Treatment of pyogenic (non-tuberculous) spondylodiscitis with tailored high-dose levofloxacin plus rifampicin

Optimal Duration of Antibiotic Therapy for Primary Osteomyelitis Discitis: A Systematic Review and Network Meta-Analysis

STUDY DESIGN

Systematic review and network meta-analysis.

OBJECTIVE

This study aimed to systematically review the literature on the management of primary osteomyelitis discitis and perform a network meta-analysis comparing the efficacy of different antibiotic treatment durations.

BACKGROUND

Primary osteomyelitis discitis is a challenging condition with varying management strategies.

MATERIALS AND METHODS

A comprehensive literature search was conducted. Studies reporting outcomes for the treatment of primary osteomyelitis discitis were included. A random-effect network meta-analysis was performed comparing antibiotic treatment durations of <4 weeks, 4 to 8 weeks, 8 to 12 weeks, and 12 to 16 weeks. The surface under the cumulative ranking curve (SUCRA) was used to rank treatment effectiveness.

RESULTS

Sixty-three articles with 4233 patients were included. Staphylococcus aureus was the most common causative agent (57.6%). The 4 to 8-week antibiotic duration ranked highest across fixed-effect and random-effect models (SUCRA: 0.8207 and 0.8343). The 12 to 16-week duration ranked highest in the fixed-effect model (SUCRA: 0.8460) but dropped substantially in the random-effect model (SUCRA: 0.3067). The <4-week duration showed mixed results. The 8 to 12-week duration consistently ranked lowest. No statistically significant differences were found between durations for symptomatic relief.

CONCLUSION

Antibiotic therapy for 4 to 8 weeks may provide the optimal balance of efficacy and treatment duration for most patients with primary osteomyelitis discitis. However, treatment should be individualized based on clinical response. Further prospective studies are needed to clarify optimal management strategies for this complex condition.

Culture-Negative Native Vertebral Osteomyelitis: A Narrative Review of an Underdescribed Condition

The incidence of culture-negative NVO (CN-NVO) cases is increasing, presenting significant diagnostic and therapeutic challenges due to the inability to isolate causative organisms with conventional microbiological methods. Factors influencing the diagnosis of CN-NVO include prior antimicrobial therapy, low pathogen burden, fastidious or intracellular organisms, technical issues, and non-infectious mimickers. Diagnosis often relies on imaging modalities like magnetic resonance imaging (MRI) and computed tomography (CT)-guided biopsy, though these methods can sometimes fail to yield positive microbiological results. Advanced diagnostic tools, such as polymerase chain reaction (PCR), metagenomic next-generation sequencing (mNGS), and cell-free DNA analysis, may be necessary to identify the pathogen. The causative pathogen cannot be isolated in some patients, among which an empirical antimicrobial therapy should be initiated. This narrative review discusses the management, monitoring, surgical indications, and outcomes for patients with CN-NVO.

Pharmacokinetic and pharmacodynamic considerations for optimizing antimicrobial therapy used to treat bone and joint infections: an evidence-based algorithmic approach

INTRODUCTION

Bone and joint infections (BJIs) are a major health concern causing remarkable morbidity and mortality. However, which antimicrobial treatment could be the best according to specific clinical scenarios and/or to the pharmacokinetic/pharmacodynamic (PK/PD) features remains an unmet clinical need. This multidisciplinary opinion article aims to develop evidence-based algorithms for empirical and targeted antibiotic therapy of patients affected by BJIs.

AREAS COVERED

A multidisciplinary team of four experts had several rounds of assessment for developing algorithms devoted to empirical and targeted antimicrobial therapy of BJIs. A literature search was performed on PubMed-MEDLINE (until April 2023) to provide evidence for supporting therapeutic choices. Four different clinical scenarios were structured according to specific infection types (i.e. vertebral osteomyelitis, prosthetic joint infections, infected non-unions and other chronic osteomyelitis, and infectious arthritis), need or not of surgical intervention or revision, isolation or not of clinically relevant bacterial pathogens from blood and/or tissue cultures, and PK/PD features of antibiotics.

EXPERT OPINION

The proposed therapeutic algorithms were based on a multifaceted approach considering the peculiar features of each antibiotic (spectrum of activity, PK/PD properties, bone penetration rate, and anti-biofilm activity), and could be hopefully helpful in improving clinical outcome of BJIs.

2022 SPILF - Clinical Practice guidelines for the diagnosis and treatment of disco-vertebral infection in adults

These guidelines are an update of those made in 2007 at the request of the French Society of Infectious Diseases (SPILF, Société de Pathologie Infectieuse de Langue Française). They are intended for use by all healthcare professionals caring for patients with disco-vertebral infection (DVI) on spine, whether native or instrumented. They include evidence and opinion-based recommendations for the diagnosis and management of patients with DVI. ESR, PCT and scintigraphy, antibiotic therapy without microorganism identification (except for emergency situations), therapy longer than 6 weeks if the DVI is not complicated, contraindication for spinal osteosynthesis in a septic context, and prolonged dorsal decubitus are no longer to be done in DVI management. MRI study must include exploration of the entire spine with at least 2 orthogonal planes for the affected level(s). Several disco-vertebral samples must be performed if blood cultures are negative. Short, adapted treatment and directly oral antibiotherapy or early switch from intravenous to oral antibiotherapy are recommended. Consultation of a spine specialist should be requested to evaluate spinal stability. Early lifting of patients is recommended.

Non-specific spondylodiscitis: a new perspective for surgical treatment

PURPOSE

Pyogenic spondylodiscitis is a relatively rare spinal disease; non-specific spondylodiscitis (NSS) cases are increasing. This study aims to identify if changes of inflammatory markers under antibiotic therapy can be used to determine which NSS patients can benefit from surgical indication earlier than others.

METHODS

Two groups of patients with NSS were examined. Group A underwent surgery, while Group B was treated conservatively. Group B was also subdivided in patients undergoing antibiotic therapy for > 6 weeks (B1) and < 6 weeks (B2). Groups were compared for age, gender, BMI, blood levels of ESR and CRP and VAS scale.

RESULTS

There were no differences (P = 0.06) in reduction in ESR at 4 weeks between two main groups. A reduction in CRP, with < 2.7 mg/dl at 4 weeks, was observed in Group A (P = 0.01). Comparing Group B1 to B2, a reduction (P = 0.0001) in VAS, ESR and CRP at 4 weeks was observed in Group B2. It was possible to isolate the pathogen in 52.8% of Group B, without any differences on VAS, ESR and CRP values and on length of the antibiotic therapy.

CONCLUSIONS

The surgical treatment should be considered for patients who, after 4 weeks of conservative therapy, do not show a reduction in the ESR < 50 mm/h and of the CRP < 2.7 g/dl. The comparison between groups underwent surgically and those treated conservatively showed a reduction in the CRP at 4 weeks and better VAS for pain at 3 months in Group A.

Diagnostic yield of image-guided biopsy in patients with suspected infectious spondylodiscitis : a prospective study from a tuberculosis-endemic country

AIMS

The aims of this study were to determine the diagnostic yield of image-guided biopsy in providing a final diagnosis in patients with suspected infectious spondylodiscitis, to report the diagnostic accuracy of various microbiological tests and histological examinations in these patients, and to report the epidemiology of infectious spondylodiscitis from a country where tuberculosis (TB) is endemic, including the incidence of drug-resistant TB.

METHODS

A total of 284 patients with clinically and radiologically suspected infectious spondylodiscitis were prospectively recruited into the study. Image-guided biopsy of the vertebral lesion was performed and specimens were sent for various microbiological tests and histological examinations. The final diagnosis was determined using a composite reference standard based on clinical, radiological, serological, microbiological, and histological findings. The overall diagnostic yield of the biopsy, and that for each test, was calculated in light of the final diagnosis.

RESULTS

The final diagnosis was tuberculous spondylodiscitis in 250 patients (88%) and pyogenic spondylodiscitis in 22 (7.8%). Six (2.1%) had a noninfectious condition-mimicking infectious spondylodiscitis, and six (2.1%) had no definite diagnosis and improved without specific treatment. The diagnosis was made by image-guided biopsy in 152 patients (56%) with infectious spondylodiscitis. Biopsy was contributory in identifying 132/250 patients (53%) with tuberculous spondylodiscitis, and 20/22 patients (91%) with pyogenic spondylodiscitis. Histological examination was the most sensitive diagnostic modality, followed by Xpert MTB/RIF assay.

CONCLUSION

Image-guided biopsy has a reasonably high diagnostic yield in patients with suspected infectious spondylodiscitis. A combination of histological examination, Xpert MTB/RIF assay, bacterial culture, and sensitivity provides high diagnostic accuracy in a country in which TB is endemic. Cite this article: Bone Joint J 2022;104-B(1):120-126.

Implementation of a consensus protocol for antibiotic use for bone and joint infection to reduce unnecessary outpatient parenteral antimicrobial therapy: A quality improvement initiative

Objective:

We aimed to decrease the use of outpatient parenteral antimicrobial therapy (OPAT) for patients admitted for bone and joint infections (BJIs) by applying a consensus protocol to suggest oral antibiotics for BJI.

Design:

A quasi-experimental before-and-after study.

Setting:

Inpatient setting at a single medical center.

Patients:

All inpatients admitted with a BJI.

Methods:

We developed a consensus table of oral antibiotics for BJI among infectious diseases (ID) specialists. Using the consensus table, we implemented a protocol consisting of a weekly reminder e-mail and case-based discussion with the consulting ID physician. Outcomes of patients during the implementation period (November 1, 2020, to May 31, 2021) were compared with those during the preimplementation period (January 1, 2019, to October 31, 2020). Our primary outcome was the proportion of patients treated with OPAT. Secondary outcomes included length of hospital stay (LOS) and recurrence or death within 6 months.

Results:

In total, 77 patients during the preimplementation period and 22 patients during the implementation period were identified to have a BJI. During the preimplementation period, 70.1% of patients received OPAT, whereas only 31.8% of patients had OPAT during the implementation period (P = .003). The median LOS after final ID recommendation was significantly shorter during the implementation period (median 3 days versus 1 day; P < .001). We detected no significant difference in the 6-month rate of recurrence (24.7% vs 31.8%; P = .46) or mortality (9.1% vs 9.1%; P = 1.00).

Conclusions:

More patients admitted with BJIs were treated with oral antibiotics during the implementation phase of our quality improvement initiative.

Outcomes and risk factors for spontaneous spondylodiscitis: Case series and meta-analysis of the literature

Despite recent improvements in surgical and antimicrobial therapies, few generally applicable guidelines exist for spondylodiscitis management. We reviewed a consecutive series of patients as well as the past 18 years of the literature and analyzed outcomes for either conservative or surgical treatment. We analyzed a consecutive series of adults with spontaneous spondylodiscitis treated at our institution over the last 6 years. We analyzed predictors for neurological deficits, vertebral collapse, and surgical treatment. We also performed a meta-analysis of the literature between 2000 and 2018, stratifying the results between surgical and conservative treatment outcomes. A younger age at diagnosis, cervical location, tubercular infection, coexistence of morbidities, and vertebral collapse were predictors of surgical intervention. Cervical spondylodiscitis, vertebral collapse, and epidural collection were associated with a higher risk of developing neurological deficits, while tubercular spondylodiscitis was associated with a higher risk of vertebral collapse. Based on the current literature, conservative treatment has success rates similar to those of surgical treatment but lower complication and mortality rates. In cases without an absolute indication for surgery, a conservative approach should be considered as the first-line treatment. A closer diagnostic and clinical follow-up should be recommended in patients with cervical tract or tubercular spondylodiscitis because of the higher risk of developing bone collapse and neurological deficits.

Safety and Efficacy of Prolonged Use of Dalbavancin in Bone and Joint Infections

Dalbavancin is a lipoglycopeptide with potent activity against Gram-positive microorganisms, a long half-life, a favorable safety profile, and a high concentration in bone, which makes it an interesting alternative for treatment of osteoarticular infections. We performed a multicentric retrospective study of all patients with an osteoarticular infection (septic arthritis, spondylodiscitis, osteomyelitis, or orthopedic implant-related infection) treated with at least one dose of dalbavancin between 2016 and 2017 in 30 institutions in Spain. In order to evaluate the response, patients with or without an orthopedic implant were separated. A total of 64 patients were included. Staphylococcus epidermidis and Staphylococcus aureus were the most frequent microorganisms. The reasons for switching to dalbavancin were simplification (53.1%), adverse events (25%), or failure (21.9%). There were 7 adverse events, and no patient had to discontinue dalbavancin. In 45 cases, infection was related to an orthopedic implant. The implant material was retained in 23 cases, including that in 15 (65.2%) patients that were classified as cured and 8 (34.8%) that presented improvement. In 21 cases, the implants were removed, including those in 16 (76.2%) cases that were considered successes, 4 (19%) cases were considered improved, and 1 (4.8%) case that was considered a failure. Among the 19 cases without implants, 14 (73.7%) were considered cured, 3 (15.8%) were considered improved, and 2 (10.5%) were considered failures. The results show that dalbavancin is a well-tolerated antibiotic, even when >2 doses are administered, and is associated with a high cure rate. These are preliminary data with a short follow-up; therefore, it is necessary to gain more experience and, in the future, to establish the most appropriate dose and frequency.

Selection of an appropriate empiric antibiotic regimen in hematogenous vertebral osteomyelitis

Background

Empiric antibiotic therapy for suspected hematogenous vertebral osteomyelitis (HVO) should be initiated immediately in seriously ill patients and may be required in those with negative microbiological results. The aim of this study was to inform the appropriate selection of empiric antibiotic regimens for the treatment of suspected HVO by analyzing antimicrobial susceptibility of isolated bacteria from microbiologically proven HVO.

Method

We conducted a retrospective chart review of adult patients with microbiologically proven HVO in five tertiary-care hospitals over a 7-year period. The appropriateness of empiric antibiotic regimens was assessed based on the antibiotic susceptibility profiles of isolated bacteria.

Results

In total, 358 cases of microbiologically proven HVO were identified. The main causative pathogens identified were methicillin-susceptible Staphylococcus aureus (33.5%), followed by methicillin-resistant S. aureus (MRSA) (24.9%), Enterobacteriaceae (19.3%), and Streptococcus species (11.7%). Extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and anaerobes accounted for only 1.7% and 1.4%, respectively, of the causative pathogens. Overall, 73.5% of isolated pathogens were susceptible to levofloxacin plus rifampicin, 71.2% to levofloxacin plus clindamycin, and 64.5% to amoxicillin-clavulanate plus ciprofloxacin. The susceptibility to these oral combinations was lower in cases of healthcare-associated HVO (52.6%, 49.6%, and 37.6%, respectively) than in cases of community-acquired HVO (85.8%, 84.0%, and 80.4%, respectively). Vancomycin combined with ciprofloxacin, ceftriaxone, ceftazidime, or cefepime was similarly appropriate (susceptibility rates of 93.0%, 94.1%, 95.8%, and 95.8%, respectively).

Conclusions

Based on our susceptibility data, vancomycin combined with a broad-spectrum cephalosporin or fluoroquinolone may be appropriate for empiric treatment of HVO. Fluoroquinolone-based oral combinations may be not appropriate due to frequent resistance to these agents, especially in cases of healthcare-associated HVO.

Clinical Characteristics and Outcomes of Patients with Culture-Negative Pyogenic Spondylitis according to Empiric Glycopeptide Use

Background

The optimal choice of antibiotics is challenging in culture-negative pyogenic spondylitis (PS). The empiric use of glycopeptides is suggested depending on various risk factors, although clinical data are sparse. This study aimed to analyze the clinical characteristics and outcomes of patients with culture-negative PS and evaluate the effect of empiric glycopeptide use on clinical outcomes in these patients.

Materials and Methods

Data on the characteristics, treatment, and outcomes of 175 patients diagnosed with PS were retrospectively obtained from the electronic database of a tertiary referral hospital from 2009 to 2016. Patients with negative culture results were grouped by the duration of glycopeptide treatment: glycopeptide therapy <28 days (Group A) and glycopeptide therapy ≥28 days (Group B).

Results

Of 89 patients with negative culture results, 78 were included in the analysis (Group A, n = 66; Group B, n = 12). The mean age of patients with negative culture results was 65.5 years, and 52.6% were male. The median follow-up duration was 573 (interquartile range [IQR], 83 – 1,037) days. The duration of intravenous glycopeptide therapy was 0.0 (IQR, 0.0 – 0.0) days and 55.5 (IQR, 37.0 – 75.7) days for Groups A and B, respectively. Patients who used glycopeptide longer empirically (Group B) had more commonly undergone a previous spinal procedure, including surgery (P = 0.024). The length of hospitalization, erythrocyte sedimentation rate, and C-reactive protein level were significantly higher in Group B compared with those in Group A (P <0.001, P <0.001, and P = 0.006, respectively). Regarding treatment modalities, patients in Group B underwent surgery more frequently (P = 0.017). The duration of parenteral antibiotic treatment was longer in Group B (P <0.001). Recurrence was noted in 7 patients (9.0%), and the recurrence rate was not significantly different between the 2 groups (Group A, 5/66 [7.6%]; Group B, 2/12 [16.7%]; P = 0.293).

Conclusion

The recurrence rate among patients with culture-negative PS was not different based on the duration of empiric glycopeptide use. However, considering the small sample size and heterogeneity of our study population, we suggest that it is reasonable to administer glycopeptide antibiotics in these patients depending on clinical risk factors. Further large-scale prospective studies are needed to obtain more evidence for appropriate antibiotic treatment.

Presentation and Outcomes After Medical and Surgical Treatment Versus Medical Treatment Alone of Spontaneous Infectious Spondylodiscitis: A Systematic Literature Review and Meta-Analysis

STUDY DESIGN

Systematic literature review.

OBJECTIVES

The aims of this study were to (1) describe the clinical features, disabilities, and incidence of neurologic deficits of pyogenic spondylodiscitis prior to treatment and (2) compare the functional outcomes between patients who underwent medical treatment alone or in combination with surgery for pyogenic spondylodiscitis.

METHODS

A systematic literature review was performed using PubMed according to PRISMA guidelines. No year restriction was put in place. Statistical analysis of pooled data, when documented in the original report (ie, number of patients with desired variable and number of patients evaluated), was conducted to determine the most common presenting symptoms, incidence of pre- and postoperative neurologic deficits, associated comorbidities, infectious pathogens, approach for surgery when performed, and duration of hospitalization. Outcomes data, including return to work status, resolution of back pain, and functional recovery were also pooled among all studies and surgery-specific studies alone. Meta-analysis of studies with subgroup analysis of pain-free outcome in surgical and medical patients was performed.

RESULTS

Fifty of 1286 studies were included, comprising 4173 patients undergoing either medical treatment alone or in combination with surgery. Back pain was the most common presenting symptom, reported in 91% of patients. Neurologic deficit was noted in 31% of patients. Staphylococcus aureus was the most commonly reported pathogen, seen in 35% of reported cases. Decompression and fusion was the most commonly reported surgical procedure, performed in 80% of the surgically treated patients. Combined anterior-posterior procedures and staged surgeries were performed in 33% and 26% of surgeries, respectively. The meta-analysis comparing visual analog scale score at follow-up was superior among patients receiving surgery over medical treatment alone (mean difference -0.61, CI -0.90 to -0.25), while meta-analysis comparing freedom from pain in patients receiving medical treatment alone versus combined medical and surgical treatment demonstrated superior pain-free outcomes among surgical series (odds ratio 5.35, CI 2.27-12.60, P < .001), but was subject to heterogeneity among studies (I ² = 56%, P = .13). Among all patients, freedom from pain was achieved in 79% of patients, and an excellent outcome was achieved in 73% of patients.

CONCLUSION

Medical management remains first-line treatment of infectious pyogenic spondylodiscitis. Surgery may be indicated for progressive pain, persistent infection on imaging, deformity or neurologic deficits. If surgery is required, reported literature shows potential for significant pain reduction, improved neurologic function and a high number of patients returning to a normal functional/work status.

Moxifloxacin plus rifampin as an alternative for levofloxacin plus rifampin in the treatment of a prosthetic joint infection with Staphylococcus aureus

OBJECTIVES

The combination of a fluoroquinolone with rifampin is one of the cornerstones in the treatment of prosthetic joint infections (PJI) caused by staphylococci. Moxifloxacin is highly active against methicillin-susceptible Staphylococcus aureus (MSSA) and, therefore, is an attractive agent to use. However, several studies reported a lowering in serum moxifloxacin levels when combined with rifampin. The clinical relevance remains unclear. We determined the outcome of patients with early acute PJI caused by MSSA treated with either moxifloxacin/rifampin or levofloxacin/rifampin.

METHODS

Medical files of patients treated with moxifloxacin/rifampin (University Medical Centre Groningen) or levofloxacin/rifampin (Hospital Clinic Barcelona) were retrospectively reviewed (2005-2015). Treatment failure was defined as the need for revision surgery and/or suppressive therapy, death by infection or a relapse of infection during follow-up.

RESULTS

Differences in baseline characteristics between the two cohorts were observed, but prognostic parameters for failure, as defined by the KLIC-score (Kidney failure, Liver cirrhosis, Index surgery, C-reactive protein and Cemented prosthesis), were similar in the two groups (2.9 [1.5 SD] for the moxifloxacin group vs. 2.2 [1.2 SD] for the levofloxacin group [P = 0.16]). With a mean follow-up of 50 months (36 SD) in the moxifloxacin group, and 67 months (50 SD) in the levofloxacin group (P = 0.36), treatment was successful in 89% vs. 87.5%, respectively (P = 0.89). None of the failures in the moxifloxacin group were due to rifampin- or moxifloxacin-resistant S. aureus strains.

CONCLUSION

Our data indicate that moxifloxacin combined with rifampin is as clinically effective as levofloxacin/rifampin for early acute PJI caused by MSSA.

Vertebral osteomyelitis in adults: an update

INTRODUCTION

The incidence of vertebral osteomyelitis is increasing, attributed to an ageing population with inherent co-morbidities and improved case ascertainment.

SOURCES OF DATA

References were retrieved from the PubMed database using the terms 'vertebral osteomyelitis' and 'spondylodiscitis' between January 1, 2009 and April 30, 2014 published in English as checked in May 2014 (>1000 abstracts checked).

AREAS OF AGREEMENT

Blood cultures and whole spine imaging with magnetic resonance imaging are essential investigations. Thorough debridement is the mainstay of surgical management, although placing metalwork in active infection is becoming increasingly common.

AREAS OF CONTROVERSY

The extent of pursuing spinal biopsies to determine aetiology, antimicrobial choices and duration, monitoring the response to treatment, and surgical techniques and timing all vary widely in clinical practice with heterogeneous studies limiting comparisons. Surgery, rather than conservative approaches, is being proposed as the default management choice, because it can, in carefully selected patients, offer faster reduction in pain scores and improved quality of life.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies are needed to define the most effective technique for spinal biopsies to maximize determining aetiology. High-quality trials are required to provide an evidence base for both the medical and surgical management of vertebral osteomyelitis, including challenging medical management as the default option.

Staphylococcus aureus-Associated Musculoskeletal Infections

Musculoskeletal infections caused by Staphylococcus aureus are among the most difficult-to-treat infections. S. aureus osteomyelitis is associated with a tremendous disease burden through potential for long-term relapses and functional deficits. Although considerable advances have been achieved in diagnosis and treatment of osteomyelitis, the management remains challenging and impact on quality of life is still enormous. S. aureus acute arthritis is relatively seldom in general population, but the incidence is considerably higher in patients with predisposing conditions, particularly those with rheumatoid arthritis. Rapidly destructive course with high mortality and disability rates makes urgent diagnosis and treatment of acute arthritis essential. S. aureus pyomyositis is a common disease in tropical countries, but it is very seldom in temperate regions. Nevertheless, the cases have been increasingly reported also in non-tropical countries, and the physicians should be able to timely recognize this uncommon condition and initiate appropriate treatment. The optimal management of S. aureus-associated musculoskeletal infections requires a strong interdisciplinary collaboration between all involved specialists.

2015 Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines for the Diagnosis and Treatment of Native Vertebral Osteomyelitis in Adultsa

These guidelines are intended for use by infectious disease specialists, orthopedic surgeons, neurosurgeons, radiologists, and other healthcare professionals who care for patients with native vertebral osteomyelitis (NVO). They include evidence and opinion-based recommendations for the diagnosis and management of patients with NVO treated with antimicrobial therapy, with or without surgical intervention.

Diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC)

Both bacteremia and infective endocarditis caused by Staphylococcus aureus are common and severe diseases. The prognosis may darken not infrequently, especially in the presence of intracardiac devices or methicillin-resistance. Indeed, the optimization of the antimicrobial therapy is a key step in the outcome of these infections. The high rates of treatment failure and the increasing interest in the influence of vancomycin susceptibility in the outcome of infections caused by both methicillin-susceptible and -resistant isolates has led to the research of novel therapeutic schemes. Specifically, the interest raised in recent years on the new antimicrobials with activity against methicillin-resistant staphylococci has been also extended to infections caused by susceptible strains, which still carry the most important burden of infection. Recent clinical and experimental research has focused in the activity of new combinations of antimicrobials, their indication and role still being debatable. Also, the impact of an appropriate empirical antimicrobial treatment has acquired relevance in recent years. Finally, it is noteworthy the impact of the implementation of a systematic bundle of measures for improving the outcome. The aim of this clinical guideline is to provide an ensemble of recommendations in order to improve the treatment and prognosis of bacteremia and infective endocarditis caused by S. aureus, in accordance to the latest evidence published.

Postoperative spondilodiscitis

INTRODUCTION

Postoperative spondylodiscitis is a primary infection of the nucleus pulposus with secondary involvement of the cartilaginous endplate and vertebral bone. Although uncommon, postoperative spondylodiscitis causes major morbidity and may be associated with serious long-term sequelae. Several risk factors had been identified, including immunosuppression, obesity, alcohol, smoking, diabetes and malnutrition.

MATERIALS AND METHODS

A review of the literature was done to analyse the diagnosis, treatment and prevention of postoperative spondylodiscitis.

RESULTS

We found that the principles of conservative treatment are to establish an accurate microbiological diagnosis, treat with appropriate antibiotics, immobilise the spine, and closely monitor for spinal instability and neurological deterioration. The purpose of surgical treatment is to obtain multiple cultures of bone and soft tissue, perform a thorough debridement of infected tissue, decompress neural structures, and reconstruct the unstable spinal column with bone graft with or without concomitant instrumentation.

CONCLUSIONS

Appropriate management requires aggressive medical treatment and, at times, surgical intervention. If recognised early and treated appropriately, a full recovery can often be expected. Therefore, clinicians should be aware of the clinical presentation of such infections to improve patient outcome. A review of the literature was done to advance our understanding of the diagnosis, treatment, prevention and outcome of these infections.

Postoperative discitis following single-level lumbar discectomy: Our experience of 17 cases

BACKGROUND

The established protocols of treatment of postoperative lumbar discitis have not been validated till date. We report a retrospective analysis of a series of patients with discitis following single level lumbar discectomy. We analyzed the outcome of conservative treatment of postoperative discitis with the objective to define when and what surgery was required when the conservative treatment failed.

MATERIALS AND METHODS

A total of 17 cases of postoperative discitis treated from 2002 to 2009 were followed up and evaluated clinically, radiologically and by laboratory investigations. All the patients were treated initially conservatively with rest and antibiotic therapy after diagnosis and those who did not respond to conservative treatment of at least 4 weeks were treated surgically. The cases were followed up with serial C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), X-ray, computed tomography (CT) scan and magnetic resonance imaging (MRI) for at least 1 year.

RESULTS

The mean followup was 40.38 months (range 12-86 months). Four cases failed to respond to conservative therapy and were treated surgically. In three of these four cases, open debridement, transpedicular fixation and posterolateral fusion was performed, and in the fourth case percutaneous transpedicular fixation was done. In the former group, one case was diagnosed to be tubercular, in another case Staphylococcus aureus was cultured where as the third case culture was sterile. All operated patients showed evidence of interbody fusion at 1 year followup.

CONCLUSIONS

Early detection and aggressive treatment are paramount in managing postoperative discitis and the majority do well with conservative treatment. Surgical management in the form of transpedicular fixation and debridement, when required, gives excellent results.

Percutaneous discectomy and drainage for postoperative intervertebral discitis

BACKGROUND

Postoperative intervertebral discitis occurs following spinal surgery. This study was done to evaluate the effect of percutaneous discectomy and drainage (PDD) for postoperative intervertebral discitis.

METHODS

A retrospective study of postoperative intervertebral discitis treated by PDD procedures was conducted from January 1997 to June 2006. There were 34 patients (24 males, 10 females); 10 cases of after lumbar discectomy (L3-4 in 3 patients, L4-5 in 7 patients), 21 cases of after percutaneous lumbar discectomy (L3-4 in 7 patients, L4-5 in 14 patient), 2 cases of after percutaneous cervical discectomy (C5-6 in 1 patient, C6-7 in 1 patient), and 1 case of C5-6 after percutaneous cervical nucleoplasty.

RESULTS

All patients tolerated the procedure well and there were 31 cases had followed up. VAS scores demonstrated statistically significant improvement after PDD when compared with preoperational values (P < 0.01). Elevated CRP and ESR values returned to normal range within 3-8 weeks. CRP and ESR values demonstrated statistically significant improvement after PDD when compared with preoperative values (P < 0.01). Biopsies of the disc were performed in all patients and pus was seen in 17 patients at the pathology levels. Inflammatory cells were observed nine cases (4 cases showed infiltration of lymphocytes and plasmacytes, 5 cases showed infiltrate of polymorphonuclear leucocytes). Cultures of disc and bone tissue showed 17 cases of sterile and 14 had positive culture. Spine X-rays films showed narrowed disc space in 29 cases, and bridging osteophytes were noted in 19 patients. Destructive and sclerotic changes of vertebral bodies with narrowing of disc spaces were observed in 14 patients.

CONCLUSIONS

The results show that PDD is a minimally invasive procedure for obtaining sufficient biopsy material for histological analysis and culture in cases of discitis, and has a good clinical outcome recommended for patients with early stage postoperative intervertebral discitis without neurologic deficit.

Influence of bacteria on spinal implant-centered infection: an in vitro and in vivo experimental comparison between Staphylococcus aureus and mycobacterium tuberculosis

STUDY DESIGN

an in vitro and in vivo experimental study.

OBJECTIVE

this study was undertaken to evaluate differences in the capability of inducing an implant-centered infection between Staphylococcus aureus and Mycobacterium tuberculosis.

SUMMARY OF BACKGROUND DATA

bacterial infection is still one of the most serious and devastating complications after orthopedic implant surgery despite the advent of new antibiotics and treatment methods.

METHODS

S. aureus and M. tuberculosis were separately cultured with titanium plates. The bacteria colonized on the plates were isolated and cultured on culture medium. They were evaluated and compared by colony-forming units enumeration. Scanning electron microscopy was used to evaluate the difference in the colonization features of the 2 pathogens. In the in vivo experiment, 22 dogs were used to assess the susceptibility to infection after a local bacterial challenge with either S. aureus or M. tuberculosis.

RESULTS

S. aureus showed heavy adhesion and multiplication on the surface of titanium plates in vitro, whereas M. tuberculosis rarely adhered to the surface of the plates. Under scanning electron microscopy, S. aureus colonization was observed: the coccoid was widespread on the surface of the plates but only a few M. tuberculosis cells scattered on the surface of the plates. In in vivo test, the infection rateforthe S. aureus inoculation was higher than that for the M. tuberculosis challenge. The infection rate for the entire test population (n = 44 sites) was 39.58% (19/48). The infection rates were 54.17% (13/24) for the S. aureus challenge and 25% (6/24) for the M. tuberculosis challenge, respectively (P < 0.05).

CONCLUSION

it is less likely for M. tuberculosis to adhere and form a biofilm on an implant surface than S. aureus. Under otherwise identical conditions, M. tuberculosis contamination following instrumented spine surgery might lead to less occurrence of infection than S. aureus contamination.

Spondylodiscitis: update on diagnosis and management

Spondylodiscitis, a term encompassing vertebral osteomyelitis, spondylitis and discitis, is the main manifestation of haematogenous osteomyelitis in patients aged over 50 years. Staphylococcus aureus is the predominant pathogen, accounting for about half of non-tuberculous cases. Diagnosis is difficult and often delayed or missed due to the rarity of the disease and the high frequency of low back pain in the general population. In this review of the published literature, we found no randomized trials on treatment and studies were too heterogeneous to allow comparison. Improvements in surgical and radiological techniques and the discovery of antimicrobial therapy have transformed the outlook for patients with this condition, but morbidity remains significant. Randomized trials are needed to assess optimal treatment duration, route of administration, and the role of combination therapy and newer agents.

Spinal Infection Multidisciplinary Management Project (SIMP): From Diagnosis to Treatment Guideline

Spine infections require a multidisciplinary approach to be treated and solved. A guide line to drive physicians in the deep complexity of such a disease is extremely helpful. SIMP suggests a flow-chart built up on clear concepts such as right and well managed antibiotic therapy, sound stability of the spine, correct and smart use of the standard and functional imaging techniques, such as f18 FDG PET/CT. In 16 months a total of 41 patients have been treated for spondylodiscitis, discitis and vertebral osteomyelitis by our team of physicians and 25 patients have been enrolled in a prospective study whose target is the assessment of the SIMP flow-chart and of every single aspect that characterize it.