Clinical and Finite Element Analysis of Acute Whiplash

ABSTRACT

Study Design: A prospective 1-year follow-up study of whiplash patients presenting with neurological signs/or symptoms (WADIII), and whiplash patients with neck pain but no neurologic findings (WADI/II). Objective: We hypothesize that WADI/II and WADIII are distinct entities, with regards to clinical presentation, pathoanatomy, and prognosis. Summary of Background Data: symptoms associated with whiplash injury range from mild neck pain (WADI/II), to injuries associated with neurologic sequellae (WADIII). To date, literature considers whiplash associated disorders (WAD) a single clinical and pathologic entity, with different grades of severity (WADI-IV). Methods: Thirty one subjects were divided into a WADIII study group and a WADI/II comparison group. All subjects underwent H&P, radiographic evaluations, and clinical outcome measures (collected at 3, 6, and 12 months). Statistical analysis was performed (Student T-test, Wilcoxon Signed-Rank test) with significance set at p=0.05. A finite element analysis (FEA) technology (SCOSIA©) was used to predict stresses within the neuraxis. Results: At day 0: Better neurologic assessments, functional performances, and higher quality-of-life measurements were noted in WADI/II compared to WADIII. VAS scores were comparable. At 12 months: Both groups reported improvements in neurologic status and disability symptoms. However functional recovery and quality-of-life measures significantly improved in WADIII, and conversely deteriorated in WADI/II along with notable worsening of pain symptoms. Litigation claims were comparable. FEA predicted higher stress within the neuraxis of WADIII, notably in subjects with preexisting stenosis and odontoid retroflexion. Conclusion: WADI/II and WADIII are distinct entities. Musculoskeletal injury precipitates WADI/II pain symptoms while neuronal stretching leads to WADIII neurologic injuries, which are mostly recoverable.