RESUMO
A 27-year-old rugby player underwent anterior cruciate ligament [ACL] reconstruction, using autograft. Postoperatively, septic arthritis was missed due to atypical presentation but diagnosed 2 days later and underwent open arthrotomy and lavage, He received antibiotics for 5 weeks. Aspirate showed clostridium perfringens. Later, extension lag was developed, which improved by arthroscopic excision of fibrous tissue and adhesions. The source of clostridial contamination remained a mystery. Skin preparation can be ineffective in eradicating clostridium perfringens prior to procedures. Routine prophylactic use of metronidazole would be controversial. In patients with postoperative infections, we suggest that samples should be routinely sent for anaerobic cultures