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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Radiation Exposure and Safety

X-rays ionize human tissue and deposit energy that can cause harmful changes within the body (break the DNA chain). Additionally, there is a cancer risk from exposure to x-rays. The dose of radiation is cumulative. X-rays are considered carcinogenic. The government is attempting to minimize the use of unnecessary CT scans and x-rays to prevent unnecessary exposure to radiation. It is important for doctors to pay close attention to the risks involved with the use of x-rays. The cancer risk associated with radiation exposure is documented in cases of atomic bomb survivors.

radiationThe risk for medical uses is controversial and usually played down by physicians. Radiation at a high level is carcinogenic but, the level of radiation from x-ray exposure is low. The effects of low level radiation is not known.

What is the safe radiation level?

The safe level of radiation is not known.

ctscanIt is known that CT scans, fluoroscopy, mammography, and x-rays expose the public to high levels of radiation, especially in young females. The risk of exposure should balance the medical benefits.

Optimize radiation doses by only exposing the patient to enough radiation to get a clear image. There is a growing concern about the risk associated with giving a patient large doses of radiation. The use of CT scans has increased recently in adults and children, possibly exposing the patient to an unnecessarily high dose of radiation. A CT scan is often the method used to diagnose cancer, diseases, and fractures, exposing the patient to a much larger dose of radiation than x-rays. Radiation from a CT scan of the pelvis equals the same amount as 100 chest x-rays. Children are ten times more sensitive to radiation than adults. 3-4 million children receive CT scans and about 1,500 of them will develop cancer two decades later. Additionally, children should not be given an adult dose of radiation.

Radiation Dose Limits

dose limitsA CT scan of the pelvis has the highest level of exposure to the skin, marrow, and gonads. A mini fluoroscopy C-arm should be used whenever possible. Fluoroscopy emits a lot of radiation. The closer the extremity is to the radiation source, the higher the dose of radiation the patient receives. When the distance from the beam increases, the dose of radiation is less. Attempt to decrease exposure time. Radiation intensity follows the inverse square law. It is all about distance!

If the intensity of radiation at 1 meter from the source is 100mR/hr, then the intensity of radiation at 2 meters from the source is ¼ or 25mR/hr in the same unit area. At 3 meters from the source, the intensity of radiation is 1/9 the original or 11.1mR/hr.

inversion square lawUnits of Radiation

  • Roentgen
    • Unit of radiation exposure in the air
  • Rad
    • Energy absorbed per gram of tissue
  • Rem
    • Biological effect of a rad

There is less exposure to the physician when imaging a smaller body part. Larger body parts create an increased exposure to the physician when imaging a patient with the C-arm. It is important to not be in the direct path of the radiation beam.

less expoMethods of protection include: monitoring, shielding, and position. A dosimeter badge records how much radiation you have received; however, it does NOT protect you from exposure to radiation. Lead gowns and aprons work to stop exposure to fluoroscopic radiation. Lead aprons attenuate scattered radiation by about 95%. Rapidly dividing cells are most sensitive to radiation exposure and include: sperm, lymphocytes, and cells inside the small intestine and stomach.

Radiation damage seldom appears at the time or irradiation. The first effects of radiation damage is usually seen as a drop in the white blood cell count. The first external sign of damage is usually a skin burn. Studies suggest that people who use fluoroscopy extensively have a higher rate of cataracts.

Early effects of radiation exposure include:

  • Death
  • Hematologic depression
  • Chromosome aberration
  • Skin erythema
  • Epilation

My recommendations:

A CT scan examination is usually done without justification by most insurances. In my opinion, 1/3 of CT scan studies that are given could be avoided; they are an added cancer risk with no benefit. The CT scan study should be justified. There is no close oversight or uniform standard in place to eliminate radiation exposure, and this is something that should be taken seriously.

shieldPatient education is important. The patient should ask if the study is necessary and what is the lowest dose possible that can be given without compromising the study. Additionally, there should be a universal x-ray bank where patient’s x-rays can be accessed by any medical facility. This would eliminate the unnecessary repeating of x-rays.

In summary, the bone marrow, breast tissue, gonads, and lymphatic tissue are susceptible to radiation induced tumors. It is important to shield the gonads from exposure. Always wear protective equipment such as lead aprons and monitor your radiation exposure with the dosimeter badge.

Tillaux Fractures

ankle anat

In adults, ligaments are weaker than bone. The anterior tibiofibular ligament in adults is torn first in the majority of ankle fractures. In children, the growth plate is weaker and can become avulsed. An avulsion injury is rarely seen in adults because the ligament gives out instead of avulsing the bone.

growth plaateTillaux fractures occur in adolescents, usually around 12-15 years of age. These fractures occur after the middle and medial parts of the epiphyseal plate closes and before the lateral part is closed. The lateral part of the growth plate remains open, which could allow for an avulsion fracture at the attachment of the anterior tibiofibular ligament. An external rotating force causes an avulsion of the distal tibial epiphyseal plate anterolaterally. Further lateral rotation displaces the fracture and may be associated with fracture of the lateral malleolus. external rotation

Treatment

If the fracture is displaced 2mm or more, the surgeon will want to perform a reduction and fixation. This fixation can be done from either lateral to medial or medial to lateral. Wagstaffe’s fracture is an avulsion of the anterior portion of the fibula by the anterior tibiofibular ligament. This type of fixationinjury is associated with supination external rotation type injuries (Lauge-Hangen) and typically occurs in adult patients.

 

 

Compartment Syndrome in Children

armswell

Compartment Syndrome in children can go unrecognized due to how difficult it can be to examine a child. Children have a poor perception of numbness and paresthesia and they tend to cry from injuries or fear. The actual amount of pain that a child feels cannot be estimated. It can also be challenging to remove splints or dressings in order to examine a child. In adults, well established compartment syndrome is historically defined by the 5 P’s:fivep

  1. Pain/Swelling
  2. Pulselessness
  3. Paresthesia
  4. Pallor
  5. Paralysis

These 5 P’s occur in established compartment syndrome and when these findings are present it is usually too late. These findings are considered late presentation. If the pressure is not released within 6-8 hours from its onset, there is irreversible damage to the muscles. Note for the diagnosis of impending Compartment Syndrome: it is better to diagnose compartment syndrome when it is impending rather than when it is established. The majority of clinicians will depend on a high index of suspicion supplemented by the clinical diagnosis and pressure measurements. Usually the clinician’s findings of impending Compartment Syndrome are—pain greater than after surgery or injury, tense swelling, and pain with passive stretch. pressure measureIf compartment syndrome is suspected, measure the compartment pressure if you can. If the compartment pressure is greater than 30mHg (absolute measurement), or within 30mmHg of the diastolic pressure, then an immediate fasciotomy should be performed. These clinical findings are different in children and physicians are usually not familiar with how compartment syndrome presents itself in children.

Clinical findings in children include:

  • Increased pain with an increase in pain medication
  • Increased agitation
  • Increased anxiety of the child, parents, and nurses

For example, if a doctor goes on the floor and finds the nurses are with the parents in the room of the child and the child is in pain and everyone else is quiet, then there is a problem. The doctor should begin with removing the dressing and checking the extremity. Bivalving the cast will decrease the pressure significantly. When in doubt, measure the pressure. Objective findings, such as measuring the pressure, may be necessary to exclude the presence of compartment syndrome in children. The doctor may rely on his clinical judgment alone to diagnose compartment syndrome and perform a fasciotomy. However, the doctor should not rely on their clinical judgment alone to exclude compartment syndrome, especially if the patient has other findings of compartment syndrome.

dressing

Areas of concern for the development of compartment syndrome in children are: high energy fractures, multiple fractures in the same extremity (such as: floating elbow), multiple closed reductions, and/or the use of a fibroblast cast—which can be two times tighter than plaster. It is important to fix the fracture and provide post-operative monitoring with a possible delay in feeding the patient. A delay in diagnosis may lead to a poor outcome.

The use of an ACell can help with skin graft regeneration and may be used in an outpatient basis to cover the defect. The use of a VAC is always helpful.