Anterior Pelvic Frx: Anterior Plate Fixation Options 


- Two Hole Implants:
    - two hole plate, usually a 4.5 mm, is fixed to the superior surface of the symphysis with two
            6.5 mm cancellous screws immediately adjacent to the symphysis pubis;
    - screws are inserted on the anterosuperior surface of the pubis on either side of the symphysis
            and directed to the full depth of pubis in a posteroinferior direction;
    - to provide satisfactory fixation, 6.5-mm cancellous screws with 32-mm threads are used and they should
            penetrate full depth of pubis;
            - usually, screws of 50-55 mm in length can be accommodated;
    - implant appears to loosen to point of accommodating physiologic motion at symphysis pubis, yet adequately resists tensile stresses
            across symphysis without loss of reduction;
    - fixation failures w/ two hole implants are more common w/ osteoporotic bone;
    - references:
            - Two-Hole Plate Fixation for Traumatic Symphysis Pubis Diastasis
            - Comparative radiographic and clinical outcome of two-hole and multi-hole symphyseal plating.

- Four Hole Implants:
    - indicated for anterior diastasis w/ or w/o an unstable posterior injury;
    - fixation usually involves a contoured 4.5 mm reconstructive plate applied to the superior surface
           surface of the pubis;
           - usually, fully threaded cancellous screws are used to secure the plate;
    - four-hole plate fixation, while maintaining reduction of diastasis, does not allow motion across joint & may
           be prone to late problems of loosening or implant fatigue;
    - locking plates:
           - references:
                  - Locked versus standard unlocked plating of symphysis pubis in a Type-C pelvic injury: A cadaver biomechanical study.
                  - Locked versus Standard Unlocked Plating of the Pubic Symphysis: A Cadaver Biomechanical Study.
                  - Failure of Locked Design-Specific Plate Fixation of the Pubic Symphysis: A Report of Six Cases.
                  - Biomechanical Study of 4-hole Pubic Symphyseal Plating: Locked Versus Unlocked Constructs
    - reference:
           - Comparative radiographic and clinical outcome of two-hole and multi-hole symphyseal plating

                

          

- Combined Two and Four Hole Plates:

    - the anterior plate may consist of a 3.5 or a 4.5 mm reconstruction plate;
           - the plate is usually secured w/ 4.5 mm cortical screws;
    - indications are mainly for unstable posterior injury;

           

- Box Plate Fixation:
    - allows for superior fixation in osteoporotic bone;
    - utilizes two 2-hole narrow 4.5 DCP plates placed parallel to each other, one above and one below the the pubic symphysis;
           - the inferior plate is recessed w/ in the symphysis;
    - the plates are inter-locked utilizing two 6.5 mm screws;
    - reference:
           - Box Plate Fixation of the Symphysis Pubis: Biomechanical Evaluation of a New Technique
           - Fixation of Pubic Symphyseal Disruptions: One or Two Plates?




Comparative radiographic and clinical outcome of two-hole and multi-hole symphyseal plating.

Radiographic Changes of Implant Failure After Plating for Pubic Symphysis Diastasis: An Underappreciated Reality?

The effect of implant failure after symphyseal plating on functional outcome and general health.

Reduction and fixation capabilities of different plate designs for pubic symphysis disruption: A biomechanical comparison.



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

Last updated by Data Trace Staff on Wednesday, March 9, 2016 5:53 am