Clinical and radiological outcomes following open door laminoplasty: a single center evolution of the technique

Background A comparison of clinical and radiological outcomes after two different variants of open door laminoplasty for cervical spondylotic myelopathy (CSM) is described. Methods Fifty-five patients underwent cervical laminoplasty for CSM. Between 2005 to 2009, 32 patients underwent open-door laminoplasty (Group A) performed with a monolateral exposure with contralateral "green stick" laminar fracture. A technical variant consisting in bilateral exposure, spinous process removal and symmetrical muscular closure was applied in the other 23 (Group B), from 2009 to 2016. A retrospective analysis of surgical results between the two groups was performed. Results In group B, the mean operative time was longer and the mean volume of intraoperative blood loss was much higher than in group A. Both differences were not significant (p=0.1601 and p=0.0884, respectively). The average hospitalization was nonsignificantly longer in group B (7.3±1.8 vs. 6.5±1.6 d; p= 0.0947). Postoperatively, axial neck pain was more severe in group A at last follow-up than preoperatively (P>0.05). mJOA scores and Nurick grades improved significantly in both groups at last follow-up; in group A, the mean recovery rates were 41.5 % by mJOA scores and 29.4 % by Nurick grades, whereas in group B they were 52.7 % and 36.8 %, respectively. Conclusions Applying some few variations to a standard monolateral approach, although slightly more time and blood consuming, could reduce the incidence of long term axial symptoms and, in our experience, are not burdened by worsening of outcomes. A prospective, multicentric study with a longer follow-up should be conducted in order to confirm our findings.