pincer: a bony overgrowth on the acetabulum

·      Mixed: a combination of the two

Orthopaedic surgeon Dr Ali Bajwa estimates hip impingement affects around 15% of the young adult population and that cam type impingement is more common in men, while women are more likely to suffer from pincer type impingement.

Who is at risk?

According to The Manchester Hip Clinic, the condition usually presents itself in young and athletic individuals. Athletes may have a higher risk of developing the disorder due to repetitive hip movements and twisting motions. Exercise is not thought to directly cause the condition, but it can make any underlying issues worse, such as anomalies in shape or placement of an athlete’s bones.

Runners with hypermobility may be at risk if they have particularly sensitive hips.

What are the early warning signs?

You might feel or hear ‘clicking’ within the joint - this is tendon inflammation or the bones rubbing on each other. This is particularly noticeable when walking, but may only occur at the end of range of motion (when your leg comes back beneath you).

One of the main symptoms is pain directly within the hip joint, groin, thigh or buttock area. This can be a dull ache providing sharp, shooting pains when particularly aggravated. This can be mild in the early stages, rapidly becoming worse. Other parts of the body may also develop pain as a result of adjusted movement to avoid the hip pain.

What are the progressive symptoms?

Symptoms typically develop when there is damage to the cartilage or labrum. These include limping, pain when moving and stiffness in the hip joint. You might also lose some of range of motion, especially during flexion past 90 degrees (bending a joint closer to the body), adduction (moving towards or across the body) and medial rotation (rotation inwards). 

If the condition is not treated, exercises like squats may become particularly problematic. Everyday activities like walking across a room may become difficult or near impossible. Pain may be present even when you're not working the affected hip, like when you're lying or sitting down.

How is it diagnosed?

Other conditions might be ruled out before hip impingement, like snapping hip syndrome or bursitis. A blood test can be recommended to rule out other inflammation that may be causing the pain.

When other conditions have been ruled out, you may be referred to a musculoskeletal clinic. A specialist will conduct an impingement test: bringing the knee to your chest and rotating it inwards towards the opposite shoulder. If this test mimics the hip pain, the test is positive for impingement.

Imaging tests such as CT or MRI scans can provide a 3D image of the joint, showing exactly where the damage has occurred. They can also show any abnormalities in the bone shapes and any cartilage damage or labral tears.

X-rays can be used, as they produce good images of bone, but will not show any soft tissue damage.

How can it be treated?

The main option would be to rest the joint and avoid activity that aggravates the pain. Non-steroidal anti-inflammatory medication like ibuprofen may also be recommended, or steroid injections may be offered.

Physiotherapy is advised to strengthen surrounding muscles (such as your hip flexors and extenders or your core) to attempt to relieve the pain.

What about surgery?

Surgery may not be recommended if impingement is not disrupting your quality of life. Arthroscopic (keyhole) surgery is the preferred option over open surgery, says Dr Bajwa.

During keyhole surgery, the bone spurs are shaved and any surrounding damage repaired.

This can be an outpatient or overnight procedure, usually performed under general anaesthetic. Patients will require crutches for several weeks, with partial weight bearing. Those with severe damage will be advised to bear less weight than someone with relatively little damage. A rehabilitation programme will be suggested following the procedure.

Is arthroscopy for everyone?

The Manchester Hip Clinic advises patients with significant arthritis, hip dysplasia or inflammation in the hip may not benefit from arthroscopy. 

Some may require a total hip replacement and there is always the chance that someone who has undergone arthroscopy may require hip replacement at an early age.

Can I run again after surgery?

A study published in the American Journal of Orthopedics advised returning to sports around 4-6 months after surgery, finding 89% of professional athletes were able to return to their previous level of ability.

A study from 2007 cites 93% of athletes resumed their sport following arthroscopy. After a follow up time of 1.6 years, 78% remained active in professional sport.

Full recovery can take up to one year per hip and the patient may typically return to running 3-4 months after surgery. Dr Bajwa states due to the lack of injuries or strains, some people feel they can train better after surgery.

However, significant cartilage damage may delay a return to running.

Who has had it?

During the Rio Games, Irish hurdler Thomas Barr mentioned that he had a tear without bone impingement. He believes he will undertake surgery later this year. 

Other athletes who have had surgery for impingement are American sprinter Tyson Gay and American baseball player Alex Rodriguez.