Common Fractures of the Upper Extremities
Fractures About the Elbow: General Considerations
• Elbow fractures are common injuries in children.
• Most pediatric elbow fractures are sustained by a fall onto an outstretched hand (FOOSH).
• Most pediatric elbow fractures result from a fall. Physical abuse as a mechanism may be considered when the child is nonambulatory or there are other indications of child maltreatment.
• Refer every swollen elbow. Referral to a pediatric orthopaedic surgeon is warranted for all suspected and proven pediatric elbow fractures (Box 44-1).
Supracondylar Elbow Fracture (of the Humerus)
• This injury is a fracture of the distal humerus.
• It is the most common and most serious pediatric elbow fracture.
• Supracondylar elbow fracture is typically caused by a FOOSH.
• The average age is between 4 and 8 years, but the injury may occur between walking age and 12 years of age. The reason for this age distribution is the frequency of falling in addition to the anatomic development of the features of the distal humerus
— During early childhood, the supracondylar region of the elbow is thin (like a wafer) and at risk for fracture at the olecranon fossa.
Box 44-1. Reasons to Refer Every Swollen Elbow to an Orthopaedic Surgeon
|While not all pediatric elbow injuries are severe, many have the potential for adverse outcomes; therefore, every elbow fracture should be referred to a pediatric orthopaedic surgeon.|
Because of the difficulty of pediatric elbow injury differential diagnosis, every child with a swollen elbow after trauma should be referred to a pediatric orthopaedic surgeon.
— The olecranon fossa accommodates the proximal end of the ulna—the olecranon—when the elbow is extended.
— Normal childhood ligamentous laxity allows the elbow to hyperextend. When the child falls onto an outstretched hand, the elbow hyperextends and drives the olecranon into the olecranon fossa, fracturing the thin distal humerus just above the medial and lateral elbow condyles proximal to the elbow joint; hence, the term supracondylar fracture of the humerus.
SIGNS AND SYMPTOMS
• Parents may incorrectly infer and state that the child “fell on the elbow.” This is true in the rare flexion type of supracondylar fracture.
• Due to the frequency of falls in toddlers, supracondylar fractures may be unwitnessed in young toddlers who are symptomatic.
• The fracture is far more likely to have serious neurovascular complications if the child fell from a height, such as a tree, window, or playground equipment, compared with a slip and fall on level ground.
• Tips for evaluating elbow fractures are shown in Box 44-2.
• Physical examination is necessary to determine the severity and displacement of the fracture.
— Type I fractures: minimal swelling and mild loss of elbow motion
— Type II fractures: moderate swelling, loss of motion, and mild deformity
Box 44-2. Tips for Evaluating Fractures About the Elbow
|Evaluate the shoulder, wrist, and hand for associated injuries.|
|Concomitant injuries include distal radius and ulna fractures, and proximal humerus or clavicle fractures.|
|In the rare flexion-type supracondylar fracture, there may be scraping or bruising over the posterior olecranon (point of the elbow).|
|Evaluate neurovascular status of the hand, including color, temperature, pulse, capillary refill in the digits, strength, and sensation. Compare with the uninjured side.|
|For the radial nerve, check sensation in the first dorsal web space and ability to actively extend the thumb.|
|For the median nerve, check sensation on the palmar surface of the index finger and active thumb interphalangeal (IP) joint flexion. The anterior interosseous nerve is the most common nerve injured in extension supracondylar humerus fracture. A terminal branch of the median nerve that controls thumb IP and index distal IP flexion, it has no testable sensory component.|
|For the ulnar nerve, check sensation in the palmar tip of the little finger and active abduction of the little finger.|
— Ability to form a circle with the thumb and index finger (the “O” sign) indicates intact median and ulnar nerve function (Figure 44-1).
— In severe fractures there is often immediate bruising and dimpling of the skin in the antecubital fossa where the sharp spike of bone of the proximal fracture fragment impales the deep dermis. The spike may completely penetrate the anterior skin, resulting in an open fracture.
— Type III fractures: severe pain, rapid swelling, ecchymosis, and major deformity
■Nerve injuries are common; fortunately, nearly all are neurapraxias (stretch injuries) and resolve spontaneously over several days to months.
■Vascular injuries are less common but can be devastating, resulting in Volkmann ischemic contracture (Figure 44-2). The brachial artery lies directly anterior to the elbow in the antecubital fossa and can be damaged by stretching or direct impalement by a spike of bone.
• Diagnosis is established with anteroposterior (AP) and lateral view radiographs of the elbow (Figure 44-3).
• If the elbow is minimally swollen and gentle positioning is comfortably allowed, an oblique view is also obtained for evaluating subtle lateral condyle, olecranon, or radial head fracture.
Figure 44-1. Clinical examination indicating the “O” sign. The anterior interosseous nerve (a branch of the median nerve) is intact.
Figure 44-2. Volkmann ischemic fracture is caused by damage to the brachial artery.
Figure 44-3. Undisplaced olecranon fracture. A, Lateral view of the elbow shows the fracture line beginning at the posterior tip of the olecranon (arrow). B, Anteroposterior view of the elbow shows mild medial displacement of the proximal metaphyseal region of the olecranon (arrows).
From Johnson TR, Steinbach LS, eds. Essentials of Musculoskeletal Imaging. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2004:871. Reproduced with permission.
Box 44-3. Modified Gartland Classification of Pediatric Supracondylar Fractures
|Type I: Fracture is non-displaced or minimally displaced. Only radiographic finding may be a posterior fat pad sign.|
|Type II: Obvious fracture line with displacement, and cortex is still intact.|
|Type III: Fracture is displaced with no cortical contact.|
• If there is an obvious deformity, the child’s arm should not be manipulated or positioned to obtain perfect radiographic views; instead, splint in place.
• Supracondylar fractures are classified as closed versus open and displaced versus non-displaced using the Gartland classification (Box 44-3).
• Type I fractures are treated in a long-arm cast for about 3 weeks.
— Recovery is rapid and full.
— Therapy is not required.
• Type II fractures are most often treated by closed reduction (ie, manipulation) and percutaneous pinning.
— Reduction is required to prevent cubitus varus (gunstock) deformity (see Chapter 4, Physical Examination, Figure 4-21) and hyperextension with lack of flexion. While this deformity causes little or no dysfunction or pain, parents are often concerned by it.
Figure 44-4. Displaced supracondylar fracture (arrow) (humerus is outlined).
From Sullivan JA, Anderson SJ, eds. Care of the Young Athlete. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2000:317. Reproduced with permission.
— Pinning is a more secure method of maintaining reduction and is safer than casting.
— Mild type II (type IIA) fractures are sometimes treated with casting alone, although this is controversial.
• Type III fractures require surgical repair with closed reduction and percutaneous pinning, using fluoroscopy under general anesthesia (Figure 44-4).
— Several recent studies have shown that these fractures may be safely observed in the hospital overnight, allowing for fasting and daytime surgery under better operating conditions.
— Open reduction (ie, incision) is not performed unless the closed reduction is difficult or there is a vascular problem.
— Open fractures are surgically débrided.
— Fasciotomies are performed if there was any significant period of ischemia.
— The immediate postoperative period may be the time of highest risk of ischemia. Tight bandages, tight casts, and hyperflexion of the elbow must be avoided during this period.
— Even with meticulous care, an initially silent intimal tear may later thrombose and obstruct arterial supply to the forearm. Microvascular surgery may be required to repair or apply a vein graft to a brachial artery injury.
— After surgery, the elbow is immobilized for 3 to 4 weeks, followed by removal of the pins in the office without the need for anesthesia.
— Normal range of motion and full activities are restored by 3 months in most cases.
• Results are favorable for all fracture types when adequate reduction is achieved.
• Little if any remodeling can be expected about a distal humerus fracture in a child; therefore, deformity (malalignment) noted shortly after fracture healing will persist.
• Unreduced type III fractures invariably lead to cubitus varus. This deformity will not remodel and requires reconstructive osteotomy for correction at a later time.
WHEN TO REFER
• All supracondylar fractures should be referred to a pediatric orthopaedic surgeon.
• The urgency of orthopaedic evaluation will depend on the severity of the fracture, the comfort of the child, and whether there are associated soft tissue injuries.
— A pulseless extremity or open fracture is an orthopaedic emergency that warrants immediate surgical evaluation.
— A non-displaced fracture that is already several days old may be splinted and seen by an orthopaedic specialist non-urgently.
Lateral Condyle Elbow Fracture
• This injury encompasses fractures of varying portions of the lateral half of the distal humerus (Figure 44-5).
• Lateral condyle elbow fractures account for 20% of pediatric elbow fractures
• There are 2 generally accepted mechanisms of injury; both occur with a FOOSH.
— The fracture is avulsed off the distal humerus by a bending varus force as the child falls onto an outstretched hand.
— The radial head impacts the lateral condyle when an axial force is applied to a partially flexed elbow.
• The large portion of cartilage and small sliver of attached bone makes lateral condyle fractures difficult to diagnose and heal. Cartilage is radiographically invisible and does not easily heal to adjacent cartilage, even if rigidly fixed.
SIGNS AND SYMPTOMS
• Non-displaced fractures manifest with minimal lateral soft tissue swelling, tenderness, and no deformity.