Clinical effects of posterior longitudinal ligament removal and wide anterior cervical corpectomy for spondylosis

Background: Removing the posterior longitudinal ligament in cervical corpectomy is a controversial issue. It is unclear whether the risks are counterbalanced by clinical benefits. Another unexplored topic is whether the width of the corpectomy affects outcome. Methods: This cross-sectional retrospective study included consecutive patients who underwent cervical corpectomy for spondylosis by 6 different neurosurgeons. We compared 2 groups, where the posterior longitudinal ligament was either removed (N = 15 patients) or preserved (N = 21 patients). The posterior width of the corpectomy was assessed postoperatively with computed tomography and magnetic resonance imaging. Clinical results were evaluated with the visual analog scale (VAS), Modified Japanese Orthopedic Association scale (MJOAS), Cooper scale, and neck disability index (NDI), in the long-term follow-up. Results: Compared to preservation, removal of the posterior longitudinal ligament produced more favorable clinical results (but not statistically significant), based on the VAS (+41%, P = 0.48), MJOAS (+26.5%, P = 0.62), Cooper scale (+19%, P = 0.75), and NDI (+62%, P = 0.22). Magnetic resonance imagings showed that removing the posterior longitudinal ligament produced greater evagination of the dural sac into the space left by the corpectomy. Improvements in clinical outcome were associated with more posterior bone wall removal in the corpectomy (corpectomy width ≥15.6 mm; P < 0.05), based on the VAS, NDI, and MJOAS. Conclusions: Removing the posterior longitudinal ligament in cervical corpectomy may produce a better outcome, particularly when associated with more posterior bone wall removal in the corpectomy.