Ortho Case of the Week Answers – Forearm
Case 1: A 9 year old male is brought in by his parents after falling of the swingset, falling on his outstretched hand. He now refuses to move his left arm
1. What is your full read of the x-ray below? What eponym is associated with this fracture pattern?
This set of x-rays demonstrates a Galeazzi fracture which is compromised of: radius fracture (distal third) + distal radioulnar dislocation. This is commonly accompanied by an ulnar styloid fracture (though not in this case).
2. How would you manage this patient?
Closed reduction and placement of a long arm posterior splint with elbow flexed 90° and forearm pronated (video).
This patient will need close follow-up with orthopedics as this fracture pattern typically requires early ORIF. Admission criteria include open fracture, clinical concern for compartment syndrome and signs of neurovascular injury. Neurovascular injury is uncommon with this fracture pattern and is typically seen only with severe (Type III) open fractures.
Case 2: A 7 year old female is brought in by her parents after falling off the monkey bars and landing on her outstretched hand.
1. What is your full read of the x-rays below? What eponym is associated with this fracture pattern?
X-rays c/o Radiopaedia
The xrays above show a Monteggia fracture. This fracture pattern consists of a proximal ulna fracture (displaced and angulated in this case) with radial head dislocation.
2. Describe your management and disposition.
The splint applied should be a long arm posterior splint with 90 degrees of elbow flexion and the hand in a neutral position. This patient will need close follow-up with orthopedics for likely ORIF (almost always in adults, peds patients sometime will have acceptable outcomes without ORIF). Admission criteria include open fracture, clinical concern for compartment syndrome and signs of neurovascular injury.
3. What nerve is commonly injured in this fracture pattern and how would you test it?
The most common nerve injury is Posterior Interosseous Neuropathy (PIN). The posterior interosseous nerve is a branch of the radial nerve. Injury to this nerve results in purely motor symptoms resulting in finger drop and radial deviation of the wrist with extension. This injury occurs in up to 10% of Monteggia fractures.
Case 3: A 32 year old male presents with right forearm pain and swelling after a direct blow to his forearm while kickboxing.
1. What is your full read of the x-ray below? What other term is used to describe this type of fracture?
X-rays c/o Radiopaedia
The x-rays above show an isolated ulnar shaft fracture with approximately 50% displacement. This fracture is also known as a “nightstick” fracture.
2. What is the most common mechanism for this type of fracture?
The most common mechanism is a direct blow to the forearm.
3. How would you manage this patient? What type of splint would you use?
The patient should be splinted in a long arm splint with 90 degrees of elbow flexion and the hand in a neutral position. The patient may require ORIF if there is >50% displacement, >10 degrees of angulation or the proximal third of the ulna is involved.
Sources/Further Reading:
https://wikem.org/wiki/Galeazzi_fracture-dislocation
https://www.orthobullets.com/trauma/1029/galeazzi-fractures
https://www.orthobullets.com/trauma/1024/monteggia-fractures
https://radiopaedia.org/articles/monteggia-fracture-dislocation?lang=us#image_list_item_155420
https://wikem.org/wiki/Monteggia_fracture-dislocation
https://radiopaedia.org/articles/nightstick-fracture-ulna?lang=us
https://wikem.org/wiki/Isolated_ulna_fracture
https://www.orthobullets.com/trauma/1025/radius-and-ulnar-shaft-fractures