Biomechanical Evaluation of the Ligamentous Stabilizers of the Scaphoid and Lunate: Part III

Abstract

Purpose: This study continued our previous investigations of the ligaments stabilizing the scaphoid and lunate in which we examined the scapholunate interosseous ligament, the radioscaphocapitate, and the scaphotrapezial ligament. In this current study, we examined the effects of sectioning the dorsal radiocarpal ligament, dorsal intercarpal ligament, scapholunate interosseous ligament, radioscaphocapitate, and scaphotrapezial ligaments. In the current study, the scapholunate interosseous ligament, radioscaphocapitate, and scaphotrapezial ligaments were sectioned in a different order than performed previously.Methods: Three sets of 8 cadaver wrists were tested in a wrist joint motion simulator. In each set of wrists, only 3 of the 5 ligaments were cut in specific sequences. Each wrist was moved in continuous cycles of flexion-extension and radial-ulnar deviation. Kinematic data for the scaphoid and lunate were recorded for each wrist in the intact state, after the 3 ligaments were sectioned in various sequences and after the wrist was moved through 1,000 cycles of motion.Results: Dividing the dorsal intercarpal or scaphotrapezial ligaments did not alter the motion of the scaphoid or lunate. Dividing the dorsal radiocarpal ligament alone caused a slight statistical increase in lunate radial deviation. Dividing the scapholunate interosseous ligament after first dividing the dorsal intercarpal, dorsal radiocarpal, or scaphotrapezial ligaments caused large increases in scaphoid flexion and lunate extension. Conclusions:Based on these findings, we concluded that the scapholunate interosseous ligament is the primary stabilizer and that the other ligaments are secondary stabilizers of the scapholunate articulation. Dividing the dorsal radiocarpal, dorsal intercarpal, or scaphotrapezial ligaments after cutting the scapholunate interosseous ligament produces further changes in scapholunate instability or results in changes in the kinematics for a larger portion of the wrist motion cycle. KeywordsScapholunate instability; wrist; biomechanics Treatment of soft tissue injuries of the wrist is clinically frustrating. The diagnosis of which specific ligaments are injured is difficult. The most common instability problem occurs at the scapholunate (SL) joint. Many surgical procedures have been advocated, but the long-term outcomes of these procedures are undetermined. One of the primary difficulties in understanding this problem is that the specific function of the carpal ligaments is not known. It is important to define the function and relative importance of these structures to develop better surgical treatments for the injured SL joint. This biomechanical study is one of a series of experiments that evaluates the importance of ligaments that attach to the scaphoid or lunate. 1,2 According to previous anatomical studies 3-9 there are 7 ligaments that crossover or attach to the scaphoid or lunate. These are the scapholunate interosseous ligament (SLIL), the radioscaphocapitate ligament (RSC), the long radiolunate liga...

Arthroscopic dorsal ligamento capsulodesis results in Geissler grade 2 and 3 scapholunate interosseous ligament injuries

“…[12] Bu ayrışmanın sonucu ise el bileğinde sekonder dejeneratif değişikliklere yol açarak SLAC ile sonuçlana-bilir. [5,13,14] Watson ve Ballet [5] skafolunat bağ yaralanmasının dorsal el bileği ağrısının başlıca nedenlerinden olduğunu bildirmiş ve radyolojik bulgu saptanmayan olgularda saptadıkları bu lezyona dorsal el bileği sendromu adını vermişlerdir.…”

“…Yedi hastada el bileği ateli ve fizik tedavi uygulandık-tan bir süre sonra ağrının gerilediği gözlendi, fakat bu hastaların ağrısız bir süreç geçirdikten sonra ağrıla-rının tekrar başlaması üzerine ameliyat kararı alındı. Yakınmaların başlangıcından cerrahiye kadar geçen süre ortalama 13.68 (dağılım [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Cerrahi öncesi direkt grafi ve manyetik rezonans görüntüleme (MRG)'leri yapıldı. Skafolunat aralığın ölçümü, yumruk halinde iken çekilen el bileği ön-arka grafilerinin radyolojik olarak değerlendirilmesi ile yapıldı.…”

Kirschner Wire Fixations for Scapholunate Dissociation: A Cadaveric, Biomechanical Study

“…This suggests that a localised tear of the SL may occur without causing instability, perhaps because of the bony architecture. 23,24 Third, the number of cadavers was limited. Despite meticulous handling of fresh-frozen cadavers, 2 displayed rather unstable bones and tissue.…”

“…Full extension and flexion inevitably produce different results, although this may not be relevant in the postoperative healing period. 19,24 Sixth, wires were placed under direct vision which is not the case in surgical settings where ideal wire placement is not obligatory in order not to further disrupt circulation. Seventh, axial compression to failure was chosen instead of cyclic testing, which shows resistance to motion.…”

Anatomical Description of the Dorsal Capsulo-Scapholunate Septum (DCSS)—Arthroscopic Staging of Scapholunate Instability after DCSS Sectioning

“…6,7,[9][10][11][12][13][14][15][16][17] In this paper we describe an attachment between the dorsal wrist capsule, the dorsal part of the scapholunate interosseous ligament (SLIOL) and the dorsal intercarpal ligament (DIC) which we have termed the Dorsal Capsuloligamentous Scapholunate Septum (DCSS). It inserts on to the Keywords ► scapholunate complex ► scaphoLunate Instability ► capsuloScapholunate Septum ► DCSS…”