Study Design. In vitro biomechanical study.
Objective. Our objective was to determine the effectiveness of cervical collars and cervicothoracic orthoses for stabilizing clinically relevant, experimentally produced cervical spine injuries.
Summary of Background Data. Most previous in vitro studies of cervical orthoses used a simplified injury model with all ligaments transected at a single spinal level, which differs from real-life neck injuries. Human volunteer studies are limited to measuring only sagittal motions or 3-dimensional motions only of the head or 1 or 2 spinal levels.
Methods. Three-plane flexibility tests were performed to evaluate 2 cervical collars (Vista Collar and Vista Multipost Collar) and 2 cervicothoracic orthoses (Vista TS and Vista TS4) using a skull-neck-thorax model with 8 injured cervical spine specimens (manufacturer of orthoses: Aspen Medical Products Inc, Irvine, CA). The injuries consisted of flexion-compression at the lower cervical spine and extension-compression at superior spinal levels. Pair-wise repeated measures analysis of variance (P < 0.05) and Bonferroni post hoc tests determined significant differences in average range of motions of the head relative to the base, C7 or T1, among experimental conditions.
Results. All orthoses significantly reduced unrestricted head/base flexion and extension. The orthoses allowed between 8.4% and 25.8% of unrestricted head/base motion in flexion/extension, 57.8% to 75.5% in axial rotation, and 53.8% to 73.7% in lateral bending. The average percentages of unrestricted motion allowed by the Vista Collar, Vista Multipost Collar, Vista TS, and Vista TS4 were: 14.0, 9.7, 6.1, and 4.7, respectively, for middle cervical spine extension and 13.2, 11.8, 3.3, and 0.4, respectively, for lower cervical spine flexion.
Conclusion. Successive increases in immobilization were observed from Vista Collar to Vista Multipost Collar, Vista TS, and Vista TS4 in extension at the injured middle cervical spine and in flexion at the injured lower cervical spine. Our results may assist clinicians in selecting the most appropriate orthosis based upon patient-specific cervical spine injuries.