The scaphotrapezial ligament complex: an anatomic and biomechanical study.

An anatomic and biomechanical study of the ligamentous stabilizers of the scaphotrapezial trapezoidal joint was performed in 25 fresh cadaver specimens. A consistent scaphotrapezial ligament complex consisting of four entities was identified. This complex is comprised of a stout scaphotrapezial ligament on the radial and palmar aspects of the scaphotrapezial joint, weak palmar and dorsal capsules, and a scaphocapitate capsular ligament. A biomechanical study subsequently found that these structures were directly related to resisting diastasis of the scaphotrapezial trapezoidal joint. This information is helpful in understanding scaphoid tuberosity fractures, scaphotrapezial instability and arthrosis, scaphoid dislocations, and perhaps scapholunate disassociations.