Clinical and Radiological Outcomes of Intermuscular "Raising Roof" Modified Cervical Laminoplasty for Cervical Spondylotic Myelopathy: A Retrospective Study of at Least 2 Years Follow-Up.

Abstract

Study designRetrospective study.ObjectivesThe aim of this study was to evaluate the outcomes of a new modified laminoplasty, intermuscular "raising roof" laminoplasty for patients with cervical spondylotic myelopathy.Methods98 patients with cervical spondylotic myelopathy were involved into the study, including 44 patients underwent intermuscular "raising roof" laminoplasty (RL) and 54 patients underwent unilateral muscle-preserve laminoplasty (UL). The data, including sagittal parameters and clinical scale was collected at preoperative stage and final follow-up (at least 2 years) and compared between RL group and UL group. Multivariable liner regressions were preformed to evaluate the relationship between parameters with significant changes at the final follow-up and changes of CL, postoperative NDI and JOA. The cumulative sum (CUSUM) analysis was used for quantitative assessment of RL learning curve. All cases were divided into the learning phase and the proficiency phase according to the peak of CUSUM curve.ResultsNo significant difference was found between RL group and UL group preoperatively. At final follow-up, patients in RL group showed higher JOA scores and recovery rate (RR) but lower NDI scores. For the cervical alignment, the ROM of RL group was greater significantly than UL group, whereas the T1S of RL group was lower than UL group. For the decompression, the RL group had larger CSA of spinal canal than UL group (C4: 278.16 ± 50.40 vs 233.84 ± 42.71, P < .001; C5: 279.12 ± 63.88 vs 232.41 ± 48.38, P < .001). For the muscle-preserve effect, the CSA of left-side PM in RL group decreased significantly compared to the preoperative stage on C5 level (2.92 ± 0.66 vs 3.16 ± 1.08, P < .05), and RL group showed better postoperative symmetry than UL group. The regression results indicated postoperative CSA of right-side PM on C4 level had positive impact on the change of CL (positive value increasing, P = .023). And the postoperative symmetry of PM at C4 had positively correlation with postoperative NDI (P = .034). However, the ages of patients showed negative correlation (P = .012) with postoperative JOA. Operation time of learning phase was significantly longer than proficiency phase (166 ± 34.78 vs 120.65 ± 20.36, P < .001), and blood loss of learning phase was significantly higher than proficiency phase (251.90 ± 171.27 vs 148.88 ± 82.02, P < .001).ConclusionCompared to UL, RL showed similar recovery of neurological functions, but with better improvement of quality of life, cervical mobility and decompression effect at 2-year follow-up. It provides a new treatment approach for degeneration cervical myelopathy.