Multivariate analysis of factors associated with spinal cord area in single-door cervical laminoplasty with miniplate fixation

OBJECTIVES: To explore the factors associated with the increased spinal cord area in single-door cervical laminoplasty (SDCL) with miniplate fixation. METHODS: A retrospective study enrolled 83 patients underwent SDCL with miniplate fixation and the patient characteristics such as age, gender, tobacco use, alcohol use, diabetes mellitus, hypertension, diagnosis, operative level, etc., were obtained. The opening angle, door shaft position and spinal canal area of the patients were measured after surgery. The sagittal canal diameter (SCD), the C2–7 Cobb angle, the cervical curvature index (CCI), the range of motion (ROM) and the spinal canal area were measured before and after operation. The increased cervical spinal cord area was also measured before and after surgery, and the correlation between the above indicators and the increased cervical spinal cord area was studied through Pearson’s correlation analysis and multivariate logistic regression analysis. RESULTS: There were 34 patients in small spinal cord area increment group (SAI group), 29 patients in middle spinal cord area increment group (MAI group) and 20 patients in large spinal cord area increment group (LAI group). The preoperative diagnosis(P = 0.001), door shaft position (P = 0.008), preoperative spinal canal area (P = 0.004) and postoperative spinal canal area (P = 0.015) were significant different among the 3 groups. The multivariate analysis showed that the preoperative diagnosis (OR = 2.076, P = 0.035), door shaft position (OR = 3.425, P = 0.020) and preoperative spinal canal area (OR = 10.217, P = 0.009) were related to increased spinal cord area. CONCLUSIONS: The preoperative diagnosis, door shaft position and preoperative spinal canal area might be associated with increased spinal cord area after cervical laminoplasty with miniplate fixation. Preoperative symptoms are mostly caused by compression of the spinal cord, so spinal cord area enlargement can bring a better recovery in patients alongside long-term. Spine surgeons should pay more attention to the accuracy of the preoperative diagnosis, the preoperative measurement of spinal canal area and the door shaft position during the operation.