Pear-shaped muscle syndrome: symptoms and treatment

Pear-shaped muscle syndrome is one of the most frequent causes of persistent pain syndrome. Its signs are present in more than half of patients with dorsopathy of the lumbosacral department. But often this syndrome remains timely not diagnosed, which significantly delays the treatment period and leads to the appointment of a significant number of different drugs.

What is the syndrome of

Pear-shaped muscle syndrome refers to compression-ischemic tunnel neuropathies. Its key manifestations are caused by the compression of the trunk of the sciatic nerve and the vessels that come with it in the so-called subgranular aperture( space).And as the main factor of compression is a spastic and altered pear-shaped muscle.

The paired tubular aperture is located in the gluteal region and is the lower part of the large sciatic hole of the pelvis. Anatomically, it has a slit-shaped shape and is limited by a sacro-tuberous ligament, the lower edge of the pear-shaped muscle( m. Piriformis), and the superior twin muscle( m. Gemellus superior).Through the subclavicular opening from the pelvic cavity into the deep gluteal space, the sciatic nerve, the posterior cutaneous nerve of the femur, the lower gluteal and vaginal( sexual) vascular-neural bundles exit. They have fascial cases, but they can not withstand external compression.

A pathological permanent contraction of the pear-shaped muscle is accompanied by a thickening of its abdomen, which leads to a substantial narrowing of the tubercular orifice. Vessels and nerves passing through it are pressed against the bone base and the sacro-osteous ligament, which is the reason for the appearance of the main symptoms. In this case, the greatest clinical significance is the compression of the trunk of the sciatic nerve. It is neuropathy and is the reason for patients to consult a doctor.

The sciatic nerve can also pass through the abdomen of the pear-shaped muscle. Its compression with such a rare anatomical variant is usually not combined with compression of other vascular-neural bundles in the sub-necked space.

Etiology

Pear-shaped muscle syndrome according to the mechanism of development can be primary and secondary, when the muscular-tonic syndrome occurs due to other pathological conditions. The share of secondary disorders accounts for more than 80% of clinical cases.

As a cause of the development of pear-shaped muscle syndrome,

• can be a long-term preservation of the non-physiological posture with asymmetric overload of the pelvic-iliac muscle group. This is possible with an incorrectly organized workplace, forced position of the limbs and pelvis in case of their illiterate fixation after injuries. Spasm of the pear-shaped muscle also often develops in the antalgic posture in the case of vertebrogenic radicular syndrome.
• Injuries of the lumbosacral and pelvic areas leading to the stretching or damage( tearing) of the pear-shaped muscle or to the formation of a compression hematoma.
• Vertebrogenic pathology( osteochondrosis with lesion of the lumbar-sacral region, spine tumors and paravertebral structures, lumbar stenosis and other lumbosacral dorsopathies).In this spasm pear-shaped muscle is a manifestation of the muscular-tonic syndrome and can have a reflex or radicular nature.
• Sacroiliitis of any etiology.
• Syndrome of twisted and skewed pelvis of various origin. It can occur with different lengths of limbs( in the absence of sufficient orthopedic correction), S-shaped scoliosis, pathology of the hip joints.
• Overtraining of the muscle, which develops due to irrational excess loads on the gluteal muscle group and the absence of a rest period between power training.
• Ossifying myositis.
• Infectious-inflammatory diseases of the pelvic organs, leading to reflex muscle spasm. The most likely cause is gynecological pathology.

To the infrequent causes of pear-shaped muscle syndrome, there is a technically incorrectly administered intramuscular injection, hypothermia.

Pathogenesis of

Spasm of muscle is accompanied not only by its shortening and thickening, although this is what leads to the narrowing of the sub-necked hole with the compression of nerves and vessels. Of great importance are other pathological changes.

In a pathologically stressed muscle, multiple micro-damages of fibers occur and accumulate under-oxidized exchange products. In response to this, mediators of inflammation begin to be produced, the permeability of small vessels increases, aseptic inflammation and tissue inducing develop. In this process, the pelvic floor muscles are often involved, which can aggravate the pain syndrome and cause mild sphincter dysfunction.

In addition, inflammatory mediators contribute to local changes in the sciatic nerve sheath, enhancing the manifestations of his compression neuropathy.

Clinical picture of

The main symptom of pear-shaped muscle syndrome is persistent and often resistant to treatment pain. It has several pathogenetic mechanisms and is usually combined with other clinical manifestations. In this case, the pain syndrome in two thirds of cases debuted with lumbargia( low back pain), which within 2 weeks is transformed into ischialgia( pain associated with sciatic nerve damage).

Pear-shaped muscle syndrome consists of several groups of symptoms:

• Local - related directly to spasm of pear-shaped muscle. Their detection allows for differential diagnosis between pear-shaped muscle syndrome and vertebrogenic pain syndrome.
• Neuropathic - associated with sciatic nerve compression. This includes characteristic sciatica, sensory, vegetative and motor disorders in the lower limb on the side of spasm of the pear-shaped muscle.
• Vascular symptoms are caused by compression of the gluteus artery and other vessels passing through the sub-tubular aperture.

Spasmodic muscle gives constant pain in the gluteal-sacral region of a pulling, aching, burdensome brain. Some patients, as the site of greatest soreness, indicate areas of the sacroiliac joint and hip joint, which can lead to an incorrect diagnostic search. Walking, bringing the hip, trying to put a foot on the leg, squatting are accompanied by increased discomfort. And a certain reduction in pain is facilitated by a moderate dilution of the legs in the supine or sitting position. But it is not possible to completely get rid of the discomfort associated with spasm.

This pain is supplemented with sciatica. In this case, the patients note lumbago and constant cerebral sensations on the back of the thigh, accompanied by a feeling of chilliness or burning, a feeling of numbness or stiffness, crawling creepy. Pain due to compression of the sciatic nerve can also be localized in the innervation zone of its main branches - tibial or peroneal nerves. In this case, patients can complain of unpleasant sensations in the lower leg and foot, which increase with changing weather, walking, in stressful situations.

The motor manifestations of pear-shaped muscle syndrome include paresis of the leg and foot muscles. Their localization and combination depend on which fibers of the sciatic nerve were subjected to compression. With severe neuropathy, even the appearance of a "dangling", "horse" or "heel" foot is possible.

The vascular component of pear-shaped muscle syndrome is, first of all, intermittent claudication. Moreover, it is associated not only with the compression of the arteries in the subgranular space, as previously thought. The main role in the development of such transient ischemia is played by spasm of middle and small caliber arteries, caused by the damage of postganglionic sympathetic fibers in the sciatic nerve. In addition to intermittent claudication, there is numbness and coldness of the fingers on the foot, blanching of the skin of the foot.

Additional symptoms are possible, for example, dysfunction of the sphincter of the urethra and rectum. It is associated with a secondary spasm of the pelvic floor muscles. Thus there are pauses before the beginning of an emiction, unpleasant sensations at a defecation, a dyspareunia( a dyscomfort and a pain in genitals at the sexual certificate or act).

Diagnostics

When a patient is examined, the doctor conducts a series of tests that allow suspected pear-shaped muscle syndrome.

The diagnosis of pear-shaped muscle syndrome consists of physical examination data and the results of additional instrumental research methods.

Key signs of this syndrome are:

• Palpable under the thickness of the gluteal muscles is a painful, dense, heavy pear-shaped muscle. Her condition can also be assessed by transrectal examination.
• Soreness in the areas of attachment of the pear-shaped muscle - along the upper inner region of the large trochanter and the lower part of the sacroiliac joint.
• The positive symptom of Freiberg is the appearance of pain when rotating inside a bent hip.
• Positive symptom Beattie( Beatti) - the appearance of pain when trying to lift the knee, lying on a healthy side.
• Positive Pace symptom - tenderness in flexion, adduction and internal rotation of the thigh. It is also called the SAVR test.
• Positive Mirkin test, for which the patient is asked to slowly bend forward from the standing position without bending the knees. Pressing on the buttock in the projection area of ​​the exit of the sciatic nerve from under the pear-shaped muscle leads to the appearance of pain.
• Positive symptom Bonnet-Bobrovnikova - pain with passive reduction and rotation inside the thigh.
• Positive symptom of Grossman( spasmodic contraction of the gluteal muscles when pokolachivanii on the upper and lower lumbar spine).
• Appearance of pain along the sciatic nerve when pokolachivanii on the buttock.

As a diagnostic test, injection of novocaine into the pear-shaped muscle is also used. Significant relief of pain is a symptom indicative of clinically significant spasm.

For additional examination of the patient, EMG is used( for detecting neuropathic and myopathic components), CT / MRI, radiography. But the main role in the everyday diagnosis of pear-shaped muscle syndrome is still assigned to clinical tests.

Principles of treatment

Treatment of pear-shaped muscle syndrome includes drug and non-pharmacological measures. With secondary muscle spasms, it is necessary to work on the primary disease, as much as possible to correct its manifestations.

Medical therapy includes the use of NSAIDs, muscle relaxants, drugs to improve microcirculation, analgesics. With a persistent and severe pain syndrome and motor disorders, a medical blockade is indicated. At the same time, the abdomen of spasmodic pear-shaped muscle is infiltrated with an anesthetic. Glucocorticosteroid preparations are often used for blockades, preferably two-phase action( with a fast and prolonged component).Their introduction allows you to reduce the severity of edema and inflammation in the muscle itself and in the sciatic nerve sheaths.

It is also possible to use compresses with dimexide, corticosteroid and anesthetic. They are imposed for 30 minutes on the gluteal-sacral region in the projection of the spasmodic muscle and the traumatized sciatic nerve passing under it.

Important components of complex therapy are also massage, physiotherapy, manual therapy using post-isometric and post-stimulatory muscle relaxation, acupuncture-based reflexotherapy, vacuum and laser acupuncture. The exercises performed with the help of the exercise instructor are aimed at relaxing the pear-shaped muscle and simultaneously activating its antagonists. Such measures supplement the action of drugs, allowing to shorten the period of treatment and avoid the use of excessively high doses of drugs with analgesic effect.

To prevent the recurrence of pear-shaped muscle syndrome, rational treatment of the underlying cause is necessary, correction of the formed pathological motor stereotypes, exercise therapy. The patient may need help from a vertebrologist, an osteopath, an orthopedist and other specialists.