Background The radiographic joint damage in patients with rheumatoid arthritis (RA) is commonly evaluated by van der Heijde total Sharp score, intended only for the assessment of small joints. For the evaluation of large joints, Larsen grade is usually used. However, this grading system, composed of only 6 grades (0-5), has several limitations such as ceiling effect within the grade. Therefore, we developed a new radiographic scoring method for large joints in RA (Assessment of Rheumatoid Arthritis by Scoring of Large Joint Destruction and Healing in Radiographic Imaging: ARASHI) 1).
Objectives The purpose of this study is to evaluate the radiographic damage of hip and knee joints in RA during TNF-blocking therapies by this new radiographic scoring method, and to clarify the pattern of the progression of damage during 2 year therapies.
Methods ‘ARASHI status score’ consists of 4 categories; joint space narrowing (0∼3 points), erosion (0∼3 points), joint surface (0∼6 points), and stability (0∼4 points), (total score range 0-16 points)1). ‘ARASHI change score’ consists of 5 categories; porosis (-1∼1 point), joint space narrowing (-1∼2 points), erosion (-2∼2 points), joint surface (-6∼6 points), and stability (-1∼1 point), (total score range -11∼12 points) 1). Increase in more than 1 point of change score was considered as progression of joint damage. Fifty one consecutive patients (6 males, 45 women, mean age of 59.9 years old) were enrolled in this study. All patients fulfilled the ACR 1987 revised criteria. The joints with history of surgical intervention were excluded from this analysis. The radiographic findings of96 hip joints and 86 kneejoints were evaluated at baseline using the ARASHI status score, and at 1 and 2 years after TNF-blocking therapies (infliximab, etanercept or adalimumab) using the ARASHI change score.
Results There were 4 hip joints and 8 knee joints with 3 and more points of the status score at baseline. All of these joints resulted in significant increase in the change score during 2-year TNF-blocking therapies. On the other hand, joints with pre-existing status score of 0-2 points showed progression of joint damage only in 4.3% of the hip joints and in 9.0% of the knee joints during the follow-up period.
Conclusions ARASHI scoring method was useful for radiographic assessment of the status and the progression of damage in large weight-bearing joints. In this study, we demonstrated that hip and knee joints with pre-existing damage greater than 2 points of the status score were highly predisposed to progressive destruction even under TNF-blocking therapies. Therefore, it is prerequisite for the hip and knee joints to be radiologically evaluated not to exceed status score 2 before the start of TNF-blocking therapies.
A. Kaneko, I. Matsushita, K. Kanbe, K. Arai, Y. Kuga, A. Abe, T. Matsumoto, N. Nakagawa, K. Nishida. Development and validation of a new radiographic scoring system to evaluate bone and cartilage destruction and healing of large joints with rheumatoid arthritis: ARASHI (Assessment of rheumatoid arthritis by scoring of large joint destruction and healing in radiographic imaging) study. Mod Rheum 2013, in-press.
Disclosure of Interest None Declared