Summary: Pyomyositis is a rare bacterial infection of skeletal muscle. Staphylococcus aureus is the most common pathogen. Pyomyositis is typically seen in tropical regions and/or in individuals with underlying conditions, and it usually affects the large muscles of the lower limbs and pelvis. We presented the case of a 60-year-old healthy man who developed pyomyositis of the sartorius muscle after sustaining a motorcycle-related contusion to his left knee. Thirteen days postinjury, he was admitted with severe thigh swelling, erythema, and systemic symptoms indicative of necrotizing soft-tissue infection. Laboratory tests revealed elevated inflammatory markers. Contrast-enhanced computed tomography was suggestive of an abscess within the sartorius muscle. Emergency surgery with incision and drainage was performed. S. aureus was isolated from the aspirated pus. The patient was treated with broad-spectrum antibiotics, including meropenem and vancomycin, followed by tailored antibiotic therapy based on culture results. Despite having an allergic reaction to one of the antibiotics, there was no recurrence, and the wound closed completely on postoperative day 11. Only 2 cases of sartorius pyomyositis have been reported previously. Thus, this condition is exceedingly rare. This case indicated that pyomyositis should be considered in patients with muscle infections after trauma, regardless of whether they are healthy and/or whether the anatomical location is unusual. This awareness will promote early diagnosis and the prompt institution of imaging-guided surgical and antibiotic intervention, thus ensuring favorable outcomes.
Fujita et al. (Thu,) studied this question.