Supracondylar Fractures of the Humerus in Children

Supracondylar fractures constitute approximately 50% of all elbow fractures. The supracondylar region is thin and weak and thus can fracture easily. These fractures are classified into two different types: extension and flexion.

fracture typesExtension type fractures are the most common type, occurring approximately 95% of the time. Extension fractures typically occur due to falling onto an outstretched hand. With extension fractures, the distal fragment of the humerus displaces posteriorly. Anterior interosseous neurapraxia is the most common nerve palsyOKsign occurring with supracondylar fractures. Injury to the anterior interosseous nerve will lead to weakness of the flexor digitorum profundus muscle to the index finger and the flexor pollicis longus muscle. The patient will not be able to make an “OK” sign or bend the tip of his index finger. Radial nerve neurapraxia is the second most common palsy and is evident by weakness in wrist and finger extension.

The second type of fractures, flexion type fractures are rare and occurs due to falling flexionfxdirectly on a flexed elbow. In flexion type fractures, the distal fragment is displaced anteriorly. This type of fracture may be accompanied with ulnar nerve neurapraxia. Injury to the ulnar nerve will lead to a loss of sensation along the little finger. Later on, the patient may also have weakness of the intrinsic hand muscles and clawing.

 

Gartland Classification System

gartland classificationThe Gartland Classification System provides physicians with a way to categorize supracondylar humerus fractures. There are four classifications and are as follows: Type I fractures are nondisplaced fractures; Type II are angulated with an intact posterior cortex; Type III are completely displaced; and Type IV has complete periosteal disruption with instability in both flexion and extension.

Radiology

Plain AP and lateral x-rays should be obtained. A posterior fat pad sign seen on a anterior humeral linelateral view x-ray should increase your suspicion of an occult fracture around the elbow. On a lateral view x-ray, the anterior humeral line is drawn along the anterior border of the distal humerus. Normally, the anterior humeral line should run through the middle third of the capitellum. In extension type fractures, the capitellum will be displaced posteriorly, relative to the anterior humeral line.

The Baumann’s Angle is formed by a line perpendicular to the axis of the humerus and a line going through the physis of the capitellum. Normally, the Baumann’s angle should measure at least 11° (variable).

 

Physical Examination

It is important to assess the neurovascular structures. The anterior interosseous nerve is assessed by asking the patient to do the “OK” sign with their hand. The radial nerve is assessed by asking the patient to extend their wrist and fingers. Ulnar nerve damage is usually indicated by the loss of sensation along the little finger; however, later on the patient may have weakness of the intrinsic hand muscles and clawing.

finger extensionTreatment

Nonoperative treatment is usually indicated for type I fractures. This treatment usually consists of splinting or casting the elbow for a duration of 3-4 weeks. It is very important to remember not to flex the elbow in the splint or cast beyond 90° in order to avoid vascular compromise and compartment syndrome.

closed reductionOperative treatment is usually indicated for Types II and III, and are usually treated by a closed reduction and percutaneous pinning. During reduction, pronation of the forearm during elbow flexion helps to correct a varus deformity. After reduction, the surgeon will want to check for a gap in the fracture, as the neurovascular bundle may be trapped there. The surgeon will need to free the brachialis muscle from the fracture site if it is interpositioned there. Fixation is usually achieved with 2-3 ulnar nerve pinningdivergent lateral pins, depending on stability. Medial pins may also be added depending on stability; however, the surgeon will need to be aware of the ulnar nerve when placing the medial pin.

Open reductions are only performed when closed techniques are unable to achieve the appropriate reduction of the fracture. The surgeon will want to avoid posterior dissection in order to preserve the vascularity of the fractured segment. Fracture reduction and fixation should be done emergently in cases of vascular compromise.

Complications

Neurapraxia is a common complication of supracondylar fractures and usually resolves on its own—thus, treatment is observation only. A cubitus varus deformity may occur due to a malunion of the fracture. This only presents as a cosmetic problem since it does not affect the function of the arm or elbow. Additionally, this cubitus varusdeformity can be corrected later on by a supracondylar valgus osteotomy. Vascular problems, such as compartment syndrome, may also occur. Volkmann’s ischemic contracture may occur due to a compression of the brachial artery with then patient is placed in a cast with the arm in hyperflexion (more than 90°).

Important Scenerios

A patient may present with a Displaced Type III fracture and a pulseless hand. He may have adequate circulation—which is evident by the normal temperature and color of the hand—or he may have inadequate circulation—indicated by a cold blue hand. In both cases, an urgent closed reduction and percutaneous pinning is required. Once this has been performed and the circulation is adequate, the surgeon can observe the patient and place them in a splint that is at a 45° angle. However, if the patient continues to have inadequate circulation after the closed reduction, then the patient will require a vascular exploration and repair.

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Stinger/Burner Nerve Injury

A “stinger” or “burner” is a common transient injury that occurs in contact sports such as football. The injury occurs from stretching the upper trunk of the brachial plexus or compression of the C5-C6 nerve root.

contactStretching of the brachial plexus is the mechanism of injury typically seen in high school aged athletes suffering from this condition. This injury occurs from a direct blow, causing the shoulder to be depressed and forcing the neck into lateral flexion, causing the neck to bend toward the opposite side.

stretchingCompression of the nerve root is the basis of injury most often associated with older athletes. It is not a cervical cord injury and it is not a transient quadriplegia.

compressionThe patient will complain of burning pain, numbness, and weakness with painful symptoms starting above the shoulder, going down to the arm. Symptoms will begin immediately after the trauma occurs and can last from several minutes up to several weeks after the accident, but they will usually resolve themselves. A stinger or burner is a transient, intensely painful nerve injury that may result in time loss from competition.

burner pain

When the injury occurs, the athlete should stop participating in sports until full recovery of strength, sensation, and pain-free range of motion is reestablished to the cervical spine. Treatment consists of alternating between ice and heat, anti-inflammatory medications, and rehabilitation exercises. An MRI may be necessary to rule out a herniated disc. Surgery is usually not necessary for a Stinger/Burner injury.

Monteggia Fracture Dislocation

Monteggia fracture is the fracture of the proximal third of the ulna with dislocation of the radial head. The fracture is more common in children and rare in adults. Treatment will depend on the age of the patient.The normal position of the radial head and shaft should line up with the capitellum in any position. Dislocation of the radial head may be missed.

normal position

Type I Monteggia fractures occur in the middle or proximal third of the ulna with anterior dislocation of the radial head and characteristic apex anterior angulation of the ulna. This is the most common type and occurs in about 60% of cases. In children, you will immobilize the fracture in flexion and supination. Flex the elbow more than 90 degrees to relax the biceps.

Only 15% of Monteggia fractures are Type II. This fracture occurs in the middle or proximal third of the ulna with posterior dislocation of the radial head and characteristic apex posterior angulation of the ulna. You will need to immobilize this fracture in extension.

type ii

20% of Monteggia fractures are type III. These fractures occur at the ulna just distal of the coronoid process with lateral dislocation of the radial head.

Type IV only occur 5% of the time and is classified as the fracture of the proximal or middle third of the ulna with anterior dislocation of the radial head, and a fracture of the proximal third of the radius below the bicipital tuberosity. This fracture will require surgery, even in children.

TypeIVWith Monteggia Fracture Dislocations, it is important to perform a neurovascular exam. Nerve injury, especially involving the posterior interosseous nerve, is not uncommon. Additionally, you will want to watch the patient for compartment syndrome.

Treatment in adults consists of ORIF of the ulna—when the ulna is properly aligned and fixed, the radial head will reduce by itself. Radial head instability may usually be caused by nonanatomic reduction of the ulna or by interposition of the annular ligament. Fracture of the ulna may need a bone graft for healing.

platingWhen treating pediatric patients, it is important to note that the radial head ossifies around age 4. For Type I-III fractures, you will perform a closed reduction of the ulna to restore the length of the ulna and reduce the radial head. Remember to immobilize in flexion and supination. Type IV fractures or cases where you are unable to reduce the radial head or the length of the ulna in pediatrics will require surgery. Fixation will be done with an IM rod or a plate.

When treating old cases, you will perform an osteotomy of the ulna and an open reduction of the radial head, followed by plating of the ulna.

Pudendal Nerve Palsy

Damage to the pudendal nerve can occur suddenly as a result of trauma to the pelvic region, prolonged bicycling, fractures, or from falls. The pudendal nerve re-enters the pelvis under the sacrotuberous ligament and gives three branches.

usepudendalThe first branch, the inferior rectal nerve, provides rectal tone and perianal sensation. The second branch, the Perineal Nerve, gives scrotal sensation. The third branch, the dorsal nerve of the penis, give branches to the corpus callosum.

The pudendal nerve arises from S2, S3, and S4. The pudendal nerve carries sensations to the external genitals, the lower rectum, and the perineum.

The symptoms of pudendal nerve palsy can start suddenly or develop over time. Symptoms include the loss of sensation or numbness, burning or stabbing pain, difficulty with bladder and bowel functions, and sexual dysfunction.

morenerves

Causes of pudendal nerve palsy include prolonged sitting exercises such as bicycling or following fracture table traction—the nerve is compressed between the ischium and the hard object.

Treatment options are typically conservative, as the condition is usually transient and will improve over time. Treatment includes:

  • Restbike
  • Physical therapy
  • Stretches and exercises
  • Anti-inflammatory medications
  • Injections/nerve blocks
  • Surgery (as a last resort)

 

Prevention options for bicyclists consists of changing the sitting position while riding the bicycle and changing the seat from a narrow seat to a wider seat.