Comparative Effectiveness and Functional Outcome of C2 Dome-like Expansive Versus C2 Expansive Open-door Laminoplasty for Upper Cervical Ossification of the Posterior Longitudinal Ligament

Retrospective Cohort Study.This study compared the function and radiographical outcomes of the patients who underwent C2 dome-like expansive laminoplasty to those C2 expansive open-door laminoplasty for the treatment of OPLL with C2 involved.There are few comparative studies of these two surgical methods. C2 dome-like and C2 expansive open-door laminoplasty are posterior approaches for posterior longitudinal ligament ossification with C2 level and above.This study performed a retrospective cohort analysis of 59 patients with OPLL up to C2 which cause compression symptoms. 31 patients underwent C2 dome-like expansive laminoplasty with C3-7 expansive open-door laminoplasty (Group Dom) and 28 underwent C2-7 expansive open-door laminoplasty (Group Exp). The preoperative and postoperative space available for cord (SAC) of C2 segment, cervical curvature index of C2-7, C2-7 range of motion, Japanese orthopedic association (JOA) score, visual analog scale (VAS) score, and neck disability index (NDI) were used to assess clinical out-comes and statistically analyzed.The cervical curvature index, JOA score, and NDI significantly changed at the final follow-up in two groups with no significant intergroup differences. There were no significant differences in preoperative SAC and VAS between the two groups. At the final follow-up, the SAC of C2/3 in Group Exp was significantly larger than Group Dom, while the VAS and range of motion of Group Dom became significantly better than Group Exp.The C2 dome-like expansive laminoplasty can reduce postoperative neck pain more obviously and achieve better cervical curvature. C2 expansive open-door laminoplasty can get more adequate decompression in the spinal canal, which may be recommend to the patients with OPLL occupying more than 50% of the vertebral canal at C2/3, or with developmental spinal stenosis.3.