Factors Predicting Poor Surgical Outcome in Patients with Thoracic Ossified Ligamentum Flavum – Analysis Of 106 Patients in a Tertiary Care Hospital in South India

Background: Ossified ligamentum flavum (OLF) is the major cause of thoracic myelopathy in our locality. Surgical outcomes and their related factors for patients with thoracic OLF (T-OLF) remain unclear because of the few studies on this condition.Objectives: The present study aimed to examine the factors predicting poor surgical outcomes and the effectiveness of decompressive laminectomy and OLF resection in patients with T-OLF.Material and Methods: A total of 106 patients with T-OLF operated at our institute from 2007 to 2018 were included. The mJOA score was used in neurological assessment preoperatively and during the follow-up. Multiple regression analysis was conducted to know the best correlation between factors and surgical outcomes.Results: The mean mJOA score was 5.67 ± 2.13 preoperatively and 7.50 ± 2.60 postoperatively at the end of follow-up. The recovery rate was 43.29 ± 30.55%. After decompressive laminectomy, the mean mJOA score, modified Nurick score, and Ashworth's grade showed significant improvement (P < 0.001). Multiple regression analysis showed that the age of the patient, associated trauma, OLF level, tuberous type OLF, intramedullary signal change on T2WI, preoperative severity of myelopathy, pre-op mJOA score, and pre-op Nurick grade were significantly correlated with the surgical outcome (P < 0.001). No correlation was identified with the duration of symptoms, dural ossification, dural tear, and CSF leak (P > 0.05).Conclusion: It is important to identify preventable risk factors for poor surgical outcomes for T-OLF. Age of the patient, associated trauma, OLF level, tuberous type OLF, intramedullary signal change on T2WI, preoperative severity of myelopathy, preoperative mJOA score, and Nurick grade were important predictors of surgical outcome in our study series.