There are a few causes of pain in the back of the hip. The article describes these and the role of imaging in the diagnosis and management, including ultrasound-guided injection treatments.
What are the causes of pain at the back of the hip?
Proximal hamstring tendinopathy
This condition is a common cause of pain in the back of the hip and the buttock area. The proximal hamstring tendons attach to the ischial tuberosity (the sit bone). The hamstrings are a big group of muscles that run at the back of the thigh. Their primary function is flexing (bending) the knee and extending (straightening) the hip. The proximal hamstring tendon is prone to strains and injuries as it undergoes many stresses during sports and repetitive activity. This can irritate and weaken the tendon, causing proximal hamstring tendonitis/tendinopathy. The condition can be associated with excess fluid build-up within a small sac on top of the tendon (called the ischio-gluteal bursa).
The condition is referred to as "Ischio-gluteal bursitis". Please read our article about Proximal Hamstrings tendinosis/tear to find out more. Patients usually present with sharp pain deep to the buttock over the sitting bone. The pain is worsened with activity and improves with rest. It can also be worse after sitting or driving. An ultrasound scan is very useful for assessing the hamstring tendons. Furthermore, ultrasound is useful for administering a steroid injection into the Ischio-gluteal bursa. Please see our article about steroid injections around the hip to learn more. Other options include platelet-rich plasma (PRP) injections and tenotomy. In PRP injection, a blood sample is taken from your vein and put in a special centrifuge machine to separate its different components. The layer on top is “the plasma”, which contains platelets and other useful growth factors. This is injected into the tendon under ultrasound guidance to help stimulate healing. Please see our PRP injection article for more details. In tendon fenestration/tenotomy, a small needle is used to fenestrate the inflamed tendon multiple times under ultrasound guidance. This is thought to result in micro injury and release of certain factors that help in tendon healing.
Piriformis syndrome
Piriformis syndrome is a condition characterised by pain in the buttock at the site of the piriformis muscle. The muscle is believed to irritate the adjacent sciatic nerve, resulting in this syndrome.
The muscle is located at the back of the hip, deep in the buttock region. The muscle is one of the external hip rotators (rotate the hip to the outside). The sciatic nerve is a major nerve that supplies the thigh and lower leg. It passes deep in the buttock and then leaves the area by exiting under the piriformis muscle.
Imaging is very useful in the assessment and ruling out other causes of back/buttock pain. An MRI scan of the lower (lumbar) spine and the hip/pelvis will be useful. This will assess for any pressure upon the sciatic nerve roots as they emerge from the spine
An ultrasound-guided piriformis muscle cortisone injection can help with the treatment. This aims to reduce the pain from the piriformis muscle and the sciatic nerve irritation, to help with the rehabilitation program. The injection usually involves a local anaesthetic (numbing medicine) and a low-dose corticosteroid. The injection can also act as a test. If you notice good results after the injection, this would confirm the diagnosis of piriformis syndrome. Please read our article to find out more about steroid injections around the hip.
It is essential to perform piriformis syndrome injections under ultrasound guidance. The piriformis muscle is a deep structure, and ultrasound allows for accurate visualisation of the needle to ensure that the injection is effective and that the procedure is safe and efficient. To find out more, please read our article about piriformis syndrome.
Sciatica
Sciatica refers to back pain symptoms that extend into the thigh and leg. This is usually secondary to pressure or pinching of the nerves as they leave the spine, resulting in pain, numbness and sometimes weakness in the leg muscles. The site of symptoms depends on the level of nerve pinching within the spine. Pressure upon the S1 nerve can cause pain felt in the buttock area. To find out more, please see our article about sciatica.
Other rare causes for pain at the back of the hip or in the buttock area include ischiofemoral impingement and hamstring muscle tears.
Hip conditions and treatments
