Scapho-lunate dissociation and arthrodesis. An experimental study with lesions of the interosseous ligament and fusions with K-wires.
The carpal mechanism is studied during a sectioning of the ligament between the lunate and the scaphoid. A tear in this ligament is frequently observed in the clinic. After experimental lesions of this ligament, some authors say there is little effect while others report significant changes. We have conducted repetitions of these sectioning experiments using roentgen stereophotogrammetry to assess the kinematics of the carpal bones. We have found very little effect. We have also fused the scaphoid to the lunate to find out what happens to the carpal mechanism when the ligament between these bones is made stiffer. Fusion is carried out with K-wires and the effect upon the carpal mechanism is studied again. Our K-wiring of the scaphoid and lunate shows that the carpus starts to behave unpredictablely. The positions of the wires influence the outcome significantly. RELEVANCE--:The ligament between the scaphoid and the lunate has been assigned a main function in the carpal mechanism. It is still in debate, however, whether a lesion of this ligament by itself leads to the typical scapho-lunate dissociation pattern of the carpus. We have shown that a disruption of this ligament hardly influences the carpal mechanism. In time though, other ligaments may become overstretched so that finally the typical pattern may show up. K-wiring of the lunate and scaphoid to restore the connection between these bones results in a primarily unstable joint.
Hurkmans
H L P
HL
Department of Anatomy and Embryology, University of Nijmegen, Nijmegen, The Netherlands.
Kooloos
J G M
JG
Meijer
R S
RS