Straight Leg Raise Cannot Replace Computed Tomography in the Detection of Spinal Column Fractures.

ABSTRACT

INTRODUCTION: An active straight leg raise (SLR) is a weight bearing test which assesses pain upon movement and a patient's ability to load their pelvis, lumbar, and thoracic spine. Since many stable patients undergo computed tomography (CT) scanning solely for spinal tenderness, our hypothesis is that performing active straight leg raising could effectively rule out lumbar and thoracic vertebral fractures. METHODS: Blunt trauma patients ≥18 years of age with Glasgow Coma Scale 15 presenting in hemodynamically stable condition were screened. Patients remaining in the supine position were asked to perform SLR at 12, 18, and 24 inches above the bed. The patient's ability to raise the leg, baseline pain, and pain at each level were assessed. Patients also underwent standard CT scanning of the chest, abdomen and pelvis. The clinical examination results were then matched post hoc with the official radiology reports. RESULTS: 99 patients were screened, 65 males and 34 females. Spinal fractures were present in 15/99 patients (16%). Mechanisms of injury included motor vehicle collision 51%, pedestrian struck 25%, fall1 9%, and other 4%. The median pain score of patients with and without significant spinal fractures at 12, 18, 24 inches was 7.5, 7, 6 and 5, 5, 4, respectively. At 24 inches, active SLR had sensitivity of 0.47, a specificity of 0.59, a positive predictive value of 0.17, and an negative predictive value of 0.86. CONCLUSIONS: Although SLR has been discussed as a useful adjunct to secondary survey and physical exam following blunt trauma, its positive and more importantly negative predictive value are insufficient to rule out spinal column fractures. Liberal indications for CT based upon mechanism and especially pain and tenderness are necessary to identify all thoraco-lumbar spine fractures.