title: Irreducible dislocation of the thumb interphalangeal joint due to displaced flexor pollicis longus tendon: case report and new reduction technique.
abstract: Dislocation of the thumb interphalangeal (IP) joint is uncommon because of the inherent stability of the joint. Cases in which reduction was blocked by the volar plate, the flexor pollicis longus (FPL) tendon, the sesamoid bone, and an osteochondral fragment have been described in the literature. This article reports a case of closed thumb IP joint dislocation caused by the displacement of the FPL tendon. A new percutaneous reduction technique for this injury will also be presented. A 63-year-old woman presented to the emergency room with an obvious thumb deformity. Radiographs confirmed dorsal dislocation of the thumb IP joint without associated fracture. Closed reduction was not successful. Percutaneous reduction was performed under locoregional anesthesia, because the dislocation was due to an FPL tendon that had displaced dorsally and radially to the proximal phalanx. After reduction, Kirschner wire fixation was not needed, but IP joint immobilization with a splint was required for 3 weeks. Postoperatively, there were no complications in soft tissues and the operative scar was almost unrecognizable. This technique enables a mini-invasive reduction by operating percutaneously on the FPL. In addition, unlike with a volar zigzag approach, it is possible to suppress the occurrence of postoperative adhesion of the flexor tendon. This new minimally invasive reduction technique is useful for irreducible dislocation of the thumb IP joint due to a displaced FPL tendon.
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University Shizuoka Hospital, 1129 Nagaoka, Izunokuni, Shizuoka, 410-2295, Japan, knaito@juntendo.ac.jp.
authors.forename: Kiyohito
authors.initials: K
authors.lastname: Naito
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Yuka
authors.initials: Y
authors.lastname: Igeta
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kaneko
authors.forename: Osamu
authors.initials: O
authors.lastname: Obayashi
mesh_terms: D000058:Accidental Falls; D001864:Bone Wires; D005260:Female; D005384:Finger Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006227:Hand Deformities, Acquired / Q000601:surgery; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D019637:Orthopedic Procedures / Q000379:methods*; D011859:Radiography; D013708:Tendon Injuries / Q000150:complications* / Q000601:surgery; D013933:Thumb / Q000293:injuries*