Few physicians or patients associate attention deficit hyperactivity disorder (ADHD) with an increased risk of traumatic or stress-related fractures. However, in the June 6, 2018 issue of JBJS, a study by Ben-Ami et al. corroborates previous research suggesting that such associations exist. The authors evaluated 100,000 Israeli Defense Forces recruits and found that subjects diagnosed with ADHD were significantly more likely to sustain a traumatic fracture than recruits having no ADHD diagnosis. Furthermore, they found that recruits with ADHD who were taking the stimulant methylphenidate to treat their symptoms had a significantly increased risk of sustaining a stress fracture compared to both recruits without ADHD and recruits who had ADHD but did not take the medication.
The association between methylphenidate exposure and increased risk of stress fracture makes sense, based on animal studies showing that the drug leads to increased bone resorption. However, until now I was unaware that patients with ADHD are at an increased risk of traumatic fracture as well. The authors postulate that such an association is secondary to the fact that ADHD often manifests with compulsive or inattentive behavior that may predispose these patients to injuring themselves. That theory is further supported by this study’s finding that the risk of traumatic fracture fell when those with ADHD took stimulant medications to control their symptoms.
When one considers that upwards of 5% of school-aged children and another 4% of adults in the US are prescribed stimulant medication (not to mention the estimated 5% to 35% of US college students who abuse stimulants without prescription), these findings take on great importance. Because of the large number of children and adults who rely on methylphenidate to control ADHD symptoms, it is important for both primary care physicians and orthopaedic surgeons to understand the association between this medication and stress fractures.
Although limited by the vulnerabilities typically found in observational, retrospective designs, this study’s findings add to a growing body of evidence highlighting the potential fracture risks associated with stimulant medication. We probably encounter patients taking such medications on a regular basis in our practices. These data should prompt us to ask more questions of patients who have sustained stress fractures to determine whether stimulant medication usage may be an underlying cause.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media