Does K-line (−) in the Neck-flexed Position Predict Surgical Outcome of Cervical Spondylotic Myelopathy?: Results of a Multivariate Analysis After Muscle-preserving Selective Laminectomy

Study Design. A retrospective single-center study. Objective. The aim of this study was to investigate the influence of the K-line in the neck-flexed position (flexion K-line) on the surgical outcome after muscle-preserving selective laminectomy (SL) for cervical spondylotic myelopathy (CSM). Summary of Background Data. Development of CSM is associated with dynamic factors and cervical alignment. The flexion K-line, which reflects both dynamic and alignment factors, provides an indicator of surgical outcome after posterior decompression surgery for patients with ossification of the posterior longitudinal ligament. However, the value of the flexion K-line for patients with CSM has not been evaluated. Methods. Our study group included 159 patients treated with SL for CSM. Patients were divided into a flexion K-line (+) group and a flexion K-line (−) group. The influence of the flexion K-line on radiological and surgical outcomes was analyzed, with multivariate analysis conducted to identify factors affecting the surgical outcome. Results. Patients in the flexion K-line (−) group were younger (P = 0.003), had a less lordotic cervical alignment (pre-and postoperatively, P 
Source: Spine - Category: Orthopaedics Tags: CERVICAL SPINE Source Type: research