"DISI deformity on sagittal images (dorsal tilt of the lunate with a scapholunate angle of >60–80° and a capitolunate angle of >30°) 8"
"MR arthrography can show contrast leakage from the radiocarpal space into the midcarpal space, which is considered very sensitive but can yield false-positive results. It also helps identify which part of the ligament is torn (dorsal, membranous, or volar), assess whether the tear is partial or complete (crucial for clinical staging and surgical planning), and detect associated injuries 12."
"Scapholunate dissociation refers to loss of normal alignment and synchronous motion between the scaphoid and lunate 8. Often, it is used synonymously with its primary pathophysiologic correlate, scapholunate interosseous ligament (SLIL) injury. Although additional ligaments are injured in scapholunate dissociation, the SLIL is the primary target of surgical reconstruction."
"Scapholunate diastasis denotes an abnormally widened scapholunate interval but is not synonymous with dissociation, as this can occur without a widened scapholunate interval 8."
"Rotatory subluxation of the scaphoid refers to pathological scaphoid rotation, which may occur with or without ligamentous injury 8."
"Dorsal intercalated segment instability (DISI) is a related carpal malalignment pattern that also results from scapholunate interosseous ligament rupture 4."
"Major injury of the SLIL (complete tear of the dorsal component) and radiolunate ligament may result in scapholunate dissociation. However, even complete SLIL transection does not result in permanent dissociation due to the presence of secondary scaphoid stabilisers, e.g. palmar radioscaphocapitate, scaphocapitate, and anterolateral scaphotrapeziotrapezoid ligaments. Long-term wear on these secondary ligamentous stabilisers may lead to permanent deformity / scapholunate advanced collapse 4."
"scapholunate diastasis: widened scapholunate interval >3-4 mm on PA view 8-10 (i.e. Terry Thomas sign) when measured at the midpoint on a well-positioned radiograph"
"PA views with wrist in ulnar deviation (causes intercalated segment extension)"
"rotatory subluxation: ringed appearance of the distal scaphoid, resulting from the scaphoid tubercle viewed en face, superimposed over the scaphoid waist (signet ring sign) 8"
"MR arthrography"
Expected headings
"Associations"
"MR arthrography"
"Carpal dissociation implies carpal instability, which has important clinical implications; thus, it is essential to identify this finding on imaging. Note that the absence of dissociation does not exclude ligamentous injury, as lower-grade injuries that result in dynamic instability may present with normal radiographic carpal alignment."
"volar component: 1 mm in thickness; obliquely orientated 5"