Idiopathic avulsion of the flexor pollicis longus: Case report and review of the literature

摘要

Atraumatic closed rupture of the flexor pollicis longus (FPL) tendon is uncommon. When it occurs, it is usually associated with a recognizable pathologic etiology. Cited contributing factors for FPL tendon rupture include rheumatoid arthritis [3, 9, 29], Colles’ fracture [6, 21, 27, 39], exostosis of the distal radius [10], scaphoid exostosis [10, 26, 29], ulnar metacarpophalangeal joint sesamoid osteophyte [36, 37], interphalangeal sesamoid osteophyte [34], scaphoid nonunion [7, 18, 19, 28, 32, 35, 40, 42], Kienb?ck's disease [14], lunate silicone replacement degradation [5], intratendinous corticosteroid injection [30], retained glass fragments [13], migration of a retained foreign body [41], intratendinous tumor proliferation [16], and mucopolysaccharidosis [38].Rarely, a cause for atraumatic FPL tendon rupture cannot be found. Boyes defined a spontaneous flexor tendon rupture as an intratendinous disruption, which occurs with normal axial loading in the absence of any identifiable underlying abnormality [3]. Seven cases of spontaneous rupture of the FPL have been reported [3, 12, 20, 25, 30]. Only one case of idiopathic avulsion of the FPL tendon insertion was found in the literature [33]. A second case of idiopathic FPL avulsion is described followed by a literature review of spontaneous FPL tendon rupture and idiopathic FPL tendon avulsion. For the sake of consistency, we will use the term spontaneous for intratendinous FPL ruptures previously reported as such in the literature. Idiopathic will be used when discussing unexplainable FPL tendon avulsions.