Plate Fixation of Olecranon Frx


- Discussion: (see olecranon frx menu)
    - indicated for comminuted olecranon frx and frx which occur at or distal to the coronoid process;
           - if frx extends distally past midpoint of trochlear notch, it no longer represents only a disruption of the triceps
                   mechanism but also comprimises the stability of elbow in withstanding varus & valgus forces / in this case,
                   plate fixation is required;
           - these fractures will be subjected to increase rotational forces that may cause tension band fixation to fail;
    - distance between coronoid process & olecranon must not be shortened by compression of the comminuted fragments;
    - always explain to patient beforehand that plate may require future removal;
    - note that in the study by Hume MC and Wiss DA (1992), plate fixation yielded significantly better clinical results than TBW;
           - comminuted olecranon fractures are another indication for plate fixation;
           - associated coronoid process fracture
                   - coronoid fracture is exposed by reflexion of the olecranon fracture and attached triceps proximally;
                   - direct exposure is achieved working through the fracture site;
                   - coronoid is stabilized with w/ screws w/ the heads screwed down to the level of the fracture site;
                   - the main olecranon fracture is then reflected back down, reduced and fixed in the usual manner;
                   - Olecranon fractures. A clinical and radiographic comparison of tension band wiring and plate fixation.

- Implants:
    - w/ pts < sixty years old, consider 3.5-mm AO DCP contoured to fit fractured olecranon following reduction;
    - this neutralizes forces across coronoid frx from tip of olecranon to shaft;
    - alternatively use  or 3.5 pelvic reconstruction plate;
    - one third tubular is another alternative in compliant patients;
    - if 3.5 DCP or 3.5 pelvic recon plate is to be used, a bending press will be required for contouring;

- Surgical Approach:
    - reduction:
           - reduction of olecranon frx is easiest w/ elbow in extension which relaxes the pull of the triceps muscle;
           - once reduced, apply towel clamp to frx site;
           - consider placing the tips of the two towel clamps in tension band holes;
           - ref: Impact of olecranon fracture malunion: Study on the importance of PUDA (Proximal Ulna Dorsal Angulation).
    - initial fixation:
           - frx of olecranon which is distal to midpoint of trochlear notch, if not comminuted, such as oblique frx, is first stabilized w/ lag screws;
           - K wires are not enough for lateral support;
           - to overcome valgus/varus instability distal frxs, need to be supplemented w/ plate, even if fixed w/ lag screws,

- Plate Fixation: (3.5-mm AO DCP)
    - contour the dorsally applied plate to allow the fully threaded proximal screw to be inserted at 90 deg to the more distal screws;
    - the next two distal screws can usually be placed in the proximal fragment, and should be aimed to avoid the proximal screw;
    - the next screw should be placed in compression mode;
          - if the coronoid process is fractured, skip the overlying screw hole and apply compression to the next most distal screw hole;
          - subsequently, a lag screw can be inserted through the plate (neutral mode) to grab the coronoid fracture fragment;

- Case Example:  


- Plate Fixation for Olecranon Nonunion: (from Danziger and Healy (1992))
    - 3.5 DCP is contoured to the proximal fragment;
    - K wires are used to achieve provisional fixation;
    - plate is secured to proximal frx fragment;
           - ensure that the plate does not block full extension;
    - external compression device is applied, and provisional fixation is removed;
    - lag screws are applied both proximal and distal to the frx line in divergent positions;
           - the proximal lag screw is directed across the frx to the coronoid process;
           - the distal lag screw is directed across the frx to the olecranon tip;

- Complications:
    - inadequate fixation: the proximal fragment was held w/ only a hook plate

             




   - references:
- Experience with the McAtee olecranon device in olecranon fractures.
- The use of the Zuelzer hook plate in fixation of olecranon fractures.
- Displaced olecranon fractures in adults. Biomechanical analysis of fixation methods.
- Methods of fixation of olecranon fractures. An experimental mechanical study.
- Olecranon fractures. A clinical and radiographic comparison of tension band wiring and plate fixation.
- An off-loading triceps suture for augmentation of plate fixation in comminuted osteoporotic fractures of the olecranon.
- Olecranon fractures. A clinical and radiographic comparison of tension band wiring and plate fixation.
- Tension Band Plating for NonUnion of Proximal Ulna and Olecranon. Healey WL. Tech Orthop. 1991;6:51-54.
- Posterior olecranon plating: biomechanical and clinical evaluation of a new operative technique.


   

   



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, November 22, 2016 4:31 pm