title: Radiographic laxity of the trapeziometacarpal joint is correlated with generalized joint hypermobility.
abstract: OBJECTIVE
  Increased joint laxity has been associated with the risk of ligament injury and development of osteoarthritis in large joints such as the knee, but this has not been investigated in depth in the hand. We hypothesized that generalized joint laxity would correlate with radiographic measures of trapeziometacarpal (TM) joint subluxation, as measured in carpometacarpal stress view radiographs.
  
  
  METHODS
  We recruited volunteer subjects of all ages and examined them for generalized laxity using the Beighton-Horan index. A total of 163 subjects, 81 men and 82 women, with an average age of 48 years (range, 20-83 y), were examined. Each subject underwent a stress view radiograph of both TM joints using a previously described technique. Different examiners independently measured radial subluxation of the thumb metacarpal over the trapezium and the articular width of the thumb metacarpal and averaged them. The ratio of the radial subluxation to the articular width was calculated as a measure of radiographic TM laxity.
  
  
  RESULTS
  The average Beighton score was 2 (range, 0-9). A total of 40 subjects had Beighton scores greater than 4. The mean stress view ratio was 0.31 (range, 0.06-0.58). When we calculated the Pearson correlation coefficient to assess the relationship between the stress view ratio and the Beighton score, a statistically significant correlation was demonstrated.
  
  
  CONCLUSIONS
  In normal volunteers generalized joint laxity is positively correlated with increased mobility of the TM joint, as demonstrated on carpometacarpal stress view radiographs.
  
  
  METHODS
  Diagnostic I.
authors.affiliation: Department of Orthopaedic Surgery, University of Colorado-Denver, and the Division of Nursing/Research, Denver Veterans Administration Medical Center, Denver, CO, USA. jmwolf@uchc.edu
authors.forename: Jennifer Moriatis
authors.initials: JM
authors.lastname: Wolf
authors.forename: Star
authors.initials: S
authors.lastname: Schreier
authors.forename: Scott
authors.initials: S
authors.lastname: Tomsick
authors.forename: Allison
authors.initials: A
authors.lastname: Williams
authors.forename: Brian
authors.initials: B
authors.lastname: Petersen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D052737:Carpometacarpal Joints / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000150:complications* / Q000000981:diagnostic imaging* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D019637:Orthopedic Procedures / Q000379:methods; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000209:etiology; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D012044:Regression Analysis; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D013314:Stress, Mechanical; D013933:Thumb / Q000000981:diagnostic imaging / Q000503:physiopathology; D051222:Trapezium Bone / Q000000981:diagnostic imaging / Q000503:physiopathology; D055815:Young Adult