A 55-year-old man in Sri Lanka required surgery after a decades-old piece of shrapnel caused a chronic bone infection, according to a case report published in the journal Surgery Case Reports. The man presented to Kandy National Hospital with sudden onset right thigh pain and swelling that persisted for seven days.
The patient reported being injured 16 years prior during military service when he sustained a fractured right femur from a mortar blast. He underwent surgery at the time, but the case report details that not all fragments from the explosion were removed.
Medical staff found a painful lump in the front of his right thigh upon examination, and his range of motion in the hip and knee joints was reduced. X-rays revealed multiple metal fragments of varying sizes embedded in the thigh. An abscess had also formed in the front of the thigh. Analysis of fluid drained from the abscess identified methicillin-resistant Staphylococcus aureus (MRSA), a bacterium resistant to several common antibiotics.
Doctors administered antibiotics effective against the resistant strain and performed surgery to remove the fragments. Complete removal proved impossible, the report states. The patient was discharged after six weeks of antibiotic treatment and follow-up care.
The medical team noted that remaining fragments are often encapsulated by the body’s fibrous tissue and become inactive. However, as seen in this case, retained fragments can lead to long-term complications. They believe the infection occurred because bacteria were present on the shrapnel and were able to survive within a biofilm, remaining dormant for an extended period before reactivating.
“Staphylococcus aureus is known to survive within biofilms and maintain a prolonged dormant state before reactivation,” the report states. “The patient likely experienced a similar mechanism leading to the adverse event.”
The medical team emphasized the importance of removing as much shrapnel as possible during initial treatment following explosive injuries. While residual fragments are generally harmless, they can pose a risk of chronic infection, particularly when located near bone. They also stressed the demand for long-term monitoring of patients with retained metal fragments.