A 55-year-old immunocompetent male was involved in a motor vehicle collision 2 years prior to presenting to our institution. He sustained an open ankle fracture after being ejected from the driver's seat into a pasture ditch, sustaining lacerations from barbed wire and resulting in a grossly contaminated open fracture. He was initially managed with irrigation and debridement (I&D) and placement of an external fixator. He subsequently underwent definitive fixation but during the next two years, experienced episodic drainage from incisions that was managed symptomatically with oral antibiotics. He had persistent pain which led him to seek evaluation at our institution.
Upon presentation to our clinic, he was noted to have a severe planovalgus alignment, two draining sinuses, radiographic hardware failure (Figure 1), and elevated inflammatory markers including a white blood cell (WBC) count of 11 K/mm3, C-reactive protein (CRP) of 18.7 mg/L, and Erythrocyte Sedimentation Rate (ESR) of 18 mm/hr. He was diagnosed with an infected nonunion with underlying chronic septic arthritis of the tibiotalar joint and osteomyelitis of the distal tibia and fibula and scheduled for a staged ankle fusion following eradication of his infection. At our index surgery, the patient underwent a complete hardware removal with the exception of a broken screw tip from the most proximal fibular screw, extensive debridement of the ankle including excision of 11 centimeters (cm) of diseased distal fibula, 1.5cm of tibial plafond, and 0.5cm of talar dome, placement of an antibiotic spacer to the residual tibiotalar joint (impregnated with 2 grams of vancomycin and 2.4 grams of tobramycin per 40 grams of cement), and application of a ringed (Ilizarov) external fixator (Figure 2). Intraoperatively, multiple tissue cultures were obtained and found to be positive for Enterococcus faecalis, Enterobacter cloacae, and Mycobacterium senegalense, which grew from regular bacterial cultures.
Postoperatively, the patient was started on a 4-week regimen of piperacillin-tazobactam for the E. faecalis and E. cloacae osteomyelitis followed by a 6-week regimen of imipenem, ciprofloxacin, and minocycline for his M. senegalense based on the in vitro antibiotic susceptibilities from the culture (Table 1). Three months after his index surgery, he continued to have drainage from 2 sites and the decision was made to undergo a repeat I&D with placement of a new antibiotic spacer (impregnated with vancomycin and tobramycin). Intraoperatively, the distal tibia had the appearance of persistent infection including purulence and caseous material which was cultured and noted to be positive for Bacillus species (not anthracis) and persistent M. senegalense growth, again from regular bacterial cultures (Table 1). At this point, based on the recurrent isolation of M. senegalense, the decision was made to continue imipenem and change the oral antibiotics to linezolid and azithromycin for another three months. Finally, after finishing 3 more months of imipenem, it was replaced with doxycycline to complete another 3 months of an all oral regimen.
Four months later, he had closure of all wounds, demonstrated downtrending inflammatory markers (WBC, ESR, CRP), and was felt to be ready for fusion. During the procedure, no purulence was encountered, iliac crest autograft was utilized to augment the tibiotalar fusion and compression through the joint was achieved through the ringed external fixator (Figure 3). Multiple tissue cultures were taken intraoperatively with no growth noted and postoperatively he was continued on his regimen of linezolid, azithromycin, and doxycycline.
Six months postoperatively, he had a successful fusion with no sinus tracts or drainage (Figure 4). He was able to have his ringed external fixator removed and one year postoperatively the patient continues to do well, fully weightbearing through the extremity and has not shown any signs of recurrence (Figure 5).