Terrible Triad

David Moss, MD

Terrible triad

Radial head fx

Postero-lateral dislocation

Coronoid fx

Poor outcomes

Elbow stiffness

Instability

Hardware failure

Pre-locking plates

MCL

Anterior band

Sublime tubercle

LUCL

Supinator crest

FOOSH

Extended elbow

Valgus load

Postero-lateral rotation (relative supination)

Body usually rotates around fixed hand

LUCL fails

Anterior and/or posterior capsule fails

Radio-capitellar dislocation

Radial head shear, fracture

Ulno-humeral dislocation

Coronoid fracture

MCL – last to fail, if it fails

Distinct from anteromedial facet fracture

Varus load

AP

Lateral

Greenspan (radiocapitellar) view

CT scan

Mason

I: <2mm

II: >2mm, possible block to motion

III: comminuted

Must aspirate and examine sup/pron for Mason II

Observation Mason I

Mason II if no bony block

Radial head resection Contra-indicated in setting of instability!

ORIF Mason III

Mason II with bony block

Radial head replacement >3 fragments

Dislocation

Essex-Lopresti

Regan Morrey

I: just the tip

II: < 50%

III: >50%

Descriptive classification

Bony block to dislocation

Not brachialis insertion

NV check

Open wounds

Examine the wrist for tenderness

PRLI test

Supine patient, arm overhead

Start in full extension, flex and apply valgus force with forearm in supination

Reduce by pronating and flexing elbow

Hand table

Mini c-arm

+/- sterile tourniquet

+/- head lamp

Hand set

Mini screws

Headless screws

Radial head prosthesis

Hinged ex fix

Suture anchors

Hewson suture passer

Radial head plates

+/- ACL guide

Need not fix coronoid if stable after radial head fixation

“Stable” if reduced up to -30°

Resected radial head can be used to augment coronoid repair, if needed