Low Back Pain and the Seronegative Spondyloarthropathies

1. Low Back Pain and the Seronegative Spondyloarthropathies Scott R. Burg, D.O. Orthopaedic and Rheumatologic Institute Cleveland Clinic

2. Spondyloarthropathies (SPA) A group of common inflammatory rheumatic disorders characterized by: Axial and/or peripheral arthritis, enthesitis, dactylitis Potential extra-articular changes such as uveitis and skin rash

3. Common Genetic Predisposition HLA-B27 gene Association varies widely among various SPAs and ethnic groups Environmental factors seem to be triggering the diseases in genetically predisposed

4. Radiographic Hallmark Sacroilitis

6. SPA Characterized by: Sacroilitis Inflammatory back pain Peripheral arthropathy Absence of rheumatoid factor/CCP and subcutaneous nodules Enthesitis Extra spinal involvement (eye, heart, lung and skin) HLA-B27 At least 6 other genes associated with ankylosing spondylitis identified to date

7. Inflammatory Low Back Pain Assumed to be characterized by inflammation of SIJ and lumbar spine Young age of onset Continuous pain > 3 months Morning stiffness Pain improving on activity

8. Inflammatorty Back Pain Unilateral or bilateral Alternates from side to side Responds well to NSAIDs

9. Sacroilitis and Inflammatory Low Back Pain Prevalence 50%

10. F.D. Hart Quarterly Journal of Medicine, 1949 A frequent feature of the pain and stiffness was the aggravation caused by immobility. Waking in the morning stiff and in pain, the patient gradually became more supple during the day, feeling at his best from the afternoon until bedtime. One patient noted that by frequent exercise, his condition was kept in check, but confinement to bed for any cause made him worse. Another woke himself up (every 2 hours) throughout the night to exercise his spine as otherwise, he suffered unduly in the morning.

11. IBP in USA Present in 6% General back pain 20% Performs well as case ascertainment tool for those who seek care SPA in 1%, what constitutes the gap?

12. IBP Concept Distinguishing feature in all criteria sets developed to identify AS and SPA Criteria sets share several key clinical features Diverge on genetic indicators and radiographic parameters

13. Value of IBP Concept in Primary Care Setting Defines a group at risk for SPA or AS Defense of further diagnostic testing i.e. imaging or genetic tests Negative tests in IBP any justification for NSAID’s or biologics to treat symptoms or prevent SPA or AS

14. Spondyloarthropathies (SPA) Ankylosing spondylitis (AS) Reactive arthritis (REA) Psoriatic arthritis (PSA) SPA associated with inflammatory bowel disease (IBD) Undifferentiated SPA (USPA) Juvenile onset spondyloarthritis

15. Ankylosing Spondylitis (AS) Most common and most typical 0.2-1.2% of Caucasian population. Variability based on regional, genetic and environmental factors Lower male to female ratio (2-3.1) based on recent epidemiologic studies Higher in HLA-B27 populations

17. Diagnosis of AS Delayed As long as 8 years Longer delays in females

18. Diagnostic and Classification Criteria European spondyloarthropathy study group (ESSG) Assessment in Spondyloarthritis International Society (ASAS) proposed new set of diagnostic criteria enabling identification of SPA before structural changes occur in the spine

20. Changes now included in new classification criteria of early axial SPA Major tool diagnostically MRI

21. AS Symptoms Early adulthood Dull pain buttock / lower lumbar area Morning stiffness relived on exertion worsened on inactivity Enthesitis Inflammation at bone insertion sites of ligaments or tendons Pain of enthesopathy varies and depends on affected location Frank arthritis 25-35% involving large joints in asymmetrical fashion Neck pain with increased ROM later manifestation

22. Dactylitis (Sausage Digit) PSA REA Joint and tenosynovial inflammation

24. Other Clinical Features of AS Acute anterior uveitis – 30% often antedates spondylitis AI, CHF, aortitis, angina, pericarditis, conduction deficits Dyspnea, cough, hemoptysis = pulmonary fibrosis

25. Reactive Arthritis (REA) Arthritis 2-4 weeks after urogenital or enteric infection often in presence of HLA B27 antigen Risk 50% higher in HLA-B27 positive HLA B-27 positive associated with severity and chronicity Enthesitis 70% of patients Heel spur and pain Achilles tendonitis Knee synovitis with large effusions Dactylitis typical

27. Extra-articular Features Urethritis Cervicitis Vulvovaginitis and salpingitis Prostatitis Oral ulcers, e. nodosum, conjunctivitis Cardiac involvement

28. Enteropathic Associated Arthritis (IBD) 10% of patients may antedate IBD Asymmetric, large joints, lower limb Occasional symmetrical, small joint polyarthritis

29. Spondyloarthritis and Sacroilitis Independent course compared to bowel disease Milder than AS HLA-B27 positivity Weaker than AS 25-60% of patients positive

30. Undifferentiated Spondyloarthropathy (USPA) Patients without criteria for well-defined SPA Fewer extra-articular changes Sacroilitis / spondylitis absent, or very mild after years of active disease Good prognosis

31. Juvenile Spondyloarthropathy Asymmetric Lower extremity peripheral Boys aged 7-16 years Enthesitis and dactylitis prominent Systemic manifestations frequent in juvenile than adult form

32. Psoriatic Arthritis (PSA) Develops in 5-40% of psoriasis patients Incidence 7.2 per 100,000/year Existing psoriasis patients prevalence rises from .2% of 7-40%

33. Arthritis in PSA Asymmetric in small and large joints Patterns include: Mutilans Peripheral oligoarthritis / polyarthritis Spondylitis DIP arthritis (fingers and toes >50%)

34. Back Pain in PSA Cervical spine disease common (>50%) Progresses in severity in parallel with disease of peripheral joints Sacroilitis – 20% of patients Spondylitis – 5% of patients

35. PSA Nails (83%) or skin precede or follow joint involvement Scalp, behind ears, umbilicus or gluteal folds Fatigue, iritis, uveitis

37. Biomarkers to Assess PSA CRP Matrix metalloproteinase-3 Circulating osteoclast precursors HLA-B27 represents axial disease sacroilitis and spondylitis

38. Conventional Radiography Important outcome domain in clinical trials of (ASAS) Recognition of early bone changes beneficial in patients early therapy response to disease progression Inexpensive, easy to generate Widely available and inexpensive; rapid and easily studied in randomized and blinded environments

39. Imaging Role in Sacroilitis MRI and CT – high sensitivity and better detection of early sacroilitis but cost prohibits use in routine diagnosis Plain radiograph initial diagnostic tool but large inter and intraobserver variations documented

40. Battistone, et. al. Oblique views not justifiable High specificity (97.8%) low sensitivity (54.4%)

41. Radiographic Hallmarks in SPA Erosions – earliest – iliac side Periostitis Bone proliferation at enthesis Normal bone mineralization

44. Progression of Erosive Disease Widening of joint Reparative bone laid down behind erosions Total fusion of SIJ (ankylosis)

46. Radiographs Poor sensitivity to soft tissue and bony changes in early SI disease Bony changes not evident until advanced stage of disease Reliability unsatisfactory and leads to therapy delays

47. Sacroiliac Joint Involvement in (SPA) Most common early clinical finding First manifestations of disease

48. Criteria for Classification of SPA ESSG Amor Criteria Modified New York Criteria Criteria sets all fall short as these all depend on presence of radiological sacroilitis (often appears late in disease course) Long delay exists between initial symptoms and establishing a diagnosis

50. Conventional Radiography Assess structural spine changes Document more chronic lesions Not sensitive to change over 2 years