From Big Medical Encyclopedia

PIRIFORMIS-SINDROM (Latin [musculus] of piriformis pear-shaped muscle; syndrome; synonym syndrome of a pear-shaped muscle) — the symptom complex arising at the combined damage of a pear-shaped muscle and a sciatic nerve.

The item - page arises at various patol, processes in a pear-shaped muscle or the anatomic educations, next to it; can be a consequence of reflex influence on this muscle remote from it patol, the center. Close anatomic relationship between a pear-shaped muscle, a sciatic nerve and the lower buttock artery under certain conditions promotes their combined defeat. So, e.g., P. - page owing to an injury, inflammatory process, a tumor, arthrosis of a hip joint can be caused by simultaneous damage of a pear-shaped muscle and a sciatic nerve, and also a prelum of the lower buttock artery. Pathogenetic P. - page is often connected with lumbar osteochondrosis.

Clinically distinguish two basic groups of symptoms of P. - page: group of symptoms of damage of the most pear-shaped muscle (morbidity in the bottom of a sacroiliac joint, a big spit of a hip, area of an exit of a sciatic nerve from subpiriform opening and in a rump during the calling of a symptom of Bonnet — Bobrovnikova — passive reduction of a leg with its rotation inside); group of symptoms of defeat of a sciatic nerve, it is frequent in combination with a radicular syndrome and an atrophy of gluteuses (the signs of irritation of a nerve and roots which are shown usually stupid, mozzhashchy meralgia which is quite often extending on all leg prevail).

For diagnoses Items - page enter 10 — 20 ml of 0,25 or 0,5% of solution of novocaine into a pear-shaped muscle. As a rule, in 7 — 30 min. pain abates for half an hour about one days. With to lay down. the purpose apply introduction to a pear-shaped muscle of solution of novocaine with addition of suspension of a hydrocortisone. In P.'s cases - the page without the radicular phenomena is observed positive, but not always a long-term effect. At the expressed radicular manifestations make also epidural blockade, skeletal traction, appoint acupuncture, physical therapy. In the presence of indications (e.g., in case of P. - the page caused by development of a tumor) carry out operational treatment.

Bibliography: Kipervas I. P. To a pathogeny and clinic of a syndrome of a pear-shaped muscle, in book: Vertebrogenny lumbosacral pathology of a nervous system, under the editorship of Ya. Yu. Popelyansky, page 35, Kazan, 1971; it, Modelling of a reflex syndrome of a pear-shaped muscle, Zhurn, neuropath, and psikhiat., t. 77, No. 8, page 1135, 1977, bibliogr.; Pop la of N with to and y Ya. Yu. and B about r about in N and - to about in and T. I. Sindr of a pear-shaped muscle and lumbar discogenic radiculitis, in the same place, t. 68, No. 5, page 656, 1968, bibliogr.

I. P. Antonov.