The most common pediatric elbow injury is the supracondylar fracture, which is a break in the humerus bone, just above elbow joint. Supracondylar fractures account for approximately 60% of elbow fractures and are most commonly found in children four to eight years of age.
The elbow is a hinged joint composed of three bones: the ulna, the radius, and the humerus. Also at the elbow are ligaments, tendons, and muscles that facilitate range of motion and maintain joint stability.
Children's bones are surrounded by a thick layer of connective tissue (periosteum) that protects the bone against injury. The periosteum also provides blood supply to the fracture area. The body uses this supply of blood to replace damaged cells. Periosteum in adults tends to be much thinner, resulting in a slower healing process.
The majority of elbow fractures occur when a child falls on an outstretched hand, which results in a hyperextension load on the elbow.
The humerus is a long bone and has growth plates (physis) located near the ends of the bone.
A fracture that includes the growth plate (physis) may result in arrested growth and/or deformity. Long-term monitoring of injuries involving the growth plate is typically indicated. This may include x-rays of contralateral elbows at three to six month intervals for up to two years. Some fractures may require ongoing evaluation until the child's growth is complete.
Non-displaced fractures are generally treated with a long arm cast or splint with elbow flexion at 90 degrees for approximately three to five weeks. Occasionally, the provider will request a second set of x-rays after 10 to 14 days to confirm the alignment has remained stable.
In approximately one out of ten cases, the bones or joints will require reduction. The provider will put direct pressure on the fracture and manipulate the elbow into acceptable alignment, often immobilizing the fragments with percutaneous pinning.
Closed reduction and percutaneous pinning is the preferred treatment for displaced or unstable fractures. In this procedure, the surgeon stabilizes the fracture with two to three laterally introduced pins.
Children will be monitored for 12 to 24 hours following the reduction, with strict elevation of the hand and elbow above heart level. Immobilization may include splinting or casting. Once adequate healing has occurred (confirmed by x-ray in three to four weeks), pins will be removed in the outpatient setting. Depending on the child and the fracture healing, an additional long arm cast may be necessary. A removable posterior elbow splint may be used for immobilization.
Children return to the clinic approximately three to four weeks post-reduction. After cast removal, many are anxious when they see the pin sites. Covering pin sites with cast padding may help alleviate anxiety. An x-ray is taken before pins are removed to confirm fracture alignment and that enough healing has occurred. In most cases, medication is not needed for removal of the pins. To lessen patient anxiety during the procedure, distractions like blowing bubbles, movies, singing, etc. are implemented. Pin removal is a very quick procedure, and many times the children don't even realize it has been completed. After the pins have been removed by the provider, an antiseptic ointment is applied on a sterile 2×2 dressing and placed over the pin sites. The patient may be casted again or sent home with the dressing in place.
Three main nerves to the hand and the brachial artery, which supplies blood to the forearm, are located extremely close to the elbow. Due to their anatomic location, there is a risk of vascular and/or nerve injury. Nerve damage occurs in 10 to 15% of cases. The most commonly injured nerve is the median nerve. To test for nerve function, ask the child to perform a "thumbs-up" sign (radial nerve), an OK sign (medial nerve), and spread fingers (ulnar nerve). A flat pinching motion instead of a round OK can be a sign of nerve injury. Test sensation in the first web space (radial nerve), little finger (ulnar nerve) and the volar aspect of the index finger (medial nerve).
The risk and seriousness of compartment syndrome must be explained to every child and his/her family. Remember the five P's: pain, paresthesia, pulselessness, pallor, and paralysis. Compartment syndrome is a medical emergency, and must be addressed immediately.
An open reduction is indicated in cases where the fracture is irreducible by closed methods or if the brachial artery has been compromised and requires exploration. Preoperative arterial insufficiency may be improved by operative reduction and pinning, in which a kinked brachial artery, draped over the distal end of the proximal fragment, may become patent after manipulative reduction of the fracture. All open supracondylar fractures warrant a surgical debridement of the fracture followed by stabilization.
While postoperative protocols vary from surgeon to surgeon, a typical regimen calls for a long arm, or a split long arm, cast to immobilize elbow motion and forearm rotation for three to four weeks, followed by pin removal and early range of motion or continued splinting for an additional three to four weeks.
If the elbow fracture has been reduced in the normal anatomical position and fixed with pins until healing occurs, the long-term outcome usually results in a normally functioning elbow. The child's elbow strength and range of motion return to normal, with only mild limitation.
If the fracture heals in an incorrect position, or if there is a growth plate injury, the elbow may remain permanently malaligned and have a limited range of motion.
Cubitus varus, or "gun-stock" deformity, is the most common late complication of elbow fractures. This is the result of fracture malunion and occasionally the partial growth arrest of the medial condylar physis. Proper anatomic reduction and fixation during initial management prevents malunion.
Minor varus angulation is generally considered a cosmetic issue, rather than functional deformity. A corrective osteotomy may be performed to improve clinically significant malunions.
Young children generally regain their elbow range of motion and strength readily. Occasionally, if there are concerns, OT may be initiated.