In clinical surgery, certain patients had a special type of cervical spondylosis, in which the responsible lesion is a single-segment cervical disc degenerative protrusion accompanied by adjacent vertebral body osteophyte formation, which compresses the nerve roots or the spinal cord, causing axial symptoms and radicular pain in the neck, damage to the conical bundles of the spinal cord, etc. The patient may have cervical spondylosis with a single-segment cervical disc protrusion and adjacent vertebral body osteophyte formation.
In 2007, Ruetten et al. from Germany first reported a case of posterior cervical percutaneous endoscopic discectomy, which is a further development and extension of the posterior cervical “key-hole” technique and cervical microendoscopic cervical discectomy (CMED) and decompression. CMED is a further development and extension of the “keyhole” technique and microendoscopic cervical microdiscectomy; however, it is only suitable for patients with typical radicular symptoms and imaging studies showing corresponding soft herniated discs lateralized or located in the foramen magnum and/or foraminal stenosis because of leptokyphotic joint hyperplasia.[4–5]. Moreover, it is not indicated for patients with segmental instability, herniated central or paracentral disc, or herniated disc degeneration with adjacent vertebral body osteophyte formation .[6]
Herein, the authors performed spinal endoscopy combined with ACDF to treat a patient with herniated disc degeneration with adjacent vertebral body osteophyte formation. Sterilization was performed according to the routine in anterior cervical spine surgery, sterile towel sheets were spread, and the incision membrane was pasted. An oblique incision was made at the inner edge of the right sternocleidomastoid muscle, and the skin, subcutaneous tissue, and cervical latissimus dorsi muscle were incised sequentially to enter the interspace between the cervical visceral sheath and carotid artery sheath and then reach the anterior edge of the cervical vertebrae to reveal the anterior fascia of the vertebral body. The “C”-arm X-ray machine was used for fluoroscopic positioning to confirm the surgical segments. After screwing in the vertebral body at the upper and lower segments and appropriately opening up the intervertebral space, the operator cut the annulus fibrosus with a small sharp knife and processed the intervertebral discs using a spatula and a nucleus pulposus forceps. Then, the discs were scraped until the upper and lower endplates were oozing with blood. The intervertebral discs and upper and lower endplates were further processed under spinal endoscopy. One bone groove was sanded out at each of the posterior inferior margin of the superior vertebral body and posterior superior margin of the inferior vertebral body using a spherical grinding drill to polish some of the cortical bones and cumbersome bones at the posterior margin of the vertebral body, paying attention to protect the nerve roots (Fig. 3). After grinding, the residual bone cribrils and cortical bones of the posterior margin of the vertebral body were removed with a vertebral plate-biting forceps. The posterior longitudinal ligament was cut, and the residual osteophytes at the posterior margin of the vertebral body were removed by microscopic decompression to the bilateral hook vertebral joints using the nucleus pulposus forceps and vertebral plate bite forceps. Moreover, the osteophytes at the posterior margin of the vertebral body were probed with the nerve peeler to check whether these osteophytes had been scraped cleanly. After satisfactory osteophyte removal and decompression, the Zero-P interbody fusion device was placed into the intervertebral space.
In ACDF, surgical decompression is often affected by the narrow intraoperative visual field space, limited surgical maneuverable range, and insufficient light in the operative field[7]. Owing to the presence of these interfering factors, the field of view cannot be shared between the operator and the assistant, which affects the degree of cooperation between them, resulting in a poor surgical process, prolonged operation time, and increased bleeding. Nowadays, most spine surgeons can improve the above situation by using a microscope[8–9]. In recent years, with its unique advantages, spinal endoscopy has gained the interest of spine surgeons. Operators combine spinal endoscopy and ACDF, place perfusion endoscopes in the intervertebral space for observation and continuous irrigation of the operative field, and use various surgical instruments for decompression operations through the endoscopic channel or directly in the intervertebral space. The operation is convenient and non-interfering, and instruments can be swung at will through multiple angles, which greatly improves the flexibility of the surgery. The magnifying effect of the spinal endoscope and the clearer vision of the operation under water can clearly identify the tissue structure around the nerve during surgery (Fig. 4). Continuous irrigation with pressure water flow helps minimize bleeding, maintains a clear field of view under the scope, and reduces the risk of damage to the dural sac and nerve roots, which greatly improves the safety of the operation. The use of spinal endoscopic drilling instruments has several advantages, such as less bleeding, shorter operation time, higher precision, and higher safety, for the removal of bony encumbrances.
Summary
This case shows that spinal endoscopy combined with ACDF has remarkable advantages in the treatment of patients with herniated disc degeneration and adjacent vertebral body osteophyte formation. We have also applied this technique to patients who had severe free cervical discs in the clinic. We plan to collect more clinical data to provide a more detailed report.