<i>Cutibacterium acnes</i> Infection as a Cause of Nonunion After Ulnar-Shortening Osteotomy.

Abstract

Ulnar-shortening osteotomy is a reliable solution to treat ulnar impaction syndrome, but it has a significant rate of nonunion as a known complication. Generally nonunion after the procedure is attributed to noninfectious causes. When infections happen, they follow the microbiological trends of nonunions elsewhere in the body. We present a case of ulnar-shortening osteotomy using an oblique-cut osteotomy system that resulted in septic nonunion. At the time of revision surgery, <i>Cutibacterium acnes</i> and <i>Staphylococcus hominis</i> were isolated from the osteotomy site. The patient was successfully treated using intravenous antibiotics and the two-stage Masquelet technique and eventually went on to bony union. As <i>C acnes</i> is rarely encountered in this context, this report highlights the need to consider all possible pathogens in the workup of a potentially septic nonunion. Surgeons should consider bacteria such as <i>C acnes</i> that require prolonged incubation for isolation from cultures, which may not be part of many institutions' usual protocol. [<i>Orthopedics</i>. 2024;47(4):e211-e213.].