Clinical practice. Vertebral osteomyelitis

Diagnostic yield of repeat CT-guided biopsy for suspected infectious spondylodiscitis

OBJECTIVE

The purpose of this study was to examine the yield of repeat CT-guided biopsy in patients with suspected infectious spondylodiscitis following an initial biopsy with negative microbiology, and to identify factors associated with successful pathogen isolation.

MATERIALS AND METHODS

In this retrospective study, 21 patients (12 men, 9 women; mean age, 52, range, 12-84) were identified with clinically and radiologically suspected infectious spondylodiscitis who underwent repeat biopsy following negative cultures from an initial biopsy. The microbe yield as well as demographic, clinical, and laboratory findings were reviewed and statistical analysis was performed.

RESULTS

Repeat CT-guided biopsy isolated a causative microbe in 3/21 patients (14.3%). Younger age (p = 0.021) was significantly associated with successful microbe isolation. All three cases of successful microbe isolation occurred in patients not exposed to antibiotics (3/9 patients) whereas no successful microbe isolation occurred in patients who received antibiotics (0/12 patients); however, this difference did not reach statistical significance (p = 0.062). Gender, duration of symptoms, white blood cell count, biopsy interval, and biopsy site were not significantly associated with microbe isolation.

CONCLUSIONS

Overall microbiologic yield of repeat CT-guided biopsy for patients with suspected infectious spondylodiscitis was low at 14.3%; however, a higher yield was identified in patients who were younger in age and not exposed to pre-biopsy antibiotics.

Appropriate duration of post-surgical intravenous antibiotic therapy for pyogenic spondylodiscitis

Background

Most guidelines recommend 6 to 12 weeks of parenteral antibiotic treatment for pyogenic spondylodiscitis. When surgical debridement is adequately performed, further intravenous antibiotic treatment duration can be reduced than that of conservative treatment alone theoretically. However, the appropriate duration of post-surgical parenteral antibiotic treatment is still unknown. This study aimed to identify the risk factors of recurrence and evaluate the appropriate duration after surgical intervention.

Methods

This 3-year retrospective review included 102 consecutive patients who were diagnosed with pyogenic spondylodiscitis and underwent surgical intervention. Recurrence was defined as recurrent signs and symptoms and the need for another unplanned parenteral antibiotic treatment or operation within one year. This study included two major portions. First, independent risk factors for recurrence were identified by multivariable analysis, using the database of demographic information, pre-operative clinical signs and symptoms, underlying illness, radiographic findings, laboratory tests, intraoperative culture results, and treatment. Patients with any one of the risk factors were considered high-risk; those with no risk factors were considered low-risk. Recurrence rates after short-term (≤3 weeks) and long-term (> 3 weeks) parenteral antibiotic treatment were compared between the groups.

Results

Positive blood culture and paraspinal abscesses were identified as independent risk factors of recurrence. Accordingly, 59 (57.8%) patients were classified as low-risk and 43 (42.2%) as high-risk. Among the high-risk patients, a significantly higher recurrence rate occurred with short-term than with long-term antibiotic therapy (56.2% vs. 22.2%, p = 0.027). For the low-risk patients, there was no significant difference between short-term and long-term antibiotic therapy (16.0% vs. 20.6%, p = 0.461).

Conclusions

The appropriate duration of parenteral antibiotic treatment in patients with pyogenic spondylodiscitis after surgical intervention could be guided by the risk factors. The duration of postoperative intravenous antibiotic therapy could be reduced to 3 weeks for patients without positive blood culture or abscess formation.

Spinal Instrumentation Rescue with Cement Augmentation

BACKGROUND AND PURPOSE

Altered biomechanics or bone fragility or both contribute to spine instrumentation failure. Although revision surgery is frequently required, minimally invasive alternatives may be feasible. We report the largest to-date series of percutaneous fluoroscopically guided vertebral cement augmentation procedures to address feasibility, safety, results and a variety of spinal instrumentation failure conditions.

MATERIALS AND METHODS

A consecutive series of 31 fluoroscopically guided vertebral augmentation procedures in 29 patients were performed to address screw loosening (42 screws), cage subsidence (7 cages), and fracture within (12 cases) or adjacent to (11 cases) the instrumented segment. Instrumentation failure was deemed clinically relevant when resulting in pain or jeopardizing spinal biomechanical stability. The main study end point was the rate of revision surgery avoidance; feasibility and safety were assessed by prospective recording of periprocedural technical and clinical complications; and clinical effect was measured at 1 month with the Patient Global Impression of Change score.

RESULTS

All except 1 procedure was technically feasible. No periprocedural complications occurred. Clinical and radiologic follow-up was available in 28 patients (median, 16 months) and 30 procedures. Revision surgery was avoided in 23/28 (82%) patients, and a global clinical benefit (Patient Global Impression of Change, 5-7) was reported in 26/30 (87%) cases at 1-month follow-up, while no substantial change (Patient Global Impression of Change, 4) was reported in 3/30 (10%), and worsening status (Patient Global Impression of Change, 3), in 1/30 (3%).

CONCLUSIONS

Our experience supports the feasibility of percutaneous vertebral augmentation in the treatment of several clinically relevant spinal instrumentation failure conditions, with excellent safety and efficacy profiles, both in avoidance of revision surgery and for pain palliation.

Musculoskeletal Infections in the Emergency Department

Bone and joint infections are potentially limb-threatening or even life-threatening diseases. Emergency physicians must consider infection when evaluating musculoskeletal complaints, as misdiagnosis can have significant consequences. Patients with bone and joint infections can have heterogeneous presentations with nonspecific signs and symptoms. Staphylococcus aureus is the most commonly implicated microorganism. Although diagnosis may be suggested by physical examination, laboratory testing, and imaging, tissue sampling for Gram stain and microbiologic culture is preferable, as pathogen identification and susceptibility testing help optimize long-term antibiotic therapy. A combination of medical and surgical interventions is often necessary to effectively manage these challenging infections.

Pyogenic Spondylodiscitis of the Thoracic Spine: Outcome of 1-Stage Posterior Versus 2-Stage Posterior and Anterior Spinal Reconstruction in Adults

OBJECTIVE

The aim of this study was to compare the clinical, radiologic, and functional outcomes of a 1-stage posterior treatment versus a 2-stage posterior-anterior treatment in patients with pyogenic thoracic spondylodiscitis.

METHODS

A 1-stage posterior debridement, stabilization, and fusion with titanium-coated polyetheretherketone (PEEK) or mesh cage through a dorsolateral approach was performed in group A. A 2-stage procedure with initial posterior stabilization and debridement and second-stage fusion with a PEEK cage or mesh cage was performed with an anterior approach in group B. Clinical outcomes included Oswestry Low Back Pain Disability Questionnaire and visual analog scale score. Radiologic outcomes included fusion rate and kyphotic angle correction. Secondary variables included pathogens, complications, blood loss, and operative time.

RESULTS

One-level spondylodiscitis was treated surgically in the thoracic spine of 47 patients: 25 patients in group A and 22 patients in group B. The most frequent segment was T12-L1 (27%). There was a significantly longer operative time and greater blood loss (P > 0.001) in group B. At last follow-up, sagittal profile reconstruction was significantly better (P > 0.05) in group B. Both groups showed similar radiologic results with fusion in 92% of cases. Improved clinical outcomes, pain, and quality of life were achieved in both groups with no significant differences between the 2 groups.

CONCLUSIONS

Better reconstruction of the sagittal profile was achieved in the posterior-anterior-treated group, but this did not affect the clinical outcome. No significant differences were found in the clinical and functional outcomes between the 2 groups. Posterior-anterior combined treatment should be considered in cases of large anterior defects if a posterior reconstruction is inadequate.

High mortality from pyogenic vertebral osteomyelitis: a retrospective cohort study

Study design

Retrospective cohort study.

Objective

In this pilot study, we aimed to assess the incidence, diagnostic strategies, treatment regimens, and outcomes of pyogenic vertebral osteomyelitis (PVO), in a non-urban, Northern European population during 1 year.

Setting

Region Zealand, Denmark.

Methods

All patients admitted to a hospital in Region Zealand during 2013 and subsequently discharged with a diagnosis of PVO or discitis were eligible for screening. Discharge diagnosis codes were obtained from a central register and patients were identified with unique identification numbers from the Danish Civil Registration System.

Results

Forty-one consecutive patients were included. Patients presented with back pain (78%), fever (76%), elevated C-reactive protein levels (95%), and bacteremia (76%). Nine patients (22%) were treated empirically, as no bacterial etiology was isolated from blood culture or biopsy. The median duration of antibiotic treatment was 92 days, and we report an in-hospital mortality of 15%.

Conclusions

This study supports previous findings of increasing incidence of PVO. In addition, we found a high rate of bacteremia and a high mortality in this single year cohort. Treatment regimens were heterogeneous and prolonged, due to delayed diagnosis and various or unknown microbial etiology. The study suggests that back pain, fever, and increased C-reactive protein levels are frequent in patients with PVO, and efforts should be made on securing early diagnosis and microbial etiology. Further studies of predictors of different clinical outcomes are warranted. Treatment of culture-negative cases and clinical value of bone biopsies are of special interest.

Daptomycin-loaded biodegradable thermosensitive hydrogels enhance drug stability and foster bactericidal activity against Staphylococcus aureus

A drug delivery system based on fully biodegradable thermosensitive hydrogels enabling controlled antibiotic release may support the management of implant-associated infections. In this work, the lipopeptide antibiotic daptomycin was encapsulated in hydrogel networks consisting of vinyl sulfonated triblock copolymers of PEG-p(HPMAm-lac_1,2) and thiolated hyaluronic acid. High concentrations of active daptomycin exceeding the minimum biofilm eradicating concentration were sustainably eluted from the biodegradable carrier. The drug release profiles were tailored by varying the degree of substitution (DS) of thiol groups of hyaluronic acid, reaching a plateau level after 200 and 330 h for DS values of 53% and 31%, respectively. The hydrogel polymeric network preserved the structural stability of the loaded antibiotic and retained the calcium-dependent daptomycin activity, showing a noticeable biofilm bactericidal effect against a 24 h-old Staphylococcus aureus biofilm in vitro. The two-component thermosensitive hydrogels demonstrated to be an excellent antibiotic releasing scaffold with potential clinical applications in the management of implant-associated infections.

[Chameleon spondylodiscitis : Challenge for geriatricians]

The incidence of spondylodiscitis is increasing and attributable to an aging population with multimorbidities. Spondylodiscitis represents a life-threatening disease. Typical clinical manifestations often involve nonspecific symptoms with back pain; however, due to the frequent absence of fever the disease is often overlooked. Pathogen detection and spinal imaging with magnetic resonance imaging (MRI) are essential for the diagnosis. Identification of the causative pathogen is particularly important for initiating targeted antibiotic treatment. Debridement and stabilization are the mainstays of surgical management, even though foreign material must be implanted into the focus of inflammation.

Vertebral Osteomyelitis Caused by Helicobacter cinaedi Identified Using Broad-range Polymerase Chain Reaction with Sequencing of the Biopsied Specimen

A 65-year-old man presented with gradually exacerbating low back pain. Magnetic resonance imaging revealed vertebral osteomyelitis in the Th11-L2 vertebral bodies and discs. The patient showed negative findings on conventional cultures. Direct broad-range polymerase chain reaction (PCR) with sequencing of the biopsied specimen had the highest similarity to the 16S rRNA gene of Helicobacter cinaedi. This case suggests that direct broad-range PCR with sequencing should be considered when conventional cultures cannot identify the causative organism of vertebral osteomyelitis, and that this method may be particularly useful when the pathogen is a fastidious organism, such as H. cinaedi.

Severe Pain Due to Paraspinal Abscess Formation in Two Patients with Squamous-Cell Carcinoma of the Head and Neck after Multimodal Treatment Including Cetuximab

BACKGROUND

Patients with squamous-cell carcinoma of the head and neck (SCCHN) on palliative therapy usually have a bad prognosis and suffer from various symptoms. With increasing use of targeted agents in cancer patients at the end of life, the correct assignment of therapy-related symptoms becomes increasingly difficult as cancer-related symptoms usually increase as well.

CASE REPORT

We report on 2 cases of patients with SCCHN who received multimodal treatment including palliative therapy with cetuximab. Both patients developed severe thoracic and cervicothoracic pain following treatment. In both cases, extensive paraspinal abscess formation proved to be the underlying cause. One patient was treated conservatively; the other one had to undergo surgical intervention.

CONCLUSIONS

Awareness of multifaceted therapy-related complications is mandatory when patients receive multimodal treatment including targeted therapies. Unexplained pain syndromes in this context should raise suspicions concerning possible infectious complications and should lead to early use of magnetic resonance imaging.

Diagnostics and antibiotic therapy for spondylodiscitis

Purpose. Spondylodiscitis as a rare disease has increased in recent years; there are only a few recommendations regarding the diagnostics and treatment. The objective of this retrospective study was to characterise these patients and identify factors for a favourable healing process - with an emphasis on antibiotic therapy.Methodology. Findings/treatment regimens for all patients with spondylodiscitis treated at a tertiary care hospital in 2012/2013 were recorded. The patients were classified into two groups, depending on the healing process.Results. Fifty-seven patients met the clinical/radiological criteria for spondylodiscitis. The main symptom was massive back pain, combined with a moderate CRP elevation (median 96 mg l^-1), and occasionally fever (39 %). CT-guided aspiration - in addition to blood cultures - improved the detection rate for the causative pathogen from 49 to 82 %. Thirty patients had a favourable clinical course; 25 had an unfavourable clinical course (prolonged clinical course, recurrence, death). Pathogen-specific antibiotic therapy had a decisive effect on the clinical course: initial high-dose intravenous therapy for at least 14 days was associated significantly more often with a favourable clinical course (90 vs 30 % after 24 months, P<0.001). Fourteen days after the start of treatment, marked pain reduction and a CRP reduction of at least 50 % were good prognostic parameters and markers of effective antibiotic therapy.Conclusion. Pathogen detection and establishment of an optimal antibiotic regimen are cornerstones of successful conservative therapy for spondylodiscitis. Targeted initial intravenous therapy for at least 14 days with a bactericidal antibiotic leads to a better clinical course.

Clinical and Radiographic Results of a Minimally Invasive Lateral Transpsoas Approach for Treatment of Septic Spondylodiscitis of the Thoracolumbar and Lumbar Spine

BACKGROUND

The minimally invasive lateral transpsoas approach allows retroperitoneal access for discectomy and graft placement. However, the procedure has rarely been used for the treatment of septic spondylodiscitis. The purposes of this study were to evaluate the clinical and radiographic outcomes from this minimally invasive procedure for septic spondylodiscitis.

METHODS

Thirty-one consecutive patients (17 males and 14 females) were included in this study from July 2013 to January 2016. Clinical outcomes were assessed by Oswestry Disability Index, visual analog scale, modified Macnab criteria, and inflammatory parameters. Radiographic results were analyzed by studying the changes in diseased disc height, lordosis, and fusion status.

RESULTS

The Oswestry Disability Index and visual analog scale score improved by 58% and 69% at the last follow-up. The modified Macnab criteria were found to be excellent in 21 patients (68%) and good in 10 (32%). Inflammatory parameters normalized over the average 24 months follow-up. There were no major complications that might have influenced the outcomes in this cohort. A complete fusion after 12 months was achieved in 87% of patients. A mean 7.5 mm restoration in disc height and 6.4° restoration in lumbar lordosis were observed in all patients, whereas an average 4.5 mm loss in restored height resulting from graft subsidence was observed in 24 patients during the follow-up. However, graft subsidence did not influence clinical outcomes significantly.

CONCLUSIONS

A minimally invasive lateral transpsoas approach in combination with instrumentation provides a novel treatment for patients with septic spondylodiscitis without severe kyphosis and neurologic impairment.

Percutaneous CT-guided sacroiliac joint sampling for infection: aspiration, biopsy, and technique

OBJECTIVE

To evaluate methods of CT-guided sacroiliac joint sampling in patients with suspected infection.

MATERIALS AND METHODS

All CT-guided sacroiliac joint sampling procedures for suspected infection were reviewed for sampling type (aspiration, lavage aspiration, biopsy), microbiology results, and clinical and imaging follow-up. The primary gold standard was anatomic pathology. If pathology was not available, then positive blood culture with the same organism as SIJ sampling, imaging and clinical follow-up, or clinical follow-up only were used. Anterior and posterior joint distention was evaluated by MRI within 7 days of the procedure.

RESULTS

A total of 34 patients (age 39 ± 20 (range, 6-75) years; 21 F, 13 M) were included. Aspiration samples only were obtained in 13/34 (38%) cases, biopsy samples only in 9/34 (26%) cases, and both samples in 12/34 (35%) cases. There was an overall 54% sensitivity and 86% specificity. For the aspiration samples, sensitivity and specificity were 60 and 81%, respectively, compared to 45 and 90% for the biopsy samples. In cases with both samples, biopsy did not add additional microbial information. Seventeen (17/34, 50%) patients had an MRI. The anterior joint was more distended than the posterior joint in 15/17 (88%) of patients, and this difference was significant (P = 0.0003). All of these 17 patients had an attempted aspiration by a posterior approach; 6/17 (35%) resulted in a successful aspiration.

CONCLUSIONS

Aspiration of the sacroiliac joint has a higher sensitivity than biopsy and should always be attempted first. MRI may be helpful for procedure planning.

Staphylococcal Osteomyelitis: Disease Progression, Treatment Challenges, and Future Directions

Osteomyelitis is an inflammatory bone disease that is caused by an infecting microorganism and leads to progressive bone destruction and loss. The most common causative species are the usually commensal staphylococci, with Staphylococcus aureus and Staphylococcus epidermidis responsible for the majority of cases. Staphylococcal infections are becoming an increasing global concern, partially due to the resistance mechanisms developed by staphylococci to evade the host immune system and antibiotic treatment. In addition to the ability of staphylococci to withstand treatment, surgical intervention in an effort to remove necrotic and infected bone further exacerbates patient impairment. Despite the advances in current health care, osteomyelitis is now a major clinical challenge, with recurrent and persistent infections occurring in approximately 40% of patients. This review aims to provide information about staphylococcus-induced bone infection, covering the clinical presentation and diagnosis of osteomyelitis, pathophysiology and complications of osteomyelitis, and future avenues that are being explored to treat osteomyelitis.

Imaging of Spondylodiscitis

Spondylodiscitis is an infection of the vertebral body or disc and may also involve the epidural space, posterior elements, and paraspinal soft tissues. It is a cause of morbidity and mortality, and warrants early diagnosis and prompt treatment. Diagnosis can be difficult because of nonspecific signs and symptoms. Magnetic resonance imaging is sensitive and specific and is the imaging modality of choice for spondylodiscitis. Gadolinium contrast can show the extent of soft tissue and bone phlegmon and abscess. The test is less useful for evaluating treatment response. When magnetic resonance imaging cannot be performed or is not diagnostic, radionuclide imaging is a useful alternative. Although bone scintigraphy frequently is used as a screening test, false-negative results can occur, especially in the elderly. This test is not useful for detecting soft tissue infections that accompany or mimic spondylodiscitis. Gallium-67 citrate improves the specificity of the bone scan, can detect infection earlier than the bone scan, may be more sensitive, especially in elderly patients, and identifies accompanying soft tissue infection. Performing SPECT and SPECT/CT improves accuracy. The 2- to 3-day delay between radiopharmaceutical administration and the relatively poor image quality are significant disadvantages of gallium-67. Indium-111 biotin, alone or in combination with streptavidin, accurately diagnoses spondylodiscitis; unfortunately, this agent is not widely available. Currently, ¹⁸F-FDG imaging is the radionuclide test of choice for spondylodiscitis. The procedure, which is completed in a single session, is sensitive, has a high negative predictive value, and reliably differentiates degenerative from infectious vertebral body end plate abnormalities. In comparative investigations, ¹⁸F-FDG has outperformed bone and gallium-67 imaging. Preliminary data suggest that ¹⁸F-FDG may be able to provide an objective means to measure response to treatment. Gallium-68 citrate and 99mTc-radiolabeled antimicrobial peptides have been investigated, but their role in spondylodiscitis has yet to be established.

Diagnostic challenges in pyogenic spinal infection: an expanded role for FDG-PET/CT

In a preliminary investigation of FDG-PET/CT for assessment of therapy response of pyogenic spine infection, it was concluded that activity confined to the margins of a destroyed or degenerated joint with bone-on-bone contact represents nonseptic inflammation, regardless of the intensity of uptake. Only activity in bone, soft tissue, or within the epidural space represents active infection. The purpose of this investigation was to assess the performance of these pattern-based interpretation criteria in a series of problem cases of proven or suspected spine infection. Eighty-two FDG-PET/CTs were done for initial diagnosis because other imaging failed to provide a definitive diagnosis and 147 FDG-PET/CTs were done to assess treatment responses. Pattern-based interpretations were compared with the clinical diagnosis based on bacterial cultures and outcomes after cessation or withholding of antibiotic therapy. Pattern-based interpretation criteria achieved a sensitivity and specificity of 98 and 100%, respectively, for initial diagnosis and a specificity of 100% for assessment of treatment response. The same data was analyzed using intensity of activity as the primary factor. Sensitivity and specificity using the intensity-based criteria were 93 and 68%, respectively, for initial diagnosis, and the specificity of a negative interpretation for therapy response was 55%. Differences from pattern-based criteria are highly significant. Pattern-based criteria perform well in problem cases with equivocal MR and for treatment response because they correctly eliminate activity from nonspecific inflammation associated with destroyed joints with bone-on-bone contact. Response occurs within a timeframe that is useful for managing antibiotic therapy.

Endocarditis associated with vertebral osteomyelitis and septic arthritis of the axial skeleton

PURPOSE

The relationship between infective endocarditis (IE) and osteoarticular infections (OAIs) are not well known. We aimed to study the characteristics of patients with IE and OAIs, and the interactions between these two infections.

METHODS

An observational study (1993-2014) which includes two cohorts: (1) patients with IE (n = 607) and (2) patients with bacteremic OAIs (n = 458; septic arthritis of peripheral and axial skeleton, and vertebral and peripheral osteomyelitis). These two cohorts were prospectively collected, and we retrospectively reviewed the clinical and microbiological variables.

RESULTS

There were 70 cases of IE with concomitant OAIs, representing 11.5% of IE cases and 15% of bacteremic OAI cases. Among cases with IE, the associated OAIs mainly involved the axial skeleton (n = 54, 77%): 43 were vertebral osteomyelitis (61%), mainly caused by "less virulent" bacteria (viridans and bovis streptococci, enterococci, and coagulase-negative staphylococci), and 15 were septic arthritis of the axial skeleton (21%), which were mainly caused by Staphylococcus aureus. OAIs with involvement of the axial skeleton were associated with IE (adjusted OR = 2.2; 95% CI 1.1-4.3) independently of age, sex, and microorganisms.

CONCLUSIONS

Among patients with IE, the associated OAIs mainly involve the axial skeleton. Transesophageal echocardiography should be carefully considered in patients presenting with these bacteremic OAIs.

Analysis of mortality in a cohort of 650 cases of bacteremic osteoarticular infections

OBJECTIVES

The mortality of patients with bacteremic osteoarticular infections (B-OAIs) is poorly understood. Whether certain types of OAIs carry higher mortality or interventions like surgical debridement can improve prognosis, are unclarified questions.

METHODS

Retrospective analysis of a prospective cohort of patients with B-OAIs treated at a teaching hospital in Barcelona (1985-2014), analyzing mortality (30-day case-fatality rate). B-OAIs were categorized as peripheral septic arthritis or other OAIs. Factors influencing mortality were analyzed using logistic regression models. The association of surgical debridement with mortality in patients with peripheral septic arthritis was evaluated with a multivariate logistic regression model and a propensity score matching analysis.

RESULTS

Among 650 cases of B-OAIs, mortality was 12.2% (41.8% of deaths within 7 days). Compared with other B-OAI, cases of peripheral septic arthritis were associated with higher mortality (18.6% vs 8.3%, p < 0.001). In a multiple logistic regression model, peripheral septic arthritis was an independent predictor of mortality (adjusted odds ratio [OR] 2.12; 95% CI: 1.22-3.69; p = 0.008). Cases with peripheral septic arthritis managed with surgical debridement had lower mortality than those managed without surgery (14.7% vs 33.3%; p = 0.003). Surgical debridement was associated with reduced mortality after adjusting for covariates (adjusted OR 0.23; 95% CI: 0.09-0.57; p = 0.002) and in the propensity score matching analysis (OR 0.81; 95% CI: 0.68-0.96; p = 0.014).

CONCLUSIONS

Among patients with B-OAIs, mortality was greater in those with peripheral septic arthritis. Surgical debridement was associated with decreased mortality in cases of peripheral septic arthritis.

Culture yield of repeat percutaneous image-guided biopsy after a negative initial biopsy in suspected spondylodiscitis: a systematic review

OBJECTIVE

To systematically review the published data on the culture yield of a repeat (second) percutaneous image-guided biopsy after negative initial biopsy in suspected spondylodiscitis.

MATERIALS AND METHODS

A systematic search was performed of the PubMed/Medline and Embase databases. The methodological quality of the studies included was assessed. The proportions of positive cultures among all initial biopsies and second biopsies (after a negative initial biopsy) were calculated for each study and assessed for heterogeneity (defined as I² > 50%).

RESULTS

Eight studies, comprising a total of 107 patients who underwent a second percutaneous image-guided biopsy after a culture-negative initial biopsy in suspected spondylodiscitis, were included. All eight studies were at risk of bias and were concerning with regard to applicability, particularly patient selection, flow of patients through the study, and timing of the biopsy. The proportions of positive cultures among all initial biopsies ranged from 10.3 to 52.5%, and were subject to heterogeneity (I² = 73.7%). The proportions of positive cultures among all second biopsies after negative initial biopsy ranged from 0 to 60.0%, and were not subject to heterogeneity (I² = 38.7%).

CONCLUSION

Although a second percutaneous image-guided biopsy may have some value in patients with suspected spondylodiscitis, its exact value remains unclear, given the available poor-quality evidence. Future well-designed studies are needed to determine the role of a second percutaneous image-guided biopsy in this setting. Such studies should clearly describe the spectrum of patients that was selected for a second percutaneous image-guided biopsy, the method of biopsy, and differences compared with the first biopsy, if any.

Spondylodiscitis: Diagnosis and Treatment Options

BACKGROUND

A recent population-based study from Denmark showed that the incidence of spondylodiscitis rose from 2.2 to 5.8 per 100 000 persons per year over the period 1995-2008; the age-standardized incidence in Germany has been estimated at 30 per 250 000 per year on the basis of data from the Federal Statistical Office (2015). The early diagnosis and treatment of this condition are essential to give the patient the best chance of a good outcome, but these are often delayed because it tends to present with nonspecific manifestations, and fever is often absent.

METHODS

This article is based on a systematic search of Medline and the Cochrane Library for the period January 2009 to March 2017. Of the 788 articles identified, 30 publications were considered.

RESULTS

The goals of treatment for spondylodiscitis are to eliminate infection, restore functionality of the spine, and relieve pain. Magnetic resonance imaging (MRI) remains the gold standard for the radiological demonstration of this condition, with 92% sensitivity and 96% specificity. It also enables visualization of the spatial extent of the infection and of abscess formation (if present). The most common bacterial cause of spondylodiscitis in Europe is Staphylococcus aureus, but tuberculous spondylodiscitis is the most common type worldwide. Antibiotic therapy is a pillar of treatment for spondylodiscitis and should be a part of the treatment in all cases. Neurologic deficits, sepsis, an intraspinal empyema, the failure of conservative treatment, and spinal instability are all indications for surgical treatment.

CONCLUSION

The quality of life of patients who have been appropriately treated for spondylodiscitis has been found to be highly satisfactory in general, although back pain often persists. The risk of recurrence increases in the presence of accompanying illnesses such as diabetes mellitus, renal failure, or undrained epidural abscesses.

Multiple Weekly Dalbavancin Dosing for the Treatment of Native Vertebral Osteomyelitis Caused by Methicillin-Resistant Staphylococcus Aureus: A Case Report

Patient: Male, 58

Final Diagnosis: Vertebral osteomyelitis

Symptoms: Back pain

Medication: Dalbavancin

Clinical Procedure: —

Specialty: Infectious Disease

Pyogenic vertebral osteomyelitis of the elderly: Characteristics and outcomes

Background

The incidence of pyogenic vertebral osteomyelitis (PVO) has increased over the past two decades. One possible cause of this increase is the aging of the population, which results in more comorbidities in high income countries.

Objective

To better characterize the clinical presentation and outcome of PVO in the elderly.

Design

We conducted a post-hoc analysis of a previously published trial that studied treatment duration in PVO and compared the presentation and outcomes according to age.

Participants

Our analysis included 351 patients among whom 85 (24%) were 75-years-old or more.

Results

There were no significant differences in the socio-demographics of the patients. Neoplasia and chronic inflammatory diseases were more common in the older group: 34% vs. 19% (p = 0.021) and 9% versus 1% (p = 0.004), respectively. There were no significant differences in clinical and radiological presentations between the groups in terms of back pain (337/351, 97%), fever (182/351, 52%), PVO localization, neurological signs and epidural abscess. Associated infective endocarditis (IE) was more frequent in the older group (37% vs. 14%, p<0.001). Streptococci were more frequently involved in infections of older patients (29% vs. 14%, p = 0.003) in contrast to Staphylococcus aureus (31% vs. 45%, p = 0.03). Older patients displayed higher mortality rates at 1 year (21% vs. 3%, p<0.001) and more adverse events related to cardiorespiratory failure (10.6% vs. 3.8%, p = 0.025), but had similar quality of life among the survivors.

Conclusion

During PVO, the clinical and radiological findings are similar in older patients. Global mortality rates are higher in older patients compared to younger patients, which could be explained by the increased frequency of neoplasia at diagnosis and higher prevalence of associated IE in the elderly.

Spondylodiscitis revisited

Spondylodiscitis may involve the vertebral bodies, intervertebral discs, paravertebral structures and spinal canal, with potentially high morbidity and mortality rates.

A rise in the susceptible population and improved diagnosis have increased the reported incidence of the disease in recent years.

Blood cultures, appropriate imaging and biopsy are essential for diagnosis and treatment.

Most patients are successfully treated by conservative means; however, some patients may require surgical treatment.

Surgical indications include doubtful diagnosis, progressive neurological deficits, progressive spinal deformity, failure to respond to treatment, and unresolved pain.

Cite this article: EFORT Open Rev 2017;2:447–461. DOI: 10.1302/2058-5241.2.160062

Lumbar Spondylodiscitis Caused by Burkholderia cepacia in a Previously Healthy Patient

Burkholderia cepacia spondylodiscitis is a rare entity that has been reported in only four cases. We hereby report the case of a 43-year-old, previously healthy, woman who was found to have a B. cepacia spondylodiscitis after a cholecystectomy. She was treated with a three-month regimen of ceftazidime and ciprofloxacin with complete clinical, biological, and radiological remission.

[Chameleon spondylodiscitis : Challenge for geriatricians]

The incidence of spondylodiscitis is increasing and attributable to an aging population with multimorbidities. Spondylodiscitis represents a life-threatening disease. Typical clinical manifestations often involve nonspecific symptoms with back pain; however, due to the frequent absence of fever the disease is often overlooked. Pathogen detection and spinal imaging with magnetic resonance imaging (MRI) are essential for the diagnosis. Identification of the causative pathogen is particularly important for initiating targeted antibiotic treatment. Debridement and stabilization are the mainstays of surgical management, even though foreign material must be implanted into the focus of inflammation.

[Chronic recurrent multifocal osteomyelitis of the spine : Children and adolescent]

Chronic non-bacterial osteomyelitis (CNO) in childhood and adolescence is a non-infectious autoinflammatory disease of the bone with partial involvement of adjacent joints and soft tissue. The etiology is unknown. The disease can occur singular or recurrent. Individual bones can be affected and multiple lesions can occur. Chronic recurrent multifocal osteomyelitis (CRMO) shows the whole picture of CNO. Accompanying but temporally independent of the bouts of osteomyelitis, some patients show manifestations in the skin, eyes, lungs and the gastrointestinal tract. The article gives an overview of the clinical manifestations, diagnostic procedures, and treatment options for CRMO involvement of the spine based on the current literature and our own cases.

Prognostic Factors for Failure of Antibiotic Treatment in Patients With Osteomyelitis of the Spine

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to identify factors independently associated with antibiotic treatment failure in patients with spinal osteomyelitis.

SUMMARY OF BACKGROUND DATA

There are few studies that have identified risk factors for antibiotic treatment failure in medically managed spinal osteomyelitis. Identifying such factors could help to identify patients who can be treated solely with antibiotics.

METHODS

All patients who underwent antibiotic treatment for spinal osteomyelitis in one of our institutions between January 1, 2001 and January 1, 2015 were identified. Patients who underwent surgery before the start of the antibiotic treatment were excluded.

RESULTS

We included 215 patients with a mean age of 58 years; 63 (29%) patients had failure of antibiotic treatment. Diabetes (hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.03-2.79, P = 0.037), fever (HR 1.61, 95% CI 0.93-2.79, P = 0.088), osteomyelitis at an additional site (HR 5.17, 95% CI 2.63-27.9, P = 0.001), and the presence of an epidural abscess (HR 1.91, 95% CI 1.05-3.45, P = 0.033) were associated with failure of antibiotic treatment. In the multivariate Cox regression analysis, diabetes (HR 1.69, 95% CI 1.03-2.79, P = 0.019), osteomyelitis at an additional site (HR 8.26, 95% CI 2.51-27.2, P = 0.001), fever (HR 1.77, 95% CI 1.00-3.12, P = 0.050), and the presence of an epidural abscess (HR 1.82, 95% CI 1.06-3.13, P = 0.030) were independently associated with failure of antibiotic treatment.

CONCLUSION

Antibiotic treatment failed in 29% of patients; diabetes, current other osteomyelitis, and having an epidural abscess were independently associated with failure of antibiotic treatment.

LEVEL OF EVIDENCE

3.

Long-term prognosis of hematogenous vertebral osteomyelitis: Mortality, quality of life, and pain

BACKGROUND

Hematogenous vertebral osteomyelitis (HVO) has a generally favorable prognosis if appropriate treatment is initiated in its early phase; however, some intractable cases with HVO can develop neurological impairment as well as spinal deformity during the course of treatment and these sequelae may lead to impaired quality of life (QOL). In this study, we aimed to evaluate the long-term relapse rate, mortality, and QOL of patients with HVO.

METHODS

In this retrospective case series study, medical records of 60 patients with HVO with a mean follow-up period of 8 years (5-23 years) were reviewed to assess demographic data, details of infection, and clinical course. Mortality rate was assessed using a Kaplan-Meier plot. QOL was measured using the EuroQol 5 Dimension (EQ-5D) questionnaire and residual pain using a numeric rating scale (NRS).

RESULTS

HVO relapsed in 4 of 60 patients (7%). Overall 5-year survival rate in 60 patients with HVO was 85%. The factors associated with increased mortality were malignant tumor, diabetes mellitus, chronic use of glucocorticoids, and drug-resistant strains of staphylococcus. Female-to-male ratio, NRS, prevalence of neurological impairment were significantly higher in patients with low EQ-5D score (poor health) compared to those with high EQ-5D score (good health).

CONCLUSIONS

Patients with HVO have shorter life expectancy if they have malignancy, diabetes mellitus, chronic use of glucocorticoids, and a history of drug-resistant strains of staphylococcus infection. Female gender, residual neurological defects and persistent back pain are associated with impaired QOL in patients with HVO.

Clinical characteristics, treatments, and outcomes of hematogenous pyogenic vertebral osteomyelitis, 12-year experience from a tertiary hospital in central Taiwan

BACKGROUND

In Taiwan, studies about hematogenous pyogenic vertebral osteomyelitis (HPVO) are limited. We conducted a retrospective study to evaluate the clinical presentations, treatment, and outcomes of patients with the diagnosis of HPVO.

METHOD

This 12.5-year retrospective study included patients with a diagnosis of HPVO. Medical records of all HPVO patients were thoroughly reviewed and their clinical data were analyzed by the SPSS software.

RESULT

414 HPVO cases were included and the mean age was 61.6 ± 13.4 years. The mean duration of symptoms was 29 ± 35.3 days and pain over the affected site was reported by most patients (86.0%). Gram-positive bacteria, especially Staphylococcus aureus (162/399 = 40.6%), were the main HPVO pathogens. Escherichia coli (42/399 = 10.5%) was the most common gram-negative isolate. Surgery was performed in 68.8% of cases and the mean duration of total antibiotic treatment was 104.7 ± 77.7 days. All-cause mortality and recurrence rates were 6.3% and 18.8%, respectively. In multivariate analysis, polymicrobial infection (OR: 4.154, 95% CI: 1.039-16.604, p = 0.044), multiple vertebral body involvement (OR: 2.202, 95% CI: 1.088-4.457, p = 0.028), abscess formation treated with antibiotics alone (OR: 2.912, 95% CI: 1.064-7.966, p = 0.037), and the duration of antimicrobial treatment less than 4 weeks (OR: 3.737, 95% CI: 1.195-11.683, p = 0.023) were associated with HPVO recurrence.

CONCLUSION

In Taiwan, HPVO mainly affected the elderly and S. aureus remained the most common HPVO pathogen. In patients with risk factors associated with HPVO recurrence, a longer duration (≥6 weeks) of antimicrobial therapy is suggested.

Incidence, Morbidity, and Surgical Outcomes of Complex Spinal Inflammatory Syndromes in Adults

BACKGROUND

Spondylodiscitis is a rare inflammatory syndrome affecting intervertebral discs and adjacent vertebral bodies. Without appropriate therapy, serious complications, such as secondary spinal epidural abscess (SEA), may prolong recovery time. In this study, we compared the main characteristics of our cohort of patients with spondylodiscitis with those of patients reported in the international literature and analyzed the impact of complications associated with spondylodiscitis on clinical outcomes.

METHODS

We designed a retrospective study based on the database of the National Institute of Clinical Neurosciences, Hungary, between 2008 and 2015. We collected 78 patients suffering from primary spondylodiscitis or primary spinal epidural abscess. Based on the main clinical characteristics of our population (demographic features, initial symptoms, concurrent diseases, laboratory findings, microbiological diagnosis, therapy and clinical outcome) we constructed a database. Odds ratio (OR) counting was used to define the correlation between etiology and stage of recovery.

RESULTS

We found a mild increase in the incidence of spondylodiscitis compared with international standards, and main demographic and clinical characteristics in concordance with international trends. Primary, noncomplicated spondylodiscitis had the best outcome results (OR, 1.25), and complicated spondylodiscitis had the worst, as well as the lowest OR for total recovery (0.6).

CONCLUSIONS

The clinical characteristics of our study cohort did not differ from the international trends. Primary, noncomplicated spondylodiscitis has the highest odds for absolute recovery. Secondary spinal epidural abscess exacerbates ongoing spondylodiscitis, and thus should be considered a poor prognostic factor for spondylodiscitis. Early diagnosis and treatment may prevent serious complications and provide better outcomes.

Concordance of results of blood and tissue cultures from patients with pyogenic spondylitis: a retrospective cohort study

OBJECTIVES

To investigate the concordance of results of blood and tissue cultures in patients with pyogenic spondylitis.

METHODS

We searched for patients with pyogenic spondylitis in whom microorganisms were isolated from both blood and tissue cultures by retrospective review of medical records in three tertiary university-affiliated hospitals between January 2005 and December 2015. The species and antimicrobial susceptibility patterns of isolates from blood and tissue cultures were compared.

RESULTS

Among 141 patients with pyogenic spondylitis in whom microorganisms were isolated from both blood and tissue cultures, the species of blood and tissue isolates were identical in 135 patients (95.7%, 135/141). Excluding the four anaerobic isolates, we investigated antimicrobial susceptibility patterns of 131 isolates of the same species from blood and tissue cultures. Antibiotic susceptibility patterns were identical in 128 patients (97.7%, 128/131). The most common isolates were Staphylococcus aureus (86 patients; 85 concordant and one discordant), followed by streptococcus (24 patients; 22 concordant and two discordant), and Escherichia coli (eight patients; all concordant).

CONCLUSIONS

We suggest that a positive blood culture from patients with pyogenic spondylitis could preclude the need for additional tissue cultures, especially when S. aureus and streptococcus grew in blood cultures.

Pyogenic Vertebral Osteomyelitis: Clinical Features, Diagnosis, and Treatment

Pyogenic vertebral osteomyelitis (PVO) may result in neurological deficits and sequelae, so early diagnosis and appropriate treatment are critical. Many previous studies on PVO exist, but our paper has aimed to comprehensively summarize the clinical aspects of PVO. Through review of the vast literature on the clinical research of PVO an overview of the clinical characteristics, diagnostic methods, treatment and prognosis is provided.

Emergency 1-stage anterior approach for cervical spine infection complicated by epidural abscess

It was a retrospective analysis.The aim of the study was to explore the safety and reliability of emergency 1-stage radical debridement and reconstruction using titanium mesh filled with autologous bone for patients with cervical spine infection complicated by epidural abscess.At present, cervical spine infection complicated by epidural abscess is known as a severe spine disease. Recently, case report of this disease is showing quite an increasing tendency, particularly in economically undeveloped areas and countries. Regarding the treatment of this disease, 1-stage radical debridement and reconstruction has been widely adopted; however, emergency 1-stage anterior approach surgery without medication is considered as a relatively taboo, since it is generally acknowledged that such operation would possibly cause unexpected infection. Nevertheless, regular elective surgery may require longer time for preparation. In addition, long hour compression and stimulation of the abscess may leave the patients with irreversible spinal neural impairment. However, our department has finished 14 cases of cervical spine infection complicated with epidural abscess without 1 single case of postoperative infection.A retrospective study was conducted on 14 patients (9 males and 5 females; average age 57.4 years) who were diagnosed with cervical spine infection complicated by epidural abscess from January 2005 to December 2014. All the patients were admitted to hospital with varying degrees of neurological function losses, and then underwent 1-stage anterior focal debridement and reconstruction using titanium mesh within 24 hours after admission. They received postoperative standard antibiotic chemotherapy for 10 to 12 weeks. They were followed up for 18 to 36 months, an average of 27.4 months. X-ray, computed tomography (CT), and MRI (magnetic resonance imaging (MRI) were used to determine the fusion state and vertebral stability. American Spinal Injury Association (ASIA) international standards for neurological classification were adopted, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were evaluated to infection activity, and Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) criteria were used to judge clinical efficacy.All the 14 patients had no postoperative spread of infection. No recurrence of infection was found during the last follow-up. ASIA grade, VAS score, and JOA score were significantly improved (P < .05) after the operation. WBC, ESR, and CRP became normal after the operation (P < .05). Postoperative follow-up imaging results showed no significant loss of cervical curvature, collapse of the grafted bone or implant displacement but good spinal canal volume.Emergency 1-stage radical debridement and reconstruction using titanium mesh filled with autologous bone, combined with antibiotic chemotherapy, is a safe and effective surgical therapy for cervical infection complicated by epidural abscess.

[Septic arthritis and spondylodiscitis : Rare but feared diseases]

Septic arthritis and spondylodiscitis are relatively rare but severe diseases with increasing incidence. Septic arthritis is an emergency situation with high morbidity (40 %) and fatality rates (11 %). The infection occurs via a hematogenous route by direct inoculation or per continuitatem. Patients with pre-existing destructive joint diseases or under immunosuppressive treatment are particularly at risk. It is mandatory to sample synovial fluid for isolation of the relevant pathogen and quantification of leucocytes before starting antibiotic therapy. In order to preserve the joint, early evacuation of the infected synovial space is necessary. Spondylodiscitis is characterized by infection of the vertebra and neighboring discs mainly via a hematogenous route. Immunosuppressed and older patients are primarily at risk of infection. Back pain represents the main symptom but due to its unspecific character and the frequent absence of fever, diagnosis is often delayed. In Europe Staphylococcus aureus is the most prevalent pathogen, whereas tuberculosis is the most frequent causal agent worldwide. Magnetic resonance imaging (MRI) respresents the method of choice for the radiological diagnostics. In stable patients isolation of the pathogen should be achieved before starting antimicrobial therapy (e.g. blood cultures or tissue samples by computed tomography guided puncture or biopsy). The recommended duration of pathogen-specific antibiotic therapy for native spondylodiscitis is normally 6 weeks.

Bacterial Osteomyelitis or Nonbacterial Osteitis in Children: A Study Involving the German Surveillance Unit for Rare Diseases in Childhood

BACKGROUND

Although bacterial osteomyelitis (BO) is a commonly recognized diagnosis in pediatrics, it is often difficult to distinguish from nonbacterial osteitis (NBO). The goal of our study was to distinguish between the 2 disease entities and better define NBO.

METHODS

Using the German Surveillance Unit for Rare Diseases in Childhood (Erhebungseinheit für Seltene Paediatrische Erkrankungen in Deutschland), this prospective study during a 5-year period captured 657 patients at first diagnosis of either BO (n = 378) or NBO (n = 279) while analyzing epidemiologic, clinical and radiologic data.

RESULTS

BO was reported in 1.2 per 100,000 children with a higher prevalence in younger male patients (58%), and NBO was reported in 0.45 per 100,000 children. BO patients tended to present with fevers (68%), elevated inflammation markers (82%) and local swelling (62%) but a shorter course of symptoms than NBO patients. NBO patients presented in good general health (86%) and were more likely to have multifocal lesions (66%). Staphylococcus aureus was the most prominent pathogen (83%), with only one methicillin-resistant S. aureus reported. Complications ranged from arthritis adjacent to the lesion to hyperostosis and vertebral fractures.

CONCLUSIONS

BO and NBO can be distinguished based on symptoms, associated diseases and inflammation markers. NBO should always be considered in pediatric patients presenting with bone lesions and pain, especially in young female patients presenting with good general health, minimal inflammation markers and multifocal lesions in the vertebrae, clavicle and sternum.

Orthopaedic biofilm infections

Many infections of the musculoskeletal system are biofilm infections that develop on non-living surfaces. Microorganisms adhere either on dead bone (sequesters) or implants. As a rule for a curative concept, chronic osteomyelitis or implant-associated bone infection must be treated with a combination of surgery and antimicrobial therapy. If an implant is kept in place, or a new device is implanted before complete healing of infection, a biofilm-active antibiotic should be used. Rifamycins are active against biofilms of staphylococci, and fluoroquinolones against those of Gram-negative bacilli. In this review, the management of chronic osteomyelitis, periprosthetic joint infection and implant-associated osteomyelitis of long bones is presented.

Infections of the Spine

Pyogenic infections of the bony spinal column and the intervertebral discs are on a steady rise in an aging western population. Despite advanced medical imaging, this clinical entity of devastating consequences if missed, still presents a diagnostic conundrum and is plagued by an unacceptably long diagnostic delay. The aim of this article is to raise awareness of the heterogeneity of spinal infections paralleling the complex structure of the spinal column and neighboring soft tissues. Emphasis is placed on the clinical presentation and management of septic facet joints and psoas muscle abscesses associated with lumbar spondylodiscitis.

Prevotella osteomyelitis after dental capping procedure

We present a 49 year old man who presented to the emergency department with severe lower back pain of 5 days duration. One week prior he had been diagnosed with a right psoas muscle abscess and was discharged with a 28 day course of moxifloxacin after the preliminary culture from the psoas grew an anaerobic organism. MRI of the lumbar spine showed marrow edema in the L2 body, occupying most of the anterior two thirds of the body, with cortical erosion at the anteroinferior aspect of L1. Blood cultures were negative and bone biopsy of L2 showed neutrophilic invasion and reactive changes. Cultures grew Prevotella oralis. Hematogenous spread from a composite bonding procedure for exposed teeth roots is thought to be the source for the vertebral osteomyelitis. This is a plausible spread of infection in our case because it was thought that the osteomyelitis occurred first and spread to the psoas muscle.

Clinical and microbiological outcomes in haematogenous spondylodiscitis treated conservatively

INTRODUCTION

Spondylodiscitis refers to infections of the intervertebral disc and the adjacent vertebral body. Although it is still considered a rare condition, its rate is projected to increase. Mortality rate is considered to be low, but an estimated one third of the survivors experience residual disabilities. Literature shows that uncomplicated spondylodiscitis can be adequately treated by early antibiotic therapy and immobilization. The aim of the study is to evaluate the outcome of conservative treatment in patients with haematogenous spondylodiscitis.

MATERIALS AND METHODS

All patients with haematogenous spondylodiscitis observed in two orthopaedic centres were retrospectively considered. The medical records, radiologic imaging, bacteriology results, treatment, and complications of all patients were reviewed.

RESULTS

Thirty patients (median age 64 years, range 15-77, females 56.7%) were considered in the study, eight (26.7%) showed residual back pain at median follow-up of 117 weeks (range 104-189). A significant difference in SF-36 physical (P < 0.001), SF-36 mental function (P < 0.002), and Oswestry Disability Index (ODI) (P < 0.001) scores was observed among patients with residual local pain compared to the ones who had not. Methicillin-resistant Staphylococcus aureus (MRSA) infection and symptoms duration before the diagnosis were associated with an increased risk of persistent back pain and permanent disability. The most important negative determinants of SF-36 mental function were the age of patients (ρ = 0.36, P < 0.05), the duration of symptoms before the diagnosis (ρ = 0.44, P < 0.05) and MRSA infection (P = 0.006). Spondylodiscitis sustained by MRSA and the duration of symptoms before the diagnosis influenced negatively the physical status (P = 0.002) and ODI (ρ = 0.36, P < 0.05), respectively.

CONCLUSIONS

Conservative approaches are safe and effective for patients without complications. A delayed diagnosis and MRSA infections are related to poor clinical outcome among patients treated by conservative treatment; this must be carried out scrupulously with close patient monitoring.

Pathogen Identification in Suspected Cases of Pyogenic Spondylodiscitis

Pyogenic spinal infection continues to represent a worldwide problem. In approximately one-third of patients with pyogenic spondylodiscitis, the infectious agent is never identified. Of the cases that lead to organismal identification, bacteria are more commonly isolated from the spine rather than fungi and parasites. This study applied universal prokaryotic 16S rRNA PCR as a rapid diagnostic tool for the detection of bacterial agents in specimens from patients suspected of pyogenic spondylodiscitis. Gram and Ziehl-Neelsen staining were used as a preliminary screening measure for microbiologic evaluation of patient samples. PCR amplification targeting 16S rRNA gene was performed on DNA extracted from 57 cases including specimens from epidural abscesses, vertebral, and disc biopsies. Positive samples were directly sequenced. MRI findings demonstrated that disc destruction and inflammation were the major imaging features of suspected pyogenic spondylodiscitis cases, as 44 cases showed such features. The most common site of infection was the lumbar spine (66.7%), followed by thoracic spine (19%), the sacroiliac joint (9.5%), and lumbar-thoracic spine (4.8%) regions. A total of 21 samples amplified the 16S rRNA-PCR product. Sanger sequencing of the PCR products identified the following bacteriological agents: Mycobacterium tuberculosis (n = 9; 42.9%), Staphylococcus aureus (n = 6; 28.5%), Mycobacterium abscessus (n = 5; 23.8%), and Mycobacterium chelonae (n = 1; 4.8%). 36 samples displayed no visible 16S rRNA PCR signal, which suggested that non-bacterial infectious agents (e.g., fungi) or non-infectious processes (e.g., inflammatory, or neoplastic) may be responsible for some of these cases. The L3–L4 site (23.8%) was the most frequent site of infection. Single disc/vertebral infection were observed in 9 patients (42.85%), while 12 patients (57.15%) had 2 infected adjacent vertebrae. Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) inflammatory markers were noted in majority of the patients. In conclusion, microbiological methods and MRI findings are vital components for the proper diagnosis of pyogenic spondylodiscitis. Our findings suggest that molecular methods such as clinical application of 16S rRNA PCR and sequencing may be useful as adjunctive diagnostic tools for pyogenic spondylodiscitis. The rapid turnaround time of 16S rRNA PCR and sequencing submission and results can potentially decrease the time to diagnosis and improve the therapeutic management and outcome of these infections. Although S. aureus and M. tuberculosis were the most common causes of pyogenic spinal infections in this study, other infectious agents and non-infectious etiologies should be considered. Based on study results, we advise that antibiotic therapy should be initiated after a definitive etiological diagnosis.

Hematogenous vertebral osteomyelitis associated with intravascular device-associated infections - A retrospective cohort study

INTRODUCTION

Aim of the study was to investigate the clinical, microbiological, radiological, and treatment characteristics of hematogenous vertebral osteomyelitis originating from infected intravascular devices.

PATIENTS AND METHODS

Patients with secondary hematogenous vertebral osteomyelitis caused by an infected intravascular device were included in this retrospective cohort study. Patients with prior spinal surgery were excluded. Categorical variables were compared using χ² or Fisher's exact tests and continuous variables using the Mann-Whitney U test.

RESULTS

Sixty-seven patients with hematogenous vertebral osteomyelitis were included. Intravenous catheters were the source of infection in 45 patients (67%) and cardiovascular devices in 22 (33%). Fever was present in 21 patients (45%). The main pathogens were coagulase-negative staphylococci, isolated in 42 patients (63%), which grew from blood culture in 52 patients (87%), from vertebral tissue in 29 patients (56%) and from the explanted intravascular device in 18 patients (60%), where it was sampled. Infective endocarditis was diagnosed in 14 of 45 patients (31%), more common with cardiovascular devices than with intravascular catheters (56% versus 15%; P=0.008).

CONCLUSIONS

In patients with vertebral osteomyelitis, growth of coagulase-negative staphylococci in blood is highly suggestive for intravascular device-associated infection. Despite absence of systemic or local signs of inflammation at the site of the device, blood cultures should be collected and echocardiography performed in these patients.