Vertebral Body Sliding Osteotomy as a Surgical Strategy for the Treatment of Cervical Myelopathy: Outcomes at Minimum Five years Follow-up

Abstract

Study Design. A retrospective cohort study. Objective. To evaluate the outcomes of vertebral body sliding osteotomy (VBSO) with a minimum follow-up of five years and compare the results with those of anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF). Summary of Background Data. VBSO reportedly results in fewer complications, better lordosis restoration, and faster bone union than corpectomy. Although previous studies demonstrate the outcomes of VBSO with follow-up of two years or longer, results in longer term surveillance remain unknown. Methods. This study included 128 patients who underwent VBSO (n= 38), ACDF (n= 62), or ACCF (n= 28) as a treatment for cervical myelopathy and was followed up for five years or more. Fusion, subsidence, C0-2 lordosis, C2-7 lordosis, segmental lordosis, C2-7 sagittal vertical axis, surgical complications, and neck pain visual analog scale, Neck Disability Index, and Japanese Orthopedic Association (JOA) scores were assessed. Comparisons between continuous variables in each group were made using independent sample t tests. For nominal variables, the Fisher exact test or the chi(2) test was used. Paired t test was used to analyze the changes in postoperative values compared with preoperative values. Results. The reoperation rate (0.0%) after VBSO was significantly lower than that after ACCF (14.3%; P= 0.028). VBSO had a higher fusion rate at six-month and one-year follow-up, but the fusion rate at five years (97.4%) was not significantly different from that of ACDF (85.5%; P= 0.054) and ACCF (85.7%; P= 0.077). Segmental lordosis at the five-year follow-up was significantly higher in the VBSO group (16.1 degrees) than in the ACDF (11.9 degrees; P= 0.002) and ACCF (6.5 degrees; P< 0.001) groups. C2-7 lordosis at five-year follow-up was significantly higher in the VBSO group than in the ACCF group (P= 0.017). Neck pain visual analog scale, Neck Disability Index, and JOA scores and the JOA recovery rate did not show significant intergroup differences during the five-year study period. Conclusions. VBSO showed promising long-term results in terms of low revision rate, fast solid union, and effective segmental lordosis restoration when compared with other anterior reconstruction techniques.