Piriformis Syndrome: Difference between revisions
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Piriformis Syndrome, also known as Deep Gluteal Syndrome, is a controversial entity that describes entrapment neuropathy of the sciatic nerve by the piriformis muscle. | Piriformis Syndrome, also known as Deep Gluteal Syndrome, is a controversial entity that describes entrapment neuropathy of the sciatic nerve by the piriformis muscle. | ||
==Controversy== | ==Controversy== | ||
It is the opinion of the author and colleagues that this condition is over-diagnosed in New Zealand and that most cases of purported piriformis syndrome can be explained by [[Somatic Referred Pain|somatic referred pain]] from other structures such as a lumbar disc, lumbar facet joint, or sacroiliac joint. | It is the opinion of the author and colleagues that this condition is over-diagnosed in New Zealand and that most cases of purported piriformis syndrome can be explained by [[Somatic Referred Pain|somatic referred pain]] from other structures such as a lumbar disc, lumbar facet joint, or sacroiliac joint. Complicating matters is that there is no gold standard for diagnosis and so different studies use different inclusion criteria. | ||
==Epidemiology== | ==Epidemiology== | ||
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==Imaging== | ==Imaging== | ||
Neurophysiology studies are not typically helpful. MRI and x-rays can help evaluate for other causes of symptoms. | Neurophysiology studies are not typically helpful. MRI and x-rays can help evaluate for other causes of symptoms. In one small study, ultrasound evaluation showing increased piriformis thickness was found to be helpful in diagnosis in those without lumbosacral radiculopathy on MRI.<ref>{{#pmid:30663080}}</ref> | ||
==Treatment== | ==Treatment== | ||
Revision as of 16:47, 8 March 2021
Piriformis Syndrome, also known as Deep Gluteal Syndrome, is a controversial entity that describes entrapment neuropathy of the sciatic nerve by the piriformis muscle.
Controversy
It is the opinion of the author and colleagues that this condition is over-diagnosed in New Zealand and that most cases of purported piriformis syndrome can be explained by somatic referred pain from other structures such as a lumbar disc, lumbar facet joint, or sacroiliac joint. Complicating matters is that there is no gold standard for diagnosis and so different studies use different inclusion criteria.
Epidemiology
The author has not found any reliable sources evaluating the prevalence of this condition in those with chronic low back pain or sciatica. A 1983 study by P Hallin is often quoted by review authors stating that piriformis syndrome accounts for between 6% to 8% of all sciatica cases.[1] However in the Hallin article there is no discussion or study of the prevalence whatsoever.[2]
Aetiology
The sciatic nerve typically passes inferior to the piriformis muscle. Sciatic nerve entrapment may occur subsequent to buttock trauma or sprain of the piriformis muscle. This is purported to cause perineural fibrosis. Another purported mechanism is through anatomical variation where the sciatic nerve branches pass through a bifid piriformis muscle.
During downhill running or sprinting, the piriformis muscle undergoes eccentric contraction and some runners may develop the syndrome via this mechanism.
Clinical Manifestations
Buttock pain that increases with sitting is the most common presenting symptom. The "wallet sign" has been described which describes a male patient finding he cannot sit on his wallet without symptoms occurring. Classic radicular symptoms are not common, but paraesthesias may be reported.
Diagnosis
The Freiburg test is performed with placing the hip in extension and internal rotation, and then resisting external rotation. A positive test is the production of pain or radicular symptoms. It has questionable clinical value.
The Pace test has the patient in a seated position. The patient then resists abduction and external rotation. A positive test is the production of pain or typical symptoms. This test also is of questionable clinical value.
Imaging
Neurophysiology studies are not typically helpful. MRI and x-rays can help evaluate for other causes of symptoms. In one small study, ultrasound evaluation showing increased piriformis thickness was found to be helpful in diagnosis in those without lumbosacral radiculopathy on MRI.[3]
Treatment
Treatment options include physiotherapy, corticosteroid injections, botulinum toxin injections, and piriformis tenotomy.
References
- ↑ Probst et al.. Piriformis Syndrome: A Narrative Review of the Anatomy, Diagnosis, and Treatment. PM & R : the journal of injury, function, and rehabilitation 2019. 11 Suppl 1:S54-S63. PMID: 31102324. DOI.
- ↑ Hallin. Sciatic pain and the piriformis muscle. Postgraduate medicine 1983. 74:69-72. PMID: 6878094. DOI.
- ↑ Zhang et al.. Ultrasound appears to be a reliable technique for the diagnosis of piriformis syndrome. Muscle & nerve 2019. 59:411-416. PMID: 30663080. DOI. Full Text.
Literature Review
Literature Review
- Reviews from the last 7 years: review articles, free review articles, systematic reviews, meta-analyses, NCBI Bookshelf
- Articles from all years: PubMed search, Google Scholar search.
- TRIP Database: clinical publications about evidence-based medicine.
- Other Wikis: Radiopaedia, Wikipedia Search, Wikipedia I Feel Lucky, Orthobullets,
