Scaphoid fractures in children and adolescents: contemporary injury patterns and factors influencing time to union.

BACKGROUND

Historically, scaphoid fractures in children and adolescents have predominantly involved the distal pole, requiring neither surgical care nor extended follow-up. Changing patient characteristics, however, appear to be altering fracture epidemiology and treatment. The purpose of this investigation was to characterize contemporary fracture patterns in children and adolescents and to identify factors influencing time to healing following both nonoperative and operative treatment.

METHODS

A retrospective analysis of 351 scaphoid fractures that had been treated from 1995 to 2010 was performed to characterize fracture patterns. The mean patient age was 14.6 years (range, seven to eighteen years). Complete clinical and radiographic follow-up data were available for 312 fractures (89%), with 222 fractures presenting acutely and ninety not acutely. Union rates following casting or surgical treatment were determined, and Cox regression analysis was utilized to identify factors influencing both the union rate and the time to union.

RESULTS

Overall, 248 fractures (71%) occurred at the scaphoid waist, eighty-one (23%) occurred at the distal pole, and twenty-two (6%) occurred at the proximal pole. Male sex, high-energy mechanisms of injury, closed physes, and high body-mass index were associated with fractures of the waist or proximal pole. Treatment of acute fractures with casting alone resulted in a 90% union rate. Lower union rates were seen in association with the use of casting alone for the treatment of chronic fractures, displaced fractures, and proximal fractures. Longer time to union was seen in association with older fractures, displaced fractures, proximal fractures, and fractures in patients with osteonecrosis. The union rate following surgery was 96.5% (109 of 113). Increased time to union was seen in association with open physes, fracture displacement, proximal fracture, the type of screw used for surgical fixation, and the use of bone graft at the time of surgery.

DISCUSSION

With changes in patient characteristics and activities, scaphoid fracture patterns in children and adolescents are now similar to the published patterns in adults. While 90% of acute nondisplaced fractures heal with nonoperative treatment, three months of cast immobilization or more may be required for more proximal injuries. Almost one-third of pediatric patients with scaphoid fractures will present late with chronic nonunions; in these instances, surgical reduction and internal fixation should be considered the primary treatment option.