Journal of Bone and Joint Infection最新文献

Aims: this study compared the patient and microbiological profile of prosthetic joint infection (PJI) for patients treated with two-stage revision for knee arthroplasty with that of lower-limb endoprostheses for oncological resection. Patient and methods: a total of 118 patients were treated with two-stage revision surgery for infected knee arthroplasty and lower-limb endoprostheses between 1999 and 2019. A total of 74 patients had two-stage revision for PJI of knee arthroplasty, and 44 had two-stage revision of oncology knee endoprostheses. There were 68 men and 50 women. The mean ages of the arthroplasty and oncology cohorts were 70.2 years (range of 50-89) and 36.1 years (range of 12-78) respectively ( $p<0$ .01). Patient host and extremity criteria were categorized according to the Musculoskeletal Infection Society (MSIS) host and extremity staging system. The patient microbiological culture, the incidence of polymicrobial infection, and multidrug resistance (MDR) were analysed and recorded. Results: polymicrobial infection was reported in 16 % (12 patients) of knee arthroplasty PJI cases and in 14.5 % (8 patients) of endoprostheses PJI cases ( $p=0$ .783). There was a significantly higher incidence of MDR in endoprostheses PJI, isolated in 36.4 % of cultures, compared with knee arthroplasty PJI (17.2 %, $p=0$ .01). Gram-positive organisms were isolated in more than 80 % of cultures from both cohorts. Coagulase-negative Staphylococcus (CoNS) was the most common Gram-positive organism, and Escherichia coli was the most common Gram-negative organism in both groups. According to the MSIS staging system, the host and extremity grades of the oncology PJI cohort were significantly worse than those for the arthroplasty PJI cohort ( $p<0$ .05). Conclusion: empirical antibiotic prophylaxis against PJI in orthopaedic oncology is based upon PJI in arthroplasty, despite oncology patients presenting with worse host and extremity staging. CoNS was the most common infective organism in both groups; however, pathogens showing MDR were significantly more prevalent in oncological PJI of the knee. Therefore, empirical broad-spectrum treatment is recommended in oncological patients following revision surgery.

Introduction: Staphylococcus aureus is the most common cause of orthopedic infections and can be challenging to treat, especially in the presence of a foreign body. The antistaphylococcal lysins exebacase and CF-296 have rapid bactericidal activity, a low propensity for resistance development, and synergize with some antibiotics. Methods: Rabbit implant-associated osteomyelitis was induced by drilling into the medial tibia followed by locally delivering exebacase, CF-296, or lysin carrier. A titanium screw colonized with methicillin-resistant S. aureus (MRSA) IDRL-6169 was inserted. Intravenous daptomycin or saline was administered and continued daily for 4 d. On day 5, rabbits were euthanized, and the tibiae and implants were collected for culture. Results were reported as log ${}_{10}$ colony forming units (cfu) per gram of bone or log ${}_{10}$  cfu per implant, and comparisons among the six groups were performed using the Wilcoxon rank sum test. Results: Based on implant and bone cultures, all treatments resulted in significantly lower bacterial counts than those of controls ( $P\le 0.0025$ ). Exebacase alone or with daptomycin as well as CF-296 with daptomycin were more active than daptomycin alone ( $P\le 0.0098$ ) or CF-296 alone ( $P\le 0.0154$ ) based on implant cultures. CF-296 with daptomycin was more active than either CF-296 alone ( $P=0.0040$ ) or daptomycin alone ( $P=0.0098$ ) based on bone cultures. Conclusion: Local delivery of either exebacase or CF-296 offers a promising complement to conventional antibiotics in implant-associated infections.

We present the rare case of a 61-year-old female with Mycobacterium fortuitum osteomyelitis of the cuboid bone following penetrating plantar trauma. The patient underwent a single-stage surgery for the condition, including lesion debridement and bone defect filling with absorbable, gentamicin-/vancomycin-loaded, calcium sulfate-hydroxyapatite biocomposites, that resolved favorably 5 months after intervention.

Introduction: The most common complication following transcutaneous osseointegration for amputees is infection. Although an obvious source of contamination is the permanent stoma, operative site contamination at the time of implantation may be an additional source. This study investigates the impact of unexpected positive intraoperative cultures (UPIC) on postoperative infection. Methods: Charts were reviewed for 8 patients with UPIC and 22 patients with negative intraoperative cultures (NIC) who had at least 1 year of post-osseointegration follow-up. All patients had 24 h of routine postoperative antibiotic prophylaxis, with UPIC receiving additional antibiotics guided by culture results. The main outcome measure was postoperative infection intervention, which was graded as (0) none, (1) antibiotics unrelated to the initial surgery, (2) operative debridement with implant retention, or (3) implant removal. Results: The UPIC vs. NIC rate of infection management was as follows: Grade 0, 6/8 $=$ 75 % vs. 14/22 $=$ 64 %, p $=$ 0.682; Grade 1, 2/8 $=$ 25 % vs. 8/22 $=$ 36.4 % (Fisher's p $=$ 0.682); Grade 2, 1/8 = 12.5 % vs. 0/22 $=$ 0 % (Fisher's p $=$ 0.267); Grade 3, 0/8 $=$ 0 % vs. 1/22 $=$ 4.5 % (Fisher's p $=$ 1.000). No differences were statistically significant. Conclusions: UPIC at index osseointegration, managed with directed postoperative antibiotics, does not appear to increase the risk of additional infection management. The therapeutic benefit of providing additional directed antibiotics versus no additional antibiotics following UPIC is unknown and did not appear to increase the risk of other adverse outcomes in our cohort.

Background and purpose: To date, the value of culture results after debridement, antibiotics, and implant retention (DAIR) for early (suspected) prosthetic joint infection (PJI) as risk indicators in terms of prosthesis retention is not clear. At the 1-year follow-up, the relative risk of prosthesis removal was determined for culture-positive and culture-negative DAIR patients after primary total hip or knee arthroplasty. The secondary aim of this work was to explore differences in patient characteristics, infection characteristics, and outcomes between these two groups. Methods: A retrospective regional registry study was performed in a group of 359 patients (positive cultures: $n=299$ ; negative cultures: $n=60$ ) undergoing DAIR for high suspicion of early PJI in the period from 2014 to 2019. Differences in patient characteristics, the number of deceased patients, and the number of subsequent DAIR treatments between the culture-positive and culture-negative DAIR groups were analysed using independent $t$  tests, Mann-Whitney $U$  tests, Pearson's chi-square tests, and Fisher's exact tests. Results: The overall implant survival rate following DAIR was 89 %. The relative risk of prosthesis removal was 7.4 times higher (95 % confidence interval (CI) 1.0-53.1) in the culture-positive DAIR group (37 of 299, 12.4 %) compared with the culture-negative DAIR group (1 of 60, 1.7 %). The culture-positive group had a higher body mass index ( $p=0.034$ ), a rate of wound leakage of $>10$  d ( $p=0.016$ ), and more subsequent DAIR treatments ( $p=0.006$ ). Interpretation: As implant survival results after DAIR are favourable, the threshold to perform a DAIR procedure for early (suspected) PJI should be low in order to retain the prosthesis. A DAIR procedure in the case of negative cultures does not seem to have unfavourable results in terms of prosthesis retention.

Prosthetic joint infection (PJI) due to Mycobacterium avium complex (MAC) is a rare entity. There is limited guidance on management strategies and outcomes. In this paper, we describe the demographics, comorbidities, and clinical course of five patients at two academic institutions, constituting the largest series described to date.

Osteocutaneous flap (OCF) mandible reconstruction is at high risk for surgical site infection. This study aimed to describe diagnosis, management, and outcome of OCF-related osteomyelitis. All patients managed at our institution for an OCF-related osteomyelitis following mandible reconstruction were included in a retrospective cohort study (2012-2019). Microbiology was described according to gold-standard surgical samples, considering all virulent pathogens, and potential contaminants if present on at least two samples. Determinants of treatment failure were assessed by logistic regression and Kaplan-Meier curve analysis. The 48 included patients (median age 60.5 (IQR, 52.4-66.6) years) benefited from OCF mandible reconstruction mostly for carcinoma ( $n=27/48$ ; 56.3 %) or osteoradionecrosis ( $n=12/48$ ; 25.0 %). OCF-related osteomyelitis was mostly early ( $\le 3$ months post-surgery; $n=43/48$ ; 89.6 %), presenting with local inflammation ( $n=28/47$ ; 59.6 %), nonunion (wound dehiscence) or sinus tract ( $n=28/47$ ; 59.6 %), and/or bone or device exposure ( $n=21/47$ ; 44.7 %). Main implicated pathogens were Enterobacteriaceae ( $n=25/41$ ; 61.0 %), streptococci ( $n=22/41$ ; 53.7 %), Staphylococcus aureus ( $n=10/41$ ; 24.4 %), enterococci ( $n=9/41$ ; 22.0 %), non-fermenting Gram-negative bacilli ( $n=8/41$ ; 19.5 %), and anaerobes ( $n=8/41$ ; 19.5 %). Thirty-nine patients (81.3 %) benefited from surgery, consisting of debridement with implant retention (DAIR) in $25/39$ (64.1 %) cases, associated with 93 (IQR, 64-128) days of antimicrobial therapy. After a follow-up of 18 (IQR, 11-31) months, $24/48$ (50.0 %) treatment failures were observed. Determinants of treatment outcomes were DAIR (OR, 3.333; 95 % CI, 1.020-10.898) and an early infectious disease specialist referral (OR, 0.236 if $\le 2$  weeks; 95 % CI, 0.062-0.933). OCF-related osteomyelitis following mandibul