ObjectiveTo compare surgical outcomes of C2 dome-like laminectomy with C2 partial laminectomy in patients with ossification of the posterior longitudinal ligament (OPLL) up to the C2 level and above.Methods32 patients underwent surgical treatment for OPLL up to C2 and were divided into: C2 dome-like laminectomy group (C2-DOM group, n = 16) and C2 partial laminectomy group (C2-PL group, n = 16). The cervical curvature (CCI), dura width at C2/3, Japanese orthopedic association (JOA) score, recovery rate (RR), neck disability index (NDI) score, and visual analogue scale (VAS) score were evaluated and compared preoperatively and postoperatively at 1 month, 3 months, 6 months, 1 year, and annually thereafter.ResultsThe JOA score and NDI significantly improved at the final follow-up in both groups with no significant intergroup differences. There were no significant differences in preoperative dura width at C2/3 and VAS between the two groups. At the final follow-up, dura width at C2/3 in the C2-PL group was significantly larger than the C2-DOM group, while the VAS of C2-DOM group was significantly lower than C2-PL group. The CCI in both groups decreased compared with before surgery, and there was no significant difference in CCI between the two groups.ConclusionC2-DOM is less demolitive and reduces postoperative neck pain, while C2-PL can achieve more adequate decompression without increasing the risk of postoperative cervical kyphosis.

Purpose:To identify potential risk factors for cage subsidence after oblique lumbar interbody fusion (OLIF) using imaging and clinical date, and provide guidance for surgical planning in clinical practice. Methods: Data of 107 patients who underwent OLIF were retrospectively analyzed. Patients with cage subsidence distance＞3 mm were included in the cage subsidence group (CS group), and the remaining patients were involved in the non-cage subsidence group (NCS group). The characteristics (age, gender, Body Mass Index (BMI), main diagnosis, comorbidities etc), vertebral body-related variables (disc height (DH), endplate morphology, and Modic changes) and surgery-related variables (internal fixation, cage position, and endplate injury) were collected. Moreover, the visual analog scale (VAS) score, and the Japanese Orthopedic Association (JOA) score were determined preoperatively, postoperatively, and at follow-up. Firstly, univariate analysis was used to compare the risk factors related to cage subsidence, and then, the multivariate logistic regression analysis was employed to determine the possible risk factors (p＜0.10) for cage subsidence after OLIF. Results:In total, 21 (19.63%) patients were involved in the CS group. The factors significantly associated with cage subsistence included intraoperative endplate injury (odds ratio (OR) =6.620; p=.020), osteoporosis (OR =6.179; p=.004), irregular endplate morphology (OR =5.192; p=.012) and without internal fixation (OR =6.672; p=.013). Conclusion:Cage subsidence did not affect the neurological function, while it led to low back pain in the later stage. The risk factors for cage subsidence included intraoperative endplate injury, osteoporosis, irregular endplate morphology, and treatment with standalone OLIF.