This document discusses the terrible triad injury of the elbow, which involves fractures of the radial head, coronoid process, and posterolateral dislocation. It notes the poor outcomes associated with this injury like stiffness, instability, and hardware failure. The document outlines the relevant anatomy of the medial collateral ligament and lateral uncular collateral ligament. It describes the mechanism of injury, known as the fall on an outstretched hand, and how the ligaments and capsule fail in this injury. Diagnostic imaging and classification of radial head and coronoid fractures are covered. Treatment options including observation, resection, open reduction internal fixation, and replacement are presented. Surgical approaches and techniques are also outlined.

1. David Moss, MD

2.  Terrible triad
 Radial head fx
 Postero-lateral dislocation
 Coronoid fx

3.  Poor outcomes
 Elbow stiffness
 Instability
 Hardware failure
 Pre-locking plates

4.  MCL
 Anterior band
 Sublime tubercle
 LUCL
 Supinator crest

5.  FOOSH
 Extended elbow
 Valgus load
 Postero-lateral
rotation (relative
supination)
 Body usually rotates
around fixed hand

6.  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

9.  Distinct from anteromedial facet fracture
 Varus load

10.  AP
 Lateral
 Greenspan (radiocapitellar) view
 CT scan

11.  Mason
 I: <2mm
 II: >2mm, possible
block to motion
 III: comminuted
 Must aspirate and
examine sup/pron for
Mason II

12.  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

14.  Regan Morrey
 I: just the tip
 II: < 50%
 III: >50%
 Descriptive
classification

16.  Bony block to dislocation
 Not brachialis insertion

17.  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

21.  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

25.  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