[Comparable study of alternative-level and all-level Arch mini-plate fixation for unilateral open-door laminoplasty].

Objectives: To compare the clinical effect of alternative-level and all-level Arch mini-plate fixation in patients undergoing unilateral open-door laminoplasty. Methods: Clinical data of 134 patients administrated in the Peking University International Hospital for multistage cervical spondylotic myelopathy from March 2015 to March 2019 were reviewed retrospectively. There were 63 males and 71 females with an average age of (62±8) years and a mean disease course of (18±7) months (3-37 months). All the patients underwent posterior cervical unilateral open-door laminoplasty with Arch titanium plate fixation. All the patients were divided into two groups according to the different amount of titanium plates used during operation as follow: group A, Arch plates were fixed at the door sides of C3, C5 and C7 (n=68) and group B, Arch plates were fixed at the door sides of C3, C4, C5, C6 and C7 (n=66). Operation time, intraoperative blood loss, postoperative hospitalization days and the cost of consumables, the Japanese orthopaedic association (JOA) score, cervical dysfunction index (NDI), the rates of improved JOA score, cervical curvature index, C2-7 Cobb angle, cervical range of motion, sagittal diameter of vertebral canal, opening angle of laminar, hinges bone healing and surgery related complications (axial symptoms, C5 nerve root palsy, screw loosening, laminar re-closing, cervical kyphosis, etc.) were recorded and compared between the two groups. Results: There was no complications during the operation, and the mean follow-up was (20±8) months (14-48 months). There was no statistically significant difference between the two groups in terms of gender, age, course of disease and compression segments (all P>0.05). There was no statistically significant differences between the two groups in operation time, intraoperative blood loss and postoperative hospital stay too (all P>0.05). The cost of consumables in group A was (34 970±1 325) yuan, and it was (57 450±2 161) yuan in group B, the difference between the two groups was statistically significant (P<0.01). The JOA and NDI score were significantly improved 3 months and 1 year after operation in both groups (both P<0.05). The sagittal diameter of each segment of the spinal canal at C3, C4, C5, C6 and C7 were all significantly increased in both groups 3 months and 1 year after surgery (all P<0.05). The C2-7 Cobb angle and cervical curvature index were all significantly reduced in both groups 3 months and 1 year after surgery (all P<0.05). The cervical range of motion in both groups was significantly reduced 3 months and 1 year after surgery compared with that before surgery (both P<0.05). The range of motion of the cervical spine in group A was significantly higher than that in group B (P<0.05). The opening angles of C4 and C6 segment lamina in group A 3 months and 1 year after operation were significantly lower than those in group B (all P<0.05). At 3 months after the operation, the hinges healing rate of C4 and C6 in group B was significantly better than that of group A (both P<0.05). At 1 year after the operation, there was no difference in the hinges healing rate of C4 and C6 in the two groups (both P>0.05). There was no statistically significant difference in postoperative complications between the two groups (P>0.05). Conclusions: The safety and early clinical efficacy of alternative-level and all-level Arch titanium plate fixation in posterior cervical unilateral open-door laminoplasty are comparable, alternative-level fixation can effectively reduce the cost of hospitalization. The open Angle loss and lower early hinges healing rate of the non-fixed segment in the alternative-level fixed group does not lead to laminar re-closing in early period of post operation.

[Comparison of percutaneous pedicle screw placement under O-arm navigation with traditional percutaneous pedicle screw placement in patients with thoracolumbar fractures without neurological symptoms].

Objective: To investigate the accuracy and clinical efficacy of percutaneous pedicle screw placement under O-arm navigation and traditional fluoroscopy in patients with thoracolumbar fractures without neurological symptoms. Methods: From July 2016 to July 2018, 72 patients with thoracolumbar fractures in Peking University International Hospital without neurological symptoms were divided into two groups, group A and group B. In group A, 36 patients underwent the surgery of percutaneous pedicle screw implantation under traditional fluoroscopy and 168 pedicle screws were inserted. In group B, 36 patients underwent the surgery of percutaneous pedicle screw implantation under O-arm guided fluoroscopy and 164 pedicle screws were inserted by the same surgeon. The general condition, operation condition, radiation dose, fluoroscopy time of single screw, screw placement time and accuracy, visual analogue score (VAS) score, Oswestry dysfunction index (ODI), kyphosis Cobb's angle, anterior edge height of 1 week and 6 months after surgery were compared. The data were compared with paired t test between the two groups. Results: There was no significant differences between the two groups in general condition, intraoperative blood loss, length of hospital stay, VAS, ODI, kyphosis Cobb's angle, and anterior edge height of the injured vertebra (all P>0.05). The operation time was (99±14) min in group A and (75±10) min in group B, the average screw setting time was (15.8±2.6) min in group A and (11.8±3.3) min in group B, the fluoroscopy time of each screw was (38.0±2.0) s in group A and (28.5±2.8) s in group B, the radiation dose of each surgery was (563±163) cGy/cm(2) in group A and (378±70) cGy/cm(2) in group B; the above-mentioned data of group A were all superior to those in group B and the differences between the two groups were all statistically significant (t=8.48, 5.73, 16.30, 6.25, all P<0.05). Rampersaud grading in group A was better than group B, and the differences between the two groups was statistically significant(χ(2)=12.2, P<0.05). Conclusion: The O-arm navigation system could not only provide high-definition navigation images and achieve high-precision navigation operations, which is more accurate than traditional pedicle screws placement, but also contribute to the reconstruction of spinal stability and reduce radiation dose, pedicle screws placement and operating time.

Association between Changes in Sagittal X-ray Measurements and Neck Extensor Muscle Atrophy after Cervical Laminoplasty.

BACKGROUND: To investigate the association between neck extensor muscles (NEM) atrophy and changes in the sagittal cervical X-ray measurements after cervical laminoplasty. BASIC PROCEDURES: This retrospective analysis was conducted on 64 patients who underwent cervical laminoplasty from March 2016 to March 2019. The preoperative and postoperative sagittal cervical X-ray images were measured, including the C2-C7 cobb angle, the C2-7 sagittal vertical axis (SVA), and the angle between the plane of the upper endplate of T1 vertebra and the horizontal plane (T1 slope). The preoperative and postoperative steatosis ratios of the NEM were measured using magnetic resonance images. MAIN FINDINGS: There were significant differences between the preoperative and postoperative measurements of the C2-7 cobb angle, the C2-7 SVA, and the T1 slope (P<0.05). The preoperative and postoperative steatosis ratios of each intervertebral level of the NEM also differed significantly (P<0.05). The muscle atrophy ratio at C3/4 was positively correlated with the change in the C2-7 SVA (R=0.646, P<0.001) and negatively correlated with the change in the C2-7 cobb angle (R=-0.445, P<0.001). The muscle atrophy ratio at C7/T1 was positively correlated with the T1 slope (R=0.446, P<0.001). CONCLUSIONS: Muscle atrophy was more severe at the attachment points of the NEM (C3/4, C7T1). There was a significant association between the muscle atrophy ratio and the changes in sagittal cervical X-ray measurements.

Ultrasonic osteotome versus high-speed burr in cervical anterior vertebral subtotal resection: A retrospective study of 81 cases.

AIM: This study aimed to investigate the safety and effectiveness of ultrasonic osteotome in cervical anterior vertebral subtotal resection. METHODS: Retrospective clinical data were collated for 81 patients with cervical spondylotic myelopathy who required cervical anterior vertebral subtotal resection. RESULTS: Group A (n=40) was treated with an ultrasonic osteotome and group B (n=41) with a high-speed burr. Vertebrectomy time, intraoperative blood loss, surgical complications, Japanese Orthopedic Association (JOA) scores and JOA score improvement were compared. Group A showed significantly shorter vertebrectomy time and significantly less intraoperative blood loss (P<0.05). In group A, dysphagia occurred in one patient, and superior laryngeal nerve injury in one. Urinary tract infection occurred in one patient in group B. JOA score in both groups significantly increased 3 days after surgery (P<0.05), and at last follow-up compared with 3 days after surgery (P<0.05). CONCLUSION: Ultrasonic osteotome was a safe and effective tool for subtotal anterior cervical vertebral resection.