Artikel
The Critical Ligamentous Stabilizers of the Intercalated Segment. A Cadaveric Study
Suche in Medline nach
Autoren
Veröffentlicht: | 6. Februar 2020 |
---|
Gliederung
Text
Objectives/Interrogation: Isolated injuries of the scapholunate interosseous ligament (SLIL) are insufficient to cause changes in scaphoid or lunate posture on static radiographs. Complete injuries of the SLIL may not produce lunate extension or increases in scapholunate gap (SLG) and scapholunate angle (SLA) acutely. Disruption of secondary ligamentous stabilizers are critical.
The aim of this study was to evaluate the role in carpal posture of the long radiolunate (LRL), scaphotrapeziotrapezoid (STT) and dorsal intercarpal (DIC) ligaments in a cadaveric SL instability model.
Methods: 30 fresh-frozen forearm specimens were randomized to 5 ligament section sequences, studying SLIL, LRL, STT and DIC. The DIC-lunate insertion (DICL) and scaphoid insertions (proximal pole and waist, DICS) were studied separately, DIC insertions on the trapezium and triquetrum were left intact. Loaded posteroanterior and lateral standardized radiographs were taken at baseline and repeated after each ligament was sectioned. After each step in the sequence, wrists were subject to cyclic loading (71 N load).
Radiolunate angle (RLA), scapholunate angle (SLA) and dorsal Scaphoid Translation (DST) were measured in lateral radiographs with load, scapholunate gap (SLG) was measured in loaded PA views. Statistical analysis was conducted using ANOVA for repeated measures with Bonferroni poshoc analysis.
Results and Conclusions: Complete sectioning of the SLIL did not increase RLA, SLA or SLG. Section of SLIL and LRL (p=0.002), STT (p=0.011) or DICL (p=0.02) significantly increased RLA. Dorsal intercalate segment instability (DISI) was recreated with SLIL + STT or SLIL + DICL+S disruption. SLA significantly increased when in addition to SLIL, the STT (p=0.0008) or DICL (p <0.03) were cut. SLG increased when SLIL, DICL, DICS, and STT were cut in Group 1, all ligaments sectioned (Groups 2, 3 and 5) or SLIL, LRL, STT and DICL in group 4.
In addition to SLIL, division of at least one major secondary ligament stabilizer of the scaphoid or lunate (STT, DICL or LRL) produced significant changes in lunate extension.
SLA increase was recreated when SLIL and scaphoid (STT) or lunate (DICL) ligamentous attachments were sectioned.
There is a spectrum of radiographic manifestations of Scapholunate dissociation, depending on the secondary stabilizers injured.