Sciatic pelvic outlet stenosis

Introduction to sciatic pelvic outlet stenosis The sciatic nerve pelvic outlet stenosis and piriformis syndrome occur in the pelvic cavity caused by local lesions before the sciatic nerve is separated from the sacral nerve and separated from the pelvis to the buttocks. The former lesion is mainly located in the pelvis. The exit is around, while the latter is mainly caused by lesions of the piriformis itself. basic knowledge Sickness ratio: 0.0001% Susceptible people: no specific population Mode of infection: non-infectious Complications: edema

Sciatic nerve pelvic outlet stenosis etiology

(1) Causes of the disease

Like other nerve embolisms, the sciatic nerve suffers from external pressure-induced compression, traction and irritation in the muscle fiber pipeline in which it travels.

(two) pathogenesis

According to a large number of clinical cases, the authors found that in addition to common hip trauma, chronic strain and long-term work in wet and cold conditions, the local muscle tissue traumatic response caused by heavy manipulation, accounting for half of all cases Above, therefore, the author does not think that heavy manipulation, even the operator standing on the patient with the pedal method is reasonable, in principle should be abandoned.

Due to local long-term trauma, strain, and the persistence of cold stimulation, it causes fibrositis in the deep gluteal tissue, and early manifestation is local edema and exudation, which causes a large amount of fibrin to precipitate, and gradually forms adhesions in the later stage. The pressure is also significantly increased, even more than 1 time above the healthy side. This high-pressure state and inflammatory changes may be more extensive in the gluteus maximus, and the pathological sections show a degeneration-like change in the reduction or disappearance of the transverse fibers of the gluteus maximus. The superficial deep fascia presents hypertrophy, adhesion and degeneration appearance, which increases the internal pressure of the local tissue and reduces the effective space at the exit. At the same time, the sciatic nerve is anatomized due to its own sensitivity. The upper part is fixed in a small pelvic outlet and is first subjected to compression, and clinical symptoms consistent with the strength and duration of compression occur.

After the nerve trunk is compressed, it will be functionally changed in the early stage. After the pressure is released, it can be recovered in a short period of time. However, when the pressure is changed for a long time, the quality of the generator changes, especially in the case of obvious trauma, it is difficult to completely recover. The mechanism of change from function to organic change after dry compression is not very clear at present, but due to compression, it will inevitably cause local ischemia of the nerve, edema of the intima, and affect the physiological functions of the axons, such as edema. The intima can form adhesions, and the secondary venous pressure is increased; in addition, local mechanical compression factors and adhesion formation, etc., cause a series of secondary changes such as vascular branch hyperplasia and arterial wall thickening, therefore, local Vascular engorgement and thick-walled blood vessel formation are not so much the cause of the disease, but rather the result of the development of the disease, and constitute the cause of the persistence and aggravation of the symptoms. This vicious circle must be managed to interrupt, so as to promote nerve function as soon as possible. restore.

Sciatic nerve pelvic outlet stenosis prevention

There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.

Sciatic nerve pelvic outlet stenosis complications Complications edema

Can be accompanied by foot drop.

Sciatic nerve pelvic outlet stenosis symptoms Common symptoms Sciatic stomata area tenderness lower extremity radiation pain edema

1. Symptoms of sciatic nerve injury: Mainly characterized by dry involvement, that is, radiation pain along the sciatic nerve and movement of its dominant area (post-femoral, calf front and back muscles), feeling (outside of the calf, sole And the anterior part of the foot and the reflection (Achilles tendon reflex and sputum reflex) obstacles, etc., the longer course of the disease, there may be symptoms such as calf muscle atrophy or even foot drop.

2. Tenderness point: The most painful (circle jump) is placed at the position of the pelvic nerve pelvic outlet, and it is radiated along the nerve trunk. In addition, it is found that about half of the cases have tenderness at the sputum or sputum. When the piriformis syndrome is present, the tender point is slightly higher than the former by 1 to 2 cm.

3. Lower limb rotation test: The limbs are rotated to make the piriformis and superior iliac muscles, the obturator inner muscles and the lower diaphragm muscles are in a state of tension, and even the stenosis at the exit can be induced, which can induce sciatic nerve symptoms, except for radiation pain along the sciatic nerve. There is also a numbness at the bottom of the calf, but in the case of simple piriformis syndrome, it is a symptom induced by external rotation. This is mainly due to contracture of the piriform muscle when the contracture is contracted and the external rotation of the lower extremity causes the outlet to be narrow. The reason.

4. Straight leg raising test: generally positive, the degree of pain is between root pain and plexus pain, this test is not specific.

5. Tissue hydraulic pressure measurement: It is more than about 1 times of the normal value (1.33 kPa, 10 mmHg), and the abnormal value is 50% higher than the normal value. This measurement is mainly used for some patients with difficulty in diagnosis.

Sciatic nerve pelvic outlet stenosis examination

1. EMG changes: If the sciatic nerve is damaged, the degeneration, EMG can show tremor potential or simply equal changes.

2. Others: If the nerve conduction velocity is measured to determine the degree of nerve damage; during the operation, the presence or absence of obstructive obstruction in the outlet and the presence or absence of pathological abnormalities in the local appearance may be helpful in the diagnosis, lumbosacral X-ray film, except In the elderly, the elderly patients showed no degenerative changes corresponding to age and trauma.

Diagnosis and diagnosis of sciatic nerve pelvic outlet stenosis

diagnosis

1. History: About half of the cases have had a history of heavy manipulation or a history of traumatic cold.

2. Clinical symptoms: The main manifestation is sciatic nerve dry pain. The tender point is located at the exit of the sciatic nerve, not the paravertebral, the neck test is positive, and the lower limb rotation test is more than 90% positive.

3. X-ray film: more than no positive.

4. Tissue hydraulic pressure measurement: The pressure test around the outlet of the sciatic nerve is higher than 50% of the healthy side, which is diagnostic.

5. Others: EMG, nerve conduction velocity and other tests can be performed as appropriate.

Differential diagnosis

1. Lumbar spinal stenosis: There are intermittent claudication, there are many complaints and less signs, limited lumbar extension and tenderness. There is no obvious tenderness at the exit of the sciatic pelvis.

2. Lumbar disc herniation: There is typical lower extremity radiation pain, but it is a radiculopathy. The symptoms caused by it are different from the symptoms of sciatic nerve pain, and the waist symptoms are more obvious. For individuals who are difficult to identify, they can further do tissue hydraulic pressure. Determination or myelography.

3. Lumbar spinal canal tumor: persistent pain, especially at night, and symptoms and signs corresponding to the compressed nerve root, and often appear early in the onset of bladder rectal symptoms, for individuals difficult to identify, feasible MRI, CT Check, or use a contrast agent with less side effects such as omnipaque, ampicillin or oxygen for myelography.

4. Pelvic disorders: more common in women, pelvic nerves caused by pelvic plexus compression, in addition to sciatic nerve stimulation and symptoms and signs, upper gluteal nerve, femoral nerve, obturator nerve, lateral femoral cutaneous nerve and genital Nerves can also be affected at the same time. Therefore, the symptoms are more extensive and consistent with the distribution of the sacral nerves. It is generally not difficult to distinguish.

5. Others: Should be different from rheumatism, local muscle fibrosis, hip injury, snoring and local tumors, especially tumors, easy to diagnose due to poor X-ray film, therefore, for suspects, The film should be removed after the enema is cleaned to exclude the lesion.

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