Background Posterior lumbar spinal fusion has been widely used in degenerative lumbar stenosis, but adjacent segment degeneration (ASD) was common. Researchers have found many risk factors for ASD after one or two levels of surgery, but few clinical studies focused on multi-level surgery. The purpose of this study was to clarify risk factors for upper ASD after multi-level posterior lumbar spinal fusion. Methods A retrospective study was performed on the clinical data of 71 patients with degenerative lumbar stenosis who underwent multi-level (at least 3 levels) posterior lumbar spinal fusion from January 2013 to December 2016. Two groups were divided according to lamina and posterior ligamentous complex (PLC) maintenance of proximal fixed vertebrae in surgery. In the 22 patients of group A, the proximal fixed vertebral lamina and PLC were not resected, and in the 49 patients of group B, the proximal fixed vertebral lamina and PLC were resected completely. Age, sex, body mass index (BMI), number of fixed vertebrae and fused levels, spinopelvic parameters, coronal Cobb angle, and modified Pfirrmann grading system were measured for each patient. A Cox proportional hazards model was used to analyze risk factors for upper ASD. Results No symptomatic ASD was found during the follow-up period. Patients who underwent proximal fixed vertebral lamina and PLC resection had a significantly higher percentage of radiographic ASD ( P = 0.042). The Cox proportional hazards model showed that age, sex, BMI, preoperative lumbar lordosis, sacral slope, pelvic tilt, coronal Cobb angle, number of fixed vertebrae, and interbody fusion levels had no significant differences for radiographic ASD. But a preoperative modified Pfirrmann grade higher than 3, a high degree of preoperative pelvic incidence, and more decompressed levels had statistical significance ( P = 0.024, 0.041, and 0.008, respectively). Conclusions A preoperative modified Pfirrmann grade higher than 3, a high degree of preoperative pelvic incidence, and more decompressed levels might be risk factors for upper radiographic ASD after multi-level posterior lumbar spinal fusion surgery.

OBJECTIVE Pedicle screw–based dynamic spinal stabilization systems (PDSs) were devised to decrease, theoretically, the risk of long-term complications such as adjacent-segment degeneration (ASD) after lumbar fusion surgery. However, to date, there have been few studies that fully proved that a PDS can reduce the risk of ASD. The purpose of this study was to examine whether a PDS can influence the incidence of ASD and to discuss the surgical coping strategy for L5–S1 segmental spondylosis with preexisting L4–5 degeneration with no related symptoms or signs. METHODS This study retrospectively compared 62 cases of L5–S1 segmental spondylosis in patients who underwent posterior lumbar interbody fusion (n = 31) or K-Rod dynamic stabilization (n = 31) with a minimum of 4 years' follow-up. The authors measured the intervertebral heights and spinopelvic parameters on standing lateral radiographs and evaluated preexisting ASD on preoperative MR images using the modified Pfirrmann grading system. Radiographic ASD was evaluated according to the results of radiography during follow-up. RESULTS All 62 patients achieved remission of their neurological symptoms without surgical complications. The Kaplan-Meier curve and Cox proportional-hazards model showed no statistically significant differences between the 2 surgical groups in the incidence of radiographic ASD (p > 0.05). In contrast, the incidence of radiographic ASD was 8.75 times (95% CI 1.955–39.140; p = 0.005) higher in the patients with a preoperative modified Pfirrmann grade higher than 3 than it was in patients with a modified Pfirrmann grade of 3 or lower. In addition, no statistical significance was found for other risk factors such as age, sex, and spinopelvic parameters. CONCLUSIONS Pedicle screw–based dynamic spinal stabilization systems were not found to be superior to posterior lumbar interbody fusion in preventing radiographic ASD (L4–5) during the midterm follow-up. Preexisting ASD with a modified Pfirrmann grade higher than 3 was a risk factor for radiographic ASD. In the treatment of degenerative diseases of the lumbosacral spine, the authors found that both of these methods are feasible. Also, the authors believe that no extra treatment, other than observation, is needed for preexisting degeneration in L4–5 without any clinical symptoms or signs.

Background: There are relatively few studies on the treatment of symptomatic adjacent segment disease(ASD) after anterior cervical discectomy and fusion(ACDF). The purpose of this study to compare the clinical efficacy of zero-profile(zero-p) intervertebral fusion and titanium plate combined with cage fusion for treating ASD after ACDF. Methods: Retrospective analysis was performed on patients who underwent ACDF and readmission due to concurrent symptomatic ASD from October 2014 to June 2019. Among them, 12 cases underwent anterior cervical decompression with zero-p intervertebral fusion (zero-p group), and 14 cases underwent anterior cervical decompression with titanium plate combined with cage fusion (titanium plate group). Operative time, intraoperative blood loss, postoperative Japanese 0rthopaedic Association (JOA) score, visual analogue scale (VAS) scores, neck disability index (NDI), dysphagia Bazaz grade, bone graft fusion Eck grade, C2-C7 Cobb Angle, and related complications were compared between the two groups. Results: The intraoperative blood loss difference between the two groups was not statistically significant (P>0.05). The operation time of the zero-p group was shorter than that of the titanium plate group, with significant differences(P<0.05). The Bazaz classification of dysphagia in the zero-p group was superior to the titanium plate group 1 month after the operation, and the difference was statistically significant (P<0.05); However, there was no statistically significant difference between the two groups in the Bazaz classification of dysphagia and the bone graft fusion Eck grade at the last follow-up (P>0.05). At the last follow-up, the JOA score, VAS score, NDI index, C2-C7 Cobb Angle were significantly different between the zero-P group and the titanium plate group (P<0.05). However, no significant difference was found between the two groups (P>0.05). During the follow-up period, all the patients did not have a rupture of the settler screw and esophageal injury and other related diseases.Conclusions: Both methods can achieve good clinical efficacy in the treatment of symptomatic ASD, and can restore and maintain the physiological curvature of the cervical spine to a certain extent. However, the advantages of zero-p intervertebral fusion including shorter operation time, reducing soft tissue injury, and less postoperative dysphagia.

No abstract