Scaphoid, lunate and capitate kinematics in the normal and ligament deficient wrist: A bi-plane X-ray fluoroscopy study

The ligamentous structures of the wrist stabilise and constrain the interactions of the carpal bones during active wrist motion; however, the three-dimensional translations and rotations of the scaphoid, lunate and capitate in the normal and ligament deficient wrist during planar and oblique wrist motions remain poorly understood. This study employed a computer-controlled simulator to replicate physiological wrist motion by dynamic muscle force application, while carpal kinematics were simultaneously measured using bi-plane x-ray fluoroscopy. The aim was to quantify carpal kinematics in the native wrist and after sequential sectioning of the scapholunate interosseous ligament (SLIL) and secondary scapholunate ligament structures. Seven fresh-frozen cadaveric wrist specimens were harvested, and cycles of flexion–extension, radial-ulnar deviation and dart-thrower’s motion were simulated. The results showed significant rotational and translational changes to these carpal bones in all stages of disruptions to the supporting ligaments (p