Journal of Bone and Joint Infection最新文献

Aims: An investigation of the impact of a multidisciplinary bone infection unit (BIU) undertaking osteomyelitis surgery with a single-stage protocol on clinical outcomes and healthcare utilisation compared to national outcomes in England. Patients and Methods: A tertiary referral multidisciplinary BIU was compared to the rest of England (ROE) and a subset of the 10 next busiest centres based on osteomyelitis treatment episode volume (Top Ten), using the Hospital Episodes Statistics database (HES). A total of 25 006 patients undergoing osteomyelitis surgery between April 2013 and March 2017 were included. Data on secondary healthcare resource utilisation and clinical indicators were extracted for 24 months before and after surgery. Results: Patients treated at the BIU had higher orthopaedic healthcare utilisation in the 2 years prior to their index procedure, with more admissions ( $p<$  0.001) and a mean length of stay (LOS) over 4 times longer than other groups (10.99 d, compared to 2.79 d for Top Ten and 2.46 d for the ROE, $p<$  0.001). During the index inpatient period, the BIU had fewer mean theatre visits (1.25) compared to the TT (1.98, $p<$  0.001) and the ROE (1.64, $p=$  0.001). The index inpatient period was shorter in the BIU (11.84 d), 33.6 % less than the Top Ten (17.83 d, $p<$  0.001) and 29.9 % shorter than the ROE (16.88 d, $p<$  0.001). During follow-up, BIU patients underwent fewer osteomyelitis-related reoperations than Top Ten centres ( $p=$  0.0139) and the ROE ( $p=$  0.0137). Mortality was lower (4.71 %) compared to the Top Ten (20.06 %, $p<$  0.001) and the ROE (22.63 %, $p<$  0.001). The cumulative BIU total amputation rate was lower (6.47 %) compared to the Top Ten (15.96 %, $p<$  0.001) and the ROE (12.71 %, $p<$  0.001). Overall healthcare utilisation was lower in the BIU for all inpatient admissions, LOS, and Accident and Emergency (A&E) attendances. Conclusion: The benefits of managing osteomyelitis in a multi-disciplinary team (MDT) specialist setting included reduced hospital stays, lower reoperation rates for infection recurrence, improved survival, lower amputation rates, and lower overall healthcare utilisation. These results support the establishment of centrally funded multidisciplinary bone infection units that will improve patient outcomes and reduce healthcare utilisation.

High-dose liquid antibiotics are uncommon in bone cement. We present a case series of patients in which up to 16 mL of liquid amikacin (250 mg mL ${}^{-1}$ ) was successfully incorporated into bone cement to treat periprosthetic joint infections. We did not observe adverse drug reactions definitively attributed to its use.

This paper presents the first report of osteomyelitis in heterotopic ossification in a patient with macrodystrophia lipomatosa. Careful review of magnetic resonance imaging allowed correct diagnosis and design of a limited surgical excision. Osteomyelitis should be considered in the differential diagnosis of pain and discharge when heterotopic ossification is present.

Introduction: Pin site infection is a common complication to external ring fixation. While the aetiology is well described, monitoring of onset, location, and the distribution of infection among the pin sites still needs further attention. The present pilot study evaluates the feasibility of a prospective registration procedure for reporting, evaluating, and monitoring of pin site infections in patients treated with external ring fixation. This may promote communication between team members and assist decision-making regarding treatment. Methods: A total of 39 trauma, limb deformity, and bone infection patients (15 female, 24 males; mean age 49 years (range: 12-88)) treated with external ring fixation were followed in the outpatient clinic using the pin site registration tool. Pin site infection (Checketts and Otterburn (CO) grade, onset, location), use of oral or intravenous antibiotics, and any unplanned procedures due to pin sites complications (wire removal and/or replacement, premature frame removal, amputation, etc.) were registered until frame removal. Results: The mean (SD) frame time was 164 (83) d (range: 44-499). We performed 3296 observations of 568 pin sites. Pin infection was registered in 171 of the 568 pin sites (30 %), of which 112 (65 %) were categorized as CO 1, 42 (25 %) as CO 2, 9 (5 %) as CO 3, and 8 (5 %) as CO 5. Neither CO 4 nor CO 6 was observed. A total of 35 patients (90 %) encountered CO 1-3 at least once during the observation time, while 1 patient (2.5 %) developed a major infection at eight pin sites (CO 5). Antibiotics were administered to $22/39$ (56 %) of the patients. Conclusion: In an effort to monitor pin site infections in this complex patient group and to ensure the best clinical outcomes, our registration procedure in the outpatient clinic helped to recognize pin site infections early and eased communication between team members providing a concise overview of the treatment course.

We describe a 79-year-old man with spondylodiscitis and unknown pathogen, treated with cefazolin and rifampicin. He developed a massive digestive hemorrhage. Prothrombin time was prolonged with severe vitamin-K-dependent clotting-factor deficiency. Severe bleeding can occur during cefazolin and rifampicin use. This deficiency should be assessed before prescribing cefazolin-rifampicin and prothrombin time monitored.

Introduction: Bacterial biofilms are an important virulence factor in chronic periprosthetic joint infection (PJI) and other orthopedic infection since they are highly tolerant to antibiotics and host immunity. Antibiotics are mixed into carriers such as bone cement and calcium sulfate bone void fillers to achieve sustained high concentrations of antibiotics required to more effectively manage biofilm infections through local release. The effect of antibiotic diffusion from antibiotic-loaded calcium sulfate beads (ALCS-B) in combination with PMMA bone cement spacers on the spread and killing of Pseudomonas aeruginosa Xen41 (PA-Xen41) biofilm was investigated using a "large agar plate" model scaled for clinical relevance. Methods: Bioluminescent PA-Xen41 biofilms grown on discs of various orthopedic materials were placed within a large agar plate containing a PMMA full-size mock "spacer" unloaded or loaded with vancomycin and tobramycin, with or without ALCS-B. The amount of biofilm spread and log reduction on discs at varying distances from the spacer was assessed by bioluminescent imaging and viable cell counts. Results: For the unloaded spacer control, PA-Xen41 spread from the biofilm to cover the entire plate. The loaded spacer generated a 3 cm zone of inhibition and significantly reduced biofilm bacteria on the discs immediately adjacent to the spacer but low or zero reductions on those further away. The combination of ALCS-B and a loaded PMMA spacer greatly reduced bacterial spread and resulted in significantly greater biofilm reductions on discs at all distances from the spacer. Discussion: The addition of ALCS-B to an antibiotic-loaded spacer mimic increased the area of antibiotic coverage and efficacy against biofilm, suggesting that a combination of these depots may provide greater physical antibiotic coverage and more effective dead space management, particularly in zones where the spread of antibiotic is limited by diffusion (zones with little or no fluid motion).

Aim: The aim of this study was to investigate whether the revision rate for periprosthetic joint infection (PJI) depends on the season of the primary procedure using a national population of knee arthroplasty (KA) patients. Seasonal variation of some surgical procedures has been observed to impact subsequent infection risks, with a higher risk of revision for surgeries performed during summer, but an analysis of PJI rates based on a national arthroplasty register has yet to be completed. We hypothesized that an increased risk of revision due to PJI could be demonstrated in a national population when primary surgery was performed during the summer. Methods: The Danish Knee Arthroplasty Registry (DKR) was used to determine the risk of revision due to PJI within 2 years after primary surgery. All primary KA procedures between 1 January 1997 and 31 December 2014 and revisions until 31 December 2016 were identified. Smoothing spline regression was used to identify possible seasonal pattern effects of the primary procedure on revision risk, and logistic regression was used to calculate risk of infection differences between seasons. Results: A total number of 124 809 primary procedures was registered in the study period. After excluding duplicates and matching primary procedures with the first revisions within 2 years after the primary procedure, 3391 were identified. Of these, 348 cases were recorded with an indication of deep infection requiring revision. Spline regression analyses did not demonstrate any clear seasonal pattern of the primary procedure regarding the risk of revision for infection or any other cause. Logistic regression found a decreased risk of revision for infection when the primary procedure was performed during the summer in the years 1997 to 2005, no influence on the risk of revision for infection in 2005 to 2012, and an increased risk of revision for infection following summer procedures during the years 2013 to 2014. Conclusion: It was not possible to demonstrate a consistent seasonal variation of the risk of revision for PJI following primary KA. This is most likely because the underlying etiologies for PJI are not subject to seasonal variation.

Osteoarticular infection with Mycobacterium bovis (M. bovis) is a rare complication of bladder cancer treatment with intravesical Bacillus Calmette-Guèrin (BCG). We describe a case of disseminated Mycobacterium bovis BCG infection masquerading as a chronic prosthetic joint infection in a patient with several risk factors for progressive mycobacterial infection.

Introduction. Systemic perioperative vancomycin may not provide sufficient prophylactic target-site concentrations in the prevention of prosthetic joint infections. Intraosseous vancomycin potentially provides high target-site concentrations. The objective of the present study was to evaluate the local bone and tissue concentrations following tibial intraosseous vancomycin administration in a porcine model. Methods. Eight pigs received 500 mg diluted vancomycin (50 mg/mL) through an intraosseous cannula into the proximal tibial cancellous bone. No tourniquet was applied. Microdialysis was applied for sampling of vancomycin concentrations in adjacent tibial cancellous bone, in cortical bone, in the intramedullary canal of the diaphysis, in the synovial fluid of the knee joint, and in the subcutaneous tissue. Plasma samples were obtained as a systemic reference. Samples were collected for 12 h. Results. High vancomycin concentrations were found in the tibial cancellous bone with a mean peak drug concentration of 1236 (range 28-5295)  $\mu g/\mathrm{mL}$ , which remained high throughout the sampling period. The mean (standard deviation) peak drug concentration in plasma was 19 (2)  $\mu g/\mathrm{mL}$ , which was obtained immediately after administration. Peak drug concentration, time to peak drug concentration, and area under the concentration-time curve were within the same range in the intramedullary canal, the synovial fluid of the knee, and the subcutaneous tissue. Conclusion. Tibial intraosseous administration of vancomycin provided high concentrations in tibial cancellous bone throughout a 12 h period but with an unpredictable and wide range of peak concentration. The systemic absorption was high and immediate, thus mirroring an intravenous administration. Low mean concentrations were found in all the remaining compartments.

A plausible cause of persistent infection after septic hip revision may be the presence of nonviable osteomyelitic bone. Since surgical excision of these necrotic fragments is often challenging, the use of fluorescent tetracycline bone labeling (FTBL) as an intraoperative tool may pose an additional assessment aid to provide a visual index of surgical debridement. Methods: We present a single-center study performed in a university hospital from January 2018 to June 2020, in which all consecutive cases of chronic hip periprosthetic joint infection (PJI) undergoing revision using FTBL were retrospectively reviewed. In all cases, the patient was under treatment with tetracyclines at the moment of the revision surgery. During the surgery, all bone failing to fluoresce was considered nonviable and thus removed and sent for both culture and histology. Results: We include three cases in which the FTBL technique was used. In all cases, the histopathological examinations of the nonfluorescent removed bone were consistent with chronic osteomyelitis. Conclusion: The intraoperative use of FTBL successfully aided the surgeon to detect the presence of nonviable bone in all the presented cases of chronic prosthetic hip infection.