Natural History of Scaphoid Nonunion

Scaphoid fracture is the most common fracture of the carpus. The excessive extension force with axial loading in the wrist can fracture the scaphoid or in the slightly flexion position with excessive axial loading, such as in a punching machine. Once the scaphoid is fractured, gradually, the distal fragment flexes, due to the force from the flexor carpi radialis, and the proximal fragment extends, as the extension force passes through the scapholunate ligament from the triquetrum. This motion inside the proximal row indicates the dorsal intercalated segment instability (DISI) deformity after scaphoid fracture/nonunion.[1] Sometimes, scaphoid fracture patients were claimless and easily neglected or misdiagnosed in the initial period of trauma. Watson[2] described degenerative arthritis with chronic scapholunate dissociation as scapholunate advanced collapse (SLAC) wrist. Similar behavior had occurred in scaphoid nonunion as SLAC wrist, and it was termed as scaphoid nonunion advanced collapse (SNAC) wrist, in which stage 1 showed degenerative condition around the radial styloid process; stage 2 showed degenerative changes between distal fragment of the scaphoid and scaphoid fossa of the radius; and stage 3 indicated degenerative changes in the midcarpal joint, resulting in the capitate proximal migration collapse. That is why we, as clinicians, usually attempted to reconstruct the scaphoid nonunion, even in cases with more than 10 years history from initial injury. However, in daily clinical practice, sometimes we observed normal alignment of the proximal carpal row in chronic scaphoid nonunion with long-term neglect.

This issue includes the “Special Review” of “Revisiting the natural history of chronic Scaphoid Nonunions: a retrospective study of 20 cases” described by Dr. Jerome. He reviewed 20 cases of scaphoid nonunion without any surgery and with history of scaphoid nonunion from 10 to 62 years. He mentioned that clinical outcomes of these 20 cases were relatively acceptable and raised six clinical questions, including “Does anyone with long duration of scaphoid nonunion need treatment?” We, however, do not know all the answers in relation to scaphoid nonunion. Interesting wrist papers pertaining to de Quervain tenosynovitis, ulnar styloid fractures, distal radioulnar joint (DRUJ) instability and meta-analysis of distal radius fracture, anatomy papers discussing the accessory ossicles of the wrist, and interesting case reports are also included. Do not miss it.

Publication History

Article published online:
04 October 2021

• References

• 1 Linscheid RL, Dobyns JH, Beabout JW, Bryan RS. Traumatic instability of the wrist. Diagnosis, classification, and pathomechanics. J Bone Joint Surg Am 1972; 54 (08) 1612-1632
• 2 Watson HK, Ballet FL. The SLAC wrist: scapholunate advanced collapse pattern of degenerative arthritis. J Hand Surg Am 1984; 9 (03) 358-365