Hip-related Sciatica, including Piriformis Syndrome and Deep Gluteal Syndrome

What is sciatica?

Pain deep in the buttock is often referred to in the literature as Deep Gluteal Syndrome.  Other conditions that may be diagnosed in this area include Pirformis Syndrome and Sciatica.  In this page we will discuss hip/pelvic related causes and treatment for pain in the area of the mid buttock.

The term “sciatica” is often used incorrectly in reference to any pain felt in the area running from the back, down into the leg. Back-related nerve pain is more correctly referred to as radicular pain. Radicular pain is pain related to an irritation of the nerve roots as they exit the spine. Nerve roots (Figure 1) leave the spinal cord via the intervertebral foramina (holes or spaces between the vertebrae) and join together from various levels of the spine to travel as cord-like structures, called nerves, to their destinations. It is these nerves that travel outside the spinal cord that are referred to as “peripheral nerves”. Along their journey these peripheral nerves run between and through muscles and fibrous tunnels.

The sciatic nerve (Figure 1) is a peripheral nerve. While radicular pain arises from a problem as the nerve root exits the spine, nerve-related pain may develop due to a problem along the pathway of a peripheral nerve, outside the spine. Pain related to a nerve is called “Neuralgia” – which simply means nerve-pain. The term “sciatica” should be used to refer to neuralgia of the sciatic nerve. Here we will discuss sciatica associated with irritation of the nerve as it runs through the buttock, across the back of the hip.

The Nervous System, demonstrating nerve roots emerging from the spine and the sciatic nerve that develop beyond the spine

Figure 1: The Nervous System, demonstrating nerve roots emerging from the spine and the sciatic nerve that develop beyond the spine

What are the usual symptoms of hip-related sciatica?

  • Hip-related sciatica often presents as deep buttock pain, which may extend down the back of the thigh and even further into the lower leg and foot.
  • Even if the irritation of the nerve is in the buttock, pain can also be felt into the lower back as well, which often results in delayed or misdiagnosis.
  • There may be odd zings or zaps of pain
  • Tingly sensations or numbness sometimes accompany the pain
  • Pain is usually aggravated in positions where the hip is bent – such as in sitting, even more so if the knee is straighter. Driving can therefore be problematic.
  • Pain may also be aggravated by any strong contraction of the buttock muscles such as walking upstairs or uphill or exercises that target the buttock muscles.
  • Pain is often worse at night and is eased somewhat in the morning by standing and walking.
  • In more severe cases, walking may be accompanied by a painful limp.

What causes hip-related sciatica?

The sciatic nerve does not exit the spine as a single nerve. Nerve roots from the lower levels of the lower back (lumbar spine) and tailbone (sacrum) join together in the pelvis. Here they form a thick, cord-like structure, called “the sciatic nerve”. This large nerve exits the inner pelvis via the greater sciatic notch and runs through the buttock and down the back of the thigh (Figure 2).

Anatomy sciatic nerve - Piriformis syndrome deep gluteal syndrome sciatica

Figure 2: View of the back of the pelvis demonstrating the relationship between the sciatic nerve and the bony and muscular structures. The light-yellow areas of the nerve indicate that these parts are on the other side of the structures you can see, that is, inside the pelvis, under the piriformis muscle and within the hamstring muscles.

Piriformis Syndrome

The sciatic nerve can sometimes be compressed, irritated or entrapped as it runs through the buttock. Traditionally, this has been called “Piriformis Syndrome” (see Figure 2 to view the piriformis muscle and the sciatic nerve). This was based on a finding that in about 20% of people, all or part of the sciatic nerve runs through the piriformis muscle. If the spine was found to be healthy, nerve-related buttock and leg pain was then always blamed on the piriformis muscle. It is now thought that this is the case in only a relatively small number of cases. In most people, the sciatic nerve runs under rather than through the piriformis muscle. The nerve is less likely to be compressed if it runs under the muscle, but it can still happen if the piriformis is particularly bulky, tight or excessively active1. It is unclear how commonly this occurs, but it should be considered as one possible cause of hip-related sciatica.

 

Deep Gluteal Syndrome

The term Deep Gluteal Syndrome has been suggested recently to include all causes of irritation of the sciatic nerve in the buttock, under the gluteus maximus2. The sciatic nerve may be compressed or irritated as it runs:
• under the piriformis muscle (piriformis syndrome)
• over the deep external rotator muscles (Figure 2) or
• through the ischial tunnel, a tunnel formed by the outer side of the sitting bone (ischial tuberosity) and the upper thigh bone (femur). In this tunnel it may be squeezed between the bones or irritated by unhealthy hamstring tendons joining onto the sitting bones1 (Figure 2).

Anywhere through the buttock, tight/overactive muscles and also tight (fibrous) bands may bind down the nerve, causing restricted movement of the nerve and reduction in normal healthy blood flow. Fibrous bands may develop after trauma such as a hard fall onto the buttock or due to inflammation related to muscle or tendon injury or overuse1. Postural and movement habits (e.g. pattern of walking, running, standing on one leg) that result in reduced space in the ischial tunnel (Figure 2), may also contribute to the development of symptoms.

fall onto sitting bone maybe aggravating hamstring tendinopathy or ischial bursitis

Getting Help. What is the treatment for Hip-Related Sciatica/Piriformis Syndrone/Deep Gluteal Syndrome?

1. Education:

  • Understanding what the problem is and what types of positions and activities are likely to irritate the sciatic nerve, can help significantly in controlling the symptoms of hip-related sciatica.
2. Exercise:
  • Exercise may be used to assist in reducing pain and improving function associated with Deep Gluteal Syndrome via a number of mechanisms:
    • Improvement in mobility and blood flow of the sciatic nerve
    • Optimisation of health of the muscles and tendons of the deep gluteal space. This might involve various stretching or strengthening exercises.
    • Improvement in control of pelvic position during dynamic movements
3. Manual Therapy:
  • Manual therapy provided by a health professional can in some cases be useful. This may temporarily reduce tension in the muscles of the deep gluteal space and increase blood flow through the region. Exercise and education will usually be required to achieve longer term changes. A Hip Pain Professional can help you.
4. Medications:
  • Particular medications that aim to calm nerve irritability may be prescribed by your doctor to help control pain, maintain activity levels and assist with sleep.
5. Injections:
  • Your doctor may also suggest an injection to assist with diagnosis and/or pain relief. Injecting local anaesthetic around the sciatic nerve in the buttock may, if pain is relieved, assist in determining if this is the problem area. A cortisone (corticosteroid) injection may also be provided to reduce inflammation and pain associated with irritation of the sciatic nerve in the deep gluteal space.
6. Surgery:
  • Surgery is always a last resort for management of Deep Gluteal Syndrome. All other measures should be exhausted prior to a surgical intervention. If all else has failed and the issue is having a substantial impact on pain levels, function and quality of life, surgery may be offered.
  • Wherever possible, surgery is usually best performed endoscopically, through small incisions and with tiny cameras3.This reduces recovery time and changes of post-operative scar tissue1.
  • Surgery may aim to release strong fibrous bands or occasionally lengthen the piriformis muscle.
  • Surgery always carries risks, does not guarantee full resolution of symptoms and the recovery from these surgeries can be prolonged. This is why it is important to ensure all other avenues have been explored first.
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