Precise Surgical Treatment of Thoracic Ossification of Ligamentum Flavum Assisted by O-Arm Computer Navigation: A Retrospective Study

O-arm computer navigation-assisted technology (OACNAT) has been widely used in the treatment of thoracic ossification of ligamentum flavum (TOLF) in recent years, but there are few in-depth studies on the safety and effectiveness of this approach. The purpose of this study was to investigate the clinical effect of accurate surgical treatment for TOLF with OACNAT.From January 2010 to January 2018, the clinical data of 64 patients with TOLF who underwent laminectomy and internal fixation in the Third Hospital of Hebei Medical University were retrospectively reviewed. The patients were divided into group A (with OACNAT, n = 33) and group B (without OACNAT, n = 31) according to the application of OACNAT during the operation. The possible operation-related variables, imaging results, and clinical effects were compared between the 2 groups.In terms of demographics, there were no significant differences between group A and group B in age, sex, body mass index, smoking, drinking, heart disease, hypertension and diabetes (P0.05). In terms of operation-related variables, imaging results, and clinical efficacy, there were significant differences in operation time, wound length, postoperative modified Japanese Orthopaedic Association (JOA) score, JOA score improvement rate, accuracy of screw placement, number of intraoperative fluoroscopy procedures, and cerebrospinal fluid leakage between group A and group B (P0.05). There were no significant differences in other variables between the 2 groups (P0.05). In contrast to group A, in group B, 2 patients had incorrect segmental localization, 3 patients had residual ossified ligamentum flavum after the operation, and 1 patient had postoperative neurologic impairment. On further analysis, compared with group B, group A had a shorter operation time, more accurate screw placement, fewer fluoroscopy procedures, higher JOA score improvement rate, and lower incidence of complications.The use of OACNAT accurately located the position, size, shape, and boundary of ossification of the ligamentum flavum during the operation, which could guide accurate decompression and improve the accuracy of pedicle screw placement. This approach not only reduced the incidence of incorrect segmental localization and incomplete or excessive decompression but also reduced the risk of related complications and improved the accuracy, safety, and effectiveness of the operation.