If you fx one, usually the other as well or a dislocation.
if you fx the radius, check the druj
if you fracture the ulna, check the radial head
X-ray at Elbow
Radiocapitellar line-line through center of radius should pass through center of capitellum
Fat Pads-large anterior or any posterior=radial head fx
Anterior Humeral Line through middle of capitellum
Radial Head
Assess radial nerve, valgus instability
Olecranon
All considered intraarticular
Can’t extend the forearm
Document Ulnar Nerve function
If wrist pain, consider DRUJ disruption (
Coronoid Fxs-antecubital tenderness
Rx: splint in 50 to 90 flexion at elbow, wrist in neutral
Radial Shaft
Signs of Rupture of DRUJ
1. Fx of Ulna Stylus
2. Widenening of Joint Space
3.
Dislocation
of the radius
4. Shortening of the radius
GFR as mnemonic
Fx of distal 1/3 of the radius c DRUJ Dislocation (tenderness or ulnar prominence)
Splint these c post/ant long arm splint with elbow at 90º and wrist in supination
Ulna
Check for radial nerve damage
Get Consult
Both Bone Fractures
Ortho consult in adults
Buckle in kids can be splinted
Peds
Greenstick on Shafts
Buckle in the Metaphysis
Distal Forearm
Colles’-dinner fork deformation. Caused by fall on outstretched arm into extension of wrist, fx of radius
? assoc. ulna styloid fx
? radioulnar joint involvement
? radiocarpal joint involvement
Check for median and ulna nerve damage and extensor pollicis longus
Splint wrist in 15 degrees of flexion and 15 degrees of ulna deviation.
Smith’s-same idea but flexion injury
Normal Wrist Anatomy
Using the “DOH” mnemonic, there are three high-risk “D”islocations of the wrist. In increasing order of severity, they include scapholunate dissociation, perilunate dislocation, and lunate dislocation. First, scapholunate dissociation is the most common ligamentous injury of the wrist. This injury occurs when a person falls on an outstretched hand, which causes a ligamentous disruption between the scaphoid and lunate bones. The scaphoid undergoes rotatory subluxation into a more transverse orientation. The primary radiographic finding is the presence of at least a 5 mm widening of the scapholunate space, named the “Terry Thomas sign”
The second “D” injury is a perilunate dislocation (Figure 4).
This injury occurs with hyperextension of the wrist and can best be visualized
on the lateral radiographic view. The lunate no longer smoothly articulates with
the capitate distally. Complications of an undiagnosed perilunate dislocation
include permanent median nerve damage and scapholunate advanced collapse (SLAC).
SLAC occurs when the scaphoid and/or lunate undergoes avascular necrosis and
consequently collapses, causing debilitating and chronic pain.
And the third “D” injury is lunate dislocation (Figure 5).
The mechanism involves falling backwards on an outstretched hand. Best
visualized on the lateral radiograph, the lunate disarticulates with both the
distal radius and the capitate. This misalignment resembles a “spilled teacup.”
A missed lunate dislocation has similar devastating consequences as a perilunate
dislocation with median nerve damage and SLAC. Most perilunate and lunate
dislocations will fail closed-reduction maneuvers and will require an emergent
orthopedic consultation for open reduction and internal fixation.
There are two frequently missed “O”ccult fractures of the wrist. First, scaphoid fractures comprise the second most commonly fractured bone of the wrist, following the distal radius (9). In a study by Freed and Shields, 13% of scaphoid fractures were missed initially, thus, giving scaphoid fractures the highest “miss rate” of all fractures in their ED (10). Patients usually have fallen on their outstretched hand and complain of pain in the anatomical “snuffbox” region of the wrist. Radiographic findings may include a subtle cortical break seen on the PA view (Figure 6); however, up to 20% of scaphoid fractures may be radiographically occult (11). Consequently, all patients with “snuffbox” tenderness require immobilization and referral to an orthopedist, regardless of a normal radiograph. Complications of a missed scaphoid fracture include avascular necrosis of the scaphoid, nonunion especially when treatment is delayed for more than four weeks 12 and SLAC.
Figure 6. Scaphoid fracture of right wrist (PA view
with ulnar deviation view)
The second “O”ccult
fracture involves the triquetrum bone (Figure 7). Accounting for 10% of all
carpal bone fractures, it occurs when a patient falls on an outstretched hand
and has tenderness over the ulnar aspect of the dorsal wrist. It is frequently
misdiagnosed as a wrist sprain. Anatomically, the triquetrum is the most dorsal
carpal bone, and radiographically the ulnar styloid “points” to it on the
lateral view.
Figure 7. Triquetrum fracture of right wrist (Oblique view)
And the last letter of the “DOH” mnemonic stands for finding “H”alf of the
injuries only. Often times the most obvious fracture is noted, while the second
concurrent injury, such as a dislocation, is overlooked. In the wrist, this is
the case in a Galeazzi fracture-dislocation (Figure 8) – a distal-third radial
fracture with an associated disruption of the distal radioulnar joint (DRUJ).
In a DRUJ disruption, the lateral radiograph can show the distal ulna no longer
overlying the distal radius and/or the ulnar styloid no longer pointing to the
dorsal triquetrum. Further on the PA view, a widened DRUJ space and/or an ulnar
styloid fracture similarly suggests a DRUJ disruption. Major complications in
diagnosing a patient with a simple radius fracture instead of a Galeazzi
fracture-dislocation include chronic wrist joint arthritis and painful
disability. It is thus crucial to examine the DRUJ before discharging a patient
with the diagnosis of an isolated distal-third radius fracture.
Figure 8. Galeazzi fracture-dislocation of the wrist (Lateral view)
More distally, radial fractures are also associated with carpal injuries.
Because distal radius fractures are frequently caused by a fall on an
outstretched hand, scapholunate dissociations often occur concurrently. A small
retrospective study of 52 patients found that 69% of distal radius fractures
were associated with scapholunate dissociations (13). Additionally, intra-articular
radial styloid fractures are frequently associated with carpal ligamentous
injuries in addition to fractures of the scaphoid and lunate bones.
