INTRAARTICULAR PRESSURE CHANGES IN RHEUMATOID AND NORMAL PERIPHERAL JOINTS

Objective-To investigate the intraarticular pressure (IAP) dynamics of a spectrum of joints in rheumatoid and normal subjects in order to de termine whether a reperfusion event is likely to occur at these sites. Methods-IAP was measured in the metacarpophalangeal (MCP) (n = 8), wr ist (n = 8), ankle (n = 4), and elbow joints (n = 4) of rheumatoid sub jects, in addition to the MCP (n = 8), wrist (n = 6), and ankle joints (n = 1) of normal healthy controls, using the hand held portable 295- 1 Intra-Compartmental Pressure Monitor System (Stryker, UK). Results-R esting IAP was positive in all rheumatoid joints, and subatmospheric o r weakly atmospheric in normal subjects (p < 0.01). Exercise produced an increase in IAP in rheumatoid subjects only (p < 0.01). The additio n of saline to normal joints mimicked the IAP changes seen in the rheu matoid group. Conclusion-These observations suggest that increased res ting IAP is a marker for chronic joint inflammation. The LAP increase seen in the rheumatoid group during exercise supports the concept of h ypoxic reperfusion mediated joint injury.