Carpal instabilities and secondary degenerative changes due to lesions of the radiocarpal ligament complex

This paper reports on trauma, rheumatoid arthritis, calcium pyrophosphate dihydrate crystal deposition (CPDD), neurologic disease, and beta2-microglobulin-related amyloid deposits in patients undergoing chronic hemodialysis that can lead to distinct lesions of the radiocarpal ligament complex, causing rotational subluxation of the scaphoid and ulnar translocation of the carpus. The clinical and radiologic findings were analyzed in 35 patients, examined from 1985 to 1989. Degenerative changes in rotational subluxation of the scaphoid develop in three steps. First there is osteoarthritis at the styloid process, then the degeneration progresses into the central midcarpal joint, and finally it progresses to the ulnar midcarpal joint. Despite different etiologies of ligament failure, the radiologic features are very similar, because the mechanism of degeneration is identical in posttraumatic, inflammatory, neurogenic, CPDD, or beta2-microglobulin-related instability. However, there are some distinct radiologic differences in relation to the primary cause of the ligament defect