The epidemiology of scaphoid fractures and non-unions in Switzerland: a nationwide analysis of the socioeconomic impact.

Scaphoid fractures are the second most common wrist injury after distal radius fractures and primarily affect young individuals in their most productive working years. Some scaphoid fractures fail to heal, potentially resulting in chronic pain, functional impairment, and long-term osteoarthritis in the wrist, which may require salvage procedures and can have a significant impact on work capacity. Considerable debate exists around the biological and injury-related risk factors for scaphoid non-unions, as well as the criteria for surgical intervention. However, epidemiological data are still limited, often derived from small populations, and incidence reports about scaphoid non-unions remain inconsistent. In a retrospective analysis of over 9 Mio injuries, recorded by the Swiss National Accident Insurance (Suva) Statistical Service from 2008 to 2021, we identified 16,691 scaphoid fractures. The male-to-female ratio was 4:1 for both scaphoid fractures and non-unions. The rate of primary surgery was 1:3. Around 14% of scaphoid fractures progressed to non-union, and 3% developed posttraumatic arthritis. Patients with non-unions were three times more likely to be unable to work for more than 12 months. Blue-collar workers were particularly at risk for a non-union and for extended work absence. Notably, the type of treatment (surgical or non-surgical) had no significant effect on work absence-non-union itself was the key determinant.