Role of scapholunate interosseous ligament in flexion-extension motion of scaphoid and lunate

Abstract

Objective To observe the resection of the scapholunate interosseous ligament (SLIL)and its subregions on the three-dimensional(3-D)movement of the scaphoid and lunate so as to discuss the role of SLIL in the 3D flexion-extension motion of the scaphoid and lunate.Methods Twelve upper extremities(six left extremities and six right extremities)from adult cadaver were used in this study and divided into five groups:normal group,proximal subregion resection group,proximal subregion plus dorsal subregion resection group,proximal subregion plus palmar subregion resection group and whole SLIL resection group.The 3-D laser scan and reconstruction technique were used for meusure ment of the 3-D flexion-extension motion of the scaphoid and lunate.Results In the normal group,the scaphoid and lunate flexed and the radial deviated at the same direction during wrist flexion-extension motion.At the same time,there was minimal scaphoid and lunate pronation-supination during wrist flexionextension.After resection of the proximal and palmar(or dorsal)subregions of the SLIL,some different movements were found compared with the normal specimen.Whole SLIL resection resulted in increase of the flexion motion of the scaphoid but decrease of the palmar flexion of the lunate.Conclusions 3-D laser scanning and image reconstruction techniques can accurately measure the 3D motion of the scaphoid and lunate.Partial or whole resection of SLIL may exert significant effect on the flexion-extension motion of the scaphoid and lunate.However,the proximal subregion of SLIL has no prominent effect on the motion of the scaphoid and lunate. Key words: Scaphoid bone; Lunate bone; Ligament; Imaging, three-dimensional; Motion analysis