Ortho Dx: Deformity of an adolescent's arm after a fall - Clinical Advisor

Ortho Dx: Deformity of an adolescent’s arm after a fall

Slideshow

  • Anteroposterior x-ray of a 13-year-old boy’s right forearm following a fall

    Slide

    Anteroposterior x-ray of a 13-year-old boy’s right forearm following a fall

  • Lateral x-ray of the patient

    Slide

    Lateral x-ray of the patient

A 13-year-old male presents to the emergency department with an obvious deformity to the right forearm after falling off his porch at home. On examination, there is no evidence of open fracture. Distal motor, sensation, and pulses are intact. X-rays were taken of the adolescent’s forearm.

This case has been brought to you in partnership with the Journal of Orthopedics for Physician Assistants.

Most pediatric forearm fractures can be treated without surgery. The exception is open fracture, which requires irrigation and debridement.Displaced fractures require closed reduction to restore alignment and function of the involved extremity. Without adequate reduction, displaced forearm fractures can result...

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Most pediatric forearm fractures can be treated without surgery. The exception is open fracture, which requires irrigation and debridement.

Displaced fractures require closed reduction to restore alignment and function of the involved extremity. Without adequate reduction, displaced forearm fractures can result in cosmetic deformity and unacceptable loss of motion, most commonly a loss of supination and pronation.

Pediatric patients with open physes have great remodeling potential and therefore, most residual deformities after closed reduction can be accepted. However, the rate of remodeling is largely dependent on age. In general, angular deformities will be corrected better in children younger than age 11 than children who are older. Unacceptable alignment following closed reduction in patients aged less than 10 years includes more than 15 degrees of angulation and more than 45 degrees of rotation. In patients older than age 10, angulation that is greater than 10 degrees and rotation that is greater than 30 degrees is unacceptable.

Rotational displacement can often be difficult to determine. Rotational deformities of forearm fractures are evident when the radius and ulna fractures occur at different levels. Both bone fractures at the same level suggest minimal torsion. The location of a forearm fracture helps determine the degree of acceptable postreduction alignment as well. For instance, distal both-bone forearm fractures can tolerate more displacement than proximal fractures. Up to 100% translation can be accepted if the associated shortening is less than 2 cm. Children approaching skeletal maturity or who have less than 2 years of growth remaining have less remodeling potential and should be treated as adults would be treated.

Physical examination should assess the skin for subtle open fractures and neurovascular injury, although neurovascular injury is rare with both-bone forearm fractures. Testing of motor nerve function can be accomplished by having the patient form a rock, paper, scissors, and OK sign with the involved hand. The rock sign tests the median nerve, the paper sign tests the radial nerve, the scissors sign tests the ulnar nerve, and the OK sign tests the anterior interosseus nerve.

Most forearm fractures are placed in a long-arm splint or an above-elbow splint after reduction. Orthopedic follow-up is scheduled for 1 week after reduction to check for fracture displacement. Serial x-rays are then taken 1 week apart for the first 2 to 3 weeks to continue monitoring for displacement. Immobilization is continued for a period of 6 to 8 weeks or until adequate healing is present on x-ray. A long-arm cast is generally used for the first 4 weeks, followed by a short-arm cast for an additional 2 weeks if the fracture is healing.

Indications for surgery include unacceptable alignment after reduction, open fracture, bayonet apposition in children aged older than 10 years, and loss of reduction after casting. Relative indications include severe displacement and children aged older than 13 years. 

Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants (JOPA).

References

  1. Pring M, Chambers HG. Pediatric forearm fractures. Orthopaedic Knowledge Online Journal. 2007;5(5). http://orthoportal.aaos.org/oko/article.aspx?article=OKO_PED002#abstract. Accessed December 8, 2015.
  2. Beaty JH, Kasser JR, eds. Rockwood and Wilkens’ Fractures in Children. 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005.
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