Mycobacterium abscessus: A Rare Cause of Periprosthetic Knee Joint Infection

Treatments for mycobacterial infections have been described with variable efficacy,^21,22 and only 2 cases of successfully treated PJIs have been reported after infection with M. abscessus. Both these cases were described in total hip arthroplasties,^23,24 and to the authors’ knowledge, this report represents the first described successfully treated case after TKA. Staged reconstruction remains a standard treatment for invasive organisms chronically infecting prosthetic joint implants, with reimplantation pending joint sterility and improvement in inflammatory markers.³ Previous successful reports of treating M. abscessus describe either resection arthroplasty²¹ or staged reconstruction.^23,24 The authors reported variable multidrug antimicrobial regimens, as summarized in Table 2, as guidelines for the treatment of mycobacterial PJI are currently not available.

CONCLUSION

This case report represents an episode of iatrogenic septic arthritis caused by Mycobacteria of the native knee after previous history of instrumentation, corticosteroid, and hyaluronic acid injections, with an overall indolent clinical course until subsequent arthroplasty. There were several important lessons learned, which are as follows: 1) Multidrug combination with antimicrobial therapy combined with aggressive surgical débridement and staged reimplantation permitted successful eradication of TKA PJI caused by M. abscessus in this patient. 2) Initial medical management alone was not successful and cannot be recommended for the treatment of M. abscessus in the setting of PJI. 3) Delaying the surgical débridement and the reconstructive course for a trial of medical management contributed to the ultimate requirement of a tibial tubercle osteotomy for an ankylosed knee at replantation. In this case, we initially had a low index of suspicion for deep infection, contributing to delayed surgical débridement. Ideally, a high degree of clinical suspicion should be maintained for joint infection in the presence of positive culture isolates of M. abscessus, as it may have a delayed clinical presentation of the typical features of PJI (fevers, swelling, erythema, etc). In such cases, the authors recommend consideration of early surgical débridement. 4) Medical management of TKA PJI is not without risks. Careful monitoring of patient side effects during antimicrobial administration remains paramount, as this patient did sustain a degree of hearing loss associated with prolonged medical therapy. 5) In complicated PJIs involving rare and intrinsically resistant organisms, a collaborative multidisciplinary approach, including specialists in orthopedic surgery, infectious disease, microbiology, pharmacy, and pathology, may be the preferred path to clinical cure.