Choice of the Open Side in Unilateral Open-Door Laminoplasty for Cervical Ossification of the Posterior Longitudinal Ligament.

Study Design: Retrospective study.

Objective: To determine the optimal open side in unilateral open-door laminoplasty (UODL) for lateral cervical ossification of posterior longitudinal ligament (OPLL).

Summary Of Background Data: No literature has reported which side of the vertebral arch should be chosen as the open side in UODL for lateral cervical OPLL.

Methods: Patients with lateral cervical OPLL who were treated with UODL between 2013 and 2018 were retrospectively analyzed in two groups: Group A, where the open side was contralateral to the ectopic bone, and Group B, where the open side was ipsilateral to the ectopic bone. The Japanese Orthopaedic Association (JOA) Score, JOA recovery rate, spinal canal enlargement rate, cervical range of motion (ROM), and spinal cord area (SCA) were measured to evaluate and compare the clinical outcomes between the two groups. Statistical analysis was performed by t test and Hotelling T2 test.

Results: There was no significant difference in patient demographics and major complications between the two groups. The postoperative JOA Score and JOA recovery rate in Group A were significantly higher than those in Group B. There was no significant difference in cervical ROM within or between the two groups during the 2-year follow-up period, nor was there significant difference in spinal canal enlargement between the two groups. However, both postoperative SCA and increased SCA in Group A were significantly higher than those in Group B.

Conclusion: The contralateral open side approach is preferable to the ipsilateral open side approach in UODL for lateral cervical OPLL.

Level Of Evidence: 3.