High incidence of venous thromboembolism after acute cervical spinal cord injury in patients with ossification of the posterior longitudinal ligament

Objective: To determine the incidence of venous thromboembolism (VTE) in patients with acute cervical spinal cord injury (SCI) and ossification of the posterior longitudinal ligament (OPLL). Design: Prospective cohort study. Setting: A department of a university hospital in Japan. Participants: This study included 57 patients (OPLL, n = 10; non-OPLL, n = 47) treated for acute cervical SCI between January 2011 and April 2017. Patients were classified according to motor complete paralysis (MC), motor incomplete paralysis (MIC), or normal motor function, based on American Spinal Injury Association (ASIA) Impairment Scale results. Interventions: N/A. Outcome Measures: All patients were screened for VTE by D-dimer monitoring, and some underwent ultrasonography. If ultrasonography indicated deep venous thrombosis (DVT) or if the D-dimers increased to >= 10 mu g/mL, patients underwent contrast venography to detect VTE, including DVT or pulmonary embolism. We compared blood coagulability and VTE incidence in the OPLL and non-OPLL groups. Results: VTE occurred in 11 (19.3%) of 57 patients. The incidence of VTE was higher in the OPLL group than in the non-OPLL group (50% vs. 12.8%; P = 0.017) and higher in the MC group (57.1%) than in the MIC (8.3%; P = 0.002) or normal group (5.3%; P = 0.002). In the MC group, VTE occurred in 50% of OPLL patients and in 62.5% of non-OPLL patients (P = 0.529). In the MIC group, VTE occurred in 50% of OPLL patients and in none of the non-OPLL patients (P = 0.022). Conclusions: Patients with OPLL tended to develop VTE after SCI with motor complete and incomplete paralysis.