Predictable Imaging Signs of Cauda Equina Entrapment in Thoracolumbar and Lumbar Burst Fractures with Greenstick Lamina Fractures

Abstract

Study DesignA retrospective study.PurposeThe aim of present study was to investigate imaging findings suggestive of cauda equina entrapment in thoracolumbar and lumbar burst fractures.Overview of LiteratureBurst fractures with cauda equina entrapment can cause neurologic deterioration during surgery. However, dural tears and cauda equina entrapment are very difficult to diagnose clinically or radiographically before surgery.MethodsTwenty-three patients who underwent spinal surgery for thoracolumbar or lumbar burst fractures were enrolled in this study. In magnetic resonance imaging T2-weighted images of the transverse plane, we defined cauda equina notch sign (CENS) as a v-shaped image that entrapped cauda equina gathers between lamina fractures. We evaluated the fractured spine by using CENS and lamina fractures and the rate of available space for the spinal canal at the narrowest portion of the burst fracture level. We classified patients into entrapment group or non-entrapment group, based on whether cauda equina entrapment existed.ResultsLamina fractures were detected in 18 (78.3%) and CENS were detected in 6 (26.1%) of 23 burst-fracture patients. Cauda equina entrapment existed in all the patients with CENS. In addition, the rate of available space for the spinal canal increased according to logistic regression. The size of the retropulsed fragment in the spinal canal was the most reliable of all the factors, suggesting cauda equina entrapment.ConclusionsCENS was the most predictable sign of cauda equina entrapment associated with burst fractures.

Comparison of Wiltse’s paraspinal approach and open book laminectomy for thoracolumbar burst fractures with greenstick lamina fractures: a randomized controlled trial

“…Clinical parameters included operative time, blood loss, average hospital stay, VAS, SWS, complications, and neurologic status (by Frankel grade). Cauda equina notch sign (CENS) [ 7 ], anterior segmental height, kyphotic angle, and bony fusion status were assessed with imaging.…”

“…Posterior retropulsion of bony fragments does not always cause a neurological deficit owing to the large dimensions of the spinal canal in the thoracolumbar region. However, previous reports have shown a significant relationship between cauda equina entrapment and neurological deficits [ 7 – 10 ]. Surgical reduction can close a lamina fracture and entrap nerve roots (Additional file 2 ).…”

Lesión dural asociada a fracturas de charnela toracolumbar y lumbares con compromiso del muro posterior. Relación con las variables del sistema de clasificación AOSpine. [Thecal sac injury secondary to burst fractures of the thoracolumbar and lumbar spine, and its association with the AOSpine Classification System variables].

“…-"Cauda equina notch sign": en cortes axiales de RM, según lo descrito por Yoshiiwa y cols. 16 -Signo de la almohadilla grasa ("fat pad sign"): en cortes axiales de RM, según lo descrito por Aydnl y cols. 16 -Examen neurológico: utilizando la variable N de la clasificación AOSpine.…”

“…16 -Signo de la almohadilla grasa ("fat pad sign"): en cortes axiales de RM, según lo descrito por Aydnl y cols. 16 -Examen neurológico: utilizando la variable N de la clasificación AOSpine. 19 -Clasificación AOSpine.…”

“…describen el "cauda equina notch sign" como un signo predecible de atrapamiento de la cauda equina en fracturas de lámina en tallo verde y el tamaño del fragmento del muro retropulsado. 16 Aydnl y cols. comunicaron que, en la TC y la RM, las señales de la almohadilla adiposa posterior desaparecieron en los cortes axiales cuando había una fractura de lámina en tallo verde y atrapamiento de la raíz nerviosa.…”