Ischiofemoral Impingement: Diagnosis and Treatment

Buttock pain is complex. There are many causes of buttock pain, such as sciatica, sacroiliac joint arthritis, piriformis syndrome, and hamstring tendonitis. However, a less common cause of buttock pain is ischiofemoral impingement. We think that abnormal contact between the long bone of the leg (femur) and the pelvic bone leads to pinching and buttock pain. So, what is ischiofemoral impingement, and what should we do to improve it? Also, is an ischiofemoral impingement injection an option? 

What is ischiofemoral space? 

The ischiofemoral space sits between the upper part of the femur (lesser trochanter) and the lower part of the pelvic bone (ischium). The quadratus femoris muscle sits between these two bones in this space. Along with the other muscles in the buttock, this muscle rotates the hip outwards. Unfortunately, this space is too narrow for some people, causing pinching and leading to muscle swelling and pain. 

Ischiofemoral impingement symptoms 

Generally, people with ischiofemoral impingement develop buttock pain. The pain can often move to the hip, groin, or back of the thigh. It is usually worse with sitting. Sometimes, people feel a hip snapping when taking a significant stride or rotating the hip into external rotation.

Overall, this condition is more common in middle-aged females than males. Dancers and rowers are particularly at risk. 

Sometimes, people have multiple conditions, such as piriformis syndrome or high hamstring tendonitis. 

When doctors examine you, they look for signs of pinching at the back of the hip. Often, pressing on the quadratus femoris muscle makes it sore. Moving and rotating the hip (flexion and internal rotation) usually makes the buttock sore.

Ischiofemoral impingement test 

We use a simple test with the person lying on their tummy with the hip stretched, and the hip is rotated inwards and outwards. A positive test means the person feels pain in the buttock. However, this test also has positive results for other causes, such as piriformis syndrome. 

Ischiofemoral impingement syndrome radiology

Generally, we use imaging to confirm the diagnosis and rule out other causes. Usually, an MRI scan of the buttock is our first choice for investigation. In ischiofemoral impingement, we see swelling in the quadratus femoris muscle. On an MRI scan, the swelling is brighter than the surrounding tissue. Often, the space between the pelvis and the femur narrows. Sometimes, in more severe cases, the muscle shrinks. 

In some cases, people have other problems, such as high hamstring origin tendonitis, which causes further narrowing of the ischiofemoral space.

Ischiofemoral impingement treatment 

Generally, simple treatments should be instigated before more invasive treatments. Recent studies suggest that most cases resolve without the need for surgery. Usually, we start with physical therapy. In general, treatment aims to improve the strength and stability of the hip and pelvis. In particular, strengthening should focus on hip muscle rotators and the posterior chain. Strengthening exercises include one-legged squats, crab walks with a theraband, side leg raises, lunges, hip thrusters, and Bulgarian squats. 

In addition, soft tissue release and joint mobilisation of the hip and lumbar spine may help improve pelvic movement and reduce pinching of the quadratus femoris.

Also, directing a needle into the quadratus femoris and injecting cortisone can help in cases that fail simple treatments.

Finally, surgery should only be reserved for cases that fail other treatments. The surgery aims to open the ischiofemoral space to reduce pressure on the quadratus muscle. Often, surgeons achieve decompression using keyholes. However, results are not guaranteed; risks include infection, nerve damage, and unsuccessful pain relief.

More about ischiofemoral impingement injection 

Injecting cortisone into the quadratus femoris muscle can reduce swelling and pinching of the muscle. Generally, ultrasound guidance is preferable as we can accurately place the needle in the muscle and avoid other structures, such as the sciatic nerve. The risks of cortisone are minimal. However, you need to be aware of the small risks of infection and temporary cortisone flare lasting up to a week. So, an ischiofemoral impingement injection is an option.

Some doctors say a CT scan is needed for an ischiofemoral impingement injection. Is this correct? 

No. Ultrasound can see the quadratus femoris muscle. An experienced practitioner can insert a needle into the muscle. Other benefits of ultrasound include a much cheaper procedure and no exposure to radiation, unlike CT-guided injection, which exposes patients to a high dose of harmful radiation. 

Final word from Sportdoctorlondon about ischiofemoral impingement 

Ischiofemoral impingement is an uncommon cause of buttock pain. Generally, we must rule out other reasons, such as sciatica, hamstring tendonitis, and sacroiliac joint arthritis. Nevertheless, simple treatments such as physical therapy and an ultrasound-guided cortisone injection are effective.

Related conditions: 

• Common causes of buttock pain
• Hamstring origin tendonitis 
• Sacroiliac joint pain 
• Hip joint arthritis 
• Piriformis syndrome 
• A pinched nerve in the groin or pelvis

Click on the image below to find out more about possible causes of hip and groin pain