Posttraumatic ankle arthritis due to a novel Nocardia species

Study protocol: short against long antibiotic therapy for infected orthopedic sites - the randomized-controlled SALATIO trials

BACKGROUND

Few studies address the appropriate duration of post-surgical antibiotic therapy for orthopedic infections; with or without infected residual implants. We perform two similar randomized-clinical trials (RCT) to reduce the antibiotic use and associated adverse events.

METHODS

Two unblinded RCTs in adult patients (non-inferiority with a margin of 10%, a power of 80%) with the primary outcomes "remission" and "microbiologically-identical recurrences" after a combined surgical and antibiotic therapy. The main secondary outcome is antibiotic-related adverse events. The RCTs allocate the participants between 3 vs. 6 weeks of post-surgical systemic antibiotic therapy for implant-free infections and between 6 vs. 12 weeks for residual implant-related infections. We need a total of 280 episodes (randomization schemes 1:1) with a minimal follow-up of 12 months. We perform two interim analyses starting approximately after 1 and 2 years. The study approximatively lasts 3 years.

DISCUSSION

Both parallel RCTs will enable to prescribe less antibiotics for future orthopedic infections in adult patients.

TRIAL REGISTRATION

ClinicalTrial.gov NCT05499481. Registered on 12 August 2022.

PROTOCOL VERSION

2 (19 May 2022).

Osteoarticular infections: a specific program for older patients?

BACKGROUND

With the increasing number of elderly patients, arthroplasties, fractures and diabetic foot infections, the worldwide number of osteoarticular infections (OAI) among the elderly is concomitantly expected to rise.

AIMS

We explore existing scientific knowledge about OAI in the frail elderly population.

METHODS

We performed a literature search linking OAIs to geriatric patients and comparing elderly patients (> 65 years) with average adults (range 18-65 years).

RESULTS

In this literature, financial aspects, comparison of diverse therapies on quality of life, reimbursement policies, or specific guidelines or nursing recommendations are missing. Age itself was not an independent factor related to particular pathogens, prevention of OAI, nursing care, and outcomes of OAI. However, geriatric patients were significantly more exposed to adverse events of therapy. They had more co-morbidities and more conservative surgery for OAI.

CONCLUSION

Available literature regarding OAI management among elderly patients is sparse. In recent evaluations, age itself does not seem an independent factor related to particular epidemiology, pathogens, prevention, nursing care, rehabilitation and therapeutic outcomes of OAI. Future clinical research will concern more conservative surgical indications, but certainly reduce inappropriate antibiotic use.

Short postsurgical antibiotic therapy for spinal infections: protocol of prospective, randomized, unblinded, noninferiority trials (SASI trials)

BACKGROUND

There are several open scientific questions regarding the optimal antibiotic treatment of spinal infections (SIs) with or without an implant. The duration of postsurgical antibiotic therapy is debated.

METHODS

We will perform two unblinded randomized controlled trials (RCTs). We hypothesize that shorter durations of systemic antibiotic therapy after surgery for SI are noninferior (10% margin, 80% power, α = 5%) to existing (long) treatment durations. The RCTs allocate the participants to two arms of 2 × 59 episodes each: 3 vs. 6 weeks of targeted postsurgical systemic antibiotic therapy for implant-free SIs or 6 vs. 12 weeks for implant-related SIs. This equals a total of 236 adult SI episodes (randomization scheme 1:1) with a minimal follow-up of 12 months. All participants receive concomitant multidisciplinary surgical, re-educational, internist, and infectious disease care. We will perform three interim analyses that are evaluated, in a blinded analysis, by an independent study data monitoring committee. Besides the primary outcome of remission, we will also assess adverse events of antibiotic therapy, changes of the patient's nutritional status, the influence of immune suppression, total costs, functional scores, and the timely evolution of the (surgical) wounds. We define infection as the presence of local signs of inflammation (pus, wound discharge, calor, and rubor) together with microbiological evidence of the same pathogen(s) in at least two intraoperative samples, and we define remission as the absence of clinical, laboratory, and/or radiological evidence of (former or new) infection.

DISCUSSION

Provided that there is adequate surgical debridement, both RCTs will potentially enable prescription of less antibiotics during the therapy of SI, with potentially less adverse events and reduced overall costs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04048304. Registered on 5 August 2019.

PROTOCOL VERSION

2, 5 July 2019.

Two weeks versus four weeks of antibiotic therapy after surgical drainage for native joint bacterial arthritis: a prospective, randomised, non-inferiority trial

Objective

The optimal duration of postsurgical antibiotic therapy for adult native joint bacterial arthritis remains unknown.

Methods

We conducted a prospective, unblinded, randomised, non-inferiority study comparing either 2 or 4 weeks of antibiotic therapy after surgical drainage of native joint bacterial arthritis in adults. Excluded were implant-related infections, episodes without surgical lavage and episodes with a follow-up of less than 2 months.

Results

We enrolled 154 cases: 77 in the 4-week arm and 77 in the 2-week arm. Median length of intravenous antibiotic treatment was 1 and 2 days, respectively. The median number of surgical lavages was 1 in both arms. Recurrence of infection was noted in three patients (2%): 1 in the 2-week arm (99% cure rate) and 2 in the 4-week arm (97% cure rate). There was no difference in the number of adverse events or sequelae between the study arms. Of the overall 154 arthritis cases, 99 concerned the hand and wrist, for which an additional subgroup analysis was performed. In this per-protocol subanalysis, we noted three recurrences: one in the 2-week arm (97 % cure); two in the 4-week arm (96 % cure) and witnessed sequelae in 50% in the 2-week arm versus 55% in the 4-week arm, of which five (13%) and six (13%) needed further interventions.

Conclusions

After initial surgical lavage for septic arthritis, 2 weeks of targeted antibiotic therapy is not inferior to 4 weeks regarding cure rate, adverse events or sequelae and leads to a significantly shorter hospital stay, at least for hand and wrist arthritis.

Trial registration number

NCT03615781.

Native septic arthritis is not an immediate surgical emergency

Acute native joint septic arthritis is generally considered a surgical emergency, requiring drainage within hours, including during night, weekend or holiday shifts. However, there are few data supporting the need for the disruption caused by this degree of urgency.

METHODS

We performed a retrospective review of all adult patients seen in our medical center from 1997-2015 with culture-proven septic arthritis and noted the epidemiology of sequelae, and their possible association with a delay in surgical drainage.

RESULTS

Of 204 septic arthritis episodes, 46 (23%) involved interdigital hand and foot joints. Large joints involved included the knee (n = 67), shoulder (48), hip (22), ankle (8), acromio-clavicular (5), elbow (4), wrist (3), and sterno-clavicular (1) regions. All patients underwent surgical drainage of the joint and received targeted systemic antibiotic therapy. Sequelae of varying severity occurred in 83 patients (41%): recurrences (n = 15); secondary arthrosis (30); persistent pain (9); Girdlestone procedure (9); arthrodesis (9); amputation (8); stiffness (8); and Chronic Regional Pain Syndrome (2). By multivariate Cox regression analysis factors did not predict sequelae included: age; treatment with systemic corticosteroids; pre-existing clinical or radiological arthropathy; total duration of antibiotic therapy; type of joint; and, number of surgical interventions. Similarly, there was no association of sequelae with the number of days of pre-hospitalization joint symptoms (hazard ratio 1.0, 95% confidence interval 0.99-1.01) or hours spent in the emergency department (HR 1.0, 0.9-1.2). Notably, patients who had joint lavage within 6 h of presentation had similar functional outcomes as those with lavage done at 6-12 h, 12-24 h, or > 24 h after presentation.

CONCLUSIONS

Our data suggest that for native septic arthritis, in the absence of clinical sepsis immediate joint drainage does not appear to reduce the risk of sequelae compared with delayed drainage.

Isolation of Nocardia mexicana from focal proliferative tenosynovitis and arthritis in a steer

CASE REPORT

An 18-month-old Charolais steer was presented with lameness and fluctuant swelling of the right stifle joint, which yielded neutrophils on fine-needle aspiration. A diagnosis of bacterial proliferative tenosynovitis and arthritis was made on postmortem and histological examination. Culture and 16S rRNA sequencing identified a Nocardia sp. with 99% homology with the corresponding DNA fragment of N. mexicana DSM 44952. Antimicrobial susceptibility testing revealed the isolate was susceptible to co-trimoxazole and third-generation cephalosporins.

CONCLUSION

We report the first case, both in Australia and internationally, of proliferative tenosynovitis and arthritis caused by Nocardia spp. infection in a bovine and the first report of pathology attributed to N. mexicana in a veterinary patient. Given the limited susceptibility of the bacteria, the poor antimicrobial penetration that would be expected and the morphological changes that had taken place in the joint; the steer would have required protracted antimicrobial treatment in addition to invasive debridement of the lesion. This case emphasises the importance of routinely performing cytology and extended incubation of cultures in cases of arthritis in order to make ethical and economically viable treatment decisions.

Nocardia Arthritis: 3 Cases and Literature Review

Nocardia are Gram-positive filamentous bacteria responsible for infections ranging from opportunistic life-threatening disseminated diseases to chronic skin and soft-tissue infections.Even if virtually all organs can be infected, articular involvement is rare. Therefore, we report 3 recent cases and performed a literature review of cases of Nocardia arthritis in order to describe clinical features, therapeutic challenges, and outcome of these patients.Among 34 patients (31 in the literature plus our 3 cases), 21 (62%) were due to hematogenous dissemination, 9 (26%) were due to direct bacterial inoculation through the skin, and in 4 cases, the mechanism of infection was unknown. Four out of these 34 cases occurred on prosthetic joints.Whereas hematogenous infections mostly occurred in immunocompromised hosts (17 of 21, 81%), direct inoculation was mostly seen in immunocompetent patients.Eighty-two percent of patients (28 out of 34) received trimethoprim-sulfamethoxazole-containing regimens and median antibiotic treatment duration was 24 weeks (range, 12-120) for hematogenous infections and 12 weeks (range, 6-24) for direct inoculations. Outcome was favorable in 27 cases despite unsystematic surgical management (17 cases) without sequelae in 70% of the cases.Nocardia arthritis is rare but its management is complex and should rely on a combined approach with rheumatologist, infectious diseases expert, and surgeon.

Gram and acridine orange staining for diagnosis of septic arthritis in different patient populations

PURPOSE

The sensitivity of Gram staining is known to be suboptimal for the diagnosis of native joint septic arthritis. We lack information about the accuracy of Gram compared to other microscopic staining techniques for predicting infection in different patient populations.

METHODS

This was a cohort study with cost evaluations at the Orthopaedic Service of Geneva University Hospitals (January 1996-October 2012).

RESULTS

Among 500 episodes of arthritis (196 with immunosuppression, 227 with underlying arthroplasties and 69 with gout or other crystals in synovial fluid), Gram staining revealed pathogens in 146 episodes (146/500, 29 %) or in 146 of the 400 culture-positive episodes (37 %). Correlation between the Gram and acridine staining of the same sample was good (Spearman 0.85). Overall, the sensitivity, specificity, positive predictive value and negative predictive value of Gram stain for rapid diagnosis of septic arthritis was 0.37, 0.99, 0.99 and 0.28, respectively, compared to microbiological cultures. Quite similar values were recorded across the different patient subpopulations, in particular for sensitivity values that were 0.33 for patients with prosthetic joint infections, 0.40 for immunosuppressed patients, 0.36 for patients under antibiotic administration and 0.52 for patients with concomitant crystalline disease.

CONCLUSIONS

The sensitivity of Gram or acridine orange staining for a rapid diagnosis of episodes of septic arthritis is suboptimal compared to microbiological culture, regardless of underlying conditions, immunosuppression or antibiotic therapy. The sensitivity in the presence of synovial fluid crystals is moderate. Acridine orange and Gram stains are equivalent.

Nocardia brasiliensis infection mimicking juvenile idiopathic arthritis in a 4-year-old girl

Nocardia are ubiquitous environmental saprophytes that cause pneumonia and disseminated disease in immunocompromised patients. They can also cause localized cutaneous and soft tissue infections in healthy people after direct percutaneous inoculation. Nocardia arthritis is rare in both forms of the disease. Here we present the first published case of a child with septic arthritis caused by N brasiliensis. Importantly, this otherwise well 4-year-old girl had no known history of trauma but presented with transient cutaneous lesions and a 6-week history of arthritis involving the right fourth digit proximal interphalangeal joint without accompanying fever or raised systemic inflammatory markers. She received a diagnosis of juvenile idiopathic arthritis and underwent antiinflammatory and immunosuppressant therapy. After 2 months she developed frank septic arthritis, which necessitated a surgical joint washout, from which an intraoperative swab grew N brasiliensis. The patient received 6 months of high-dose trimethoprim-sulfamethoxazole and remains well more than 4 years after treatment. This unusual case highlights the importance of considering an indolent infection from slow-growing organisms, including Nocardia, when diagnosing the oligoarthritis subtype of juvenile idiopathic arthritis. This is especially relevant when a single joint is involved and response to antiinflammatory therapy is suboptimal because antiinflammatory agents may mask evolving signs of infection.

Remission after treatment of osteoarticular infections due to Pseudomonas aeruginosa versus Staphylococcus aureus: a case-controlled study

PURPOSE

Osteoarticular infections due to methicillin-susceptible Staphylococcus aureus (MSSA) or its methicillin-resistant variant (MRSA) are feared due to treatment failures. According to clinical experience, Pseudomonas aeruginosa may reveal less long-term remission than S. aureus.

METHODS

A case-controlled study comparing outcomes of osteoarticular infections due to P. aeruginosa vs S. aureus was performed at Geneva University Hospitals.

RESULTS

A total of 111 S. aureus (including 37 MRSA) and 20 P. aeruginosa osteoarticular infections were analysed in 131 patients: arthroplasties (n = 38), fracture fixation devices (n = 56), native joint arthritis (n = 7) and osteomyelitis without implant (n = 30). The median active follow-up time was 4 years. The patients underwent a median number of two surgical interventions for P. aeruginosa infections compared to two for S. aureus (two for MRSA), while the median duration of antibiotic treatment was 87 days for P. aeruginosa and 46 days for S. aureus infections (58 days for MRSA) (all p > 0.05). Overall, Pseudomonas-infected patients tended towards a lower remission rate than those infected with S. aureus (12/20 vs 88/111; p = 0.06). This was similar when P. aeruginosa was compared with MRSA alone (12/20 vs 30/37; p = 0.08). In multivariate logistic regression analyses adjusting for case mix, odds ratios (OR) for remission were as follows: P. aeruginosa vs S. aureus [OR 0.4, 95% confidence interval (CI) 0.1-1.2], number of surgical interventions (OR 0.6, 95% CI 0.5-1.0) and duration of antibiotic treatment (OR 1.0, 95% CI 1.0-1.0).

CONCLUSIONS

Despite a similar number of surgical interventions and longer antibiotic treatment, osteoarticular infections due to P. aeruginosa tended towards a lower remission rate than infections due to S. aureus in general or MRSA in particular.