Wassenberg et al developed a score for evaluating bony changes in a patient with psoriatic arthritis as seen on radiographs. It takes into account both the joint destruction and bone proliferation that characterizes psoriatic arthritis. This can be used during the initial evaluation and to monitor the patient over time. The authors are from Evangelische Fachkrankenhaus in Ratingen and Innere Abteilung in Emmerich, Germany.
40 separate joints are examined:
(1) distal interphalangeal (DIP) joints from left hand (4)
(2) proximal interphalangeal (PIP) joints from left hand (4)
(3) interphalangeal (IP) joint from the left thumb (1)
(4) metacarpophalangeal (MCP) joints from left hand (5)
(5) left wrist (1)
(6) distal interphalangeal (DIP) joints from right hand (4)
(7) proximal interphalangeal (PIP) joints from right hand (4)
(8) interphalangeal (IP) joint from the right thumb (1)
(9) metacarpophalangeal (MCP) joints from right hand (5)
(10) right wrist (1)
(11) interphalangeal (IP) joint from left great toe (1)
(12) metatarsophalangeal (MTP) joints from left toes 2, 3, 4 and 5 (4)
(13) interphalangeal (IP) joint from right great toe (1)
(14) metatarsophalangeal (MTP) joints from right toes 2, 3, 4 and 5 (4)
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Extent of Joint Destruction
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Points
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none (normal)
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0
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1 or more definite erosions with an interruption of the cortical plate > 1 mm and with destruction of the total joint surface < 10%
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1
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1 or more erosions with destruction of 11 - 25% of joint surface
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2
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destruction of 26 - 50% of joint surface
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3
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destruction of 51 - 75% of joint surface
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4
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destruction of > 75% of joint surface OR bony ankylosis
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5
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total score for joint destructi>
= SUM(points for all 40 joints)
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Extent of Bony Proliferation (Increased Bone)
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Points
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none (normal)
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0
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1 - 2 mm OR 1 - 25% of original diameter
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1
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2 - 3 mm OR 26 - 50% of original diameter
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2
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> 3 mm OR > 50% of original diameter
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3
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bony ankylosis
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4
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total score for bony proliferati>
= SUM(points for all 40 joints)
Interpretation:
• minimum scores: 0
• maximum score for joint destruction: 200
• maximum score for bony proliferation: 160
