AAOS Now

Published 12/1/2011
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Maureen Leahy

Pediatric fracture patterns are changing

Location influences treatment options: casting or surgery?

Research presented at the American Society for Surgery of the Hand annual meeting reveals that scaphoid fracture patterns in children and adolescents are now similar to those in adults and that most acute nondisplaced fractures heal with cast immobilization. However, the authors recommend surgical reduction and internal fixation as the primary treatment approach for chronic nonunions.

“Historically, scaphoid fractures in children were largely injuries of the distal pole with little risk of osteonecrosis or nonunion. Nonsurgical treatment resulted in high rates of fracture healing,” said J. Joseph Gholson, BS, of Harvard Medical School, who presented the study. “In recent years, however, body mass index (BMI) in children has increased while bone mineral density has decreased. Children today also engage in higher-energy activities. We hypothesized that children and adolescents are now sustaining more waist and proximal scaphoid injuries and that surgical reduction and fixation should be the treatment of choice for acute displaced fractures as well as for chronic injuries.”

Most fractures occur at the scaphoid waist
Mr. Gholson and his colleagues conducted a retrospective analysis to characterize contemporary scaphoid fracture patterns in children. They also wanted to identify factors that influence union rate and time to healing following nonsurgical and surgical treatment.

The researchers examined 351 scaphoid fractures in 342 children who were treated between 1995 and 2010 at a single institution. Complete clinical and radiographic follow-up was available for 312 fractures (patient mean age = 14 years, range: 7 to 18 years; median BMI percentile = 76 percent; mean follow-up = 26 weeks). They identified 222 acute fractures and 90 chronic fractures; 287 patients had open physes. Patients were considered to have a chronic fracture if treatment was initiated more than 6 weeks after the injury.

Overall, 71 percent of the fractures occurred at the scaphoid waist, 23 percent occurred at the distal pole, and 6 percent occurred at the proximal pole. Patients with scaphoid waist and proximal pole fractures had significantly higher median BMI percentiles (78 percent and 80 percent, respectively) than patients with distal pole fractures (62 percent) (P = 0.002). The following factors were also associated with fractures of the scaphoid waist or proximal pole:

  • male gender
  • high-energy mechanisms of injury, such as extreme sports, heavy-contact sports, and falls from heights
  • closed physes

Casting heals most acute nondisplaced fractures
Among the 222 acute fractures, 201 were treated initially with casting, and 21 were treated initially with surgical fixation; 209 were displaced. Among the 90 chronic fractures, 77 were treated initially with casting, and 13 were treated initially with surgical fixation. All patients with unsuccessful casting (n = 79) required surgery
(Fig. 1).

Overall, 199 fractures achieved union after casting and 113 fractures achieved union after surgery. Cast patients were treated with a long-arm thumb-spica cast for 3 to 6 weeks, followed by a short-arm thumb-spica cast until radiographic healing. Surgical treatment for acute fractures was either open reduction and screw fixation (for displaced fractures) or percutaneous screw fixation (for nondisplaced fractures). Surgical treatment for chronic fractures consisted of open reduction and screw fixation and, if necessary, bone graft.

Using regression analysis, the researchers determined that the union rate with casting was affected by fracture chronicity, displacement, and location. Specifically, increased time to union with casting was associated with chronic fractures, displaced fractures, proximal fractures, and cases of osteonecrosis (Fig. 2). Factors increasing time to union following surgery included proximal location, displacement, use of a bone graft, implant choice, and open physes.

“According to our model, 181 (90 percent) of the acute nondisplaced scaphoid fractures healed with cast treatment, regardless of fracture location. The probability of union with casting for chronic displaced fractures of the waist and proximal pole was only 2 percent, whereas 69 (96 percent) of the 72 chronic nonunions treated surgically achieved union,” said Mr. Gholson.

Based on their results, the researchers concluded that scaphoid fracture patterns in children and adolescents are now similar to adults and that children’s participation in higher-energy activities or increased BMI has likely contributed to this change.

“The standard of care for acute nondisplaced scaphoid fractures continues to be cast immobilization, although 3 months or longer of treatment may be required to achieve union,” said Mr. Gholson. “Because casting is unlikely to yield union in the almost one-third of patients who have chronic nonunions, we recommend surgical reduction and internal fixation as the primary treatment option for chronic nonunions.”

He added, “Interestingly, patients with open physes had longer healing times following surgery. We hypothesized that the more cartilaginous scaphoid may actually have a less robust blood supply. For this reason, percutaneous screw fixation—which is a popular treatment for adults with acute nondisplaced scaphoid fractures—may not be applicable to younger, more skeletally immature patients.”

Mr. Gholson’s coauthors of “Scaphoid Fractures in Children: Contemporary Injury Patterns and Factors Influencing Healing,” are Donald S. Bae, MD; David Zurakowski, PhD; and Peter M. Waters, MD.

Disclosure information: The authors report no conflicts.

Maureen Leahy is assistant managing editor of AAOS Now. She can be reached at leahy@aaos.org