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

Abstract

Objective: 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).

Methods: 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.

Results: 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 ± 31.6 ml, 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).

Conclusions: 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.

Keywords: Axial symptoms; Centerpiece titanium plate; Cervical spondylotic myelopathy; Open door laminoplasty.

FIGURE 1

A 59‐year‐old male patient presented with numbness in the limbs and walking asthenia for 20 months. (A) Preoperative plain radiography showed hyperosteogeny at the anterior and posterior margins of the cervical vertebrae (cervical spine angle [CSA] = 17.5°). (B) Sagittal magnetic resonance imaging (MRI) showing disc herniations at the C3–C7 segments with ligamentum flavum hypertrophy. The spinal cord was compressed and appeared “beaded.” (C) Front and side images of the modified centerpiece titanium plate. (D) Intraoperative picture illustrating the modified centerpiece titanium plate fixed at C3, C4, and C7 (black arrow). (E) Rebuilding of the posterior cervical muscles to the reserved additional hole. (F) Postoperative computed tomography showing that the C3 lamina open angle was 38.0°. The preformed hole (red arrow) was used to suture the posterior cervical muscles. (G) Plain radiography 1 year after surgery shows the open door laminoplasty with modified centerpiece plates at C3, C4, and C7 (CSA = 20.1°). (H, I) Postoperative MRI showing that the spinal canal was open with adequate decompression and sufficient spinal cord posterior drift. The cross‐sectional area of the posterior cervical muscles was 34.7 cm²

FIGURE 2

A 61‐year‐old female patient presented with numbness in the upper limbs and asthenia for 18 months. (A) Preoperative plain radiography showing degenerative changes in the cervical vertebrae (cervical spine angle [CSA] = 28.8°). (B) Preoperative magnetic resonance imaging (MRI) showing cervical disc herniation at the C2–C7 segments and multi‐segmental spinal cord compression. (C) Postoperative computed tomography showing that the lamina open angle at C4 was 43.9°. (D) Plain radiography 1 year after surgery showing laminoplasty with the conventional centerpiece titanium plate at the C3–C7 segments (CSA = 17.1°). (E) Postoperative MRI showing adequate decompression and significant posterior spinal cord drift