(12) Because of the extension force from the triquetrum transmitted through the lunotriquetral ligament, the lunate extends the proximal pole through the scapholunate ligament and the distal pole fexes producing a "humpback deformity." Volar flexion
of the scaphoid and dorsiflexion of the lunate can result in dorsal intercalated segmental instability (DISI) deformity.
The range of wrist motion (volar flexion, dorsal flexion, radial deviation, ulnar deviation, supination and pronation) was measured with a goniometer and grip strength was assessed with a hand dynamometer (Vigorimeter, Martin, Tuttlingen, Germany).
In the XCSR group, in comparison with the contralateral wrist, the following values were achieved: volar flexion, 82.5%; dorsal flexion, 82.0%; radial deviation, 85.7%; ulnar deviation, 61.3%; pronation, 92.6%; supination, 88.8 % and grip strength, 73.8%.