title: A new autocentering hinged external fixator of the elbow: a device that stabilizes the elbow axis without use of the articular pin.
abstract: BACKGROUND
  Hinged external fixation of the elbow is an important tool for the orthopedic surgeon. It enables early postoperative mobilization that may result in better outcomes. All models require correct alignment with the elbow axis of rotation. There is a long learning curve to this procedure, it may be time-consuming, and it can be associated with a high dose of x-ray exposure. An axial pin can interfere with bone-ligament suture anchors and bone reconstruction plates.
  
  
  METHODS
  A new external fixator has been designed and mechanically tested. The hinge has a special gear able to freely align itself with the center of elbow rotation during passive flexion-extension movements. It has been clinically tested on 7 patients affected by traumatic and post-traumatic elbow disorders. The maintenance of the correct position has been tested clinically with computed tomography scans and radiographs.
  
  
  RESULTS
  All patients had correct alignment of the axis of rotation of the external fixator with the axis of elbow rotation. No cases of misalignment, loss of fixation, pin loosening, or instability were found.
  
  
  CONCLUSIONS
  A new self-centering hinged external fixator correctly aligns itself with the axis of elbow rotation. It does not interfere with ligamentous reconstruction anchors, distal plates, or screw fixation. The surgical technique is easy to learn and relatively quick. It can also be positioned without performing an arthrotomy to maintain reduction of simple dislocations of the elbow.
authors.affiliation: Department of Hand Surgery and Reconstructive Microsurgery, Azienda Ospedaliero Universitaria Careggi, Florence, Italy. Electronic address: pbigazzi@prosperius.it.
authors.forename: Prospero
authors.initials: P
authors.lastname: Bigazzi
authors.affiliation: Department of Hand Surgery and Reconstructive Microsurgery, Azienda Ospedaliero Universitaria Careggi, Florence, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Biondi
authors.affiliation: Department of Engineering, Università degli Studi di Firenze, Florence, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Corvi
authors.affiliation: Department of Hand Surgery and Reconstructive Microsurgery, Azienda Ospedaliero Universitaria Careggi, Florence, Italy.
authors.forename: Sandra
authors.initials: S
authors.lastname: Pfanner
authors.affiliation: Department of Hand Surgery and Reconstructive Microsurgery, Azienda Ospedaliero Universitaria Careggi, Florence, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Checcucci
authors.affiliation: Department of Hand Surgery and Reconstructive Microsurgery, Azienda Ospedaliero Universitaria Careggi, Florence, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Ceruso
mesh_terms: D000328:Adult; D000368:Aged; D004551:Elbow Joint / Q000601:surgery*; D004867:Equipment Design; D016267:External Fixators; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000601:surgery; D007593:Joint Instability / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D000092464:Elbow Injuries
keywords: External fixator of the elbow; elbow collateral ligament injury; elbow dislocation; elbow fracture; elbow instability; elbow trauma