Cervical fusion combined with cervical artificial disc replacement (hybrid) surgery for three-segment cervical spondylosis Cervical spondylosis involving three segments often requires surgery due to soft disc degeneration and herniation, or hard vertebral body posterior border bone bulge compressing multiple short cervical medulla or nerve roots. Currently, multi-segmental cervical spondylosis is mostly treated by posterior canal expansion decompression or anterior long-segmental decompression and internal fixation. The posterior decompression is an indirect decompression with limited effect, while the anterior long segment decompression implant is too long, with too many fused segments, and the internal fixation is prone to collapse and displacement, as well as loss of motor function in multiple segments and possible acceleration of disc degeneration in adjacent segments, making the treatment of multisegmental cervical spondylosis very difficult. 1.1 General data There were 19 patients with 3-segment spondylosis from 2008 to 2011, including 10 males and 9 females; age ranged from 32 to 64 years old, with an average age of 45 years old and a disease duration of 4 to 18 months. The main clinical symptoms included neck and shoulder pain, numbness and weakness of the extremities, feeling of thoracic and knee or thigh girdling, dysfunction of urination and defecation, feeling of stepping on cotton in the lower extremities, and positive pathological signs. Preoperative imaging excluded the replacement segment with a spinal space <3 mm, developmental spinal stenosis, osteoporosis, infection and tumor. Preoperative MRI examination showed cervical disc degeneration protrusion in three segments, compression of cervical medulla or nerve roots by the posterior edge of the vertebral body, including four cases with high signal formation in the spinal cord, and wave-like changes in the anterior dural sac compression as shown by T2WI. 1.2 Surgical method The patient was placed in the supine position, and general anesthesia was applied with endotracheal intubation. The anterior cervical incision was taken on the right side, and the anterior fascia was entered along the cervical vascular sheath and the visceral sheath. the anterior fascia was cut open after fluoroscopic positioning of the surgical gap on the C-arm X-ray machine to reveal the vertebral body and intervertebral disc, and the artificial disc was replaced after adequate decompression. the width of the gap, the depth of the vertebral body, and the height of the gap were measured, and a suitable trial mold was selected. The artificial cervical intervertebral disc is placed into the intervertebral space after installation of the trial mold and fluoroscopic determination of satisfaction, and the C-arm fluoroscopy is used to determine the correct position. Dexamethasone and antibiotics were routinely administered for 3 d. The cervical brace was used for bed activity on postoperative day 3, and cervical brace braking was continued for 4 w after discharge, and nonsteroidal anti-inflammatory drugs were routinely given for 2 months after surgery to prevent heterotopic ossification. The neurological function indexes were assessed by the JOA scoring system developed by the Japanese Orthopaedic Association, and the VAS and NDI scores were used to assess the recovery of neurological function. The imaging assessment indexes were examined by radiographs at the postoperative follow-up, and CT examination was performed in cases where it was uncertain whether the bone was healing or not. The mobility of the replaced segment was measured on lateral radiographs before surgery, 1 week after surgery and at the last follow-up. [Results] None of the operated patients in this group had intraoperative nerve injury or aggravation of postoperative symptoms, and there were no complications such as laryngeal edema, epidural hematoma, incisional infection, hoarseness, or dysphagia. The follow-up time was 26.5±5.4 months (12~36 months). At 1 week, 3 months, 6 months, and 1 year postoperatively, radiographs in the ortholateral and hyperflexion-extension positions showed good position of the internal fixation and artificial disc. All fused segments achieved bony fusion within 6 months, none had loosening of the internal fixation, and no heterotopic ossification or retroconvex deformity occurred in the replaced segments (Figure 1). joa score: 9.6±1.7 before surgery increased to 14.4±1.1 at the last follow-up (p >0.05), and the mean improvement rate of joa score was 70.1%. Neck pain VAS scores decreased from 7.1 ± 1.1 to 1.0 ± 0.7 (P > 0.05) and preoperative NDI 40.4 ± 3.7 to 9.3 ± 2.2 at the last follow-up (P > 0.05) . The preoperative mobility of the artificial disc replacement segment was 16.0°±3.03°, and at the last follow-up it was 15.6°±3.1°, which was not significant compared with the preoperative one (P<0.05). In conclusion, the use of anterior decompression artificial disc replacement combined with fusion technology can achieve satisfactory clinical results in the treatment of three-segment cervical spondylosis, while preserving the motion segment can effectively solve the degeneration of the adjacent segment.