Compass hinge fixator for acute and chronic instability of the elbow.
OBJECTIVE
To maintain concentric reduction of an unstable elbow and to allow active exercises after the treatment of complex elbow injuries or their sequelae.


METHODS
Recurrent dislocation or subluxation of the elbow after repair or reconstruction of bony, capsuloligamentous, and/or musculotendinous stabilizers. Tenuous fixation of large coronoid fractures due to fragmentation or osteopenia. Stabilization of the joint after fascial arthroplasty or debridement for infection, if the debridement destabilizes the elbow. Relative indication: maintenance of range of motion after release of contractures.


METHODS
Absent patient compliance. Lack of familiarity of surgeon with elbow anatomy and function as well as with hinged external fixation techniques.


METHODS
Preferably posterior longitudinal midline incision. Placement of axis pin in the center of rotation of the distal humerus. Application of the fixator over this wire. Placement of Schanz screws into humerus und ulna taking care to protect the radial and ulnar nerves. Removal of axis pin. Rechecking of entire frame and tightening.


RESULTS
The authors' experience with the Compass Hinge Fixator documents restoration of stability and excellent motion after relocation of a chronic simple elbow dislocation, a useful role in reconstructing acute and chronic elbow instability after fracture-dislocation, and a limited role in restoring mobility after severe contracture release.
Ring
David
D
Hand and Upper Extremity Service, Department of Orthopaedic Surgery, Massachusetts General Hospital, ACC 525, Boston, MA 02114, USA. dring@partners.org
Jupiter
Jesse B
JB
D000208:Acute Disease; D001858:Bone Nails; D001864:Bone Wires; D002908:Chronic Disease; D004551:Elbow Joint / Q000601:surgery*; D019544:Equipment Failure Analysis; D016267:External Fixators; D005592:Fracture Fixation / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D007593:Joint Instability / Q000534:rehabilitation* / Q000601:surgery*; D007595:Joint Prosthesis; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians'; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome