Six weeks antibiotic therapy for all bone infections: results of a cohort study

Prosthetic joint infections: 6 weeks of oral antibiotics results in a low failure rate

BACKGROUND

Need for parenteral administration and total duration of antibiotic therapy for prosthetic joint infection (PJI) are debated. We report our PJI management, in which outpatient care is privileged.

METHODS

This was a retrospective multicentre cohort study of PJI managed from January 2017 to Jun 2021. Microbial diagnosis was based on surgical samples. Surgical procedures and antibiotic treatments were reported. Chronic PJI was defined by a course >1 month. Oral antibiotic therapy (OAT) was defined by exclusive use of oral antibiotics or by ≤3 days of parenteral treatments. Management failure was defined by clinical and/or microbial relapse of PJI over 24 months after surgical treatment.

RESULTS

One hundred and seventy-two patients from 13 institutions were included: 103 were male (60%) and mean age was (±SD): 73 ± 12 years. Sites for PJI were mainly hip (50%) and knee (35%), being chronic infections in 70 cases (41%). The main bacterial genus in monomicrobial infections was Staphylococcus spp. (60%). We recorded 41 (24%) implant exchanges. An OAT was prescribed in 76 cases (44%), and the median (range) course for parenteral route was 6 days (4-180) for 96 cases. Median (range) duration of antimicrobials was 42 days (21-180). Management failure was observed in 7/76 (9.2%) cases treated with OAT and 15/96 (15.6%) treated with prolonged parenteral therapy. In multivariate analysis, risk factors for failure were a knee PJI [adjusted OR (95% CI) = 3.27 (1.27-8.40)] and a polymicrobial infection [4.09 (1.46-11.49)].

CONCLUSIONS

OAT for 6 weeks for PJI was associated with a low rate of management failure.

Acute Sternoclavicular Joint Sepsis With Medial Clavicle Osteomyelitis (Staphylococcus aureus) and Cervical-Thoracic Epidural Phlegmon in an Adult Female With No Apparent Risk Factors

This is a case of a 71-year-old female with a history of only one known medical problem (hypertension) who presented with a right sternoclavicular joint (SCJ) infection in addition to (1) a contiguous lower cervical and upper thoracic epidural phlegmon and (2) cellulitis and a phlegmon in her posterior neck, which was subcutaneous and near the lower cervical and upper thoracic spinous processes. These loci of infection developed several days after she had pricked her fingers when cutting rose bushes and were initially considered to be epidural abscesses. However, after the patient was transferred to our tertiary medical center, a neurosurgeon and radiologist determined that the cervicothoracic infections were phlegmons rather than fully developed abscesses. The phlegmons were treated with only IV antibiotics. The SCJ infection was surgically debrided, and the medial clavicle was excised. Bone and fluid cultures grew methicillin-sensitive Staphylococcus aureus (S. aureus). The patient recovered uneventfully (the final follow-up was four years later). This case is uncommon because of the concurrent SCJ infection with medial clavicle osteomyelitis, cervical-thoracic epidural, and paraspinous phlegmons.

The Impact of a Dedicated Multidisciplinary Team Approach for Prosthetic Joint Infections of the Lower Limb

Introduction

Prosthetic joint infections (PJI) of the hip and knee have significant morbidity and mortality, and present with varying local, host and microbiological factors. Given the broad presentation and complexity of PJI’s, we developed a dedicated multidisciplinary team (MDT) to manage this complex patient cohort, and report on our early outcomes.

Methods

This was a retrospective observational study of all patients diagnosed with a prosthetic joint infection of the hip or knee (n = 71) at our institution during a 4.5-year period. Patients treated after development of the MDT (post-MDT) (n = 44), were compared to a control group prior establishment of the MDT (pre-MDT) (n = 27).

Results

85.2% of individuals in the pre-MDT, and 85.7% of individuals in the post-MDT group were considered cured at a minimum 2 years post-operatively according to the Delphi-based definition. The total number of admissions to hospital (2.44 vs. 1.84) and total number of antibiotics used (3.37 vs. 2.75) decreased in the post-MDT group; however, differences were not considered statistically significant.

Discussion

Implementation of a dedicated MDT in the management of individuals with PJI’s of the lower limb at our hospital has allowed early and effective collaboration between healthcare personnel, with early promising results. Given the broad nature of PJI, future studies are ongoing to determine modifiable risk factors to reduce the incidence and improve outcomes of individuals with PJI’s where systems can then be implemented into already established MDTs to achieve the best clinical outcome for our patients.

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).

Off-Label Use of Dalbavancin for Sequential Treatment of Spondylodiscitis by Methicillin-Resistant Staphylococcus aureus: A Retrospective Single-Centre Experience

Background: Our aim was to describe the clinical outcome and safety of the sequential treatment with off-label dalbavancin in patients with spondylodiscitis that is caused by methicillin-resistant Staphylococcus aureus (MRSA). Methods: We retrospectively included all patients >18 years of age with spondylodiscitis that is caused by MRSA that was treated with dalbavancin from January 2018−January 2021, recording the instances of clinical cure/failure, adverse events, and the need to be re-hospitalized after the initiation of dalbavancin. In 2/15 patients, we performed therapeutic drug monitoring (TDM) for dalbavancin. Results: We included 15 patients, 53.3% of them were females, with a median age of 67.9 years (57.4−78.5); 100% patients reported back pain, while a fever was present only in 2/15 cases. The spondylodiscitis was localized in 86.6% cases at the lumbar level. A median of a 2-week in-hospital intravenous vancomycin was followed by dalbavancin with a median duration of 12 weeks (12−16). All patients reported a clinical cure, except for a woman who is still on a suppressive treatment. No patient needed to be re-hospitalized, access to emergency department, or experienced adverse events. The TDM for dalbavancin showed that more than 90% of the determinations were above the pharmacodynamic target against staphylococci. Conclusions: The results from our unique, even if it was small, cohort demonstrated that dalbavancin can be a safe/effective option as a sequential treatment in patients with serious infections requiring prolonged antibiotic therapy, such as spondylodiscitis.

Antibiotic Therapy for 6 or 12 Weeks for Prosthetic Joint Infection

BACKGROUND

The management of prosthetic joint infection usually consists of a combination of surgery and antimicrobial therapy. The appropriate duration of antimicrobial therapy for this indication remains unclear.

METHODS

We performed an open-label, randomized, controlled, noninferiority trial to compare 6 weeks with 12 weeks of antibiotic therapy in patients with microbiologically confirmed prosthetic joint infection that had been managed with an appropriate surgical procedure. The primary outcome was persistent infection (defined as the persistence or recurrence of infection with the initial causative bacteria, with an antibiotic susceptibility pattern that was phenotypically indistinguishable from that at enrollment) within 2 years after the completion of antibiotic therapy. Noninferiority of 6 weeks of therapy to 12 weeks of therapy would be shown if the upper boundary of the 95% confidence interval for the absolute between-group difference (the value in the 6-week group minus the value in the 12-week group) in the percentage of patients with persistent infection within 2 years was not greater than 10 percentage points.

RESULTS

A total of 410 patients from 28 French centers were randomly assigned to receive antibiotic therapy for 6 weeks (205 patients) or for 12 weeks (205 patients). Six patients who withdrew consent were not included in the analysis. In the main analysis, 20 patients who died during follow-up were excluded, and missing outcomes for 6 patients who were lost to follow-up were considered to be persistent infection. Persistent infection occurred in 35 of 193 patients (18.1%) in the 6-week group and in 18 of 191 patients (9.4%) in the 12-week group (risk difference, 8.7 percentage points; 95% confidence interval, 1.8 to 15.6); thus, noninferiority was not shown. Noninferiority was also not shown in the per-protocol and sensitivity analyses. We found no evidence of between-group differences in the percentage of patients with treatment failure due to a new infection, probable treatment failure, or serious adverse events.

CONCLUSIONS

Among patients with microbiologically confirmed prosthetic joint infections that were managed with standard surgical procedures, antibiotic therapy for 6 weeks was not shown to be noninferior to antibiotic therapy for 12 weeks and resulted in a higher percentage of patients with unfavorable outcomes. (Funded by Programme Hospitalier de Recherche Clinique, French Ministry of Health; DATIPO ClinicalTrials.gov number, NCT01816009.).

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.

Four versus six weeks of antibiotic therapy for osteoarticular infections after implant removal: a randomized trial

BACKGROUND

The optimal duration of antibiotic therapy for treating orthopaedic implant infections after surgical drainage and complete implant removal is unknown.

METHODS

This was a single-centre, unblinded, prospective trial randomizing (1:1) eligible patients to either 4 or 6 weeks of systemic, pathogen-targeted antibiotic therapy. Clinical trial registration number: ClinicalTrials.gov (NCT0362209).

RESULTS

We analysed 123 eligible patients (62 in the 4 week antibiotic arm and 61 in the 6 week arm) in the ITT analysis. The patients' median age was 64 years, 75 (61%) were men and 38 (31%) were immunocompromised. The most common types of infection treated included: two-stage exchange procedure for prosthetic joint infection (n = 38); orthopaedic plate infection (44) and infected nail implants (11). The median duration of post-explant intravenous antibiotic therapy was 4 days. Overall, 120 episodes (98%) were cured microbiologically and 116 (94%) clinically after a median follow-up period of 2.2 years. During follow-up, four patients had a clinical recurrence with a pathogen other than the initial causative agent. We noted recurrence of clinical infection in four patients in the 4 week arm and three patients in the 6 week arm (4/62 versus 3/61; χ2 test; P = 0.74); in all cases, this occurred at around 2 months following the end of antibiotic treatment.

CONCLUSIONS

We found no statistically significant difference in the rates of clinical or microbiological remission between patients randomized to only 4 compared with 6 weeks of systemic antibiotic therapy after removal of an infected osteoarticular implant.

Six-week antibiotic therapy after one-stage replacement arthroplasty for hip and knee periprosthetic joint infection

OBJECTIVES

One-stage replacement arthroplasty for treatment of periprosthetic joint infection (PJI) results in similar cure rate than two-stage (around 85-92%), but antibiotic therapy duration is not well established. The aim of this study was to evaluate the efficacy of a short six-week antibiotic course in periprosthetic joint infections after onstage exchange.

PATIENTS AND METHODS

Retrospective, observational study conducted at Orthopaedic Department of Cochin Hospital, Paris, between 1st January 2010 and 31 December 2015. Patients with a microbiologically proven PJI, treated with one-stage replacement and 6 weeks (+/1week) of antimicrobial therapy were included. Pearson's-χ² and Wilcoxon tests were used to compare categorical and continuous variables.

RESULTS

Fifty patients with periprosthetic joint infections (42 hip, 8 knee PJI) treated with one-stage replacement arthroplasty were included. Median age was 69.3 years (IQR 24.5-97.4). Infections occurred after a mean of 36 months (IQR 1-216). Bone biopsy cultures were positive for Staphylococcus spp. in 29 patients (58%), Cutibacterium acnes in 19 (38%), Gram-negative bacilli in 6 (12%). Polymicrobial infections occurred in 12 (24%). Intravenous antibiotics were administered for a median of 11 days (IQR 4-45) and 46 patients (92%) were switched to an oral therapy. Medium follow-up was of 32 months (IQR 12-101). Overall remission rate was 90%.

CONCLUSIONS

A six-week course of antibiotics in knee and hip PJIs treated with one-stage RA has a satisfactory remission rate in this open study.

What Is the Optimal (Type, Dose and Route of Administration) Antibiotic Treatment for Patients With Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

Though literature specific to total ankle arthroplasty (TAA) is lacking, based on recommendations for the management of hip and knee arthroplasties, the choice of antibiotic should be made based on the identification and sensitivities of the infecting organism(s). Dosing, frequency, and route of administration of antibiotics may be determined in consultation with an infectious disease specialist and by taking into account the patient's weight and comorbidities, such as renal impairment and the antibiogram.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Efficacy and safety of clindamycin-based treatment for bone and joint infections: a cohort study

Clindamycin has high bioavailability together with good diffusion in bone tissue and could represent an alternative antibiotic compound for the treatment of bone and joint infections (BJIs). However, data regarding the efficacy and safety of clindamycin for BJIs are limited. A monocentric cohort study based on our medical dashboard, which prospectively recorded 28 characteristics for all hospitalized patients since July 2005, was performed. BJIs were selected, and then, all mono-microbial BJI managed with clindamycin-based therapy were included. Remission was defined as the absence of clinical and/or microbiological relapse after treatment. The duration of follow-up without relapse was determined retrospectively using computerized medical records. For 10 years, 196 BJIs, of which 80 (41%) were device-associated infections, were treated with clindamycin-based therapy. The bacterial causative agent was Staphylococcus aureus in 130 cases (66%), coagulase-negative staphylococci in 29 cases (15%), streptococci in 31 cases (16%) and other bacteria in 6 cases (3%). When used in combination therapy, clindamycin was mainly paired with fluoroquinolones (31%) or rifampin (27%). The mean duration of clindamycin treatment was 7.4 ± 3.2 weeks (range, 1-24). An AE was recorded for 9 (4.5%) patients. Remission was recorded for 111 (57%) patients, with a mean duration of clinical follow-up of 28 ± 24 months. Treatment failure occurred in 22 (11%) patients, 50 patients (25%) were lost to follow-up, and 8 (4%) required long-term suppressive therapy. Among the assessable patients, clindamycin-based therapy was efficient in 111/133 cases (83%) and thus represents a reliable and safe alternative treatment option.

Medical table: A major tool for antimicrobial stewardship policy

Infectious diseases are unpredictable, with heterogeneous clinical presentations, diverse pathogens, and various susceptibility rates to anti-infective agents. These features lead to a wide variety of clinical practices, which in turn strongly limits their evaluation. We have been using a medical table since 2005 to monitor the medical activity in our department. The observation of heterogeneous therapeutic practices led to drafting up our own antibiotic guidelines and to implementing a continuous evaluation of their observance and impact on morbidity and mortality associated with infectious diseases, including adverse effects of antibiotics, duration of hospital stay, use of intensive care, and deaths. The 10-year analysis of medical practices using the medical table is based on more than 10,000 hospitalizations. It shows simplified antibiotic therapies and a reduction in infection-related morbidity and mortality. The medical table is a major tool for antimicrobial stewardship, leading to constant benefits for patients.

Proposal for shorter antibiotic therapies

OBJECTIVES

Reducing antibiotic consumption has now become a major public health priority. Reducing treatment duration is one of the means to achieve this objective. Guidelines on the therapeutic management of the most frequent infections recommend ranges of treatment duration in the ratio of one to two. The Recommendation Group of the French Infectious Diseases Society (SPILF) was asked to collect literature data to then recommend the shortest treatment durations possible for various infections.

METHODS

Analysis of the literature focused on guidelines published in French and English, supported by a systematic search on PubMed. Articles dating from one year before the guidelines publication to August 31, 2015 were searched on the website.

RESULTS

The shortest treatment durations based on the relevant clinical data were suggested for upper and lower respiratory tract infections, central venous catheter-related and uncomplicated primary bacteremia, infective endocarditis, bacterial meningitis, intra-abdominal, urinary tract, upper reproductive tract, bone and joint, skin and soft tissue infections, and febrile neutropenia. Details of analyzed articles were shown in tables.

CONCLUSION

This work stresses the need for new well-conducted studies evaluating treatment durations for some common infections. Following the above-mentioned work focusing on existing literature data, the Recommendation Group of the SPILF suggests specific study proposals.

Orthopaedic device-related infection: current and future interventions for improved prevention and treatment

Orthopaedic and trauma device-related infection (ODRI) remains one of the major complications in modern trauma and orthopaedic surgery.Despite best practice in medical and surgical management, neither prophylaxis nor treatment of ODRI is effective in all cases, leading to infections that negatively impact clinical outcome and significantly increase healthcare expenditure.The following review summarises the microbiological profile of modern ODRI, the impact antibiotic resistance has on treatment outcomes, and some of the principles and weaknesses of the current systemic and local antibiotic delivery strategies.The emerging novel strategies aimed at preventing or treating ODRI will be reviewed. Particular attention will be paid to the potential for clinical impact in the coming decades, when such interventions are likely to be critically important.The review focuses on this problem from an interdisciplinary perspective, including basic science innovations and best practice in infectious disease. Cite this article: Moriarty TF, Kuehl R, Coenye T, et al. Orthopaedic device related infection: current and future interventions for improved prevention and treatment. EFORT Open Rev 2016;1:89-99. DOI: 10.1302/2058-5241.1.000037.

Antimicrobial stewardship policy: time to revisit the strategy?

Recent data indicate that both the overall numbers of antibiotic prescription and the frequency of multidrug-resistant bacteria are increasing significantly. These threatening features are observed, despite national antimicrobial stewardship (AMS) policies aimed at decreasing antibiotic use. AMS should also focus on the initial steps leading to antibiotic prescription. Physicians and their patients should benefit from the structured clinical pathways, the latter being adapted to regional epidemiological data and resources. Continuous evaluation of these predefined clinical paths through a computerized medical dashboard will allow a critical review and finally the optimization of medical practices. These innovative behavioural approaches for clinicians will supply precise information on the relationship among the diagnosis, therapeutics and outcome. This changing environment will carry out the adapted therapeutic procedures, and appropriate antibiotic use will inherently improve.

Propionibacterium acnes: from commensal to opportunistic biofilm-associated implant pathogen

Propionibacterium acnes is known primarily as a skin commensal. However, it can present as an opportunistic pathogen via bacterial seeding to cause invasive infections such as implant-associated infections. These infections have gained more attention due to improved diagnostic procedures, such as sonication of explanted foreign materials and prolonged cultivation time of up to 14 days for periprosthetic biopsy specimens, and improved molecular methods, such as broad-range 16S rRNA gene PCR. Implant-associated infections caused by P. acnes are most often described for shoulder prosthetic joint infections as well as cerebrovascular shunt infections, fibrosis of breast implants, and infections of cardiovascular devices. P. acnes causes disease through a number of virulence factors, such as biofilm formation. P. acnes is highly susceptible to a wide range of antibiotics, including beta-lactams, quinolones, clindamycin, and rifampin, although resistance to clindamycin is increasing. Treatment requires a combination of surgery and a prolonged antibiotic treatment regimen to successfully eliminate the remaining bacteria. Most authors suggest a course of 3 to 6 months of antibiotic treatment, including 2 to 6 weeks of intravenous treatment with a beta-lactam. While recently reported data showed a good efficacy of rifampin against P. acnes biofilms, prospective, randomized, controlled studies are needed to confirm evidence for combination treatment with rifampin, as has been performed for staphylococcal implant-associated infections.

The impact of bacteremia on the outcome of bone infections

We have used a medical database to analyze our activity since 2005. We observed a frequent association between bone and joint infection (BI) and bacteremia. Our aim was to characterize patients with BI and bacteremia, and focus on the outcome.

PATIENTS AND METHOD

Our database includes the prospective recording of 28 characteristics of all hospitalized patients, including diagnosis, comorbid conditions, microbiological data, therapy, and outcome. We selected patients presenting with BI in this database, from July 2005 to December 2012. Fever before blood culture was retrospectively documented from the patient's chart. Chronic BI was defined as a disease lasting more than 1 month. An unfavorable outcome was defined by the need for intensive care or death.

RESULTS

Six hundred and thirty-two patients presented with BI and 125 with bacteremia (19.8%). We used a stepwise logistic regression analysis and determined that bacteremia was associated with vertebral osteomyelitis, OR, 3.97, P<0.001; alcohol abuse, OR, 2.51, P=0.010; fever, OR, 2.43, P<0.001; neurological and/or psychiatric diseases, OR, 2.41, P ≤ 0.001; and Staphylococcus aureus infection, OR, 2.32, P<0.001. The outcome was unfavorable in 23 cases (3.6%), associated with bacteremia, OR, 8.00, P<0.001, age> 60 years, OR, 4.78, P=0.018, and S. aureus infection, OR, 3.96, P=0.010. No single comorbid condition was significantly associated with an unfavorable outcome.

CONCLUSION

Bacteremia occurred in nearly 20% of the patients presenting with BI, and was associated with identifiable comorbid conditions; it was the main risk factor for an unfavorable outcome.

An in vitro study of composites of poly(L-lactide-co-ε-caprolactone), β-tricalcium phosphate and ciprofloxacin intended for local treatment of osteomyelitis

Osteomyelitis is a bacterial disease that can become chronic, and treatment often includes a surgical operation to remove infected bone. The aim of this study was to develop and investigate in vitro bone filling composite materials that release ciprofloxacin to kill any remaining bacteria and contain bioceramic to help the bone to heal. Three composites of poly(L-lactide-co-ε-caprolactone), β-tricalcium phosphate and ciprofloxacin were compounded using twin-screw extrusion and sterilized by gamma irradiation. Drug release and degradation of the composites were investigated in vitro for 52 weeks. The composite with 50 wt% of β-TCP had the most promising ciprofloxacin release profile. The ceramic component accelerated the drug release that occurred in three phases obeying first-order kinetics. Inhibition zone testing using bioluminescence showed that the released ciprofloxacin had effect in eradicating a common osteomyelitis causing bacteria Pseudomonas aeruginosa. During the in vitro degradation test series, molar weight of the polymer matrix of the composites decreased rapidly. Additionally, ¹H-NMR analysis showed that the polymer had blocky structure and the comonomer ratio changed during hydrolysis. The tested composites showed great potential to be developed into bone filler materials for the treatment of osteomyelitis or other bone related infections.

Antibiotic therapy in necrotising external otitis: case series of 32 patients and review of the literature

Necrotising external otitis (NEO) is a rare but severe bone infection, usually due to Pseudomonas aeruginosa, the management of which is not standardised. Systemic antibiotic therapy is usually prescribed for at least 6 weeks, but no review has been published on this topic. We report our experience and have reviewed the literature regarding antibiotic therapy in NEO. Here we describe a case-series of consecutive NEO cases seen over an 8-year period (2004-2011) in a French tertiary-care teaching hospital. Since 2009 we have shortened the duration of antibiotic therapy to 6 weeks. We also present a review of the literature regarding antibiotic therapy in NEO. We include 32 NEO cases, with positive microbiological cultures in 30 cases. Among the 30 patients with suspected or proven P. aeruginosa infections, 27 received an initial combination therapy of ceftazidime and ciprofloxacin. The duration of antibiotic therapy and length of hospital stay were significantly reduced after 2009 (9.4 ± 3.2 weeks versus 5.8 ± 0.7, P < .0.001; and 18.2 ± 8.7 days versus 11.6 ± 6.9, P = .0.03, respectively). Patient outcomes were favorable in all cases, with a 14-month median duration of follow-up. Our literature review (30 case series) shows that initial combination therapy is associated with better outcomes as compared with single therapy (97 % versus 83 %, P < .0.001). We suggest 3 weeks of initial combination therapy (ceftazidime + ciprofloxacin, high doses) followed by 3 weeks single therapy with ciprofloxacin in susceptible P. aeruginosa NEO. A close collaboration between ear, nose and throat and infectious diseases specialists is needed.

[Duration of antibiotic therapy in bone infection and biological or radiological data]

Modalities of bone infection therapeutic follow-up are controversial, notably for biological and radiological parameters. We have proposed six weeks of antibiotic therapy for all patients presenting with bone infection, since July 2005. Therefore, biological and radiological exams performed during the treatment were not taken into account when determining the duration of antibiotherapy. This protocol allows determining the usefulness of these biological and radiological parameters.

METHODS

All patients presenting with bone infection, from July 2005 to July 2008, were included. Inflammatory biological parameters such as C-reactive protein (CRP) and sedimentation rate were analyzed, and values were considered as normal when less than 10 mg/L and less than 15 mm respectively. All available CT- and MR imaging were analyzed by the same referent radiologist.

RESULTS

Eighty-seven patients presenting with bone infection received antibiotic therapy for a mean [SD] 42 ± 0.3 days. Cure was reported in 82 patients (94%) with a mean follow-up after antibiotic therapy of 36 ± 9 months, five patients relapsed. CRP was available in 66 cases by the end of antibiotic therapy, it was normal in 40/64 of patients with favorable outcome (62%) and in one case of unfavorable outcome. The sedimentation rate was available in 22 cases, and normal in seven cases of favorable outcome (32%). By the end of antibiotic therapy, CT-scan showed active bone infection for 15/23 of patients with favorable outcome (65%), while MR imaging suggested the same diagnosis in 8/14 cases (57%).

CONCLUSION

Biological parameters and radiological findings are inadequate to determine the duration of antibiotic therapy in bone infection.

Six weeks of antibiotic treatment is sufficient following surgery for septic arthroplasty

OBJECTIVES

In the treatment of prosthetic joint infections (PJI), the benefit of antibiotic therapy for more than 6 weeks after surgery is uncertain. We compared PJI cure rates according to the duration of antibiotics, 6 versus 12 weeks.

METHODS

A prospective observational non-randomized study in Geneva University Hospitals 1996-2007.

RESULTS

A total of 144 PJI (62 hip arthroplasties, 62 knee arthroplasties, and 20 hip hemiarthroplasties) were included with a prolonged follow-up ranging from 26 to 65 months. Surgical treatment included 60 débridements with implant retention, 10 one-stage exchanges of the prosthesis, 57 two-stage exchanges, and 17 Girdlestone procedures or knee arthrodeses. Seventy episodes (49%) received 6 weeks antibiotic therapy and 74 episodes, 12 weeks. Cure was achieved in 115 episodes (80%). Cure rate did not change according to the duration of intravenous antibiotics (>8 days, 8-21 days, >21 days) (Kruskal-Wallis-test; p = 0.37). In multivariate analysis, none of the following parameters was statistically significantly associated with cure: two-stage exchange (odds ratio 1.1,95%CI 0.2-4.8); number of débridements (0.9, 0.4-1.9); six weeks antibiotherapy (2.7, 0.96-8.3); duration of intravenous course (1.0, 0.96-1.03); sinus tract (0.6, 0.2-1.7); or MRSA infection (0.5, 0.2-1.5), although implant retention showed a tendency for less cure (0.3, 0.1-1.1).

CONCLUSIONS

Following surgery for treatment of PJI, antibiotic therapy appears able to be limited to a 6-week course, with one week of intravenous administration. This approach needs confirmation in randomized trials.