Objective: To present the motor deficits and type of neurogenic bladder dysfunction (NBD) in patients with vertebral fractures at thoracolumbar junction.
Methods: Fifty-two patients with single level vertebra fracture over T11-L2 with onset duration of longer than 3 years were enrolled. All participants provided basic demographic data, ambulatory status and received neurologic examination and urodynamic studies. The differences in distribution of NBD types, neurologic injury sites and functional walkers in patients with different levels of vertebral injury were analyzed. Receiver operating characteristic curve analysis was used to define the cutoff value of lower extremities motor score (LEMS) in functional walker and non-walker.
Results: Of the 52 patients, the injured levels were 3 (5.8%) in T11, 21 (40.4%) in T12, 22 (42.3%) in L1, and 6 (11.5%) in L2 vertebrae. Eight (15.4%) patients had upper lumbar cord lesions, 26 (50.0%) had epiconus and lumbar roots lesions, 18 (34.6%) had conus medullaris or/and cauda equina lesions. Mean LEMS was 0 ± 0, 5.4 ± 7.7, 11.1 ± 10.2, and 28.0 ± 11.0 for patients with T11, T12, L1, and L2 fractures, respectively. Patients with L2 fractures had higher LEMS than other levels (p < 0.001). The cutoff value of LEMS for functional walking was set at 20, and both the sensitivity and specificity was 100%. Thirty-one (59.6%) patients had spastic NBD, 18 (35.6%) had flaccid NBD, and 3 (5.8%) had mixed type NBD. Positive prediction value of ankle spasticity for bladder and sphincter spasticity was 95.2 and 100%, respectively.
Conclusion: Half of the patients had epiconus lesion following thoracolumbar junction fracture, and they had a clinical presentation of flaccid legs and spastic NBD. Patients with L2 fracture had higher LEMS than patients with T11, T12, and L1 fracture. Patients whose LEMS was higher than 20 could all walk functionally. Fracture at the thoracolumbar junction may cause spastic, flaccid, or mixed type NBD, and urodynamic study is an essential tool for the correct diagnosis and management. Ankle spasticity has a high positive predictive value for spastic bladder or sphincter.