Abstract
The pathoanatomy of carpal instability is multifactorial and usually complex. A thorough
medical history and clinical examination are essential, as well as profound knowledge
of the specific instability patterns. The stability of the wrist is ensured by the
carpal joint surfaces, by intact intra-articular (particularly the scapholunate interosseous
ligament) and intracapsular ligaments, and by crossing extensor and flexor tendons,
the latter making the proximal carpal row an “intercalated segment.” An important
classification feature is the distinction between dissociative and nondissociative
forms of carpal instability. Among others, scapholunate dissociation, lunotriquetral
dissociation, midcarpal instability, and ulnar translocation are the most common entities.
Early forms of instability are considered dynamic. In the natural course, static instability
of the wrist and osteoarthritis will develop. This review focuses on the pathoanatomical
fundamentals of the various forms of carpal instability.
Keywords
carpal alignment - dissociative - instability - ligaments - nondissociative
