Minocycline Combined with Vancomycin for the Treatment of Methicillin-Resistant Coagulase-Negative Staphylococcal Prosthetic Joint Infection Managed with Exchange Arthroplasty.

Introduction: Treatment of methicillin-resistant (MR) staphylococcal prosthetic joint infections (PJIs) remains a matter of discussion, with vancomycin-rifampin combination therapy being the preferred treatment for DAIR and one-stage exchange arthroplasty strategies. This study analyzes the outcomes of patients with chronic methicillin-resistant coagulase-negative staphylococcal PJIs treated with vancomycin-minocycline combination therapy. Methods: This prospective, single center cohort study included all chronic MR coagulase-negative staphylococcal PJIs (01/2004-12/2014) treated with exchange arthroplasty and at least 4 weeks of minocycline-vancomycin. The following endpoints were considered: reinfection including relapse (same microorganism) and a new infection (different microorganism) and PJI-related deaths. Their outcomes were compared with PJIs treated with rifampin-vancomycin during the same period. Results: Thirty-four patients (median age, 69 years) with 22 hip and 12 knee arthroplasty infections were included. Sixteen (47%) had previously been managed in another center. Median vancomycin MIC of strains was 3 mg/L. Nineteen underwent one-stage, 15 two-stage exchange arthroplasty. After a median [IQR] follow-up of 43 [26-68] months, 2 patients relapsed and 6 developed a new PJI. Compared to 36 rifampin-vancomycin treated PJIs, relapse- or reinfection-free survival rates didn't differ, but more new infections developed in the minocycline group (6 vs 3; P 0.3). Conclusions: Minocycline-vancomycin combination therapy for chronic MR coagulase-negative staphylococcal PJIs seems to be an interesting therapeutic alternative.

Hematogenous osteomyelitis in childhood can relapse many years later into adulthood: A retrospective multicentric cohort study in France.

To describe the epidemiological, clinical, laboratory, and radiological features and the management of adult patients who experienced a relapse between 2003 and 2015 of an acute hematogenous osteomyelitis acquired in childhood.A retrospective multicentric cohort study was conducted in 5 centers in France.Thirty-seven patients were included. The median age was 40 years (28-56), and 26 (70%) were male. The first site of infection was the distal femur (n = 23, 62%). The median time between the osteomyelitis in childhood and the relapse in adulthood was 26 years (13-45). Thirty-four (92%) patients reported inflammatory local clinical manifestations, 17 (46%) draining fistula, 10 (27%) fever. Most patients had intramedullary gadolinium deposition (with or without abscess) on magnetic resonance imaging. Most relapses were monomicrobial infections (82%). Staphylococcus aureus was the most commonly found microorganism (82%), expressing a small colony variant phenotype in 3 cases. Most patients (97%) had a surgical treatment, and the median duration of antibiotics for the relapse was 12 weeks. All patients had a favorable outcome, no patient died and no further relapse occurred. We count 2 femoral fractures on osteotomy site.Osteomyelitis in childhood can relapse later in adulthood, especially in patients with lack of care during the initial episode. Osteotomy and prolonged antimicrobial therapy are required for clinical remission.

Prosthetic joint infections due to Mycobacterium tuberculosis: A retrospective study.

OBJECTIVE: Tuberculous prosthetic joint infection (PJI) is uncommon and often diagnosed late. The objective here is to describe the management of tuberculous PJI at an osteoarticular infection referral center. METHODS: A single-center retrospective study of patients managed between 1987 and 2016 was performed. RESULTS: We identified 9 patients with a median age of 80 years. The hip was involved in all 9 patients. A known history of tuberculosis was noted in 2 patients and tuberculosis was present at other sites in 4 patients (lung, n = 3; urinary tract and scrotum, n = 1; and spine, n = 1). The diagnosis was established by routine intra-operative microbiological sampling, during (n = 4) or at a distance from (n = 5) hip arthroplasty. In the 8 patients with available follow-up data, mean antibiotic therapy duration was 16 months (range, 12-18 months). None of the 4 patients in whom the infection was diagnosed during arthroplasty required surgical revision because of the infection. Of the other 5 patients, 3 were managed by exchange arthroplasty and 1 by excision of the hip without subsequent prosthesis implantation; the remaining patient did not undergo revision surgery. The infection was eradicated in all 9 patients, after 15 months to 10 years. CONCLUSION: Tuberculous PJI is uncommon. The prognosis is good with prolonged antibiotic therapy, although the optimal duration remains unclear. The surgical strategy should be discussed on a case-by-case basis. The prosthesis can be retained if the tuberculous infection is an unexpected finding during arthroplasty.

Analysis of postoperative and hematogenous prosthetic joint-infection microbiological patterns in a large cohort.

OBJECTIVES: This study was undertaken to analyze prosthetic joint infection (PJI)-causing microorganisms and compare their distribution patterns according to PJI classification. METHODS: Cohort study from a single referral center for bone-and-joint infections from January 2004 to December 2015. RESULTS: Nine hundred and twenty-six patients, who developed 997 PJIs, involving the hip (62%), knee (35%) and/or shoulder (1%), were included. PJIs were classified as early postoperative (19%), late chronic (30%), hematogenous (35%) and undetermined (16%). Pathogens most frequently isolated from early-postoperative PJIs were staphylococci (57%), with 25% each Staphylococcus aureus or Staphylococcus epidermidis; 21% were polymicrobial and 10% Gram-negative rods. For late-chronic PJIs, the most frequent microbes were staphylococci (61%), predominantly S. epidermidis (35%); anaerobic bacteria were isolated from 15%; 11% were polymicrobial. Hematogenous PJIs were 99% monomicrobial. Although S. aureus was the most frequently isolated species (28%), streptococci were isolated slightly more often than staphylococci (39% vs. 36%). Among streptococci, group B streptococci were the most frequent (15%). The portal of entry was identified for 52% of hematogenous PJIs: 15% cutaneous, 11% dental, 9% gastrointestinal, 6% urinary, and 11% miscellaneous. CONCLUSION: Although a wide variety of microorganisms was isolated from PJIs, specific microbiological patterns were observed according to infection classification.

Concomitant Multiple Joint Arthroplasty Infections: Report on 16 Cases.

BACKGROUND: Concomitant infections of several prostheses are very rare, serious events that pose particular medical and surgical therapeutic challenges. This study was undertaken to describe epidemiologic, clinical, and microbiological characteristics of concomitant multiple joint arthroplasty infections, their treatments, and outcomes. METHODS: Retrospective (January 2000 and January 2014), single-center, cohort study in a referral center for bone and joint infections. All patients with at least 2 concomitant, microbiologically documented, prosthetic joint infections, that is, during the same septic episode, were included. RESULTS: Sixteen patients were included. Median (range) age was 78 years (46-93 years), gender ratio was 1, and median (range) body mass index was 27 (21-42). Multiple joint arthroplasties (bilateral hip in 8 patients; bilateral knee in 3 patients; hip and knee in 1 patient; and 2 knees and 1 hip in 1 patient) were contaminated hematogenously in all patients, 2 after early postoperative infections. Eight Staphylococcus aureus, 1 Staphylococcus epidermidis, 6 Streptococcus, and 1 Escherichia coli strains were isolated. A curative strategy was applied to 11 patients: 3 underwent bilateral synovectomies, 6 had successive 1-stage exchange arthroplasties, and 2 were treated with other strategies. After 37 months (range, 24-132 months) of follow-up, reinfection occurred in 1 patient. The 5 other patients received prolonged suppressive antibiotic therapy. CONCLUSION: These complex infections occur during staphylococcal or streptococcal bacteremia. Treatment strategies should be discussed by a multidisciplinary team on a case-by-case basis.

Crystal-induced arthritis after arthroplasty: 7 cases.

OBJECTIVES: To describe the occurrence in prosthetic joints of crystal-induced arthritis (CIA) defined as the deposition within the synovial membrane and/or joint cavity of calcium pyrophosphate dehydrate (CPPD) (chondrocalcinosis), sodium urate (gout), or hydroxyapatite. METHODS: We retrospectively reviewed the 7 cases of prosthetic-joint CIA seen between 1993 and 2013 at a medical-surgical center specialized in the management of osteoarticular infections. RESULTS: The 4 females and 3 males ranged in age from 67 to 79 years. Acute CIA occurred at the knee in 6 patients (5 with total knee arthroplasty and 1 with unicompartmental knee arthroplasty) and at the hip in 1 patient (with total hip arthroplasty). Time from arthroplasty to CIA varied from 7 days to 9 years. An abrupt onset was a consistent feature, with pain, complete loss of function, and local evidence of inflammation. A single patient had a fever and 6 patients had laboratory evidence of systemic inflammation. Joint aspiration showed hemarthrosis in 3 patients and inflammatory joint fluid with 20,000 to 79,000neutrophils/mm(3) in 6 patients. Joint fluid cultures were negative in 6 patients. CPPD crystals were evidenced in 5 patients, including 1 who also had hydroxyapatite crystals detected by electron microscopy after alizarin red staining. Monosodium urate crystals were found in 1 patient. The remaining patient had both CPPD crystals and positive cultures for Campylobacter fetus. In 5 patients, treatment with colchicine or a nonsteroidal antiinflammatory drug ensured prompt control of the symptoms and systemic inflammation. The patient with total hip arthroplasty underwent joint aspiration for hemarthrosis. In 1 patient, an intraarticular injection of triamcinolone hexacetonide improved the symptoms and systemic inflammation. The patient with Campylobacter fetus infection was treated with antibiotics, excision of the abscess, and synovectomy. CONCLUSION: CIA may occur after arthroplasty, within synovial membrane remains or neosynovium developed around the prosthetic joint. CIA is a manifestation of a metabolic disease that persists and can reactivate after surgery. Routine testing for crystals is rarely performed in patients with sterile arthritis of a prosthetic joint, and crystals are difficult to detect in joints with hemarthrosis; consequently, the frequency of prosthetic-joint CIA may be underestimated. Although rare, CIA should be considered routinely when symptoms suggesting septic arthritis develop in a prosthetic joint, in order to avoid unnecessary prolonged antibiotic therapy and, in some cases, surgery. The treatment is usually simple.

Resistance and virulence potential of uropathogenic Escherichia coli strains isolated from patients hospitalized in urology departments: a French prospective multicentre study.

We characterized antibiotic resistance and virulence of uropathogenic Escherichia coli (UPEC) strains isolated from urinary tract infections (UTIs) in patients hospitalized in urology departments. A prospective multicentre study was initiated from March 2009 and lasted until February 2010 in French urology units. All patients with asymptomatic bacteriuria (ABU), acute cystitis, acute pyelonephritis or acute prostatitis in whom UPEC was detected were included. Antimicrobial resistance and virulence factors were compared among the different groups. To identify independent associations between virulence markers and the risk of UTI, we used a multivariate logistic regression. We included 210 patients (mean age: 65.8 years; 106 female). Episode of UTI was community acquired in 72.4 %. ABU was diagnosed in 67 cases (31.9 %), cystitis in 52 cases (24.7 %), pyelonephritis in 35 cases (16.7 %) and prostatitis in 56 cases (26.7 %). ABU was more frequent in patients with a urinary catheter (76.1 vs 23.9 %, P<0.001). The resistance rate was 7.6 and 24.8 % for cefotaxime and ciprofloxacin, respectively. UPEC isolated from infections belonged more frequently to phylotypes B2 and D (P =0.07). The papG allele II and papA, papC, papE, kpsMTII and iutA genes were significantly more frequent in infecting strains (P<0.05). In multivariate analysis, strains susceptible to ciprofloxacin were significantly associated with papG allele II (P=0.007), kpsMTK1 (P<0.001) and hlyA (P<0.001) compared with the ciprofloxacin-resistant strains. To the best of our knowledge, this is the first study evaluating the antibiotic resistance and virulence features of UPEC isolated from patients hospitalized in urology departments. High resistance rates were observed, notably for ciprofloxacin, highlighting the importance of a reinforced surveillance in this setting.

Multiplex Antibody Detection for Noninvasive Genus-Level Diagnosis of Prosthetic Joint Infection.

We developed and evaluated a multiplex antibody detection-based immunoassay for the diagnosis of prosthetic joint infections (PJIs). Sixteen protein antigens from three Staphylococcusspecies (Staphylococcus aureus,Staphylococcus epidermidis, and Staphylococcus lugdunensis) (8 antigens),Streptococcus agalactiae(4 antigens), and Propionibacterium acnes(4 antigens) were selected by comparative immune proteomics using serum samples from PJI cases versus controls. A bead-based multiplex immunoassay that measured serum IgG against purified, recombinant forms of each of the 16 antigens was developed. We conducted a prospective study to evaluate the performance of the assay. A PJI was defined by the presence of a sinus tract and/or positive intraoperative sample cultures (at least one sample yielding a virulent organism or at least two samples yielding the same organism). A total of 455 consecutive patients undergoing revision or resection arthroplasty (hip, 66.3%; knee, 29.7%; shoulder, 4%) at two French reference centers for the management of PJI were included: 176 patients (38.7%) were infected and 279 (61.3%) were not. About 60% of the infections involved at least one of the species targeted by the assay. The sensitivity/specificity values were 72.3%/80.7% for targeted staphylococci, 75%/92.6% forS. agalactiae, and 38.5%/84.8% forP. acnes The assay was more sensitive for infections occurring >3 months after arthroplasty and for patients with an elevated C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR). However, it detected 64.3% and 58.3% of targeted staphylococcal infections associated with normal CRP and ESR values, respectively. This new multiplex immunoassay approach is a novel noninvasive tool to evaluate patients suspected of having PJIs and provides information complementary to that from inflammatory marker values.

Large Cohort Study of Central Venous Catheter Thrombosis during Intravenous Antibiotic Therapy.

The frequency and risk factors for central venous catheter-related thrombosis (CRT) during prolonged intravenous (i.v.) antibiotic therapy have rarely been reported. The primary objective of this study was to evaluate the frequency, incidence, and risk factors for CRT among patients being treated with prolonged i.v. antibiotic therapy. The secondary objective was to describe the clinical manifestations, diagnostic evaluation, and clinical management. This cohort study was conducted between August 2004 and May 2010 in a French referral center for osteoarticular infections. All patients treated for bone and joint infections with i.v. antimicrobial therapy through a central venous catheter (CVC) for ≥2 weeks were included. Risk factors were identified using nonparametric tests and logistic regression. A case-control study investigated the role of vancomycin and catheter malposition. A total of 892 patients matched the inclusion criteria. CRT developed in 16 infections occurring in 16 patients (incidence, 0.39/1,000 catheter days). The median time to a CRT was 29 days (range, 12 to 48 days). Local clinical signs, fever, and secondary complications of CRT were present in 15, 8, and 4 patients, respectively. The median C-reactive protein level was 95 mg/liter. The treatment combined catheter removal and a median of 3 months (1.5 to 6 months) of anticoagulation therapy. The outcome was good in all patients, with no recurrence of CRT. Three risk factors were identified by multivariate analysis: male sex (odds ratio [OR], 5.4; 95% confidence interval [CI], 1.1 to 26.6), catheter malposition (OR, 5.3; 95% CI, 1.6 to 17.9), and use of vancomycin (OR, 22.9; 95% CI, 2.8 to 188). Catheter-related thrombosis is a rare but severe complication in patients treated with prolonged antimicrobial therapy. Vancomycin use was the most important risk factor identified.

Outcome of patients over 80 years of age on prolonged suppressive antibiotic therapy for at least 6 months for prosthetic joint infection.

OBJECTIVES: To describe elderly patients treated with prolonged suppressive antibiotic therapy for a prosthetic joint infection (PJI) in cases where the infected prosthesis could not be removed. METHODS: All patients aged ≥80 years with a documented PJI and treated with prolonged suppressive antibiotic therapy for more than 6 months were included retrospectively in this study. The following events were noted: failure including persisting infection, relapse, new infection, treatment discontinuation due to severe adverse events, and related death, and also unrelated death. RESULTS: Thirty-eight patients with a median age of 84 years (80-95 years) were included; there were 24 hip infections, 13 knee infections, and one shoulder infection. The main causative organisms were Staphylococcus aureus (39%) and Streptococcus agalactiae (16%). The most commonly prescribed antibiotics as prolonged suppressive therapy were penicillins. The median follow-up duration was 24 months; 60% of the patients were event-free at 24 months and were still on prolonged suppressive antibiotic therapy. Fifteen events (six failures and nine unrelated deaths) were observed. Hypoalbuminaemia, the presence of a sinus tract, and a staphylococcal PJI were associated with an increased risk of an event. CONCLUSIONS: Prolonged suppressive antibiotic therapy is an alternative therapy in elderly patients with PJI when surgery is contraindicated and when the bacteria are susceptible to well-tolerated oral antimicrobial therapy such as beta-lactams.

One-stage exchange arthroplasty for chronic periprosthetic hip infection: results of a large prospective cohort study.

BACKGROUND: Exchange arthroplasty of one or two stages is required for the treatment of chronic periprosthetic joint infections. Two-stage exchange is costly and has high morbidity with limited patient mobility between procedures. One-stage exchange has been promoted by several European teams as the preferred alternative. The aim of this study was to prospectively analyze the outcome of patients with a periprosthetic hip infection treated with one-stage exchange arthroplasty. METHODS: We performed a prospective cohort study in a French referral center for osteoarticular infections including all periprosthetic hip infections treated with one-stage exchange arthroplasty from November 2002 to March 2010. Direct exchange was performed in chronic periprosthetic hip infection with no or minor bone loss and preoperative identification of a microorganism from joint fluid aspirate. No antibiotic-loaded bone cement was used. Antibiotic therapy was administered for twelve weeks: intravenously for four to six weeks, followed by an oral regimen for six to eight weeks. Follow-up was a minimum of two years. The following events were noted: relapse, new infection, joint revision for mechanical reasons, and periprosthetic hip infection-related and unrelated deaths. RESULTS: One hundred and fifty-seven patients with periprosthetic hip infections with a median infection duration of 258 days (interquartile range, 120 to 551 days) prior to our index surgical procedure for infection were included. Periprosthetic hip infection occurred in ninety-nine cases of primary hip arthroplasty, twenty-seven cases of revision arthroplasty, and thirty-one cases in which the periprosthetic hip infection had been treated previously. A difficult-to-treat organism was isolated in fifty-nine cases (38%). After a median follow-up of 41.6 months (interquartile range, 28.1 to 66.9 months), two relapses, six new infections, nine revisions for mechanical reasons, two related deaths, and nineteen unrelated deaths occurred. CONCLUSIONS: One-stage exchange arthroplasty is an effective surgical procedure in patients with periprosthetic hip infection who have good bone quality. Precise identification of the microorganism(s) and prolonged administration of appropriate intravenous antibiotic therapy are key factors for successful treatment.

Campylobacter infection after prosthetic joint surgery.

Few cases of Campylobacter prosthetic joint infection (PJI) have been reported so far. We describe the demographic characteristics, underlying conditions, clinical features, treatment, and outcome of 8 patients with Campylobacter PJI in our hospital. All strains were confirmed at the French National Reference Center for Campylobacter and Helicobacter. Seven patients were infected with C. fetus and 1 with C. jejuni. Most patients were elderly and immunocompromised. Four had bacteremia, one of these with a pacemaker endocarditis. All the patients received at least 3 months of antibiotic treatment and 6 were treated surgically. The outcome was favorable at 2 years of follow-up in all except for 1 patient. Campylobacter PJI cases are rare but likely to become more frequent. C. fetus bacteremia should motivate physicians to look for a secondary localization such as a Campylobacter PJI.

Staphylococcus aureus osteitis of the dens: a rare location.

An immunocompetent 84-year-old woman was admitted for severe neck pain with a fever. Magnetic resonance imaging showed osteitis of the dens. She had methicillin-susceptible Staphylococcus aureus bacteremia related to a dental extraction. She then developed an infection of a hip prosthesis due to the same organism. Her treatment consisted in intravenous antibiotics followed by oral suppressive antibiotic therapy for 2 years. Exchange arthroplasty was not performed given the advanced age of the patient, her unwillingness to undergo the procedure, and the risk of neurological complications during endotracheal intubation. The outcome was favorable at last follow-up more than 2 years after antibiotic treatment initiation.

Discitis and sacroiliitis diagnosed 15 years after iatrogenic Mycobacterium xenopi inoculation.

A patient was diagnosed with discitis and sacroiliitis due to Mycobacterium xenopi. He had a history of percutaneous nucleotomy performed 15 years earlier (in 1992) at the Clinique du Sport, Paris, France, during an outbreak of nosocomial M. xenopi infection at that institution. In 1997, magnetic resonance imaging performed as part of the routine follow-up program for patients who had surgery at the Clinique du Sport during the outbreak was not interpreted as indicating discitis; this assessment was confirmed by our review of the images. Bone and joint infections due to atypical mycobacteria are rare and can develop very slowly. To our knowledge, this is the first reported case of M. xenopi discitis with secondary extension to the sacroiliac joint in an immunocompetent patient.

Listeria monocytogenes-associated joint and bone infections: a study of 43 consecutive cases.

BACKGROUND: Little is known about Listeria monocytogenes-associated bone and joint infections. Only case reports of this infection have been published. METHODS: Retrospective study of culture-proven bone and joint cases reported to the French National Reference Center for Listeria from 1992 to 2010. RESULTS: Forty-three patients were studied: 61% were men, and the median age was 72 (range, 16-89); 24 patients exhibited comorbidities (56%). Thirty-six patients (84%) had orthopedic implant devices: prosthetic joints (n = 34) or internal fixation (n = 2); the median time after insertion was 9 years (0.1-22). Subacute infection was more frequent (median, 4 weeks [range, 2-100], 74%) than acute infection (<7 days, 23%), with nonspecific clinical features; 45% of patients had no fever. Blood cultures were positive in 3 of 19 cases. Isolate polymerase chain reaction genogrouping revealed 4 patterns: IVb (21 of 42, 50%), IIa (17 of 42, 40%), IIb (2 of 42, 5%), and IIc (2 of 42, 5%). Five groups of strains with similar pulsotype patterns were identified without an epidemiological link. Antibiotics, primarily amoxicillin (80%) with aminoglycosides (48%), were prescribed for a median duration of 15 weeks (range, 2-88). Eighteen patients (50%) underwent prosthesis replacement; all were successful after median follow-up of 10 months (range, 1-75). Five of 13 patients for whom material was not removed had protracted infection despite prolonged antibiotherapy; 3 of these patients later underwent prosthesis replacement with sustained recovery. CONCLUSIONS: Osteoarticular listeriosis primarily involves prosthetic joints and occurs in immunocompromised patients. It requires intensive treatment with antibiotherapy and usually requires implant removal or replacement for cure.

Osteomyelitis in adults: an underrecognized clinical entity in immunocompetent hosts. A report of six cases.

OBJECTIVE: Osteomyelitis is rare in adults and typically occurs in patients with risk factors such as sickle cell disease or immune deficiency. Cases in immunocompetent adults without sickle cell disease are extremely rare. The objective of this work was to describe the epidemiological, clinical, laboratory, and radiological features and the management of long-bone osteomyelitis in immunocompetent adults without sickle cell disease. METHODS: We conducted a retrospective descriptive study of all immunocompetent adults without sickle cell disease who were admitted to our center between November 2002 and November 2008 for long-bone osteomyelitis. In all patients, the clinical symptoms started in adulthood, in the absence of a childhood history of osteomyelitis. RESULTS: We identified six patients meeting our inclusion criteria over the 6-year study period. The causative microorganism was methicillin-susceptible Staphylococcus aureus in four patients and Salmonella in two patients (wild-type S. typhi and S. enterica, respectively). In each patient, there was a single focus of osteomyelitis and a single causative microorganism. The symptoms developed insidiously and lacked specificity. At presentation, the patients had moderate pain with or without a swelling. There was no fever initially in five patients, three of whom had major diagnostic delays as a result. Treatment associated antibiotics and surgery in all patients and the initial outcome was consistently favorable (median follow-up: 15 months; range: 8-72). CONCLUSION: Osteomyelitis can occur even in immunocompetent adults. The protracted course and atypical presentation of osteomyelitis in immunocompetent adults may lead to major diagnostic delays.

Continuous clindamycin infusion, an innovative approach to treating bone and joint infections.

The feasibility, safety, and efficacy of prolonged, continuous, intravenous clindamycin therapy were retrospectively evaluated for 70 patients treated for bone and joint infections, 40% of whom were treated as outpatients. The median treatment duration was 40 days, the median daily clindamycin dose was 2,400 mg, and three moderate-grade adverse events occurred. The median serum clindamycin concentrations on days 3 to 14 and days 8 to 28 were 5 and 6.2 mg/liter, respectively; the median concentration was significantly lower (P < 0.02) in patients treated with rifampin (5.3 mg/liter) than in those not treated with rifampin (8.9 mg/liter). Among 53 patients with a median follow-up of 30 months (range, 24 to 53 months), 49 (92%) were considered cured (1 patient had a relapse, and 3 patients had reinfections).

Outcome of group B streptococcal prosthetic hip infections compared to that of other bacterial infections.

BACKGROUND: Outcome of streptococcal prosthetic hip infection is often thought to be better than that caused by other pathogens. That supposition was not confirmed in our experience with group B streptococcal prosthetic joint infection. OBJECTIVE: We compared outcomes of group B streptococcal and other-pathogen prosthetic hip infections. METHODS: One hundred and thirty nine patients, 24 with group B streptococcal and 115 other-pathogen prosthetic hip infections, were included. The primary outcome was the time from surgical treatment to treatment failure, defined as relapse, infection- or treatment-related death. Secondary outcomes were the times from surgical treatment to relapse or any event (event-free survival). The cumulative incidence estimator was used to model primary and secondary outcomes. Multivariable regression analysis was used to determine a set of independent predictors of treatment failure. RESULTS: With a median follow-up of 22 months, treatment failed more frequently in patients with group B streptococcal prosthetic hip infections (hazard ratio, 4.88 [95% CI, 1.4-17], P=.012). Multivariable analysis retained the American Society of Anesthesiologist score and group B streptococcal infection as independent risk factors of treatment failure; event-free survival was lower for these patients (hazard ratio, 2.64 [95% CI, 1.2-6], P=.02). CONCLUSION: Despite high antibiotic susceptibility, outcomes of group B streptococcal and other-pathogen prosthetic hip infection differ.

Group B streptococcal prosthetic joint infections: a retrospective study of 30 cases.

OBJECTIVE: To describe the epidemiological, clinical, and laboratory characteristics of patients with group B streptococcal (GBS) prosthetic joint infections, their diagnoses, treatment, and long-term outcomes. METHODS: We conducted a retrospective cohort study including all patients hospitalized from January 1994 through May 2006 for a GBS prosthetic joint infection. RESULTS: The study included 30 patients, aged 35-87 (median 74) years with prosthetic hip (24) or knee (6) infections, 20 with at least one underlying disease. The route of infection was presumed to be hematogenous in 27 patients, and a portal of entry was identified in 9 (genitourinary tract 4, skin 2, gastrointestinal tract 2, oropharynx 1). All patients underwent surgery (6 debridement-synovectomy, 9 1-stage exchange arthroplasty, 8 2-stage exchange arthroplasty, 6 hip resection arthroplasty, and 1 knee arthrodesis) and received prolonged intravenous antibiotics. Four patients relapsed. One patient developed 2 other infections on her knee prosthesis. Two deaths were infection-related, and one was treatment-related. Nineteen patients followed for >/=2 years were cured. One patient was lost to follow-up and 3 died of causes unrelated to infection or treatment within 2 years. CONCLUSION: GBS prosthetic joint infections are mostly acute hematogenous infections that require prompt management for satisfactory outcome. Despite high antibiotic susceptibility, treatment failure is frequent because of the severity of the infection and patients' advanced age, underlying diseases, and relapses.