The intra-operative radius joystick test to diagnose complete disruption of the interosseous membrane

Abstract

Disruption of the interosseous membrane is easily missed in patients with Essex-Lopresti syndrome. None of the imaging techniques available for diagnosing disruption of the interosseous membrane are completely dependable. We undertook an investigation to identify whether a simple intra-operative test could be used to diagnose disruption of the interosseous membrane during surgery for fracture of the radial head and to see if the test was reproducible. We studied 20 cadaveric forearms after excision of the radial head, ten with and ten without disruption of the interosseous membrane. On each forearm, we performed the radius joystick test: moderate lateral traction was applied to the radial neck with the forearm in maximal pronation, to look for lateral displacement of the proximal radius indicating that the interosseous membrane had been disrupted. Each of six surgeons (three junior and three senior) performed the test on two consecutive days. Intra-observer agreement was 77% (95% confidence interval (CI) 67 to 85) and interobserver agreement was 97% (95% CI 92 to 100). Sensitivity was 100% (95% CI 97 to 100), specificity 88% (95% CI 81 to 93), positive predictive value 90% (95% CI 83 to 94), and negative predictive value 100%). This cadaveric study suggests that the radius joystick test may be useful for detecting disruption of the interosseous membrane in patients undergoing open surgery for fracture of the radial head and is reproducible. A confirmatory study in vivo is now required.

Radial axial interosseous load (RAIL) test for essex lopresti type injuries

“…6,[7][8][9][10][11] The current techniques to evaluate integrity of the interosseous membrane have been met with moderate success. 14,15 Smith et al described longitudinal traction to the radial shaft to evaluate proximal radial migration in ELI forearms. Soubeyrand et al reported lateral translation of the radial shaft as a confirmation of IOM and DRUJ incompetence.…”

Essex-Lopresti injuries: an update

“…22 The intra-operative joystick test describes the application of lateral traction to the radial neck in full pronation while looking for lateral translation of the radius; it has been suggested to be a sensitive and reproducible test. 23…”

Management of the Essex-Lopresti Injury

“…15 Other dynamic fluoroscopic tests have been described using compression force on the radius, 16 radioulnar transverse distraction, 17 and radioulnar translation (radius joystick test). 18 However, all of these tests may remain negative in the case of partial IOM injury or attenuation. 19…”