Chronic asymptomatic contralateral wrist scapholunate dissociation

Background: The authors report a series of six patients who presented with scapholunate dissociation, with no significant contralateral antecedent trauma and no rheumatoid arthritis or congenital ligamentous laxity. Such patients may present with pain or a snapping/popping sensation in one wrist, undergo radiographs of both wrists, and are discovered to have scapholunate gapping bilaterally. The literature contains few reports of this condition, and this series of six is a relatively large one for this infrequently reported condition. Methods: The six charts were reviewed retrospectively; each patient was asked to return for follow-up and radiographic examination and each participated in a telephone questionnaire about pain, activity changes, new treatments, and exacerbation of wrist problems. The average follow-up was 39 months, with a range of 6 months to 13.5 years. Results: One patient with severe unilateral instability and persistent pain underwent soft-tissue surgical repair (Blatt reconstruction); another demonstrated unilateral dorsal intercalated segment instability with moderate pain symptoms but declined surgical reconstruction. The other 10 wrists, despite radiographically demonstrated widened scapholunate angles and rotatory subluxation of the scaphoid, had mild or no pain and no dorsal intercalated segment instability deformity. Conclusions: The evolution of the bilateral form of scapholunate dissociation seems to be benign unless dorsal intercalated segment instability deformity is present, which may then rapidly progress to degenerative arthritis and scapholunate advanced collapse wrist. Severe or minor repetitive trauma, inflammation, infection, tumors, and congenital ligamentous laxity have been etiologically implicated in scapholunate dissociation. The natural history of scapholunate dissociation involves volar rotation of the scaphoid and dorsal rotation of the lunate, progressing to malalignment and eventual arthrosis between the scaphoid and radius, the capitate and lunate, and the lunate and hamate bones.