Novel Three-Holed Titanium Plate Fixation during Open Door Laminoplasty for Cervical Spondylotic Myelopathy: Comparison with Conventional Titanium Plate.

Abstract

For reconstructing the posterior cervical muscular-ligament complex, attachment points and various modified techniques were designed and applied in clinical practice. This study investigated the clinical and radiographic outcomes of open door laminoplasty with modified centerpiece mini-plate fixation and extensor attachment point reconstruction in the treatment of cervical spondylotic myelopathy (CSM). Sixty-nine patients with CSM who underwent C3-C7 open door laminoplasty at our hospital from January 2016 to May 2018 were divided into two groups: 37 and 32 patients underwent laminoplasty with modified and conventional centerpiece titanium plate fixation (MPF and CPF groups), respectively. Changes in cervical spinal angle (CSA), cervical range of motion (ROM), posterior cervical muscle atrophy, neurological function (Japanese Orthopaedic Association [JOA] score), Neck Disability Index (NDI), and axial symptom severity were compared between the two groups. There were no significant differences in operative duration (136.7± 23.9 vs 128.3± 21.5 min, t=1.525, p > 0.05), volume of intraoperative blood loss (275.9± 33.1 vs 268.2± 31.6ml, t=0.984, p > 0.05), lamina open angle (41.2° ± 4.5° vs 39.4° ± 4.1°, t=1.726, p > 0.05), and spinal cord drift distance (2.4± 0.3 vs 2.3± 0.4 mm, t=1.184, p > 0.05) between the two groups. After surgery, JOA score significantly increased (p < 0.05), and neurological recovery rates were similar (62.7% vs 63.4%, t=0.208, p > 0.05). The NDI score was significantly decreased in both the groups (p< 0.05); however, the MPF group recovered to a greater degree than the CPF group (8.3± 1.2 vs 9.8± 1.4) (t=4.793, p< 0.05). There was no significant change in cervical ROM postoperatively compared with preoperatively in either group (p > 0.05). CSA decreased from 21.7° ± 2.8° to 18.3° ± 2.1°, and posterior cervical muscle cross-sectional area decreased from 35.2± 4.9 cm2 to 31.0 ± 4.1 cm2 in the CPF group (p < 0.05), but no significant change was observed in the MPF group (20.6° ± 2.5° to 20.4° ± 2.6°and 35.9± 5.1 to 34.1± 4.6 cm2 , respectively) (p> 0.05). Postoperative axial symptom severity was significantly worse in the CPF group than in the MPF group (Z=-2.357, p < 0.05). As an improvement to the conventional titanium plate, the modified centerpiece titanium plate effectively provides an attachment point for the posterior muscle-ligament complex, reducing posterior cervical muscle atrophy and improving neck function, without inflicting additional surgical trauma.