Compass hinge fixator for acute and chronic instability of the elbow [Der Compass-Gelenkfixateur bei akuter und chronischer Instabilität des Ellenbogens]

Objective: To maintain concentric reduction of an unstable elbow and to allow active exercises after the treatment of complex elbow injuries or their sequelae. Indications: 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. Contraindications: Absent patient compliance. Lack of familiarity of surgeon with elbow anatomy and function as well as with hinged external fixation techniques. Surgical Technique: 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 in-stability after fracture-dislocation, and a limited role in restoring mobility after severe contracture release. © Urban & Vogel Müchen 2005.