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Prosthetic joint infections secondary to rapidly growing Mycobacterium fortuitum
Abstract:
Infection is an uncommon but catastrophic complication of joint arthroplasty, usually requiring removal of the implant. In a 30-year-old woman a knee arthroplasty was infected with the rapidly growing mycobacterium Mycobacterium fortuitum. Review of other reports of arthroplasties infected with this organism illustrates the problem, diagnosis, and treatment. M. fortuitum is widely distributed in nature, and although usually of low pathogenicity, it can cause infection in conditions of reduced local tissue resistance, i.e. hypodermic abscesses, implant inflammations, and trauma. Only six cases of M. fortuitum prosthetic joint infection have been previously described. Persistent drainage characterized cases in which the prosthesis was left in place. Although antibiotic treatment temporarily suppressed the signs and symptoms of infection, cure required removal of the prosthesis, as in the present case. Diagnosis of M. fortuitum infection is difficult because acid-fast stains of the organisms are often negative. Routinely bacterial cultures are continued for less than about five days, a period not long enough for growth of M. fortuitum. M. fortuitum infections should be considered in draining prosthetic joints with negative bacterial cultures and in those that have had repeated glucocorticoid intraarticular injections.
Insights
Mycobacterium fortuitum can cause rare but severe prosthetic joint infections, often requiring implant removal for a cure. Early diagnosis is challenging due to slow growth and negative initial tests.
Area of Science:
- Infectious Diseases
- Orthopedic Surgery
- Microbiology
Background:
- Joint arthroplasty infections are rare but serious complications.
- Mycobacterium fortuitum is a rapidly growing mycobacterium.
- This organism can cause infection in compromised local tissue resistance.
Observation:
- A case of knee arthroplasty infected with Mycobacterium fortuitum in a 30-year-old woman is presented.
- Persistent drainage was a hallmark in cases where the prosthesis remained.
- Antibiotic therapy provided only temporary symptom relief.
Findings:
- Cure of Mycobacterium fortuitum prosthetic joint infection typically necessitates prosthesis removal.
- Diagnosis is difficult due to negative acid-fast stains and short bacterial culture durations.
- M. fortuitum should be suspected in draining prosthetic joints with negative bacterial cultures or history of intraarticular glucocorticoid injections.
Implications:
- Highlights the diagnostic challenges of Mycobacterium fortuitum in prosthetic joint infections.
- Emphasizes the need for prolonged bacterial cultures in suspected cases.
- Informs treatment strategies, often requiring surgical intervention beyond antibiotics.