Modified Laminoplasty Preserving the Posterior Deep Extensor Insertion into C2 Improves Clinical and Radiologic Results Compared with Conventional Laminoplasty: A Meta-Analysis.

BACKGROUND: Whether modified laminoplasty is better than conventional laminoplasty is unclear. Thus, a meta-analysis comparing the outcomes of preserving or repairing the posterior deep extensor insertion to C2 in laminoplasty was conducted for patients with multilevel cervical spondylotic myelopathy (MCSM). METHODS: Several electronic databases were chosen to search for relevant studies. The primary indices included preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, JOA recovery rate, muscle atrophy rate, preoperative and postoperative range of motion (ROM), ROM decrease rate, and incidence of axial pain. Results are expressed as odds ratios with 95% confidence intervals for the dichotomous outcomes and mean differences for continuous outcomes. RESULTS: Eight studies involving 763 patients were included in this study. The postoperative cervical ROM was significantly higher in the modified group (P = 0.01, MD = 3.0 [0.66, 5.35]), as was the cervical posterior muscle volume (P = 0.02, MD = 28.28 [4.42, 52.3]) and the operation time (MD = -45.04, 95% CI -49.79, -40.29; P < 0.01). The incidence of axial symptoms in the modified group was lower than that in the conventional group (P < 0.01, OR 0.28 [0.17, 0.46]), as was the rate of decrease of cervical ROM (P = 0.004, MD = -6.72 [-11.25, 2.19]). There was no significant difference (P > 0.05) between the groups in blood loss, preoperative and postoperative JOA score, or JOA recovery rate. CONCLUSIONS: Modified laminoplasty had shorter operation times, a lower incidence of axial pain, a higher cervical ROM, and a lower atrophy rate compared with conventional laminoplasty. The clinical and radiologic results of modified laminoplasty have been partly superior to those of conventional laminoplasty to date.