A DYNAMIC BIOMECHANICAL STUDY OF SCAPHOLUNATE LIGAMENT SECTIONING

A biomechanical study was performed on fresh cadaver forearms to inves tigate the role of the scapholunate interosseous ligament in carpal st ability. Scaphoid and lunate motion and radiocarpal and ulnocarpal pre ssure patterns were continually monitored while the wrist was moved ph ysiologically. Prior to ligament sectioning, it was found that the pos ition of the scaphoid and lunate were dependent on both the wrist posi tion and the direction of wrist motion. Sectioning the scapholunate in terosseous ligament caused increased scaphoid flexion, scaphoid pronat ion, and lunate extension. Pressure in the radiocarpal and ulnocarpal joint was redistributed following ligament sectioning. These findings support the clinical impression that the scapholunate interosseous lig ament is an important stabilizer of the scaphoid and lunate.