title: Intra-articular pressure changes in rheumatoid and normal peripheral joints.
abstract: OBJECTIVE
  To investigate the intraarticular pressure (IAP) dynamics of a spectrum of joints in rheumatoid and normal subjects in order to determine whether a reperfusion event is likely to occur at these sites.
  
  
  METHODS
  IAP was measured in the metacarpophalangeal (MCP) (n = 8), wrist (n = 8), ankle (n = 4), and elbow joints (n = 4) of rheumatoid subjects, 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
  Resting IAP was positive in all rheumatoid joints, and subatmospheric or weakly atmospheric in normal subjects (p < 0.01). Exercise produced an increase in IAP in rheumatoid subjects only (p < 0.01). The addition of saline to normal joints mimicked the IAP changes seen in the rheumatoid group.
  
  
  CONCLUSIONS
  These observations suggest that increased resting IAP is a marker for chronic joint inflammation. The IAP increase seen in the rheumatoid group during exercise supports the concept of hypoxic reperfusion mediated joint injury.
authors.affiliation: Bone and Joint Research Unit, London Hospital Medical College, United Kingdom.
authors.forename: K
authors.initials: K
authors.lastname: Gaffney
authors.forename: R B
authors.initials: RB
authors.lastname: Williams
authors.forename: V A
authors.initials: VA
authors.lastname: Jolliffe
authors.forename: D R
authors.initials: DR
authors.lastname: Blake
mesh_terms: D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000503:physiopathology; D001172:Arthritis, Rheumatoid / Q000503:physiopathology*; D004551:Elbow Joint / Q000503:physiopathology; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D007596:Joints / Q000503:physiopathology*; D008297:Male; D008662:Metacarpophalangeal Joint / Q000503:physiopathology; D008875:Middle Aged; D011312:Pressure; D015427:Reperfusion Injury / Q000503:physiopathology; D014955:Wrist Joint / Q000503:physiopathology