Choice of open side affects clinical outcomes of unilateral open-door laminoplasty for inconsistent cervical ossification of the posterior longitudinal ligament

Background: The best open side for unilateral open-door laminoplasty (UODL) to treat inconsistent cervical ossification of the posterior longitudinal ligament (OPLL) needs to be identified.

Methods: Thirty-one individuals with inconsistent OPLL who underwent UODL between January 2016 and December 2018 were retrospectively divided into two groups: when the side of the open door was consistent with the side of the larger ossification occupancy area, patients were placed in the Consistent group; when the side of the open door was contralateral to the side of the larger ossification occupancy area, patients were placed in the Contralateral group. The following parameters were evaluated: neck disability index (NDI) score, Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score, postoperative laminoplasty opening width and angle, and spinal cord diameter ratio. Spinal cord shifts were also evaluated to compare the clinical results between the two groups.

Results: Patient demographics and major problems did not differ significantly between the groups. Transient pain in the deltoid region was more frequent in the Consistent treatment group. The spinal cord diameter ratio, VAS and NDI scores, opening width, and angle in postoperative laminoplasty did not differ significantly between the two groups. The JOA scores improved in the Consistent group. The spinal cord diameter ratio and spinal cord shift were more significantly improved in the Consistent group.

Conclusions: For inconsistent cervical OPLL, the open-door side that was consistent with a larger ossification occupancy area was preferred in UODL.