Miniarthroscopy of metacarpophalangeal joints in rheumatoid arthritis. Rating of diagnostic value in synovitis staging and efficiency of synovial biopsy

Objective. To evaluate miniarthroscopy (MA) (needle arthroscopy) of involve d joints in rheumatoid arthritis (RA) in the early detection and staging of synovitis and its application in visual guided synovial biopsies. Methods. 1.0 and 1.9 mm (0 degrees/30 degrees) arthroscopes were used in a 2 portal technique. MA performance was developed and evaluated first on han d cadavers (n = 20) and then transferred to metacarpophalangeal (MCP) joint s under local anesthesia conditions. Joints of 20 patients with RA with dif ferent disease activity and duration were scoped and rated according to sco res adapted from arthroscopy of other joints. Results, In 20/20 cases MA provided visualizing and magnification of intraa rticular features of MCP joints in RA and allowed grading of synovial alter ations, chondromalacia, and bony alterations. Synovial surface changes, thi ckness, and fibrosis were related to disease duration, as was damage to car tilage and bone. The degree of acute inflammatory reactions like vascularit y and hyperemia varied independently of chronic changes; synovial prolifera tion was reflected to some extent by C-reactive protein. In 2 patients with early RA, synovitis criteria were found macroscopically and histologically . In 18/20 joints, biopsies were taken under visual control; in the other 2 , progression of disease (Larsen score >3) limited arthroscopy to 1.0 scope imaging only. Sampling sizes were sufficient for histologic and molecular analysis. Conclusion. The developed standardized procedure of MCP arthroscopy is mini mally invasive, practicable, and well tolerated by patients, and may allow synovitis monitoring, staging, and biopsy in patients with early as well as chronic arthritis.