Degenerative change in symptomatic scaphoid nonunion.

A retrospective radiographic analysis of 64 patients with symptomatic scaphoid nonunions without previous surgical treatment was accomplished. The results showed a high frequency of degenerative changes occurring in a predictable sequence. For nonunions of 4 years duration, 75% of patients had radioscaphoid changes, and for those of 9 years duration 60% of the patients had midcarpal changes. The pattern of arthritis in scaphoid nonunion is that of scapholunate advanced collapse (SLAC) wrist resulting from rotary subluxation of the distal scaphoid fragment. The radius-proximal scaphoid fragment joint and the radiolunate joint were consistently spared from degenerative changes, even with severe arthritis. Instability was progressive and associated with an earlier onset of arthritis. Patients with symptomatic scaphoid nonunions appear to have a significant likelihood of arthritis developing.