title: [Relationships between piriformis muscle and sciatic nerve: radioanatomical study with 104 buttocks].
abstract: OBJECTIVE
  The relationships between the piriformis muscle and the sciatic nerve are close and may be changing. In some cases, these relationships are the cause of a piriformis syndrome, an under-diagnosed etiology of non discal sciatica. The aim of the study was to explore, by the MRI, the sciatic nerve and the piriformis muscle. MATERIELS AND METHODS: One hundred and four buttocks were explored by MRI for 52 randomly selected patients.
  
  
  RESULTS
  In 59.6% of cases, no variation of the piriformis muscle and sciatic nerve were found. In 26% of cases, the sciatic nerve was divided into the pelvis. In 9.6% of cases, it was divided into the pelvis, the piriformis muscle was bifid and the common peroneal nerve ran between both heads. The piriformis muscle was bifid in 10.6% of cases, hypertrophic in 13.5% of cases and atrophic in 2.9% of cases.
authors: Laboratoire d'anatomie et d'organogenèse, faculté de médecine, université de Picardie Jules-Verne, rue des Louvels, 80036 Amiens cedex 1, France. aurelien.delabie@gmail.com
authors: A
authors: A
authors: Delabie
authors: J
authors: J
authors: Peltier
authors: E
authors: E
authors: Havet
authors: C
authors: C
authors: Page
authors: P
authors: P
authors: Foulon
authors: D
authors: D
authors: Le Gars
mesh_terms: D000328:Adult; D002081:Buttocks / Q000033:anatomy & histology / Q000294:innervation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D009408:Nerve Compression Syndromes / Q000209:etiology; D010543:Peroneal Nerve / Q000033:anatomy & histology; D011859:Radiography; D012016:Reference Values; D012494:Sampling Studies; D012584:Sciatic Nerve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D013979:Tibial Nerve / Q000033:anatomy & histology