Surgical Outcomes of Selective Laminectomy for Patients With Cervical Kyphosis: A Retrospective Study of 379 Cases

Study Design: A retrospective study. Objectives: This study aimed to investigate the impact of cervical kyphosis on patients with cervical spondylotic myelopathy (CSM) following selective laminectomy (SL) regarding posterior spinal cord shift (PSS), and a number of SLs. Methods: We evaluated 379 patients with CSM after SL. The patients with kyphosis (group K) were compared with those without kyphosis (group L). Moreover, groups K and L were divided into subgroups KS and KL (SLs <= 2) and LS and LL (SLs >= 3), respectively, and analyzed. Receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off value of the C2-C7 angle for satisfactory surgical outcomes, which was defined as a Japanese Orthopaedic Association (JOA) recovery rate of >= 50% in group KS. Results: The average PSS (mm) in group K was smaller than that in group L (.8 vs 1.4; P < .01), but the JOA recovery rate was comparable between the 2 groups. Meanwhile, the mean PSS and JOA recovery rate (%) in group KS was lower than those in group KL, respectively (.3 vs 1.0; P < .01, 35.1 vs 52.3; P = .047). Moreover, the average PSS of group KS (.6) was smaller than those of other subgroups (<.01). In addition, the ROC curve analysis showed that the C2-C7 angle of -14.5 degrees could predict satisfactory surgical outcomes in group KS. Conclusion: Selective laminectomy is not contraindicated for patients with kyphosis, but a larger number of SLs may be indicated for the patients with C2-C7 angles of <= -14.5 degrees.