ObjectiveTo explore the effect of spinal dural release on the effectiveness of expansive cervical laminoplasty for treating multi-segmental cervical myelopathy with ossification of posterior longitudinal ligament. MethodsA retrospective analysis was made on the clinical data of 32 patients with multi-segmental cervical myelopathy with cervical ossification of posterior longitudinal ligament who underwent expansive cervical laminoplasty and spinal dural release between February 2011 and October 2013 (group A); and 36 patients undergoing simple expansive cervical laminoplasty between January 2010 and January 2011 served as controls (group B). There was no significant difference in gender, age, disease duration, affected segments, combined internal disease, preoperative cervical curvature, Japanese Orthopaedic Association (JOA) score, and visual analogue scale (VAS) score between 2 groups (P>0.05). Postoperative JOA score and improvement rate, VAS score, posterior displacement of the spinal cord, and the change of cervical curvature were compared between 2 groups. ResultsSpinal dural tear occurred in 3 cases (2 cases in group A and 1 case in group B) during operation. Cerebrospinal fluid leakage occurred in 3 cases (2 cases in group A and 1 case in group B) after operation. The patients were followed up 12-46 months (mean, 18.7 months). At last follow-up, the JOA score and VAS score were significantly improved in 2 groups when compared with preoperative scores (P<0.05). JOA score and improvement rate of group A were significantly higher than those of group B (P<0.05), but VAS score of group A was significantly lower than that of group B (P<0.05). At last follow-up, no significant difference in cervical curvature was found between 2 groups (P>0.05); posterior displacement of the spinal cord of group A was significantly larger than that of group B (P<0.05). No reclosed open-door was observed during follow-up. ConclusionFor patients with multi-segmental cervical myelopathy with ossification of posterior longitudinal ligament, full spinal dural release during expansive cervical laminoplasty can increase the posterior displacement of spinal cord, and significantly improve the effectiveness.