Imaging does not predict the clinical outcome of bacterial vertebral osteomyelitis

Risk Factors and Outcomes of Hematogenous Vertebral Osteomyelitis in Patients With Staphylococcus aureus Bacteremia

BACKGROUND

Hematogenous vertebral osteomyelitis (HVOM) is an incompletely understood complication of Staphylococcus aureus bacteremia (SAB).

METHODS

Eligible SAB patients with and without HVOM were prospectively enrolled from 1995 through 2019 at Duke University Health System. HVOM was diagnosed either radiographically or microbiologically. Multivariable logistic regression analysis was performed to identify clinical and microbial factors associated with HVOM risk. All bloodstream S. aureus isolates were genotyped using spa typing.

RESULTS

Of 3165 cases of SAB, 127 (4.0%) developed HVOM. Patients who experienced HVOM were more likely to have community-acquired SAB (30.7% vs 16.7%, P < .001), have a longer time to diagnosis of SAB (median, 5 days; interquartile range [IQR], 2-10.5 vs median, 2 days; IQR, 0-4; P < .001), and to exhibit persistent bacteremia (48.8% vs 20.6%, P < .001). A significant number of HVOM patients developed infective endocarditis (26% vs 15.2%, P = .002). Overall, 26.2% (n = 33) of SAB patients with HVOM underwent surgical intervention. Methicillin resistance (46.6% vs 41.7%, P = .318) and bacterial genotype were not associated with the development of HVOM. At the 12-month follow-up, 22% of patients with HVOM had died. Of the surviving patients, 20.4% remained on antibiotic therapy, and 29.6% had recurrence of either HVOM or SAB.

CONCLUSIONS

Among patients with SAB, HVOM risk was associated with clinical factors and not bacterial genotype. Despite being a rare complication of SAB, patients with HVOM had high all-cause mortality rates and healthcare resource requirements up to 1 year after their HVOM diagnosis. Close clinical monitoring is indicated in this vulnerable population.

Diagnostic Sensitivity of Blood Culture, Intraoperative Specimen, and Computed Tomography-Guided Biopsy in Patients with Spondylodiscitis and Isolated Spinal Epidural Empyema Requiring Surgical Treatment

BACKGROUND

the successful treatment of spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) depends on early detection of causative pathogens, which is commonly performed either via blood cultures, intraoperative specimens, and/or image-guided biopsies. We evaluated the diagnostic sensitivity of these three procedures and assessed how it is influenced by antibiotics.

METHODS

we retrospectively analyzed data from patients with SD and ISEE treated surgically at a neurosurgery university center in Germany between 2002 and 2021.

RESULTS

we included 208 patients (68 [23-90] years, 34.6% females, 68% SD). Pathogens were identified in 192 cases (92.3%), including 187 (97.4%) pyogenic and five (2.6%) non-pyogenic infections, with Gram-positive bacteria accounting for 86.6% (162 cases) and Gram-negative for 13.4% (25 cases) of the pyogenic infections. The diagnostic sensitivity was highest for intraoperative specimens at 77.9% (162/208, p = 0.012) and lowest for blood cultures at 57.2% (119/208) and computed tomography (CT)-guided biopsies at 55.7% (39/70). Blood cultures displayed the highest sensitivity in SD patients (SD: 91/142, 64.1% vs. ISEE: 28/66, 42.4%, p = 0.004), while intraoperative specimens were the most sensitive procedure in ISEE (SD: 102/142, 71.8% vs. ISEE: 59/66, 89.4%, p = 0.007). The diagnostic sensitivity was lower in SD patients with ongoing empiric antibiotic therapy (EAT) than in patients treated postoperatively with targeted antibiotic therapy (TAT) (EAT: 77/89, 86.5% vs. TAT: 53/53, 100%, p = 0.004), whereas no effect was observed in patients with ISEE (EAT: 47/51, 92.2% vs. TAT: 15/15, 100%, p = 0.567).

CONCLUSIONS

in our cohort, intraoperative specimens displayed the highest diagnostic sensitivity especially for ISEE, whereas blood cultures appear to be the most sensitive for SD. The sensitivity of these tests seems modifiable by preoperative EAT in patients with SD, but not in those with ISEE, underscoring the distinct differences between both pathologies.

Clinical phenotyping of spondylodiscitis and isolated spinal epidural empyema: a 20-year experience and cohort study

Background

The incidence of spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) has been increasing in the last decades, but the distinct differences between both entities are poorly understood. We aimed to evaluate the clinical phenotypes and long-term outcomes of SD and ISEE in depth.

Methods

We performed a chart review and analyzed data from our cohorts of consecutive SD and ISEE patients who were treated and assessed in detail for demographic, clinical, imaging, laboratory, and microbiologic characteristics at a university neurosurgical center in Germany from 2002 to 2021. Between-group comparisons were performed to identify meaningful differences in both entities.

Results

We included 208 patients (72 females: age 75 [75 32-90] y vs. 136 males: 65 [23-87] y, median [interquartile range], p < 0.001), of which 142 (68.3%) had SD and 66 (31.7%) had ISEE. Patients with SD were older than ISEE (ISEE: 62 y vs. SD: 70 y, p = 0.001). While SD was more common in males than females (males: n = 101, 71.1% vs. females: n = 41, 28.9%, p < 0.001), there was no sex-related difference in ISEE (males: n = 35, 53.0% vs. females: n = 31, 47.0%, p = 0.71). Obesity was more frequent in ISEE than in SD (ISEE: n = 29, 43.9% vs. SD: n = 37, 26.1%, p = 0.016). However, there were no between-group differences in rates of diabetes and immunodeficiency. In the entire study population, a causative pathogen was identified in 192 (92.3%) patients, with methicillin-susceptible staphylococcus aureus being most frequent (n = 100, 52.1%) and being more frequent in ISEE than SD (ISEE: n = 43, 65.2% vs. SD: n = 57, 40.1%, p = 0.003). SD and ISEE occurred most frequently in the lumbar spine, with no between-group differences (ISEE: n = 25, 37.9% vs. SD: n = 65, 45.8%, p = 0.297). Primary infectious sources were identified in 145 patients (69.7%) and among this skin infection was most common in both entities (ISEE: n = 14, 31.8% vs. SD: n = 25, 24.8%, p = 0.418). Furthermore, epidural administration was more frequent the primary cause of infection in ISEE than SD (ISEE: n = 12, 27.3% vs. SD: n = 5, 4.9%, p < 0.001). The most common surgical procedure in SD was instrumentation (n = 87, 61%) and in ISEE abscess evacuation (n = 63, 95%). Patients with ISEE displayed lower in-hospital complication rates compared to SD for sepsis (ISEE: n = 12, 18.2% vs. SD: n = 94, 66.2%, p < 0.001), septic embolism (ISEE: n = 4/48 cases, 8.3% vs. SD: n = 52/117 cases, 44.4%, p < 0.001), endocarditis (ISEE: n = 1/52 cases, 1.9% vs. SD: n = 23/125 cases, 18.4%, p = 0.003), relapse rate (ISEE: n = 4/46, 8.7% vs. SD: n = 27/92, 29.3%, p = 0.004), and disease-related mortality (ISEE: n = 1, 1.5% vs. SD: n = 11, 7.7%, p = 0.108). Patients with SD showed prolonged length of hospital stay (ISEE: 22 [15, 30] d vs. SD: 38 [29, 53] d, p < 0.001) and extended intensive care unit stay (ISEE: 0 [0, 4] d vs. SD: 3 [0, 12] d, p < 0.002).

Conclusions

Our 20-year experience and cohort analysis on the clinical management of SD and ISEE unveiled distinct clinical phenotypes and outcomes in both entities, with ISEE displaying a more favorable disease course with respect to complications and relapse rates as well as disease-related mortality.

[A vertebral polymicrobial osteomyelitis with atypicial microorganisms: A case report]

Vertebral Osteomyelitis (VO) is a rare disease, which has seen a gradual increase in its incidence over the past years. Here, we report a case, showing how difficult it can be to diagnose and manage a therapy in case of atypical microorganism. A 68-year-old man was hospitalized for a VO documented by blood cultures at Bacteroides fragilis. He first progressed favorably, but an increase in lumbar pain prompted, after an IRM, a percutaneous needle biopsy (PNB) that documented a recurrent VO at Corynebacterium striatum. In the face of this multi-microbial VO with atypicals microorganisms, a first PNB could have been discussed despite the positive blood cultures. This case report illustrates the complexity of management of VO, and its evolution according to the latest recommendations (interest of RMI during the follow-up, place of the TEP-scan, terms and conditions of immobilization, antibiotic administration methods).

Amoxicillin Did Not Reduce Modic Change Edema in Patients With Chronic Low Back Pain: Subgroup Analyses of a Randomised Trial (the AIM Study)

STUDY DESIGN

Exploratory subgroup analyses of a randomised trial [Antibiotics in Modic changes (AIM) study].

OBJECTIVE

The aim was to assess the effect of amoxicillin versus placebo in reducing Modic change (MC) edema in patients with chronic low back pain.

SUMMARY OF BACKGROUND DATA

The AIM study showed a small, clinically insignificant effect of amoxicillin on pain-related disability in patients with chronic low back pain and MC type 1 (edema type) on magnetic resonance imaging (MRI).

MATERIALS AND METHODS

A total of 180 patients were randomised to receive 100 days of amoxicillin or placebo. MC edema was assessed on MRI at baseline and one-year follow-up. Per-protocol analyses were conducted in subgroups with MC edema on short tau inversion recovery (STIR) or T1/T2-weighted MRI at baseline. MC edema reductions (yes/no) in STIR and T1/T2 series were analyzed separately. The effect of amoxicillin in reducing MC edema was analyzed using logistic regression adjusted for prior disk surgery. To assess the effect of amoxicillin versus placebo within the group with the most abundant MC edema on STIR at baseline ("STIR3" group), we added age, STIR3 (yes/no), and STIR3×treatment group (interaction term) as independent variables and compared the marginal means (probabilities of edema reduction).

RESULTS

Compared to placebo, amoxicillin did not reduce MC edema on STIR (volume/intensity) in the total sample with edema on STIR at baseline (odds ratio 1.0, 95% CI: 0.5, 2.0; n=141) or within the STIR3 group (probability of edema reduction 0.69, 95% CI: 0.47, 0.92 with amoxicillin and 0.61, 95% CI: 0.43, 0.80 with placebo; n=41). Compared with placebo, amoxicillin did not reduce MC edema in T1/T2 series (volume of the type 1 part of MCs) (odds ratio: 1.0, 95% CI: 0.5, 2.3, n=104). Edema declined in >50% of patients in both treatment groups.

CONCLUSIONS

From baseline to one-year follow-up, amoxicillin did not reduce MC edema compared with placebo.

LEVEL OF EVIDENCE

2.

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.

Diagnosis of vertebral osteomyelitis

Native vertebral osteomyelitis (NVO) is a potentially fatal infection which has seen a gradual increase in its incidence over the past decades. The infection is insidious, presenting with symptoms of back pain. Fever is present in about 60 % of patients. Prompt diagnosis of NVO is important to prevent the development of complications. Numerous laboratory and imaging tools can be deployed to accurately establish the diagnosis. Imaging techniques such as magnetic resonance, nuclear imaging, and computed tomography are essential in diagnosing NVO but can also be useful in image-guided biopsies. Laboratory tools include routine blood tests, inflammatory markers, and routine culture techniques of aspirated specimens. Recent advances in molecular techniques can assist in identifying offending pathogen(s). In this review, we detail the arsenal of techniques that can be utilized to reach a diagnosis of NVO.

Severity and Outcome of Neurologic Deficits in Patients with Pyogenic Spondylodiscitis: A Systematic Review

Patients with advanced pyogenic spondylodiscitis can present with neurologic deficits. However, the prevalence, severity, and outcome of the neurologic deficits are not well known. A systematic review was performed to improve the knowledge of this commonly encountered clinical scenario. The considerable number of severe neurologic deficits in addition to their poor recovery, even after surgical intervention, demonstrates that the early diagnosis of pyogenic spondylodiscitis is crucial. Prompt surgical intervention is likely associated with a greater chance of improvement of neurologic status than nonsurgical treatment.

The diagnostic value of cytokines for the discrimination of vertebral osteomyelitis and degenerative diseases of the spine

Vertebral osteomyelitis (VO) is a primary infection of the endplates of the vertebral bodies with secondary infection of the adjacent intervertebral discs. Diagnosis is often delayed due to unspecific symptoms and a lack of specific infection markers. In this prospective study, we determined the suitability of 27 cytokines for the discrimination of VO and degenerative diseases of the spine and compared its diagnostic potential in relation to the C-reactive protein (CRP), which is widely used as a non-specific inflammation marker in clinical diagnostics. The patients included in this study underwent surgical stabilization of the lumbar and/or thoracic spine with removal of 1 or more affected intervertebral discs, as therapy for VO (n = 16) or for erosive osteochondrosis (EO, control group, n = 20). We evaluated the cytokine and CRP concentrations before (pre-OP = -20-0d where 0 means the day of surgery) and after surgery (post-OP) on days 3-5, 6-11, 40-56, and 63-142. Compared to the control patients pre-OP, a significantly higher elevation of the 4 cytokines IL-6, IL-8, IL-12 (p70), and VEGF as well as CRP were found in the VO patients, showing an area under the curve > 0.80 pre-OP. No significant differences were observed between VO patients with high and low virulent bacteria with respect to all 5 elevated biomarkers. This is the first prospective study in which a broad spectrum of 27 cytokines was analysed via multiplex assay using sera from patients with and without VO. Our results show that, in addition to CRP, 4 different cytokines were significantly altered in VO but not control patients. The results implicate that these candidate cytokines may be used in a multiplex assay for discrimination between VO and degenerative diseases of the spine.

Validity of Clinical Assessment Using Clinical Symptoms and C-Reactive Protein for Therapeutic Response in Pyogenic Vertebral Osteomyelitis: Analysis Based on 18F-FDG-PET

Backgroundand objectives: The clinical assessment of therapeutic response in pyogenic vertebral osteomyelitis (PVO) has been usually performed based on the changes of clinical symptoms and blood inflammatory markers. Recently, ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET) has emerged as an alternative independent method. We analyzed the validity of the clinical assessment for detecting residual PVO based on ¹⁸F-FDG-PET. Materials and Methods: This study was conducted with 53 patients confirmed as lumbar PVO under retrospective design. All patients underwent clinical assessment using clinical symptoms and C-reactive protein (CRP) for therapeutic response after parenteral antibiotic therapy, which led to the decision of placement in the uncontrolled (group UC) or controlled (group C) group. The validity of clinical assessment was analyzed based on the cut-off values of FDG uptake for detecting residual PVO as references, which are already established in the previous literature. Results: The mean duration of parenteral antibiotic therapy and recurrence rate were 42.19 ± 15.84 (21-89) days and 9.4% (5/53), respectively. ¹⁸F-FDG-PETs were performed at 80 rounds of clinical assessment on 37.40 ± 13.15 (21-83) days of parenteral antibiotic therapy and divided: 31 into group UC and 49 into group C, according to the decisions of clinical assessment. Based on the cut-off values of FDG uptake, clinical assessment showed 48.4-58.1% of false positive for residual PVO in group UC. However, ¹⁸F-FDG-PET showed 8.2% (4/49) of false negative for residual PVO in group C, which led to recurrences. Conclusions: Clinical assessment using clinical symptoms and CRP for evaluating therapeutic response in PVO is still a useful method in terms of similar recurrence rate compared to ¹⁸F-FDG-PET. However, the high rate of false positive for residual PVO can prolong the use of unnecessary antibiotics and overall treatment period.

Clinical and Radiological Features Predicting Intervertebral Autofusion after Successful Antibiotic Therapy in Pyogenic Vertebral Osteomyelitis

Background: Pyogenic vertebral osteomyelitis (PVO) is a bacterial infection involving the intervertebral disc, vertebral body, and paravertebral soft tissues. Damaged intervertebral structure is a major cause of persistent back pain even after successful antibiotic therapy, which can be improved by achieving autofusion or via additional surgical fixation. In this study, we analyzed the clinical and radiological features predicting intervertebral autofusion after successful antibiotic therapy in lumbar PVO. Methods: This study was retrospectively conducted with 32 patients (20 men and 12 women) diagnosed with lumbar PVO that was completely cured with no recurrences after antibiotic therapy. They were divided into two groups with (group A, n = 18) and without (group B, n = 14) intervertebral autofusion at six-month follow-up. Differences in back pain, blood inflammatory markers, and radiological features of PVO on simultaneous ¹⁸F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (¹⁸F-FDG-PET/MRI) of the intervertebral structure between the two groups were analyzed. Results: The mean duration of antibiotic therapy was 41.44 ± 14.21 (21–89) days. Group A showed a statistically higher erythrocyte sedimentation ratio (ESR; 59.28 ± 32.33 vs. 33.93 ± 18.76 mm/h, p = 0.014; normal range of ESR < 25), maximum standardized ¹⁸F-FDG uptake (SUV_max; 5.56 ± 1.86 vs. 3.98 ± 1.40, p = 0.013), and sustained extensive edematous changes on T2-weighted fat saturation (T2FS) MRI (p = 0.015) immediately after successful antibiotic therapy. However, no significant differences were observed in back pain, C-reactive protein, or the distribution of ¹⁸F-FDG uptake/contrast enhancement on ¹⁸F-FDG-PET/MRI (p > 0.05). Conclusions: Higher ESR and SUV_max of the intervertebral structure and sustained extensive edematous change on T2FS MRI immediately after successful antibiotic therapy are related with subsequent intervertebral autofusion, which should be carefully considered when assessing therapeutic response in PVO.

Interest of Follow-Up Radiological Imaging in Patients with Pyogenic Vertebral Osteomyelitis

No recommendations are established for monitoring pyogenic vertebral osteomyelitis (PVO). Thus, the realization of systematic follow-up radiological imaging is controversial. The objective of this study was to evaluate the interest in follow-up radiological imaging in patients with PVO. We conducted a retrospective cohort analysis of patients with PVO who had both baseline and follow-up radiological imaging. We classified the follow-up images into two groups, improvement/stability, and deterioration, compared with the baseline data. For each patient, we compared their radiological imaging follow-up to their clinical-biological condition assessed at the same time. Eighty-six patients were included. The mean age was 68 years (±13). A total of 99 radiological imaging examinations at diagnosis and at follow-up were analyzed, 69 Magnetic Resonance Imaging (MRI), and 30 Computerized Tomography (CT scans). The mean delay between the follow-up radiological imaging and clinical evaluation was 2.8 +/- 2.1 months. Of the 36 patients with clinical and biological recovery, 24 patients (67%) had improved radiological imaging and 12 patients (34%) had radiological worsening (new abscesses (n = 4), extension of soft tissue infiltration (n = 2) and/or epiduritis (n = 2) or appearance of new locations (n = 1)). Among the 50 patients considered as unhealed, on the contrary, radiological imaging showed an improvement in imaging in 39 patients (78%) and a worsening in 11 patients (22%). Our study showed that there was no correlation between the clinical condition of patients and their follow-up radiological imaging in the context of PVO.

Relapsed Symptoms in a Patient Treated for Pubic Symphysis Septic Arthritis/Adjacent Osteomyelitis: Diagnostic Challenges

We describe the case of a 14-year-old girl with relapsed pain following adequate treatment of pubic symphysis septic arthritis with adjacent osteomyelitis. Evaluation of her symptoms was challenging, because magnetic resonance imaging (MRI) was not helpful and repeat surgical exploration was not favored. She was treated with a combination of prolonged antimicrobial therapy and local steroid injection. This case highlights the limitations of MRI as a follow-up study for evaluating symptom relapse of acute osteomyelitis.

Efficacy of Daptomycin-Containing Regimen for Treatment of Staphylococcal or Enterococcal Vertebral Osteomyelitis: A Prospective Clinical Experience

Vertebral osteomyelitis (VO) is a compelling clinical entity for clinicians, because of its insidious and indolent course that makes diagnosis difficult. A concern is reported about the choice of antibiotic regimens, duration of therapy, and criteria to switch to oral therapy. We conducted a prospective observational study. All consecutive hospitalized patients with a confirmed diagnosis of VO caused by staphylococcal or enterococcal strains were analyzed. The primary endpoint was the analysis of clinical cure at the end of therapy. A propensity score for receiving therapy with daptomycin was added to the model. During the study period, 60 episodes of confirmed VO were observed. The main etiology of infection was methicillin-resistant Staphylococcus aureus (29%). Overall, clinical failure at end of therapy was reported in 11 (18.3%) patients. Logistic regression analysis, after propensity score, showed that >2 vertebrae involved (OR 2.4, CI95% 1.12–5.24, p = 0.002) and inadequate drainage of infection (OR 4.8, CI95% 2.45–8.51, p < 0.001) were independently associated with failure of therapy, while the use of a daptomycin-containing-regimen (OR 0.15, CI 95% 0.04–0.46, p < 0.001) with clinical cure. VO caused by staphylococcal or enterococcal strains is associated with an important rate of clinical failure. Daptomycin-containing regimen was strongly associated with clinical cure. Considering that over 70% of VO etiology is caused by Gram-positive strains but the etiology of infection is obtained in about 75% of cases, these data may help physicians to choose the appropriate antibiotic regimen.

Assessment of Therapeutic Response in Pyogenic Vertebral Osteomyelitis Using 18F-FDG-PET/MRI

Purpose: There is still no definite method to determine therapeutic response in pyogenic vertebral osteomyelitis (PVO). We analyzed the value of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) for assessing therapeutic response in PVO. Methods: This retrospective study included 53 patients (32 men and 21 women) with lumbar PVO. The results of clinical assessments for therapeutic response were divided into “Cured” (group C) and “Non-cured” (group NC). The differences in clinical and radiological features of PVO lesions between the two groups were analyzed using clinical data and simultaneous FDG-PET/magnetic resonance imaging (MRI) obtained at each clinical assessment. Results: Clinical assessments and FDG-PET/MRIs were performed at 41.89 ± 16.08 (21–91) days of parenteral antibiotic therapy. There were 39 patients in group C and 14 in group NC. Diagnostic accuracies (DAs) of FDG uptake intensity-based interpretation and C-reactive protein (CRP) for residual PVO were as follows (p < 0.01): 84.9% of the maximum standardized uptake value of PVO lesion (PvoSUV_max), 86.8% of ΔPvoSUV_max−NmlSUV_max (SUV_max of normal vertebra), 86.8% of ΔPvoSUV_max−NmlSUV_mean (SUV_mean of normal vertebra), and 71.7% of CRP. DAs were better (92.5–94.3%) when applying FDG uptake intensity-based interpretation and CRP together. Under the FDG uptake distribution-based interpretation, FDG uptake was significantly limited to intervertebral structures in group C (p = 0.026). Conclusion: The interpretations of intensity and distribution of FDG uptake on FDG-PET are useful for detecting residual PVO in the assessment of therapeutic response of PVO. The combination of FDG-PET and CRP is expected to increase DA for detecting residual PVO.

Clinical and Radiological Analysis of Pyogenic Vertebral Osteomyelitis Immediately after Successful Antimicrobial Therapy: Considerations for Assessing Therapeutic Response

Purpose: The clinical and radiological abnormal findings continue even after successful treatment in pyogenic vertebral osteomyelitis (PVO). We analyzed the clinical and radiological features of cured PVO based on ¹⁸F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (FDG-PET/MRI) and compared the radiological differences between FDG-PET and MRI for assessing therapeutic response in PVO. Methods: This study included 43 patients (28 men and 15 women) with lumbar PVO who had no recurrence after successful antimicrobial therapy. They were divided into two groups based on the location of maximum standardized FDG uptake value (SUV_max) of PVO lesion on FDG-PET/MRI when parenteral antibiotics were discontinued (31 in group A: Intervertebral structure; 12 in group B: Vertebral body and paravertebral muscle). The differences of clinical symptoms, hematological inflammatory indices, and radiological features were retrospectively analyzed. Results: The patients were treated with 42.28 ± 14.58 (21–89) days of parenteral antibiotics. There were significant differences in C-reactive protein (0.97 ± 1.10 vs. 0.51 ± 0.31 mg/dL, p = 0.041; normal range of CRP < 0.5), back pain (4.29 ± 1.13 vs. 3.50 ± 1.00, p = 0.040; visual analog scale), and SUV_max (4.34 ± 1.24 vs. 5.89 ± 1.57, p < 0.001) between the two groups. In the distribution pattern of PVO lesions, FDG-PET overall showed recovery pattern earlier than MRI did (p < 0.001). Conclusions: In cured PVO, the clinical features vary depending on the location of major structural damage of PVO lesion. The involvement of intervertebral structure is related with sustained back pain and elevation of CRP, and vertebral body/paravertebral muscle shows favorable clinical features despite advanced structural damages.

The correlation between follow-up MRI findings and laboratory results in pyogenic spondylodiscitis

BACKGROUND

Although MRI is the gold-standard imaging method in the diagnosis of spondylodiscitis, role of follow-up imaging is debated and there can be discrepancies with regard to the significance of bony or soft tissue responses to treatment. Purpose of our study is to test whether the MRI changes on follow-up imaging correlate with laboratory findings of treatment response.

METHODS

A total of 48 patients with pyogenic spondylodiscitis who underwent baseline and follow-up MRI were retrospectively reviewed. The extent of bone marrow edema, paravertebral soft tissue inflammation, and disc height were compared on baseline and follow-up MRIs with the C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels obtained from the medical records at baseline and on follow-up. Relationships between the MRI and laboratory changes were analyzed using the Spearmann correlation test.

RESULTS

The mean MRI follow-up period was 42.25 days. Based on the CRP (resolved: n = 19, resolving: n = 19, and aggravated: n = 10), there was significant correlation between the laboratory results and the changes in the bone and soft tissues (p < 0.01, both). The correlation was best with soft tissue changes (rho: 0.48) followed by bony changes (rho: 0.41). Based on the ESR (resolved: n = 8, resolving: n = 22, and worsened: n = 18), the correlation was stronger with bone changes (rho: 0.45, p < 0.01) than it was with soft tissue changes (rho: 0.39, p = 0.01).

CONCLUSION

Follow-up MRI findings of pyogenic spondylodiscitis show variable tissue responses. CRP was best correlated with soft tissue changes, while ESR showed the best association with bony changes.

Combination of Imaging Features and Clinical Biomarkers Predicts Positive Pathology and Microbiology Findings Suggestive of Spondylodiscitis in Patients Undergoing Image-Guided Percutaneous Biopsy

BACKGROUND AND PURPOSE

Pathology and microbiology results for suspected spondylodiscitis on MR imaging are often negative in up to 70% of cases. We aimed to predict whether MR imaging features will add diagnostic value when combined with clinical biomarkers to predict positive findings of spondylodiscitis on pathology and/or microbiology from percutaneous biopsy.

MATERIALS AND METHODS

In this retrospective single-center institutional review board-approved study, patients with radiologically suspected spondylodiscitis and having undergone percutaneous biopsies were assessed. Demographic characteristics, laboratory values, and tissue and blood cultures were collected. Pathology and microbiology results were used as end points. Three independent observers provided MR imaging-based scoring for typical MR imaging features for spondylodiscitis. Multivariate logistic regression and receiver operating characteristic analysis were performed to determine an optimal combination of imaging and clinical biomarkers in predicting positive findings on pathology and/or microbiology from percutaneous biopsy suggestive of spondylodiscitis.

RESULTS

Our patient cohort consisted of 72 patients, of whom 33.3% (24/72) had spondylodiscitis. The mean age was 63 ± 16 years with a male/female ratio of 41:31. Logistic regression revealed a combination with an area under the curve of 0.72 for pathology and 0.68 for pathology and/or microbiology. Epidural enhancement on MR imaging improved predictive performance to 0.87 for pathology and 0.78 for pathology and/or microbiology.

CONCLUSIONS

Our findings demonstrate that epidural enhancement on MR imaging added diagnostic value when combined with clinical biomarkers to help predict which patients undergoing percutaneous biopsy will have positive findings for spondylodiscitis on pathology and/or microbiology.

Red flags for the early detection of spinal infection in back pain patients

BACKGROUND

Red flags are signs and symptoms that are possible indicators of serious spinal pathology. There is limited evidence or guidance on how red flags should be used in practice. Due to the lack of robust evidence for many red flags their use has been questioned. The aim was to conduct a systematic review specifically reporting on studies that evaluated the diagnostic accuracy of red flags for Spinal Infection in patients with low back pain.

METHODS

Searches were carried out to identify the literature from inception to March 2019. The databases searched were Medline, CINHAL Plus, Web of Science, Embase, Cochrane, Pedro, OpenGrey and Grey Literature Report. Two reviewers screened article texts, one reviewer extracted data and details of each study, a second reviewer independently checked a random sample of the data extracted.

RESULTS

Forty papers met the eligibility criteria. A total of 2224 cases of spinal infection were identified, of which 1385 (62%) were men and 773 (38%) were women mean age of 55 (± 8) years. In total there were 46 items, 23 determinants and 23 clinical features. Spinal pain (72%) and fever (55%) were the most common clinical features, Diabetes (18%) and IV drug use (9%) were the most occurring determinants. MRI was the most used radiological test and Staphylococcus aureus (27%), Mycobacterium tuberculosis (12%) were the most common microorganisms detected in cases.

CONCLUSION

The current evidence surrounding red flags for spinal infection remains small, it was not possible to assess the diagnostic accuracy of red flags for spinal infection, as such, a descriptive review reporting the characteristics of those presenting with spinal infection was carried out. In our review, spinal infection was common in those who had conditions associated with immunosuppression. Additionally, the most frequently reported clinical feature was the classic triad of spinal pain, fever and neurological dysfunction. This is an Open Access article distributed in accordance with the Creative Commons Attribution Non-Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.

More complications in cervical than in non-cervical spine tuberculosis

Purpose: Cervical spine tuberculosis (CST) is a rare disease that may lead to severe neurological complications. The goal of the study was to compare the characteristics of patients with CST with those of patients with non-cervical spine tuberculosis (NCST).Methods: Between 1997 and 2016, we reviewed all cases of proven tuberculosis from a cohort of spine infections in a tertiary care hospital. Clinical, biological, and imaging data were collected at baseline and after treatment.Results: Fifty-one cases of spine tuberculosis were included: 14 with CST on imaging (27%) and 37 with no cervical localization. Median age was 39 y. Demographic characteristics, duration of symptoms and neurological findings of spine compression were similarly present at presentation in CST and NCST patients. On imaging, lesions were more often multifocal in CST than in NCST patients (9/14 [64%] versus 10/37 [27%], p = .014). Spinal surgery was required in 32/51 (63%) patients. At the end of follow-up (median: 20 months), cure rates were similar in CST and NCST patients but motor and/or sensitive functional sequel were more frequent in CST than NCST patients (6/14 [43%] versus 2/37 [5%], p = .003).Conclusions: Cervical involvement is present in more than a quarter of patients with spinal tuberculosis. Patients with CST had more frequent neurological sequelae than patients with NCST. This was mainly due to a more multifocal disease at presentation. Screening for cervical localization should be systematic in patients with spinal tuberculosis even in the absence of cervical symptoms.

Management of vertebral osteomyelitis over an eight-year period: The UDIPROVE (UDIne PROtocol on VErtebral osteomyelitis)

OBJECTIVES

Vertebral osteomyelitis (VO) is a compelling clinical entity for clinicians because of its insidious and indolent course, which makes diagnosis difficult.

METHODS

All patients with a suspected diagnosis of VO were analyzed over an 8-year period (January 2009 to January 2017). The UDIPROVE protocol (UDIne PROtocol on VErtebral osteomyelitis) was applied in all cases. The primary endpoint was the performance of the UDIPROVE protocol to obtain the causal bacteria of infection.

RESULTS

During the study period, 133 episodes of confirmed VO were observed. The etiology of infection was obtained in 73.6% of cases: 70.5% were gram-positive, 16.3% were gram-negative, and 13.2% were mycobacteria. ¹⁸F-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) showed that for tubercular VO, the median standard uptake value (SUV) was higher when compared with VO caused by other bacteria. Clinical cure at the end of therapy was reported in 85.7% of patients. Previous antimicrobial therapy and a delay of more than 5 days in performing biopsy were associated with an undiagnosed etiology of VO. Targeted antibacterial therapy and follow-up with FDG-PET/CT were associated with clinical cure at the end of therapy, while the involvement of more than two vertebrae and inadequate drainage were associated with failure.

CONCLUSIONS

Rigorous application of the UDIPROVE protocol allowed the causative pathogens of VO to be obtained - at about twice the rate reported in the literature. The use of FDG-PET/CT for the follow-up of infection was more reliable when compared to magnetic resonance imaging (MRI).

Joint EANM/ESNR and ESCMID-endorsed consensus document for the diagnosis of spine infection (spondylodiscitis) in adults

PURPOSE

Diagnosis of spondylodiscitis (SD) may be challenging due to the nonspecific clinical and laboratory findings and the need to perform various diagnostic tests including serologic, imaging, and microbiological examinations. Homogeneous management of SD diagnosis through international, multidisciplinary guidance would improve the sensitivity of diagnosis and lead to better patient outcome.

METHODS

An expert specialist team, comprising nuclear medicine physicians appointed by the European Association of Nuclear Medicine (EANM), neuroradiologists appointed by the European Society of Neuroradiology (ESNR), and infectious diseases specialists appointed by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), reviewed the literature from January 2006 to December 2015 and proposed 20 consensus statements in answer to clinical questions regarding SD diagnosis. The statements were graded by level of evidence level according to the 2011 Oxford Centre for Evidence-based Medicine criteria and included in this consensus document for the diagnosis of SD in adults. The consensus statements are the result of literature review according to PICO (P:population/patients, I:intervention/indicator, C:comparator/control, O:outcome) criteria. Evidence-based recommendations on the management of adult patients with SD, with particular attention to radiologic and nuclear medicine diagnosis, were proposed after a systematic review of the literature in the areas of nuclear medicine, radiology, infectious diseases, and microbiology.

RESULTS

A diagnostic flow chart was developed based on the 20 consensus statements, scored by level of evidence according to the Oxford Centre for Evidence-based Medicine criteria.

CONCLUSIONS

This consensus document was developed with a final diagnostic flow chart for SD diagnosis as an aid for professionals in many fields, especially nuclear medicine physicians, radiologists, and orthopaedic and infectious diseases specialists.

Treatment algorithm for spontaneous spinal infections: A review of the literature

Background:

Primary spinal infections are rare pathologies with an estimated incidence of 5% of all osteomyelitis. The diagnosis can be challenging and this might result in a late identification. The etiological diagnosis is the primary concern to determine the most appropriate treatment. The aim of this review article was to identify the importance of a methodological attitude toward accurate and prompt diagnosis using an algorithm to aid on spinal infection management.

Methods:

A search was done on spinal infection in some databases including PubMed, ISI Web of Knowledge, Google Scholar, Ebsco, Embasco, and Scopus.

Results:

Literature reveals that on the basis of a clinical suspicion, the diagnosis can be formulated with a rational use of physical, radiological, and microbiological examinations. Microbiological culture samples can be obtained by a percutaneous computed tomography-guided procedure or by an open surgical biopsy. When possible, the samples should be harvested before antibiotic treatment is started. Indications for surgical treatment include neurological deficits or sepsis, spine instability and/or deformity, presence of epidural abscess and failure of conservative treatment.

Conclusion:

A multidisciplinary approach involving both a spinal surgeon and an infectious disease specialist is necessary to better define the treatment strategy. Based on literature findings, a treatment algorithm for the diagnosis and management of primary spinal infections is proposed.

Spontaneous spondylodiscitis: review, incidence, management, and clinical outcome in 44 patients

OBJECTIVESpontaneous spondylodiscitis remains uncommon but is a serious complication of the vertebral column. Risk factors include diabetes, hemodialysis, intravenous drug abuse, and chronic steroid use, and pain is the most common presenting symptom. This study aims to review the literature and report on the incidence, management, and clinical outcome of spontaneous spondylodiscitis in 44 patients.METHODSThis is a prospective study including 44 patients with spontaneous spondylodiscitis managed in the neurosurgery department of Cairo University Hospitals during the period between January 2012 and October 2017. All patients had a full clinical assessment, laboratory tests, radiological studies in the form of MRI with and without contrast, and a postoperative follow-up of up to 12 months.RESULTSTwelve cases underwent conservative treatment in the form of complete bed rest, intravenous antibiotics, and a spinal brace. Ten cases underwent surgical intervention in the form of laminectomy, debridement, and open biopsy. Twenty-two cases underwent laminectomy and surgical stabilization with fusion. There were 15 cases of tuberculous spondylodiscitis, 6 cases of brucellosis, 6 cases of pyogenic infection, and 17 cases in which no organism could be detected.CONCLUSIONSOnce the primary diagnosis is confirmed, early and adequately prolonged antibiotic therapy is recommended for spontaneous spondylodiscitis. Some cases can be successfully treated with conservative treatment alone, whereas surgery may be needed in other cases such as severe destruction of endplates, spinal abscess formation, mechanical instability, neurological deficits, and severe pain that have failed to respond to conservative treatment.

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.

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.

Prolonged back pain attributed to suspected spondylodiscitis

Objective: This study aimed at investigating the diagnostic value of 18F-FDG PET/CT in cases of suspected spondylodiscitis after inconclusive results in initial diagnostic imaging. Patients, methods: We analysed 38 consecutive cases of suspected spondylodiscitis (mean age: 67 ± 14 years) with chronic back pain referred to our Department during a fouryear- period after inconclusive results in MRI or other conventional modalities. Clinical histories were retrospectively worked up and results of 18F-FDG PET/CT and MRI were analysed and related to the results of biopsy, blood culture and a one-year clinical followup. 18F-FDG PET/CT was analysed qualitatively by visual analysis and quantitatively. We measured the maximum standardized uptake value (SUVmax) in the region of back pain and in a corresponding reference region (RR) in each patient and calculated a SUVmax-ratio. Results: 22/38 patients had confirmed spondylodiscitis, while 16 were negative. 18F-FDG PET/CT established a correct diagnosis in 34 out of 38 patients by visual analysis. 18F-FDG PET/CT reached a sensitivity, specificity and accuracy of 81.8%, 100%, 89.5% and a PPV and NPV of 100% and 80%. MRI, performed in 27 patients reached a sensitivity, specificity and accuracy of 75%, 71.4%, 74.1% and a PPV and NPV of 88.2% and 50%. Patients with confirmed spondylodiscitis showed a significantly (p < 0.05) higher SUVmax of 5.1 ± 1.9 and SUVmax-ratio of 1.9 ± 0.8 than patients without it (SUVmax (3.8 ± 1.5), SUVmaxratio (1.2 ± 0.3). Conclusion: 18F-FDG PET/CT provided diagnostic information in most patients with chronic back pain and suspected spondylodiscitis. It was helpful in establishing a correct diagnosis in challenging cases of spondylodiscitis with mostly unclear findings in previous MRI.

Spontaneous Spondylodiscitis - Epidemiology, Clinical Features, Diagnosis and Treatment

Spontaneous spondylodiscitis is a rare but serious infectious disease which is a combination of an inflammatory process, involving one or more adjacent vertebral bodies (spondylitis), the intervertebral discs (discitis) and finally - the neighboring neural structures. In most cases the condition is due to a hematogenous infection and can affect all regions of the spinal cord, but it is usually localized in the lumbar area. The most common clinical symptom is a pronounced, constant and increasing nocturnal paravertebral pain, while consequently different degrees of residual neurological symptoms from nerve roots and/or spinal cord may appear. The disease course is chronic and the lack of specific symptoms often prolongs the time between its debut and the diagnosis. This delay in diagnosis determines its potentially high morbidity and mortality. Treatment is conservative in cases with no residual neurological symptoms and consists of antibiotic therapy and immobilization. Surgical treatment is necessary in patients with neurological deficit, spinal instability or drug resistance.

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.

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.

Computed Tomography and Magnetic Resonance Imaging Parameters Associated with Poor Clinical Outcome in Spondylodiscitis

BACKGROUND

Prognostic factors for the disease course of patients with spondylodiscitis have not been well studied.

METHODS

The prognostic value of initial magnetic resonance imaging (MRI) and computed tomography imaging parameters was analyzed in 62 patients (47% women; mean age ± SD, 71.6 ± 9.6 years) with a confirmed diagnosis of spondylodiscitis. The disease course was separately evaluated during initial treatment response during hospitalization, relapse, and clinical short-term follow-up at 3 months.

RESULTS

Overall CT findings graded as definitely inflammatory (P = 0.006), reduced disc height on MRI (P = 0.044) and fluid-equivalent hyperintensity of discs on T2 short tau inversion recovery-weighted sequences (P = 0.047) were associated with poor initial treatment response. High initial C-reactive protein value (>10.1 mg/dL) was associated with a higher relapse rate (P = 0.038). Risk factors for poor outcome were infection with low-virulence bacteria (P = 0.040) and overall MRI findings atypical for infection (P = 0.027).

CONCLUSIONS

Compared with MRI, CT imaging parameters have a higher prognostic value regarding the disease course. Patients infected with low-virulence bacteria and atypical MRI findings are at higher risk for poor clinical outcome and thus warrant closer monitoring.

A comparison of the diagnostic value of MRI and 18F-FDG-PET/CT in suspected spondylodiscitis

Purpose

The purpose of this study was to evaluate the diagnostic value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT scan) and magnetic resonance imaging (MRI) in diagnosing spondylodiscitis and its complications, such as epidural and paraspinal abscesses.

Methods

From January 2006 to August 2013 patients with a clinical suspicion of spondylodiscitis, with an infection, or with fever of unknown origin were retrospectively included if ¹⁸F-FDG-PET/CT and MRI of the spine were performed within a 2-week time span. Imaging results were compared to the final clinical diagnosis and follow-up data were collected.

Results

Sixty-eight patients were included of whom 49 patients were diagnosed with spondylodiscitis. MRI showed an overall sensitivity of 67 % and specificity of 84 %. Diagnostic accuracy was 58 %, when MRI was performed within 2 weeks after the start of symptoms and improved to 82 %, when performed more than 2 weeks after onset of symptoms. ¹⁸F-FDG-PET/CT showed a sensitivity of 96 % and a specificity of 95 %, with no relation to the interval between the scan and the start of symptoms.

Conclusions

As compared to MRI, ¹⁸F-FDG-PET/CT has superior diagnostic value for detecting early spondylodiscitis. After 2 weeks both techniques perform similarly.

Is There an Association Between Magnetic Resonance Imaging and Neurological Signs in Patients With Vertebral Osteomyelitis?: A Retrospective Observational Study on 121 Patients

Neurological complications can occur in up to 51% of vertebral osteomyelitis (VO) in surgical series. The aim of our study was to estimate the frequency of neurological signs in a nonselected population of patients with VO and to assess clinical and MRI changes associated with these complications.We reviewed medical charts of patients with VO from 2007 to 2014 in our University Hospital and their MRIs were analyzed by a radiologist blinded from clinical data. Neurological status was defined as follow: normal, minor signs (radiculalgia or sensory loss), and major signs (motor deficit and/or sphincter dysfunction).A total of 121 patients were included. Mean age was 64.3 years. Overall, 50 patients (40%) had neurological signs, 26 were major signs (21.5%). Neurological signs were present at the time of admission in 37 patients and happened secondarily in 13 cases. MRI changes associated with major neurological signs were: Cervical involvement (P = 0.011), dural sac compression (P = 0.0012), ventral effacement of the subarachnoidal space (P < 0.001), compressive myelopathy (P = 0.006). More than 50% of the vertebral body destruction (P = 0.017), angular kyphosis (P = 0.016) partial or complete destruction of posterior arch (P = 0.032) were also associated with these signs. Neither epidural abscesses, multifocal lesions, loss of disk height, nor nerve roots compression were associated with major neurological signs.Neurological signs occurred in 40% of our patients with one half being major signs. Cervical involvement, vertebral destruction, angular kyphosis, dural compression, effacement of subarachnoid space and compressive myelopathy on MRI were risk factors associated with neurological complications.

An educational forum to engage infectious diseases and microbiology residents in resource stewardship modelled after the Choosing Wisely campaign

BACKGROUND:

Rising costs present a major threat to the sustainability of health care delivery. Resource stewardship is increasingly becoming an expected competency of physicians. The Choosing Wisely framework was used to introduce resource stewardship at a national educational retreat for infectious disease and microbiology residents.

METHODS:

During the 2014 Annual Canadian Infectious Disease and Microbiology Resident Retreat in Toronto, Ontario, infectious disease (n=50) and microbiology (n=17) residents representing 11 Canadian universities from six provinces, were invited to participate in a modified Delphi panel. Participants were asked, in advance of the retreat, to submit up to five practices that infectious disease and microbiology specialists should not routinely perform due to lack of proven benefit(s) and/or potential harm to patients. Submissions were discussed in small and large group forums using an iterative approach involving electronic polling until consensus was reached for five practices. A finalized list was created for both educational purposes and for residents to consider enacting; however, it was not intended to replace formal society-endorsed statements. A follow-up survey at two-months was conducted.

RESULTS:

Consensus was reached by the residents regarding five low-value practices within the purview of infectious diseases and microbiology physicians. After the retreat, 20 participants (32%) completed the follow-up survey. The majority of respondents (75%) believed that the session was at least as relevant as other sessions they attended at the retreat, including 95% indicating that at least some of the material discussed was new to them. Since returning to their home institutions, nine (45%) respondents have incorporated what they learned into their daily practice; four (20%) reported that they have considered initiating a project related to the session; and one (5%) reported having initiated a project.

CONCLUSIONS:

The present educational forum demonstrated that trainees can become actively engaged in the identification and discussion of low-value practices. Embedding residence training programs with resource stewardship education will be necessary to improve the value of care offered by the future members of our profession.

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.

Subcutaneous fluid collection: An imaging marker for treatment response of infectious thoracolumbar spondylodiscitis

PURPOSE

To evaluate prevalence of subcutaneous fluid collection (SFC) in infectious thoracolumbar spondylodiscitis (SD) compared with control patients and to investigate correlation between volume changes of SFC and treatment response of SD.

MATERIALS AND METHODS

This retrospective study was approved by our institutional review board. From April 2011 to March 2012, 49 patients (24 SD and 25 non-SD patients) were enrolled. Prevalence of SFC was evaluated respectively for SD and non-SD patients using magnetic resonance imaging (MRI) on the sagittal short tau inversion recovery (STIR) imaging or fat-saturated T2-weighted imaging (T2WI), and compared. In SD patients with SFC, correlation was investigated between SFC volume on the 1st MRI and initial clinical status. The same analysis was conducted also for SFC volume changes from the 1st to 2nd or last MRI.

RESULTS

SFC was found in 20 patients with SD (83.3%) and 3 non-SD patients (12%) with significant difference (p<.001). In 20 SD patients with SFC, 17 patients had follow-up MRI. For the 1st MRI, no significant correlation was found between volume of SFC and initial status of patients, including body weight, body mass index (BMI), white blood cell (WBC), and erythrocyte sedimentation rate (ESR). However, significant positive correlations were found between changes of C-reactive protein (CRP) and SFC volume from the 1st to 2nd as well as from the 1st to the last MRI (each p<.05).

CONCLUSION

SD patients had significantly higher prevalence of SFC than non-SD patients. Volume changes of SFC had significant correlation with changes of CRP, which can be used as an imaging marker for treatment response of SD on MRI.

A retrospective study of 113 consecutive cases of surgically treated spondylodiscitis patients. A single-center experience

BACKGROUND

Recommendations for the operative treatment of spondylodiscitis are still a controversial issue.

METHODS

A retrospective review identified 113 consecutive patients who underwent surgical debridement and instrumentation for spondylodiscitis between 2006 and 2010 at our department.

RESULTS

The mean age at presentation was 65 years; 78 patients were male (69 %). Distribution of the inflammation was lumbar in 68 (60 %), thoracic in 19 (17 %) and cervical in 20 (18 %) cases. Six patients (5 %) had two concomitant non-contiguous spondylodiscitis foci in different segments of the spine. Epidural abscess was found in 33 patients (29 %). One hundred four patients (92 %) had pain. Neurological deficit was found in 40 patients (35 %). In the thoracic and lumbar cases, dorsal instrumentation alone was considered sufficient in 26 cases; additional interbody fusion from the posterior was performed in 44 cases. A 360° instrumentation was performed in 22 cases. In the cervical cases, only ventral spondylodesis and plating were performed in eight cases, only dorsal instrumentation in five and 360° instrumentation in seven. Postoperative intravenous antibiotics were administered for 14.4 ± 9.3 (mean ± SD) days followed by 3.2 ± 0.8 (mean ± SD) months of oral antibiosis. Complete healing of the inflammation was achieved in 111 (98 %) cases. Two patients died because of septic shock, both with fulminant endocarditis. Pain resolved in all cases. Neurological deficits were completely resolved in 20 patients, and 14 patients had a partial recovery.

CONCLUSION

The results of our retrospective study show that surgical treatment of spondylodiscitis with a staged surgical approach (if needed) and a short 1-2-week period of intravenous antibiotics followed by 3 months of oral antibiotics is appropriate for most patients in whom conservative treatment has failed or is not advisable. Furthermore, surgical treatment of newly diagnosed spondylodiscitis might be recommended as an initial treatment option in many cases. Thereby the choice of fusion material (autologous bone, titanium, PEEK) seems less important.

Association Between Follow-Up Magnetic Resonance Imaging and Clinical Status Among Patients With Spinal Infections

BACKGROUND

Spinal infections, including paraspinal and/or epidural abscesses and vertebral discitis and osteomyelitis, can have devastating consequences. The diagnostic imaging modality of choice has traditionally been magnetic resonance imaging (MRI) given the very high sensitivity and specificity, although the role of MRI in follow-up of spinal infections and how this relates to follow-up clinical status is poorly understood. We sought to understand the relationship between follow-up MRI and clinical status.

METHODS

We conducted a retrospective review of adults with spinal infection to assess the relationship between follow-up MRI and clinical course. The degree of agreement between MRI and clinical follow-up was assessed using the Cohen kappa coefficient. A multinomial logistic regression model was applied to assess the impact of covariates in affecting the clinical outcome and MRI at follow-up independently.

RESULTS

Ninety-eight patients met inclusion criteria during a 13-year period. We observed a lack of correlation between clinical follow-up status and MRI (κ = 0.065, P = 0.322). The McNemar-Bowker test for symmetry revealed that this disagreement was asymmetric (P < 0.001). Notably, clinical worsening was never associated with an improved MRI, and clinical improvement was overall not predictive of MRI result and vice versa.

CONCLUSIONS

Routine follow-up MRI does not seem to correlate with clinical follow-up among patients with spinal infections. The use of MRI without new clinical indications in routine follow-up testing should be interpreted with caution.

Imaging of spine infection

This article reviews the imaging and relevant clinical details of infection of the extradural spine. Spine infections are increasing in incidence and in frequency of diagnosis. They are clinically important despite their relative rarity, because they may be life-threatening, and because early diagnosis leads to improved outcomes. The focus is on pyogenic spondylodiscitis. The also typically pyogenic conditions of epidural and subdural abscess, facet joint infection, and pyomyositis are discussed. Nonpyogenic, granulomatous infections are also addressed. Magnetic resonance imaging is emphasized. The radiologist's role in performing minimally invasive sampling procedures is highlighted.

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

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Pyogenic vertebral osteomyelitis: identification of microorganism and laboratory markers used to predict clinical outcome

The aim of this study is to determine the predictive values of laboratory indicators of pyogenic vertebral osteomyelitis (PVO) and a potential cure if the microorganism cannot be identified. Forty-five consecutive patients with PVO were enrolled. Antibiotic therapy with or without surgery was performed according to microorganism. In the negative-culture (NC) group, cefazolin was administered in cases of hematogenous PVO, and vancomycin was administered in cases of postoperative or procedure-related PVO. The clinical, laboratory, and radiological findings were followed up with regard to an appropriate response to antimicrobial therapy. Nine patients were treated with antibiotics alone. We were able to identify the microorganism in 34 cases (75.6%). Ten cases in NC group were cured without recurrence, but one was not. Identification of the microorganisms did not have any significant influence on the treatment outcome, duration of antibiotic administration or normalization of laboratory profiles. For erythrocyte sedimentation rate (ESR) values over 55 mm/h and C-reactive protein (CRP) values of 2.75 mg/dL at fourth week after antibiotic administration by means of ROC curve analysis, we expect significantly high rates of treatment failure by Pearson chi(2) test (chi(2) = 4.344, Odds ratio = 5.15, p = 0.037, 95% CI 1.004-26.597). Even in patients with negative culture findings, it is expected that a good outcome will be achieved by the administration of cefazolin or vancomycin for about 6 weeks. It is concluded that antibiotics selected according to the etiological setting can be initiated without the need to start empirical antibiotics. In every instance at fourth week after the initiation of antibiotic therapy, the values of CRP and ESR can provide meaningful information regarding whether clinicians need to reevaluate the effectiveness of antibiotics by performing follow-up imaging studies and monitoring the patient's clinical manifestations.