1. Assessment of enthesitis in psoriatic arthritis
Philip Helliwell
University of Leeds

2. Assessment of enthesitis in psoriatic arthritis – why bother?
Enthesis suggested as hallmark patho-anatomical feature
Clinical and radiological enthesopathy one of distinguishing clinical features for spondyloarthropathy and psoriatic arthritis
Active clinical involvement may reflect general disease activity

3. What instruments already exist?
Mander enthesitis index (MEI)
Mander M, Simpson JM, McLellan A, Walker D, Goodacre JA, Dick WC. Studies with an enthesis index as a method of clinical assessment in ankylosing spondylitis. Ann rheum Dis 1987; 46:
MASES
Heuft-Dorenbosch L, Spoorenberg A, van Tubergen A, Landewe R, van der Tempel H, Mielants H et al. Assessment of enthesitis in ankylosing spondylitis. Annals of the Rheumatic Diseases 2003; 62:
SPARCC
Gladman DD, Cook RJ, Schentag C, Feletar M, Inman RI, Hitchon C et al. The clinical assessment of patients with psoriatic arthritis: results of a reliability study of the spondyloarthritis research consortium of Canada. J Rheum 2004; 31(6):
MAJOR
Braun J, Brandt J, Listing J, Zink A, Alten R, Golder W et al. Treatment of active ankylosing spondylitis with infliximab: a randomised controlled multicentre trial. Lancet 359(9313): , 2002.

4. Mander (MEI) enthesitis index
Nuchal crests
Manubriosternal joints
Costochondral joints
Greater tuberosity of humerus
Lateral and medial epicondyles of humerus
Iliac crests
Ant sup iliac spines
Greater trochanter of femur
Medial and lateral condyles of femur
Insertion of Achilles tendons
Insertion of plantar fascia
Cervical, thoracic and lumbar spinous processes
Ischial tuberosities
Post sup iliac spines
Basic score uses graded response with score range 0-90
Modified score uses binary response with score range 0-30

5. MASES enthesis index Reduced number of sites (13)
Removed grading of tenderness (binary response)
Avoided joint margins
Better reliability
1st Costochondral joints
7th costochondral joints
Iliac crests
Ant sup iliac spines
Insertion of Achilles tendons
lumbar spinous processes
Post sup iliac spines

6. SPARCC enthesis index 8 sites Not graded
Reliability shown in SPARCC study (Gladman et al. J Rheum 2004; 31(6): )
Greater tuberosity of humerus
Insertion of Achilles tendons
Insertion of plantar fascia
Tibial tuberosity

7. MAJOR enthesis index Graded as present/absence of tenderness
Iliac crests
Greater trochanter of femur
Medial and lateral condyles of femur
Insertion of Achilles tendons
Insertion of plantar fascia

8. Reliability of enthesitis indices Results from INSPIRE study
Figures are ICC (95% CI)
Psoriatic arthritis
Ankylosing spondylitis
MAJOR
0.70 (0.5 – 0.89)
MASES
0.56 (0.34 – 0.82)
SPARCC
0.81 (0.64 – 0.93)

9. A new index for psoriatic arthritis
28 Ss with ‘active’ psoriatic arthritis starting treatment with new DMARDs
All had enthesitis assessed at each of 5 visits over 6 months
MEI (x2), MASES, SPARCC, MAJOR
On final dataset performed data reduction using method of Heuft-Dorenbosch
Heuft-Dorenbosch L, Spoorenberg A, van Tubergen A, Landewe R, van der Tempel H, Mielants H et al. Assessment of enthesitis in ankylosing spondylitis. Annals of the Rheumatic Diseases 2003; 62:

10. A new index for psoriatic arthritis
All MEI entheseal points graded to binary
Frequency tables – entheseal point found to be most frequently tender, noted, and these patients not included in next ‘round’
Process repeated until 80% assessments included

11. A new index for psoriatic arthritis
80% of assessments included after just 3 ‘rounds’
1st round: right lateral epicondyle (49%)
2nd round: right medial femoral condyle (70%)
3rd round: right PSIS, Cx spinous process and left Achilles insertion were equal (80%)
LENIN: right and left lateral epicondyle humerus, right and left medial femoral condyle, right and left AT insertion (max 6)

12. Change in enthesis scores following treatment change
MEI scores are divided by 10

13. Relationship between enthesis indices and other measures of disease activity
Values >±0.2 are significant

14. Assessment of enthesitis in psoriatic arthritis
Indices developed in patients with ankylosing spondylitis seem to function well in psoriatic arthritis
Repeatability
Responsiveness
Relation to other measures of disease activity
New index derived from psoriatic arthritis population also functions well, although possibly not as well, has good effect size, and is quick and simple to perform

15. The OMERACT filter Truth Discrimination Feasability
Poor relationship between clinical and U/S detected enthesitis
Juxta-articular position of entheses may lead to confounding with articular pain
Discrimination
All indices able to discriminate between states of low and high disease activity (data not shown)
All indices show good responsiveness and effect sizes
Feasability
LENIN is quickest and easiest but all others, excepting MEI, are also simple to perform

16. Acknowledgements Rose Hellaby Trust supported Paul Healy
Sanofi-Aventis provided funding for the study and the MRI scans (dactylitis)

17. Clegg et al A+R :
Enthesopathy index

18. Infliximab in PsA: Enthesitis Over Time*
*P = 0.05 vs placebo
Antoni C, et al. Arthritis Rheum. 2002;46:S380.

19. Scores on the Mander (coded to binary) and the new index for each participant

20. Histogram of scores on new index

21. The new dactylitis index for psoriatic arthritis
Lateral epicondyle of elbow
Medical condyle of femur
Achilles tendon insertion