Fig. 1 AP radiograph of the left forearm in a 9-year-old male patient with midshaft transverse fractures of the radius and ulna. The ulna fracture appears nondisplaced on this view. The radius is 100 percent displaced with 2 mm to 3 mm of shortening and bayonet apposition.
Courtesy of Derek M. Kelly, MD

AAOS Now

Published 8/1/2016
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Terry Stanton

Study: Longer Initial Reduction Time a Risk Factor for Repeat Procedures in Pediatric Forearm Fractures

A study to determine what factors may predict instability in pediatric diaphyseal both-bone forearm fractures found that patients requiring lengthy initial reduction times are at greater risk of having a repeat procedure than those with short initial reduction times. Age, initial translation, complete fracture of the radius, and residual translation on follow-up were highly predictive of the need for a second closed reduction and casting or an open surgical stabilization.

The study, presented by Derek M. Kelly, MD, at the annual meeting of the Pediatric Orthopaedic Society of North America (POSNA), evaluated radiographs and records of skeletally immature patients who underwent closed reduction and casting of diaphyseal forearm fractures in the emergency department.

Study group patients were identified by retrospective review of those who presented with diaphyseal forearm fractures at a pediatric hospital; the identifying billing code (CPT 25565) referred to closed treatment of radial and ulnar shaft fractures with manipulation. Of 188 patients meeting the inclusion criteria, 174 had adequate follow-up to union. Patients were considered eligible for the study if they were younger than 18 years of age and had an isolated both-bone forearm injury treated with closed reduction with fluoroscopic assistance and cast immobilization under conscious sedation in the emergency department. The average patient age was 7.7 years, and 68 percent were male. The primary outcome measures were (1) union and discontinuation of immobilization and (2) instability, defined as loss of reduction necessitating repeat intervention beyond prolonged passive immobilization.

Nineteen patients (11 percent) required a repeat procedure. Patients who had repeat procedures had an average initial reduction time of 36.9 ± 22.2 minutes; patients who did not require additional procedures had an initial reduction time of 23.4 ± 11.8 minutes (P < 0.0103).

Risk factors for repeat reduction were fractures translated 50 percent or more in any plane, age older than 9 years, complete fracture of the radius, follow-up angulation of the radius of more than 15 degrees on lateral radiographs, follow-up angulation of the ulna of more than 10 degrees on anteroposterior (AP) radiographs (Fig. 1), and translation of either bone of more than 50 percent at follow-up. Neither the degree nor direction of angulation of the ulna or radius in either radiographic plane at presentation was predictive of a repeat procedure. The location of the fracture within the shaft also was not significantly predictive of a repeat reduction.

The authors report that their finding of an 11 percent remanipulation rate is consistent with published studies, in which the rate ranged from 7 percent to 21 percent. They comment:

"Our study is, to our knowledge, the first to identify a relationship between time spent during initial closed reduction with casting and failure of this treatment method. In our analysis, longer reduction times were associated with an increased likelihood of more aggressive interventions being required in the early follow-up period compared with shorter reduction times. The average time of reduction for fractures that required a repeat procedure was nearly 14 minutes longer than for fractures that united uneventfully. Additionally, reductions lasting longer than 35 minutes from start to stop were more than seven times more likely to require a subsequent reduction. Clinically, this is relevant because it is likely that longer reduction times are indicative of fractures that are innately unstable and more likely to displace. This information can be used to plan for closer follow-up of these patients and to counsel families that more aggressive intervention may be required."

They also singled out the finding that older children were more likely to require subsequent intervention after initial closed reduction and immobilization; analysis showed that patients older than 9 years had a 4.1-times higher likelihood of having further intervention, an association echoed in other studies.

Dr. Kelly said that the idea for the study arose "from a question from one of our residents who speculated that sedation time might serve as a surrogate to identify more challenging or unstable fractures," noting that at his facility (the Campbell Clinic and Le Bonheur Children's Hospital in Memphis, Tenn.), emergency department sedation is the mechanism used to control pain during reduction, as opposed to Bier block, plexus block, or hematoma block.

He said the results were not unexpected. "Those fractures that are more challenging and harder to reduce will require longer sedation times," Dr. Kelly said.

Limitations of the study, he said, include "a bit of selection bias, as the decision to proceed with repeat manipulation and surgical stabilization was made by the treating physician." Also, "This is retrospective, so we had no clearly defined criteria for who needs a repeat reduction at the time the decision is made."

The authors concluded: "Lengthy reduction times, degree of translation, and increasing age all carried a high risk of repeat intervention in the short-term follow-up after closed reduction and casting of diaphyseal forearm fractures in children. Clinicians can use this information to aid in surgical decision making to maximize radiographic and clinical outcomes in children with diaphyseal forearm fractures and to be aware of the necessity of close follow-up of patients at risk."

Dr. Kelly's coauthors of "Factors that Predict Instability in Pediatric Diaphyseal Both Bone Forearm Fractures" are Jeffrey Kutsikovich, MD; Christopher M. Hopkins, MD; Edwin Gannon, BS; and Jeffrey R. Sawyer, MD.

The authors' disclosure information can be accessed at www.aaos.org/disclosure

Terry Stanton is the senior science writer for AAOS Now. He can be reached at tstanton@aaos.org

Bottom Line

  • Displacement occurs frequently after closed reduction and casting of diaphyseal forearm fractures in children.
  • In this retrospective review of patients with diaphyseal both-bone forearm fractures, 11 percent required a repeat procedure.
  • Patients with repeat procedures had average initial reduction time of 36.9 minutes versus 23.4 minutes for those who did not require additional procedures.
  • Factors associated with remanipulation included longer initial reduction time, higher degree of translation, older age, and complete fracture of the radius.