The mid-to-long term efficacy of open-door laminoplasty for cervical ossification of posterior longitudinal ligament

English Keywords:Cervical ossification of posterior longitudinal ligament  Laminoplasty  Outcome

English Abstract:

  【Abstract】 Objectives: To investigate the mid-to-long term clinical and radiological outcome of open-door laminoplasty for the cervical ossification of posterior longitudinal ligament(OPLL). Methods: A retrospective study was performed on 44 cervical OPLL patients receiving open-door laminoplasty from March 2005 to April 2012. There were 26 males and 18 females with an average age of 57.1 years old(range, 28-72 years). Preoperative modified JOA score was 1.5-16(11.39±3.27), and neck pain VAS score was 0-10(2.32±2.59). The average levels of OPLL were 3.2(range, 1-6 levels). The surgery level included: C3-C7 in 34 cases, C2-C7 in 7 cases, C2-C6 in 3 cases. Clinical outcome was evaluated by means of JOA score and axial symptoms VAS score. Radiological outcomes such as cervical curvature and curvature index on lateral radiographs, the posterior shift of center of spinal cord(PCS), posterior shift of the anterior margin of spinal cord(PAS) and the expansion of spinal cord(ESC) of each level from C2/3 to C6/7 on mid-sagittal images of MRI T2-weighted were recorded. Results: The follow-up period ranged from 24 to 96 months with an average of 36.8 months. The JOA score significantly improved from 11.39±3.27 preoperatively to 14.70±1.96(P<0.05) at final follow-up with an improving rate of (57.59±30.88)%. The VAS score for axial symptoms increased slightly from 2.32±2.59 preoperatively to 3.59±2.97 at final follow-up. Cervical curvature and curvature index remained unchanged(P>0.05). The PCS and PAS were more severe at C3/4 to C6/7 levels than C2/3(P<0.05). The ESC was more severe at C3/4 to C5/6 levels than C2/3 and C6/7(P<0.05). The progression of OPLL was observed in 10 cases at final follow-up(range, 2-8 years after surgery). Conclusions: The open-door laminoplasty for cervical OPLL has a satisfactory mid-to-long term neurofunction improvement, but axial symptoms deteriorate. Since the posterior shift and expansion of the cephalic spinal cord are less than the others, complete decompression should be considered.