Smith-Robinson method for anterior decompression of cervical spinal cord injury

Smith Robinson reported in 1958 the use of cervical anterior resection of the intervertebral disc and interbody fusion to treat cervical spondylosis and cervical disc herniation. Many authors later applied this method to treat spinal cord injury caused by cervical spine fracture. Treatment of diseases: cervical spine fracture and dislocation Indication Smith-Robinson method for anterior decompression of cervical spinal cord injury is applicable to: 1. Cervical vertebrae fracture or fracture dislocation, spinal cord insufficiency injury, incomplete recovery of function after transcranial traction, there are still compression objects such as upper anterior horn of the vertebral body, ruptured intervertebral disc tissue and vertebral body fracture piece in front of the spinal cord. 2. The lower cervical vertebra (6~7) fracture or fracture dislocation, the complete damage of the spinal cord function is below the damaged plane. The operation can relieve the compression of 1~2 cervical nerve roots, which can improve the function of the fingers, but the lower limbs More difficult to recover. Contraindications 1. Cervical fractures and dislocations are severe, more than 1/3 of the anteroposterior diameter of the vertebral body, which is characterized by complete damage of spinal cord function. 2. Difficulty breathing or tracheotomy. Preoperative preparation 1. Preparation of skin and instruments for bone removal on one side of the tibia. 2. Prepare the X-ray cervical lateral radiograph to determine the fracture site. Surgical procedure Neck incision In the plane of the fractured vertebral body, from the anterior cervical line to the left or right sternocleidomastoid anterior border, the left or right transverse incision is 6-8 cm long, and the recurrent laryngeal nerve can be less pulled when the left incision is made. . The incisions are peeled up and down along the subcutaneous tissue, respectively. 2. Reveal the front of the vertebral body The platysma and deep fascia were cut along the anterior border of the sternocleidomastoid, and the sternocleidomastoid and carotid sheath were pulled to the outside; the thyroid, trachea and esophagus were pulled to the medial side. Often thyroid venous obstruction is revealed and can be sheared after electrocoagulation or ligation. The loose connective tissue is peeled off to the deep part, and the finger can touch the front of the cervical vertebra in the middle line, revealing 3 to 4 vertebral bodies. At this point, the automatic retractor can be replaced, taking care not to damage the esophagus. In the 3~4 plane of the neck, the superior thyroid artery and the superior laryngeal nerve can be encountered, and the upper thyroid artery should be cut off when the 2~3 intervertebral space of the neck is exposed. In the 7-plane of the neck, the inferior thyroid artery and the recurrent laryngeal nerve can be encountered. Carefully pull it down and do not damage the recurrent laryngeal nerve. 3. Fracture vertebral body positioning Cervical vertebrae fractures are compressed by the spinal cord. The compression mainly comes from the posterior superior angle of the compressed vertebral body and the intervertebral disc tissue protruding from the vertebral space above the fractured vertebral body. It can also come from the posterior part of the dislocated vertebral body and the fracture piece protruding into the spinal canal. Therefore, it is often necessary to determine The intervertebral space between the fractured vertebral body and its superior vertebral body. Generally, after the front of the vertebral body is exposed, two syringe needles are applied, respectively, and the depth of the intervertebral space and the adjacent intervertebral space are respectively penetrated to a depth of 1.5 cm. If the depth is too deep, there is a risk of stabbing the cervical spinal cord. The X-ray cervical lateral radiograph is taken next to the operating table, and after the wet film is washed out, the fractured vertebral body and the upper intervertebral space can be determined. 4. Square bone window formation After the upper intervertebral space of the fractured vertebral body is determined, the anterior longitudinal ligament is lobed and turned to the left or right side. Smith Robinson uses a curette and a nucleus pulposus to enter the intervertebral space and remove the nucleus pulposus and the upper and lower cartilage plates. Some authors also cut off the edge parts of the adjacent upper and lower vertebral bodies to make a square, bone, groove with height, width and depth of 10, 12, and 15 mm. The domestic Yang Keqin applied the self-made engraved bone chisel to make the same square bone. The trough is prepared for bone graft fixation. A high-speed micro drill can also be used to make a square bone window with a height of 10 mm and a width of 12 mm, which is deep and anterior to the vertebral body. 5. Compression removal In the first few authors, bone graft fusion was performed after the disc tissue was removed and the square bone groove was made, and the bone tissue protruding into the spinal canal was not completely removed. However, Cloward, Verbiest, Nakamura, Duan Guosheng, etc. believe that the neurological function improvement will be more significant if the osteoporosis is broken into the spinal canal. In recent years, some authors have advocated operation under a surgical microscope, using a curette and a special Kerrison rongeur to remove the intrusion into the spinal canal, and in the case of opening the intervertebral space with the intervertebral spreader, the oppression The excision is more thorough. 6. Take the humeral fusion Smith Robinson uses a bone chisel in a vertical direction with the iliac crest, about 2 cm apart, and a depth of about 2 cm. One or two full-thick patella slices are drilled. The cortical bone of the section is horseshoe-shaped and placed in the cervical vertebrae. The cancellous bone portion of the humerus piece is in contact with the upper and lower sides of the cervical vertebrae, and the cortical bone portion of the bone piece contacts both sides of the bone window and the front of the vertebral body. The thickness of the tibial plate should be 2~3mm larger than the height of the bone window, so that the bone piece is more firmly fused after implantation, and the bone piece is easy to penetrate into the bone window. Therefore, it is best to make the bone piece when the bone piece is cut. The upper and lower narrow wedge-shaped bone pieces, the length of the bone piece is trimmed according to the length of the anteroposterior diameter of the plane cervical vertebra. Generally, the length of the sliced bone piece should be less than 2~3 mm of the anteroposterior diameter of the vertebral body, so as to prevent the spinal cord from being exceeded by the posterior edge of the vertebral body. Pressure. The patient's head is then towed by an anesthesiologist, who then hammers the patella piece into the bone window with a little force. 7. Suture incision The anterior longitudinal ligament flap should be sutured as much as possible to prevent the bone column from coming out. Before withdrawing the automatic retractor and closing the incision, the bipolar electrocoagulation is used to stop the bleeding, because once the neck hematoma occurs, it may cause difficulty in breathing and even suffocation. The drainage of the silicone tube should be deep in front of the vertebral body. The sternocleidomastoid and deep fascia are sutured, and the platysma, subcutaneous tissue and skin are sutured layer by layer. complication 1. Postoperative hematoma. The swelling of the operation should be closely observed within 1 to 2 days after the operation. If it is found that the breathing is difficult and the local hematoma is suspected, the wound should be opened quickly for treatment. 2. Postoperative neurological symptoms worsened. The cause should be analyzed. If there is bleeding or the sacral column is inserted into the deep compression spinal cord, surgery should be performed again. 3. The bone column is prolapsed. When affecting hypopharyngeal function, re-implantation should be taken out. 4. The sound is low and hoarse. Intraoperative injury caused by laryngeal and recurrent laryngeal nerve. The superior laryngeal nerve is accompanied by the vagus nerve and is accompanied by the superior thyroid artery. It enters the larynx to innervate the inferior pharyngeal muscle, the ring muscle and the laryngeal mucosa. After the injury, the sound is low and thick, and the throat has no sensation. The recurrent laryngeal nerve is adjacent to the thyroid gland. The artery moves upwards in the outer edge of the trachea and esophageal sulcus, and enters the larynx to control the movement of the vocal cords. The vocal cords on one side are paralyzed and hoarse. Therefore, the surgeon must be familiar with the vagus nerve and the two major branches of the walking and anatomical relationship, when separating and cutting the upper and lower thyroid artery must pay attention to protect the two nerves, such as due to the retractor tension and excessive hoarseness, should be hoarse Relax the retractor.