Profiles of and correlation between objective and subjective outcome assessments following open-door laminoplasty for cervical spondylotic myelopathy

Background Open-door laminoplasty is widely used in the treatment of cervical spondylotic myelopathy(CSM). This study aimed to investigate the profiles of and correlation between objective and subjective short-term outcome assessments after open-door laminoplasty for CSM.Methods We retrospectively analyzed surgical outcomes in 129 consecutive CSM patients who underwent open-door laminoplasty in Peking University Third Hospital from February 2008 to November 2011. Both objective and subjective assessments were evaluated before surgery, 3 months after surgery, and 1 year after surgery. We then analyzed the profiles of and correlation between objective and subjective short-term outcomes.Results The Modified Japanese Orthopaedic Association(mJOA) score was significantly improved at 3 months(P<0.01) and 1 year(P<0.01) after surgery. Bivariate Logistic regression showed that sensory improvement contributed more to the recovery rate than motor function improvement at 3 months after surgery, while motor function contributed more to the recovery rate at 1 year after surgery. On the subjective assessment(the short form(SF)-36), there was no significant improvement at 3 months after surgery(P>0.05), while physical function(PF), role–physical(RP), and social function(SF) were notably improved at 1 year after surgery(P<0.01). Improved mJOA score correlated with improvements in PF, RP, bodily pain, general health(GH), vitality(VT), and SF(P<0.05) at 3 months after surgery; PF, GH, VT, and SF were associated with improved mJOA scores at 1 year after surgery.Conclusions Patients benefit from surgery by postoperative restitution of neurological function with early recovery of sensory function, followed by a gradual transition to motor function improvement. At the early stage of recovery, improvement in the mJOA score essentially correlated with improvements in the physical domains of the SF-36, while at the later stage, mJOA score improvement was associated with improvements in both mental and physical domains of the SF-36.