Floating Thumb with Simultaneous Carpometacarpal and Metacarpo-phalangeal Dislocation: A Case Report

Abstract

Double dislocation of carpometacarpal and metacarpo-phalangeal joints of thumb is also called ‘floating thumb metacarpal’. This rare injury usually presents with combined joints dislocation and collateral ligaments rupture, which may be predisposing to joint instability after closed reduction. We report a case of traumatic and chronic dislocation of carpometacarpal and metacarpo-phalangeal joints of left thumb in a 63-year-old housewife. Failure of non-operative treatment was found up to 1 month after injury due to missed follow-up. Closed reduction was tried but failed because of joints stiffness. Open reduction and K-wire fixation were performed and radial collateral ligaments were repaired. Patient restored good functional outcome with no evidence of arthritis or subluxation at 1 year. Open reduction and fixation show good result in our case with delayed surgical intervention. The management of a floating thumb could be non-operative by close reduction and cast immobilization. However, closed monitoring and regular follow-up are critical after non-operative treatment to avoid potential risk of post-operative complications.