Rapidly-growing mycobacterial infection: a recognized cause of early-onset prosthetic joint infection

Incidence and Risk Factors for Acid-fast Bacillus/Fungal Culture Positivity in Primary, Conversion, and Revision Hip and Knee Arthroplasty

INTRODUCTION

Previous literature has reported minimal incidences of positive fungal/AFB cultures, questioning the routine use of these tests. With growing concern for excessive use, predictive factors for patients at higher risk for intraoperative AFB/fungal infections would help surgeons limit unnecessary testing. This study evaluates the positivity rate and predictive factors of positive fungal and/or acid-fast bacillus (AFB) cultures after primary, conversion, or revision hip and knee arthroplasty.

METHOD

Two hundred thirty-eight knee and hip procedures were done between January 2007 and 2022 where intraoperative AFB/fungal cultures were obtained. Procedures included primary total knee arthroplasty, primary total hip arthroplasty, conversion, first of two-stage, second of two-stage, irrigation and débridement polyexchange, and aseptic revision. Positivity rates of intraoperative AFB/fungal cultures were calculated as binomial exact proportions with 95% confidence intervals and are displayed as percentages. Univariable generalized linear mixed models estimated the unadjusted effects of demographics, individual comorbid conditions, and procedural characteristics on the logit of positive AFB/fungal cultures.

RESULTS

Two hundred thirty-eight knee and hip procedures recorded an overall positivity rate of 5.8% for intraoperative AFB/fungal cultures. Aseptic revisions showed the lowest rates of positivity at 3.6%, while conversions showed the highest rates of positivity at 14.3%. The positivity rates are highest among patients who are male (9.0%), of Hispanic origin (12.0%), with body mass index <30 (6.4%), and a Charlson Comorbidity Index <5 (6.1%). History of a prior infection in the same surgical joint showed statistically significant influence of odds of culture positivity with an odds ratio of 3.47 ( P -value: 0.039). Other demographic factors that we investigated including age, sex, race, ethnicity, body mass index, and Charlson Comorbidity Index did not show any notable influence on AFB/fungal positivity rates.

CONCLUSION

These results suggest utility in obtaining routine intraoperative AFB/fungal cultures, given the relatively high positivity and poor predictive factors.

Management of M. abscessus subsp. abscessus early-onset prosthetic joint infection: Case report and literature review

Nontuberculous mycobacteria are a rare but still emerging cause of difficult-to-treat prosthetic joint infection. To our knowledge only 17 cases of M. abscessus complex prosthetic joint infection are reported in literature, of which only 1 is by M. abscessus subps. abscessus. No guidelines are available for this clinical scenario. We describe a 68-years-old female patient with an early-onset M. abscessus subsp. abscessus prosthetic joint infection, successfully treated with a tailored medical-surgical strategy, and present an overview of cases currently available in the literature to assist physicians in the management of these uncommon infections.

Characteristics and management of periprosthetic joint infections caused by rapidly growing mycobacteria: a retrospective study and a review of the literature

Background: Periprosthetic joint infection (PJI) following total joint arthroplasty is a serious complication associated with significant morbidity. While Gram-positive cocci are the predominant causative organisms, PJIs caused by rapidly growing mycobacteria (RGM) have been reported, albeit at a lower frequency. This study aimed to investigate the characteristics and management of PJI caused by RGM. Methods: A retrospective review was conducted using an institutional PJI database to identify patients diagnosed with PJI due to RGM from January 2010 to December 2021. Clinical data, including demographics, symptoms, comorbidity information, laboratory parameters, surgical procedures, medical treatment and outcomes, were collected and analyzed. Results: A total of eight patients were identified with PJI caused by RGM during the study period. The median age was 66 years old, and most cases occurred in patients with total knee arthroplasty (n = 6 ). The isolated RGM species included Mycobacterium abscessus (three cases), M. fortuitum (three cases), and one case each of M. immunogenum and M. mageritense. Surgical debridement was performed in all cases, with six patients undergoing two-stage revision and two patients requiring amputation. Combination antimicrobial therapy was administered based on antimicrobial susceptibility testing, and the median duration of treatment was 7.5 months. Adverse events related to therapy occurred in 75 % of cases. No relapses were observed during the median follow-up period of 39.6 months. Conclusions: PJI caused by RGM is a rare complication of total joint arthroplasty. Surgical debridement and combination antimicrobial therapy are the mainstays of treatment. Although clinical cure rates are high, amputation may be required in severe cases.

Mycobacterium flavescens Infection - An Unusual Case of Prosthetic Joint Infection

INTRODUCTION

The onset of prosthetic joint infections (PJIs) is characterized by early onset defined as within 90 days of the procedure, delayed onset defined as within 3 to 12 months, and late onset defined as over 12 months. In only a scant number of case reports, Mycobacterium flavescens associated infections are typically found in sputum cultures and associated with various forms of penetrating joint traumas, particularly post-surgical interventions. Due to its rarity in presentation among cases of PJIs, we have presented a case of PJI caused by Mycobacterium flavescens.

CASE PRESENTATION

We have, herein, reported a case of a 70-year-old male presenting with stabbing left knee pain over the past several months along with accompanying erythema and swelling with the presence of purulent discharge. Outpatient cultures have shown the growth of Mycobacterium flavescent; subsequently, the patient underwent a 2-stage revision arthroplasty and was treated with a three-drug regimen and implant 5 months later. Although being an atypical cause of PJIs, we emphasize the importance of considering NTM as a differential for immunocompromised patients, especially those with prior surgical intervention.

DISCUSSION

Mycobacterium spp. related PJIs manifest clinical features similar to other bacteriacausing PJIs, such as warm, indurated edema at the surgical site resulting in wound dehiscence and joint effusion. Diagnosis of Mycobacterium spp. related PJIs includes history and physical examination findings, serum inflammatory markers, synovial fluid analysis, and culture. Concurrently with surgical interventions, utilization of antimicrobial agents provides additional control in Mycobacterium- related PJI. Mycobacterium flavescens should be included among other NTMs as a possible cause of PJIs.

A case report on Mycobacterium houstonense infection after total hip arthroplasty

BACKGROUND

Mycobacterium houstonense is a category of rapidly growing mycobacteria that is gram-positive, acid-fast, polycrystalline, and non-spore-forming. There have been few reports of human infection caused by Mycobacterium houstonense worldwide.

CASE PRESENTATION

We present a case of chronic periprosthetic joint infection caused by Mycobacterium houstonense in an elderly female patient. The patient developed signs of infection after undergoing total hip arthroplasty. Despite receiving antibiotic treatment and revision surgery, the signs of infection recurred repeatedly. Multiple bacterial cultures during the treatment period were negative. Later, we identified the pathogenic bacteria Mycobacterium houstonense through mNGS testing, isolated the bacteria from the ultrasonically centrifuged fluid of the prosthesis and obtained drug sensitivity results. Finally, we performed a revision surgery and treated the patient with moxifloxacin and clindamycin. After treatment, the patient did not show signs of infection recurrence during 24 months of follow-up.

CONCLUSION

Through a relevant literature search, we believe that Mycobacterium houstonense may show higher sensitivity to amikacin and quinolone antibiotics. Additionally, clarifying occult infection sources through methods such as gene testing will improve the diagnosis and treatment of periprosthetic joint infection.

Periprosthetic Joint Infection Diagnosis: A Narrative Review

Replacement of native joints aims to restore patients' quality of life by relieving pain and improving joint function. While periprosthetic joint infection (PJI) affects a small percentage of patients, with an estimated incidence of 1-9% following primary total joint replacement, this postoperative complication necessitates a lengthy hospitalisation, extended antibiotic treatment and further surgery. It is highlighted that establishing the correct diagnosis of periprosthetic infections is critical in order for clinicians to avoid unnecessary treatments in patients with aseptic failure. Of note, the PJI diagnosis could not purely rely upon clinical manifestations given the fact that heterogeneity in host factors (e.g., age and comorbidities), variability in infection period, difference in anatomical location of the involved joint and discrepancies in pathogenicity/virulence of the causative organisms may confound the clinical picture. Furthermore, intra-operative contamination is considered to be the main culprit that can result in early or delayed infection, with the hematogenous spread being the most prevalent mode. To elaborate, early and hematogenous infections often start suddenly, whereas chronic late infections are induced by less virulent bacteria and tend to manifest in a more quiescent manner. Last but not least, viruses and fungal microorganisms exert a role in PJI pathogenesis.

Non-Tuberculosis Mycobacterium Periprosthetic Joint Infections Following Total Hip and Knee Arthroplasty: Case Series and Review of the Literature

OBJECTIVE

Periprosthetic joint infection (PJI) caused by non-tubercular mycobacteria (NTM) is uncommon but catastrophic. However, conclusive clinical data on PJI caused by NTM are lacking. In this case series and systematic review, the clinical manifestations, diagnosis, and management of NTM PJI are summarized and analyzed.

METHODS

From 2012 to 2020, we retrospectively analyzed consecutive PJI cases caused by NTM in our institution. A literature review was also conducted from January 2000 to December 2021, utilizing the PubMed, MEDLINE, Cochrane Library, and EMBASE databases to identify all reported NTM-induced PJI cases. The clinical characteristics, demographics, pathogen identification, treatment protocols, and prognosis of NTM PJI were summarized and analyzed.

RESULTS

In this retrospective analysis, seven patients infected with NTM following total joint arthroplasty at our institution were included, including six cases of PJI caused by NTM and one case of septic arthritis (SA) caused by NTM. There were six men and one woman, and their average age was 62.3 years. The average interval between TJA and PJI onset was 4 months. The preoperative serological markers, including the mean ESR (51 mm/h), CRP (4.0 mg/dL), fibrinogen (5.7 g/L), and D-dimer (1.1 g/L), were increased. Six patients underwent staged revision surgery, and one patient with SA received antibiotic-loaded bone cement beads to treat the infection. After an average of 33 months of observation following surgical intervention, none of the patients showed any symptoms of infection recurrence. From 2000 to 2021, 68 patients with NTM PJI were found in 39 studies in the published literature. Reinfections occurred within 1 year after arthroplasty in more than half (53.2%) of the patients. M. fortuitum and M. abscesses were the most prevalent rapidly growing mycobacteria (RGM) in all PJI patients, whereas Mycobacterium avium intracellulare (MAC) was the most prevalent slowly growing mycobacterium (SGM). The corresponding antibiotics were amikacin and ethambutol. The rate of culture-negative without specific clinical symptoms was as high as 36.4% (12/33), while 45% (18/40) utilized additional diagnostic techniques such as NGS. A final clinical follow-up record was available for 59 patients (86.7%; mean follow-up period, 29 months), and 10.1% of patients failed to respond to treatment.

CONCLUSION

Orthopaedic surgeons should consider NTM in patients with negative routine cultures who are at risk for Mycobacterium infection. Treatment options rely on the accurate result of microbiologic identification and drug sensitivity testing, and to achieve this, it may be necessary to send multiple culture specimens, extend the culture time, and change the culture medium. Every effort should be made to identify NTM and its various subtypes through modern diagnostic tools if necessary.

Prosthetic joint infection of the hip and knee due to Mycobacterium species: A systematic review

BACKGROUND

Mycobacterium species (Mycobacterium sp) is an emerging cause of hip and knee prosthetic joint infection (PJI), and different species of this organism may be responsible for the same.

AIM

To evaluate the profile of hip and knee Mycobacterium PJI cases as published in the past 30 years.

METHODS

A literature search was performed in PubMed using the MeSH terms “Prosthesis joint infection” AND “Mycobacterium” for studies with publication dates from January 1, 1990, to May 30, 2021. To avoid missing any study, another search was performed with the terms “Arthroplasty infection” AND “Mycobacterium” in the same period as the previous search. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses chart was used to evaluate the included studies for further review. In total, 51 studies were included for further evaluation of the cases, type of pathogen, and treatment of PJI caused by Mycobacterium sp.

RESULTS

Seventeen identified Mycobacterium sp were reportedly responsible for hip/knee PJI in 115 hip/knee PJI cases, whereas in two cases there was no mention of any specific Mycobacterium sp. Mycobacterium tuberculosis (M. tuberculosis) was detected in 50/115 (43.3%) of the cases. Nontuberculous mycobacteria (NTM) included M. fortuitum (26/115, 22.6%), M. abscessus (10/115, 8.6%), M. chelonae (8/115, 6.9%), and M. bovis (8/115, 6.9%). Majority of the cases (82/114, 71.9%) had an onset of infection > 3 mo after the index surgery, while in 24.6% (28/114) the disease had an onset in ≤ 3 mo. Incidental intraoperative PJI diagnosis was made in 4 cases (3.5%). Overall, prosthesis removal was needed in 77.8% (84/108) of the cases to treat the infection. Overall infection rate was controlled in 88/102 (86.3%) patients with Mycobacterium PJI. Persistent infection occurred in 10/108 (9.8%) patients, while 4/108 (3.9%) patients died due to the infection.

CONCLUSION

At least 17 Mycobacterium sp can be responsible for hip/knee PJI. Although M. tuberculosis is the most common causal pathogen, NTM should be considered as an emerging cause of hip/knee PJI.

Fungal and mycobacterial cultures should not be routinely obtained for diagnostic work-up of patients with suspected periprosthetic joint infections

AIMS

Fungal and mycobacterial periprosthetic joint infections (PJI) are rare events. Clinicians are wary of missing these diagnoses, often leading to the routine ordering of fungal and mycobacterial cultures on periprosthetic specimens. Our goal was to examine the utility of these cultures and explore a modern bacterial culture technique using bacterial blood culture bottles (BCBs) as an alternative.

METHODS

We performed a retrospective review of patients diagnosed with hip or knee PJI between 1 January 2010 and 31 December 2019, at the Mayo Clinic in Rochester, Minnesota, USA. We included patients aged 18 years or older who had fungal, mycobacterial, or both cultures performed together with bacterial cultures. Cases with positive fungal or mycobacterial cultures were reviewed using the electronic medical record to classify the microbiological findings as representing true infection or not.

RESULTS

There were 2,067 episodes of PJI diagnosed within the study period. A total of 3,629 fungal cultures and 2,923 mycobacterial cultures were performed, with at least one of these performed in 56% of episodes (n = 1,157). Test positivity rates of fungal and mycobacterial cultures were 5% (n = 179) and 1.2% (n = 34), respectively. After a comprehensive review, there were 40 true fungal and eight true mycobacterial PJIs. BCB were 90% sensitive in diagnosing true fungal PJI and 100% sensitive in detecting rapidly growing mycobacteria (RGM). Fungal stains were performed in 27 true fungal PJI but were only positive in four episodes (14.8% sensitivity). None of the mycobacterial stains was positive.

CONCLUSION

Routine fungal and mycobacterial stains and cultures should not be performed as they have little clinical utility in the diagnosis of PJI and are associated with significant costs. Candida species and RGM are readily recovered using BCB. More research is needed to predict rare non-Candida fungal and slowly growing mycobacterial PJI that warrant specialized cultures. Cite this article: Bone Joint J 2022;104-B(1):53-58.

Management of Mycobacterium tuberculosis Prosthetic Joint Infection: 2 Cases and Literature Review

Prosthetic joint infection caused by Mycobacterium tuberculosis (TBPJI) is uncommon but can be encountered in immunocompromised patients or those from tuberculosis-endemic regions. A lack of clinical suspicion and experience with TBPJI often leads to a delay in diagnosis. We report 2 cases of TBPJI in a Hungarian-Canadian and Iranian-Canadian immigrant, respectively. Both were treated with concurrent surgical and medical therapy. We also performed a literature review on TBPJI case reports, outlining their diagnosis and management.

Pin tract infection caused by Mycobacterium neoaurum in a 14-year-old child: A case report

Although rapidly growing non-tuberculosis mycobacterium can occasionally cause postoperative infections, Mycobacterium neoaurum is a rare pathogen of surgical site infection. We report a case of pin tract infection caused by M. neoaurum in a 14-year-old girl who was admitted for lengthening of her right fourth metatarsal bone. Pain, redness, and exudate were observed 18 days after external fixator insertion. Repeated exudate cultures revealed M. neoaurum, and she was diagnosed with a mycobacterial pin tract infection. She was initially administered intravenous ciprofloxacin and minocycline, and then was switched to oral trimethoprim-sulfamethoxazole and minocycline for a total of 6 months. Despite the pin tract infection, bone lengthening was completed under antibiotic treatment without removal of the pin; no other complications were noted. There are no prior reports of external fixator pin tract infection by M. neoaurum. While such cases may be rare, this case demonstrates that bone distraction may still be successfully completed using appropriate antibiotic therapy without pin removal.

Elbow arthroplasty complicated by Mycobacterium tuberculosis infection: A case report

INTRODUCTION

Total elbow arthroplasty (TEA) is an orthopedic procedure that is relatively infrequently performed, but its use has been increasing over time. Infection remains one of the most concerning complications after TEA, although Mycobacterium tuberculosis (TB) as a microbial etiology, is extremely rare. Here, we present a case of M. tuberculosis infection after TEA.

PATIENT CONCERNS

A 45-year-old woman underwent TEA for severe traumatic arthritis of the elbow following failure of conservative treatment. Four months after TEA, the patient experienced progressive elbow pain and swelling, without other external signs of infection such as a sensation of local heating and erythematous alterations.

DIAGNOSIS

Pulmonary computed tomography showed stable pulmonary TB in the right upper lobe. The T-SPOT, TB, and purified protein derivative test results were positive, and M. tuberculosis exhibited growth on cultures. The final diagnosis was periprosthetic infection of M. tuberculosis.

INTERVENTIONS

The patient was treated with debridement with submission of deep tissue cultures. According to these cultures and suggestions of a bacteriologist, anti-TB treatment was administered for 12 months.

OUTCOMES

The symptoms of the infection were controlled, and the prosthesis was retained. At the time of writing this case report, the elbow prosthesis had survived for more than 2 years, and no recurrent infection had been observed.

CONCLUSION

The diagnosis of TB infection after TEA is difficult to confirm due to its nonspecific signs and symptoms. Despite the extremely low incidence, failure to consider this possibility for diagnosis can lead to delayed treatment. Proper diagnosis allows for antitubercular therapy with retention of a prosthesis.

Mycobacterium fortuitum Prosthetic Joint Infection After Total Hip Arthroplasty: A Case Report

CASE

A 57-year-old man presented with a Mycobacterium fortuitum prosthetic joint infection (PJI) after right total hip arthroplasty refractory to the initial revision surgery and cement spacer placement. The patient was subsequently treated with 2-stage total joint arthroplasty revision surgery using an antibiotic-laden spacer customized to include meropenem and delayed reimplantation to allow for prolonged, systemic antimicrobial treatment with multiple antimicrobials, including levofloxacin and linezolid.

CONCLUSIONS

There is little evidence to guide practitioners in the diagnosis and treatment of PJI caused by rare, rapidly growing mycobacteria (RGM) such as M. fortuitum. This case demonstrates a successful strategy for the treatment of RGM PJI.

Nail Salon a Potential Source of a Rare Mycobacterium Fortuitum Infection In Proximal Tibia Megaprosthesis? A Case Report

Mycobacterium Fortuitum (M. Fortuitum) is a type of opportunistic pathogen commonly found in water/soil and belongs to the nontuberculosis mycobacteria (NTM) family. Prosthetic joint infection due to M. Fortuitum is extremely rare. We present a case of a 21-year-old female with an infection following a radical resection of the proximal tibia due to a parosteal osteosarcoma.

Characteristics of clinical extrapulmonary nontuberculous mycobacteria isolates in Minnesota, 2013-2017

Approximately 80 species of nontuberculous mycobacteria (NTM) that cause disease are found environmentally and in animal reservoirs. Typically, pulmonary NTM infections are sporadic; extrapulmonary NTM (ENTM) infections are commonly outbreak associated. Recent sources of ENTM outbreaks in Minnesota include contaminated heater-cooler units used during cardiac surgery and contaminated hormone injections. We examined patient demographics and characteristics of ENTM isolates characterized by four Minnesota reference laboratories during 2013-2017 to assess potential value of systematic laboratory-based ENTM surveillance in Minnesota. Laboratories characterized 490 ENTM isolates, representing an estimated burden of 1.8/100,000 people/year in Minnesota. Thirty-one species or complexes were identified; most common were M. avium complex (31%), M. chelonae (22%), M. fortuitum (11%), and M. abscessus (4%). Most common specimen collection sites included skin and soft tissue (38%), blood (15%), neck lymph node or tissue (12%), sinus (8%), joint or bone (5%), device or implant (4%), and eye (3%). Median age of patients was 55 years (range: 2-98 years); 18% were from patients aged <18 years, 20% aged 18-44 years, 28% aged 45-64 years and 34% aged >65 years. Sex was documented for 238 (49%) patients; 127 (53%) were males. County information was available for 313 patients (64%); approximately half (49%) resided in metropolitan Minneapolis-Saint Paul. Laboratory data can be used for ENTM surveillance in Minnesota. Implementing laboratory-based surveillance can detect ENTM cases, provide a mechanism for obtaining clinical and epidemiological information, and enable earlier identification of potential health care transmission or community clusters.

Treating Primary Arthroprosthesis Infection Caused by Mycobacterium abscessus subsp. abscessus

Prosthetic joint infections (PJI) caused by nontuberculous mycobacteria are very rare, and results of treatment can be unpredictable. A 72-year-old female underwent hip replacement after an accidental fall in a local hospital in Santo Domingo. The postoperative period was uneventful except for a traumatic wound near the surgical scar. PJI caused by Mycobacterium abscessus subsp. abscessus was diagnosed 6 months later. A two-stage reimplantation was performed after a 3-month period of aetiology-directed therapy, including amikacin, imipenem, and clarithromycin. M. abscessus isolate was reported to be resistant to clarithromycin when incubation was protracted for 14 days and to harbour the gene erm(41). The patient manifested major side effects to tigecycline. At reimplant, microbiologic investigations resulted negative. Overall, medical treatment was continued for a 7-month period. When discontinued and at 6-month follow-up, the patient was clinically well, inflammatory markers were normal, and the radiography showed well-positioned prosthesis. Mycobacterium abscessus subsp. abscessus is a very rare cause of PJI, yet it must be included in the differential diagnosis, especially when routine bacteria cultures are reported being negative. Further investigations are needed to determine any correlations between clinical results and in vitro susceptibility tests, as well as the clinical implications of M. abscessus subsp. abscessus harbouring the functional gene erm(41). Moreover, investigations are needed for determine optimal timings of surgery and lengths of medical therapy to improve patient outcome.

Inhibition of Mycobacterium abscessus, M. chelonae, and M. fortuitum biofilms by Methylobacterium sp

Methylobacterium sp. is isolated from water distribution systems and has been linked in the biofilms of the systems with a lower presence of Mycobacterium avium. In this study we aimed to determine the in vitro activity of Methylobacterium sp. in the development of rapidly growing mycobacteria (RGM) biofilms. Methylobacterium sp. CECT 7805 was added as a suspension of living bacteria (LB), an autoclaved suspension (AS), and an extract obtained after sonication (ES) at different times (24, 48, and 72 h), to preformed biofilms of Mycobacterium abscessus DSM 44196, Mycobacterium chelonae ATCC 19235, and Mycobacterium fortuitum ATCC 6841, using a 96 h control of each species. The biofilms were analyzed by confocal laser scanning microscopy and by the Calgary biofilm device using the plates MBEC^TM Biofilm Inoculator. A statistically significant reduction in the thickness and covered surface was observed in all mycobacterial biofilms with all forms of Methylobacterium sp. A statistically significant increase in the autofluorescence was observed in M. abscessus biofilms but not in other biofilms. The increased percentage of dead mycobacteria was statistically significant in all cases. The reduced log CFU (colony-forming units)/peg recount was statistically significant in M. chelonae biofilms after treatment with AS and ES, but in M. fortuitum biofilms the recount decreased only with AS. M. abscessus biofilms were always significantly reduced with AS at 72 h and with ES. Methylobacterium sp. could inhibit RGM biofilm formation. Living cells of Methylobacterium sp. were not necessary to inhibit the growth of a preformed biofilm. M. chelonae biofilms were the most greatly reduced.

Mycobacterium wolinskyi: A Rare Strain Isolated in a Persistent Prosthetic Knee Joint Infection: A Case Report

CASE

A patient who underwent first-stage revision procedure elsewhere for prosthetic joint infection (PJI) of the knee with Kocuria rosea presented to us 9 months after the index surgery, with persistent infection. First-stage revision surgery was repeated and Mycobacterium wolinskyi, a rare rapidly growing nontuberculous mycobacterium (RGM), was isolated from samples obtained by sonication of the cement spacer. After a prolonged antibiotic course, definitive implantation surgery was done. One-year postimplantation, patient remains infection free.

CONCLUSIONS

This is only the second known case of knee PJI caused by M. wolinskyi. This case highlights the possibility of RGM getting masked by other organisms.

Mycobacterium abscessus Periprosthetic joint infection following bilateral Total Knee arthroplasty

Periprosthetic joint infection (PJI) can be protracted, incapacitating, needing multiple interventions and could even lead to mortality. Early post-operative PJI has been ascribed to peri-operative introduction of highly virulent bacteria, while delayed post-operative to low-virulence bacteria. Non-tuberculous mycobacteria (NTM) do not figure in the usual list of etiological agents. We report a case of difficult diagnosis of bilateral PJI caused by Mycobacterium abscessus, following bilateral total knee arthroplasty in an elderly male, but treated successfully despite prolonged infection. M. abscessus complex comprises a group of rapidly growing, multidrug-resistant NTM, capable of forming biofilms on prostheses, responsible for wide spectrum of hospital acquired infections. M. abscessus as a cause of PJI is not reported widely. There are a few cases described in literature worldwide. There are no policy guidelines available for treating such cases. High clinical suspicion, with a concerted effort to grow and identify the causal pathogen is important. Standard anti-tubercular therapy is not recommended for treatment due to inherent resistance. Complete excision of infected tissues and removal of prosthesis along with prolonged combination antimicrobial regimen is the treatment of choice.

Prepatellar Bursal Infection Caused by Mycobacterium tuberculosis with an In Situ Total Knee Arthroplasty: A Case Report and Comprehensive Literature Review

Prepatellar bursal infection is a rare occurrence. The incidence of tuberculosis, including musculoskeletal type, is increasing. We present a case of isolated prepatellar bursal swelling associated with a discharging sinus; the condition developed in an elderly patient 4 years after total knee arthroplasty. Aspiration of the bursa revealed acid-fast bacilli on Ziehl–Neelsen staining, typical of Mycobacterium tuberculosis; this was confirmed later on culture. The patient was successfully treated with a 6-month course of antituberculous chemotherapy. To the best of our knowledge, only two previous cases of tuberculous prepatellar bursal infection have been reported in English literature. Our case illustrates the importance of considering tuberculous prepatellar bursal infection in the differential diagnosis of anterior knee swelling. All physicians treating patients with musculoskeletal disease should be aware of the possibility of this diagnosis and maintain a high index of suspicion; this is especially true in areas where tuberculosis is still endemic and in high-risk patients, such as the elderly.