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34th Annual Scientific Meeting proceedings


Stream: LA   |   Session: Disaster session I: Learning from my mistakes
Date/Time: 04-07-2025 (09:00 - 09:30)   |   Location: Okapi 2+3
Technical Failures in Fracture Repair
Ruggles AJ*
Rood & Riddle Equine Hospital, Lexington, USA.

Technical errors using screws and plates technique occur to all surgeons and under all circumstances.  Obviously with experience the failure rate is reduced (we hope!!).  Technical failures occur in the following categories: poor preoperative planning, improper intra-operative radiographic control, improper use of the equipment, improper application of the implant and any combination of the above.  This lecture will demonstrate many technical errors that can happen in plate fixation of fracture repairs in the horse.

Careful preoperative radiographic evaluation and technique will reduce the rate of technical errors.  Imaging control during surgery whether by radiographs, fluoroscopy or CT will prevent errors, ensure proper placement and use of implants improve results and allow the surgeon to gain confidence in the surgical techniques.

In my personal encounters with technical failures, failure to understand the biomechanical forces of the fracture, improper use of the equipment and failure to have adequate radiographic control has led to the most frequent cause of failure.

Some examples of mistakes used in plate fixation include:

Poor preoperative planning

  • Inadequate understanding of the fracture biomechanics
  • Inadequate familiarity with surgical anatomy
  • Failure to identify all fractures lines – post operative fracture or poor reduction
  • Inadequate or improper implant inventory to complete task
  • Inadequate understanding of techniques and pitfalls of specific fractures

Inadequate radiographic control

  • Screw head incompletely seated – reduce compression, soft tissue pain
  • Screw has bottomed out - failure to compress fracture
  • Screw in fracture line – additional fractures
  • Screw too long – soft tissue problems
  • Screw did not pass through medullary cavity where appropriate
  • Plate placed incorrectly – not central to bone, insufficient length

Improper use of equipment

  • Instrument breakage – little morbidity
  • Improper compression of fracture
  • Poor staggering of plates inhibits screw placement – especially with LCP’s

Improper application of implants

  • Poor understanding of biomechanics of fracture or specific issues with individual fracture

Lag screws reduce shear forces and provide interfragmentary compression of fracture fragments.  They should be used whenever possible even through plates or in concert with other repair techniques.  When high torsional, bending or compressive forces are present lag screws are relatively weak when compared to plate fixation.  It is common and recommended to use lag screw function, when possible, in plate fixation. Cortex screws used in plate function provide stability by compressing (lagging) the plate to the bone. Fixes angle screws lock their heads in the plate for stability but do not compress the plate to the bone and cannot be angled.  They also may create a problem during placement in areas with large muscle masses.  Additional it important to anticipate the location of the entire screw length when applying fixed angle screw to make sure the medullary cavity is entered in long bone repair. A common technical error with fixed angle screws is the failure to recognize bone is not fully engaged or placing them entirely in 1 cortical surface

Plates can function as neutralization, compression or buttress fashion. Double plating is the rule in unstable fractures except in areas of significant biomechanical advantage like the tension surface of the caudal ulna.  In general, the following principles apply when plates in long bone repairs

  1. One plate should span the length of the bone, do not cross the physis (unless indicated)
  2. The plate(s) centered over the bone so that the ends of the plate make solid contact with the bone and do not impede soft tissues.
  3. The plates are contoured well to the bone surface even with fixed angle plates.
  4. In double plate application, the plates are staggered or placed in such a way to avoid impeded of the screws on each other, cross threading and / or single cortex placement
  5. All holes in the plates are filled when possible
  6. The plates are placed in a biomechanically advantageous position based on the fracture location
  7. At least one plate is placed over the distal end of a proximal fracture fragment in an oblique fracture to capture that leading edge under the plate.
  8. When using fixed angled plating system the cortex bones should be placed in the plate first and the screws heads proper threaded in the plates.

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