Does T1 slope minus cervical lordosis mismatch affect surgical outcomes of cervical laminoplasty in the absence of preoperative severe kyphosis?

Abstract

Background The impact of the T1 slope minus cervical lordosis (T1S-CL) on surgical outcomes in patients with degenerative cervical myelopathy undergoing laminoplasty (LP) remain uncertain. Methods One hundred patients who underwent cervical LP were retrospectively reviewed. Radiographic measurements included C2–C7 lordosis (CL), T1 slope (T1S), and C2–C7 sagittal vertical axis (SVA). Additionally, pain numeric rating scale, neck disability index (NDI), 12-Item Short-Form Health Survey, Euro QOL 5 dimensions (EQ5D), and Japanese Orthopedic Association score were investigated. According to past reports, T1S–CL > 20° was defined as mismatched. Then, based on T1S-CL mismatching, patients were divided into 2 groups. Results This research understudied 67 males and 33 females with a mean age of 67 y. Preoperatively, only eight patients showed a T1S-CL mismatch. While the C2–7 Cobb angles did not change significantly after surgery, the T1 slope (T1S) angle increased, increasing the T1S-CL as a result. As we compared the clinical outcomes based on the preoperative T1S-CL mismatching, there were no significant differences between the two groups. On the other hand, the number of patients in the mismatched group increased to 21 patients postoperatively. As we compared clinical outcomes based on the postoperative T1S-CL mismatching, the postoperative NDI score and preop/postop EQ5D score were significantly worse in the mismatch group. Conclusions Although cervical LP showed inferior outcomes in patients with postoperative T1S-CL mismatch even in the absence of severe preoperative kyphosis (> 10°), preoperative T1S-CL mismatch was not adversely prognostic.

Sagittal sequence and clinical efficacy of cervical disc replacement and hybrid surgery in the treatment of cervical spondylotic myelopathy: a retrospective study

“…This parameter combines radiological features of both the cervical and thoracic spine, similar to the lumbar lordosis parameter in cases of thoracolumbar deformities. Currently, there are numerous studies that have confirmed the correlation between T1S-CL and the severity of symptoms in patients with degenerative cervical spine diseases, as well as the efficacy of postoperative outcomes (37)(38)(39). When T1S decreases, the cervical spine will compensate by reducing CL, leading to the progression of the cervical curvature toward a straight state.…”

Effect of preoperative dynamic cervical sagittal alignment on the loss of cervical lordosis after laminoplasty

“…T1S-CL [8,17,22] and CL/T1S [26] have also been considered as predictors for LCL after CLP. However, there are some studies showing different results regarding the correlation between T1S and LCL [16,[27][28][29]. Michael et al [12] and Seo et al [8] emphasize the importance of cephalad vertebral level and cervical foraminal stenosis in LCL after laminoplasty.…”

Effect of preoperative dynamic cervical sagittal alignment on the loss of cervical lordosis after laminoplasty

“…T1S-CL [7,16,21] and CL/T1S [24] have also been considered as predictors for LCL after CLP. However, there are some studies showing different results regarding the correlation between T1S and LCL [15,[25][26][27]. Michael et al [11] and Seo et al [7] emphasize the importance of cephalad vertebral level and cervical foraminal stenosis in LCL after laminoplasty.…”