Two surgical strategies for treating multilevel cervical spondylotic myelopathy combined with kyphotic deformity

Abstract

This study compared the surgical outcomes of two surgical methods for treating multilevel cervical spondylotic myelopathy (MCSM) combined with cervical kyphotic deformity (CKD): (1) the ELTA method consisted of expansive open-door laminoplasty (EOLP) followed by three-segment anterior cervical discectomy fusion (ACDF), and (2) the LAPI method consisted of long-segment ACDF followed by long-level posterior instrumented fusion (PIF). Surgical treatment of CKD combined with MCSM remains challenging. Surgical considerations should include adequate spinal cord decompression and restoration of satisfactory cervical sagittal alignment (CSA). In certain situations, a solid PIF structure is vital to prevent failure.We included 105 patients who underwent the aforementioned surgical methods for MCSM combined with CKD from January 2013 to December 2017. The minimum follow-up period was 1 year. Comparative analysis was performed to compare the two surgical strategies' preoperative and postoperative functional outcomes, including a visual analog scale for neck pain, neck disability index, the Japanese Orthopedic Association cervical myelopathy score, and the Nurick score, as well as the CSA radiographic outcomes, including C2-7 Cobb angle, C2-7 sagittal vertical axis, and C7 slope. The risk factors related to reduced improvement in functional status were analyzed.A total of 63 patients underwent ELTA and 42 patients underwent LAPI. Improvements in functional outcomes were considerable in both groups. The mean C2-7 Cobb angle was restored from 7.4° ± 2.1° kyphosis to 8.8° ± 4.7° lordosis in the ELTA group and from 15.3° ± 4.2° kyphosis to 15.8° ± 8.1° lordosis in the LAPI group. The maximal correction angle was 22.6° in the ELTA group and 42.6° in the LAPI group.Although changes in CSA seemed to be significantly correlated with improvements of functional status, the ELTA and LAPI methods were both effective for treating MCSM combined with CKD, when appropriately selected. The ELTA method was indicated for MCSM patients who had a low degree of CKD, whereas the LAPI method was indicated for MCSM patients who had poor function scores and a high degree of CKD.