{'fraction_non_alphanumeric': 0.033085194375516956, 'fraction_numerical': 0.016542597187758478, 'mean_word_length': 4.931372549019608, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Spontaneous isolated lunate dislocation with migration into the forearm

A 78-year-old female with long-standing rheumatoid arthritis (RA) presented with an 18 month history of numbness and paraesthesia in the median nerve distribution of her left hand. There was no history of trauma. Radiographs showed complete volar dislocation of the lunate with migration into the forearm, without any subluxation of the other carpal bones (Figure 1). A radiograph 3 years earlier showed the lunate to be in the normal position but with a degree of dorsal intercalated segment instability (DISI) and an increased scapholunate gap. In addition, there was scaphotrapezio-trapezoid (STT) and scapho-capitate degenerative changes (Figure 2). The patient had a carpal tunnel release and removal of the lunate, which was not attached to any local tissues (Figure 3). This operation relieved her symptoms of carpal tunnel syndrome. The wrist is a commonly affected joint in RA. About 90% of patients who have had RA for 10 years will have wrist pathology (Muramatsu et al., 2004). Several reports in the literature mention traumatic dislocation of the lunate (Draaijers et al., 2003). However, only two previous reports mention