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

Abstract

Background The best open side for a unilateral open-door laminoplasty (UODL) to treat inconsistent cervical ossification of the posterior longitudinal ligament (OPLL) must be identified. Methods Retrospective analysis involving 31 individuals with inconsistent OPLL who received UODL between January 2016 and December 2018 were divided into two groups: when the side of the open door was consistent to the larger ossification occupancy area side, patients were placed into the Consistent Group; when the side of the open door was contralateral to the larger ossification occupancy area side, patients were placed into the Contralateral Group. The following parameters were evaluated; neck disability index (NDI) score, Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score, postoperative laminoplasty opening width and angle, and diameter of spinal cord ratio. To assess the clinical results between the two groups, the spinal cord shift was also evaluated. Results Patient demographics and major problems did not differ significantly between groups. Transient pain in the deltoid region was more frequent in the Consistent Group. The diameter-to-spinal cord ratio, VAS and NDI scores did not significantly differ from one another, opening width and angle in postoperative laminoplasty between the two groups. The JOA scores improved in the Consistent Group. The diameter of spinal cord ratio was more significantly improved in the Consistent Group, as well as the spinal cord shift. Conclusions For inconsistent cervical OPLL, the side of the open door that was consistent with the larger ossification occupancy area side is preferred in UODL.