Drill guides, Imaging of screws, CHAPS

Question 1

Pardo VS 2021

Retrospective
4.5mm transcondylar screw in 34 elbows with HIF
IMEX aiming device medial -> lateral

Answer 1

97% screws within humeral condyle

Question 2

Easter VS 2020

Retrospective
3D printed patient-specific drill guides for HIF
5mm transcondylar screw medial -> lateral

Answer 2

No intraarticular penetration

Question 3

Neal VS 2023

Randomised, match pair, prospective ex vivo
Universal aiming device vs fluoro

Answer 3

Aiming device similar to fluoro
Aiming device 8x increased risk of joint penetration vs fluoro

Question 4

Brash VCOT 2022

CT of fractured transcondylar screws

Standard CT scale and extended CT scale (wider dynamic range, reduces blurring and distortion around metallic implants, higher bit depth but maintains contrast resolution)

Answer 4

Hypoattenuating streak perpendicular to implant in standard CT suggestive of screw fracture

Standard CT picks up large fracture gaps, 50% were not visible compared to extended CT

Question 5

Labrador VCOT 2022

Extended CT for metallic sc rews

Answer 5

Positioning screws perpendicular to Z axis of gantry is ideal

Extended CT useful for seeing nondisplaced screw fracture

Question 6

Burton VS 2023

Transcondylar screw based on Herbert screw
Experimental on 3D printed models
Canine humeral anatomic plating system (CHAPS) - precontoured for HCF in spaniels

Answer 6

CHAPS minimises need for plate contouring and reduces incidence of locking screw interference