The pear-shaped muscle syndrome is a common disorder causing acute and chronic sciatica. It is generally believed that a high branch of the common peroneal nerve, which penetrates between the pear muscle bundles or the sciatic nerve penetrates from the belly of the pear muscle. When the pear-shaped muscle is injured, congestion, edema, spasm, adhesion and contracture occur, the muscle gap or the upper and lower holes of the muscle become narrow, squeezing the nerve and blood vessels that penetrate between them, so that a series of clinical symptoms and signs appear called pear-shaped muscle injury syndrome.
1.Etiology
Bleeding, adhesion, scar formation of hip trauma; injection of drugs to degenerate the pear-shaped muscle, fiber contracture; the upper posterior acetabular fracture displacement, excessive bone scab can make the sciatic nerve in the pear-shaped muscle pressure. In addition, a few patients, because of the sciatic nerve out of the pelvis when the path is different, penetrate in the pear-shaped muscle, but when the hip external rotation muscle strong contraction, can make the sciatic nerve under excessive pressure, and in the long run produce chronic injury to the sciatic nerve.
2.Clinical manifestations
Pain is the main manifestation of the disease, mainly in the hip, and can be radiated to the lower limbs, in serious cases can not walk or walk a distance after the pain is intense, need to rest for a moment before continuing to walk. Patients may feel the pain is deeper and radiates mainly to the back or rear of the ipsilateral lower limb, and some may also have numbness in the lateral calf and discomfort in the perineum. In severe cases, the pain in the buttocks is “cut-like” or “burning-like”, and it is difficult to bend the legs, kneel on both knees, and sleep at night. The pain in the affected limb is aggravated by the increase in abdominal pressure when urinating or defecating, coughing or sneezing.
3.Check
1.Straight leg elevation test
The test is positive if the pain occurs before the straight leg raise at 60°.
2.Pear muscle tension test
It is a method to check the injury of the pear muscle, the specific steps are as follows: the patient lies supine on the examination bed, straighten the affected limb, do internal rotation, if the sciatic nerve has radioactive pain, then quickly abduct the affected limb and rotate it, the pain is then relieved, that is, the pear muscle tension test is positive. This is the common examination method of pear-shaped muscle syndrome.
4.Diagnosis
The diagnosis is based on the main clinical manifestations of pear-shaped muscle syndrome: pain in the buttocks and radiates to the back or posterior lateral side of the ipsilateral lower limb; urination and defecation, coughing and sneezing can increase the pain. In addition, the diagnosis of pear-shaped muscle syndrome also requires the support of some tests: the affected hip has obvious pressure pain, especially in the pear-shaped muscle area, which may be accompanied by atrophy, and on palpation, diffuse blunt thickness, striated or pear-shaped muscle bundles, and local hardness.
The pain is positive before the straight leg raise at 60°, because the pear muscle is stretched to the tension state, which makes the compression stimulation of the injured pear muscle on the sciatic nerve more serious, so the pain is obvious. However, after 60°, the pear-shaped muscle is no longer stretched, and the pain is reduced. In addition, in addition to the straight leg raise test, also do the pear muscle tension test. Usually, the pyriform muscle tension test is also positive in the case of pyriform muscle syndrome.
5.Differential diagnosis
The main manifestation of pear-shaped muscle syndrome is sciatic nerve compression symptoms. There are various diseases that cause sciatic nerve compression symptoms in the clinic, so the diagnosis of pear-shaped muscle syndrome needs to exclude other diseases that cause sciatic nerve pain.
The main diseases are sciatica and radicular sciatica. Sciatica has an acute onset, and the pain dissipates along the sciatic nerve pathway from the buttock through the posterior thigh and N fossa to the lateral calf to the distal end, with a persistent dull pain that may increase episodically or with a burning stabbing pain that is relieved when standing.
Root sciatica is usually caused by disc herniation, spinal osteoarthritis, spinal bone tumors and thickening of the ligamentum flavum, and other intra-vertebral canal and spinal lesions. The onset of the disease is slow, with a history of chronic low back pain, which is more pronounced in sitting than in walking, and relieved or disappeared in lying down. The skin sensation of the lateral calf and dorsum of the foot is diminished or absent, the flexor strength of the foot and toe is reduced during dorsiflexion, and the ankle reflex is diminished or absent. X-rays can be done to assist in the diagnosis of these lesions.
In addition, pear-shaped muscle syndrome should be differentiated from other diseases that cause dry sciatica, such as gluteal abscess and sciatic nerve syringomyelia.
6.Treatment
Non-surgical methods: including manipulation, local closure, intramuscular injection, physiotherapy, Chinese herbal medicine, acupuncture, etc. Manipulation is the main method to treat pear-shaped muscle syndrome, which can significantly improve the symptoms and relieve the patient’s pain. When using manual therapy, the first thing is to choose the right site. The patient should be placed in prone position with both lower limbs posteriorly extended to relax the muscles of the lumbar and hip areas. The operator makes a line from the posterior superior iliac spine to the greater trochanter of the femur, and the midpoint of the line is 2cm straight down the site of the sciatic nerve out of the inferior foramen of the pear muscle, and the two sides of it are the pear muscle. Local closure has a certain effect on pain relief.