7 of 12 Top Hip Papers – Beyond piriformis syndrome

PAPER 7: Piriformis and Related Entrapment Syndromes: Diagnosis & Management

Aaron Filler bravely published this paper in 2008, defending the diagnosis of 'piriformis syndrome' at a time when there was so much negative emotion around this condition. So strong was this emotion, that piriformis syndrome almost became permanently assigned to the mythologies of clinical practice. This was primarily due to misuse of the diagnosis and to a lack of understanding about the condition and how to assess and manage it. There was such a divide. Some steadfastly ignored the possibility of a local source of nerve irritation in the buttock, attributing all sciatic symptoms to radicular pain. Others seemed to use the diagnosis indiscriminately to label any presentation of buttock pain, regardless of the area of pain or presence or not of nerve symptoms.

This paper was one that I found incredibly helpful at the time to clarify the role of nerve related pain in buttock pain. Filler presents a pictorial account of various presentations of sciatic nerve impingement through the deep gluteal space, using high-quality MRI sequences. He also described the impact of anatomical variations on the course of the sciatic nerve and the potential for impingement of other smaller nerves in this region. While pain is always multifactorial, if structural impingement of a nerve is a factor, a good understanding of the local anatomical relationships may assist in reaching an early diagnosis and facilitating optimal management strategies.

Key learnings about piriformis syndrome:

1. 1. The evidence suggests that peripheral entrapment of the sciatic nerve in the deep gluteal space does occur, giving rise to local and referred pain
   2. The diagnosis ‘piriformis syndrome’ should be limited to sciatic nerve entrapment through or under the piriformis muscle
   3. The sciatic nerve may also be impinged at the level of the obturator internus-gemelli tendon, in the ischial tunnel and by fibrous bands and other structural abnormalities anywhere through the deep gluteal space
   4. All ‘sciatica’ does not emanate from the lumbar spine. Ensure a thorough differential diagnosis to avoid unnecessary and unhelpful lumbar interventions.

There are many considerations for assessment and management of nerve related buttock pain. If you are findings patients with such presentations difficult to treat, you might like to take a course or benefit from the extended resources available in Hip Academy. See below.