The cauda equina compresses the nerves

Cauda equina injury is a difficult problem in the world. Clinically, violent spinal fractures, lumbar degenerative lesions, cholesteatoma in the cauda equina, neurilemmoma, spinal meningioma, lipoma or metastatic tumors that stimulate and damage the cauda equina nerve. Currently, Western medical treatment mainly focuses on surgical removal of vertebral bone fragments that are compressed and fractured in the spinal canal, herniated intervertebral discs, and tumors that stimulate the cauda equina nerve, supplemented by dehydrating agents, corticosteroids, nutrients or free radical scavengers. Not only that, but these symptoms make it very difficult for us to urinate and defecate, so let us now understand what to do if the coccyx compresses our urination and defecation.

1. Clinical manifestations

(1) In complete damage, motor impairment is manifested as involvement of the knee joint and the muscles below it, dysfunction of the knee, ankle and foot joints, and obvious unstable gait. Due to the loss of foot extension and flexion function, the hip joint needs to be lifted when taking a step, presenting a "wading gait"; there is also incontinence of stool and urine. Impaired sensory function is a loss of deep or shallow sensation below the injury level, manifested as weakened or absent sensation in the posterior thigh, posterior calf, foot, and saddle area. Reflexes: Anal reflex and Achilles tendon reflex disappear, pathological reflexes cannot be elicited, and penile erection is also impaired.

(2) Incomplete cauda equina damage only manifests as dysfunction of the muscle movement and sensory areas in the area innervated by the damaged nerve root, while the remaining undamaged cauda equina nerves can still perform normal sensory and motor functions. The presence of CES in lumbar disc herniation is an important signal of worsening disease.

2. Treatment Methods

(1) Decompressive laminectomy aims to expand the spinal canal and achieve decompression. Suitable for fractures or fracture-dislocations. The decompression range is sufficient to completely remove the compressive object in the compressed area or to be centered on the dislocated segment, not exceeding the lamina of one vertebra above or below.

(2) Anterior decompression or internal fixation is mainly used to remove pressure-causing objects from the front of the spinal cord. It has a direct decompression effect and can be given different methods of internal fixation to enhance stability. Artificial vertebrae can also be used to replace fractured or diseased vertebrae to restore their original height.

(3) Cauda equina anastomosis.

① Proximal cauda equina anastomosis: the 1st and 2nd lumbar cauda equina nerves have not yet dispersed, so the nerve roots are gathered and the damaged cauda equina is disordered. The site of injury can be clearly identified. After diagnosis, the incision is wrapped with brain cotton to protect the surrounding tissues, and the normal saline is repeatedly rinsed to remove blood accumulation and blood clots. Then use microsurgery to suture, carefully align the cauda equina nerve according to its thickness, and suture the perineurium with 1 to 2 stitches;

② Distal cauda equina anastomosis: According to the anatomical characteristics of the cauda equina, the motor nerves of the cauda equina below L3 gradually move toward the ventral side, while the sensory nerves are distributed on the dorsal side. In order to preserve the function of the lower limbs, its motor nerve, namely the ventral root, is matched as much as possible. The cauda equina has no epineurium but has perineurium, so it is difficult to sew. (4) Cauda equina release is suitable for patients with CES caused by chronic injury that causes adhesion of the cauda equina. The operation must be performed under microsurgical techniques.

3. Reasons that affect the efficacy of surgery include:

(1) Long-term compression of the cauda equina and nerve roots without timely decompression can lead to secondary arachnoiditis, cauda equina paralysis and intractable low back and leg pain. Therefore, early surgical treatment is necessary. If early surgery is not possible, the cauda equina should be explored during surgery, and cauda equina release should be performed if adhesions are present.

(2) Improper surgical procedure selection destroys spinal stability, resulting in iatrogenic lumbar instability, spondylolisthesis, and spinal canal stenosis. Therefore, fenestration decompression should be adopted as much as possible.

(3) The surgeon is unskilled, moves roughly, and does not clearly define the anatomical layers, which further damages the cauda equina.

(4) Incomplete discectomy or missed diagnosis or mistreatment.

(5) Lumbar spinal stenosis is a pathological basis for CES, and incomplete decompression may lead to surgical failure. Therefore, attention should be paid to the expansion and decompression of the central canal and nerve root canal during surgery.

(6) Angiography can increase damage to the cauda equina nerve. Careful operation and selection of contrast agents are required during angiography.

(7) Postoperative re-adhesion and scar tissue compression are important reasons for surgical ineffectiveness or aggravation of symptoms. There are many studies on CES, but its pathogenesis is still not fully understood, and the treatment effect of severe CES is not optimistic.