Whiplash Associated Disorders

1. Whiplash Associated Disorders J. Scott Bainbridge, MD Denver Back Pain Specialists www.denverbackpainspecialists.com

2. Definition • Quebec Task Force on Whiplash-Associated-Disorders redefined the term in 1995 as “an acceleration-deceleration mechanism of energy transfer to the neck which may result from rear-end or side impact, predominately in MVAs, and from other mishaps.

3. Definition • The energy transfer may result in bony or soft tissue injuries (whiplash injury), which may in turn lead to a wide variety of clinical manifestations (whiplash Associated Disorders)”.

4. WAD – Scope of Problem • Yearly Incidence 4/1,000 (.8-8) • $3.9 billion/yr in USA, $29 b w litigation • 4-42% of pts w MVA related neck injuries with sx several yrs later

5. Quebec Classification • Grade 0: No neck c/o or PE signs • Grade I: Neck c/o pain, stiffness or tenderness but no PE signs • Grade II: Neck c/o AND mskl signs • Grade III: Neck c/o AND neuro signs • Grade IV: Neck c/o AND fracture or dislocation

6. MVA – Spectrum Beyond WAD • Cervicothoracic • Other Musculoskeletal • Brain Injury, Post Concussive Syndrome • Other Neurological • Vestibular Dysfunction • Psychological • Social/Economic/Litigation

7. Motion Analysis of C-Spine During Whiplash Loading • Kaneoka, et al; Spine 24:8 pp 763-770 • 10 males – sled glided back into damper at 4 km/hr • Cineradiography of C-spine • Each vertebra’s rotational angle and C5-6 instantaneous axes of rotation quantified • SEMG of SCM and C-paraspinals

10. Pathological Forces • 8 km/hr 5 mph • 135 N

11. Pathology • Facet: synovial fold (meniscoid) impingement, facet capsular subcatastrophic failure, capsular failure w/wo fracture or subluxation, microfracture – cart/bone • Disc rim lesions/herniation, anterior vs. posterior • Neural • Muscular • Start or speed degenerative cascade

13. Degenerative Cascade • Three Joint Complex • Two Zygapophyseal joints (facets joints) • Intervertebral disk • pathologic changes in one part results in changes in other segments Kirkaldy-Willis

14. Degenerative Cascade – Segmental Dysfunction • reactive z-joint synovitis • Inflammation & joint pain

15. Degenerative Cascade – Segmental Dysfunction • articular cartilage z-joint degeneration

16. Subchondral Sclerosis

17. Cartilage Degeneration

18. Degenerative Cascade – Instability Phase • Annular fibers less competent • Disc protrusions

19. Uncovertebral Joints - Joints of Luschka • Uncinate processes hook posterolaterally between one vertebra & the base of the next • With shearing stresses to anular tissue, degenerative spurs begin to develop in teenage years • Spurring can cause foraminal stenosis

20. Degenerative Cascade – Instability Phase Normal Foraminal narrowing

21. Degenerative Cascade – Stabilization Phase • foraminal stenosis • radiculopathy • central spinal stenosis

22. Degenerative Cascade – Stabilization Phase • ankylosis of motion segment • multilevel degenerative changes & spondylosis

23. Degenerative Cascade – Stabilization Phase • ankylosis of motion segment

24. Cervical Z Joint Pain • Prevalence of chronic cervical z-joint pain after whiplash injuries: 60% (Lord, Spine, 1996) • Z Joint pain referral patterns characterized with provocative injections (Dwyer) • Imaging is unremarkable • Confirm suspicions with dx intra-articular z-jt injections or medial branch blockade

26. Dwyer Z-joint Referral Patterns Spine 1990

27. Fukui Thoracic Z-joint Referral Patterns Regional Anesthesia 1997

28. HNP Lig. flavum dura Spinal cord

29. “Annular fibers restrict axial rotation more than the facet joints.” (Krismer 1996)

30. Posterior Tear with epidural leak Normal disc

31. Grubb, Kelly. Spine 25:1382-1389, 2000 Cervical Discography Pain Referral Patterns 173 discograms, 404 positive discs >50% with >3 positive discs C2-3 C3-4 C4-5 C5-6 C6-7

32. C2-3 Provocative Cervical DiscographySlipman NASS 2002 C3-4 C4-5

33. C5-6 Provocative Cervical DiscographySlipman NASS 2002 C6-7 C7-T1

35. Treatment - Acute • Oral Steroids? • NSAIDs? • Immobilize? • Early Therapy?

36. Treatment Facet Joints

37. Treatment of Facet Injury • Manual Therapy • Postural Education • Neuromuscular Reeducation/Stability • Cervical Traction • Spinal Injections • Surgical Stabilization

38. Manual Therapy • Grade 1: Small amplitude, beginning range • Grade 2: Large amp, resistance free • Grade 3: Large amp into resistance (MET) • Grade 4: Small amp well into resis (HVLA) • Grade 5: Past end-range

39. Spinal Injection/Nerve Ablation • Intraarticular Corticosteroid • Facet Denervation (Lord,et al; NEJM 1996; 335:1721-6)

40. Treatment of Disk Disorders • Posture/ Spine Stability Training • Cervical Traction • Treat Assoc Muscle/Facet Disorders • Spinal Injections • Surgical (ACDF, other); Treatment for axial neck pain?

41. Surgical Intervention • Neurological Compromise • Axial Pain?

42. Treatment of Muscle Disorders • Massage: CMT, self, theracane • Postural Educ • Neuromuscular Reeducation/Stability • Biofeedback • Trigger Point Injections/Acupuncture • Botulinum Toxin: Botox/Myoblock

43. Movement Dysfunction Dynamic Stabilityand Muscle Balanceof the Cervical Spine

44. Segmental Dysfunction

45. Movement Dysfunction

46. Local stability segmental control • The segmental stability of the spine is dependent on recruitment of the deep local stability muscles • The spine will fail if local activity is insufficient even if the global muscles work strongly • 1 –3 % MVC  muscle stiffness significantly increases stability • 25% MVC = optimal stiffness & stability (Cholewicki & McGill 1996, Crisco & Panjabi 1991, Hoffer & Andreasson 1981)

47. Inhibition • Inhibition: failure of normal recruitment • poor recruitment under low threshold stimulus • delayed recruitment timing • altered recruitment sequencing Inhibition ‘off’

48. Afferent Input & Recruitment • Recruitment is partially due to the influence of proprioceptive activity • Proprioceptive afferent (γ loop) input is essential for tonic (low threshold) recruitment • Sensation of effort is linked to recruitment • (Eccles et al. 1957, Grimby & Hannerz 1976)

49. Proprioception and Pathology • Whiplash patients have significant  in ability to reposition head after movement • worse with mid range movement than end range • worse in direction of injury mechanism (flex/ext) • Kinesthetic accuracy improves with specific proprioceptive exercise (Loudow et al 1997, Revel et al 1991 1994, Heikkla & Astrom 1996)

50. Evidence of Local Dysfunction • Uncontrolled segmental translation • Segmental change within cross-sectional area • Altered pattern of low threshold recruitment • Motor recruitment timing deficit • (review: Comerford & Mottram 2001)