Diagnosis and management of pyogenic vertebral osteomyelitis in adults

CT guided biopsy for osteodiscitis reduces cost of hospitalization in the landscape of increasing intravenous drug use: A single center retrospective analysis

OBJECTIVE

Osteodiscitis has been demonstrated to show significant morbidity and mortality. Cultures and CT guided biopsy (CTB) are commonly used diagnosis of osteodiscitis. This study's purpose is to evaluate the cost burden of CTB and to evaluate how IVDU affects patient management in the setting of osteodiscitis.

METHODS

Patients admitted for osteodiscitis from 2011-2021 were retrospectively reviewed and stratified into cohorts by CTB status. Additional cohorts were stratified by Intravenous Drug Use (IVDU). Patient demographics, total cost of hospitalization, length of hospitalization, time to biopsy, IVDU status, and other factors were recorded. T-Test, Chi-squared analysis, and ANOVA were used for statistical analysis.

RESULTS

Total cost of hospitalization was recorded for 140 patients without CTB and 346 patients with CTB. Average cost of hospitalization for non-CTB was $227,317.86 compared to CTB at $119,799.20 (p < 0.001). Length of stay (LOS) was found to be 18.01 days for non-CTB and 14.07 days for CTB patients (0.00282). When stratified by days until biopsy, patients who had CTB sooner, had significantly reduced cost of hospitalization (p = 0.0003). Patients with IVDU history were significantly younger (p < 0.001) with lower BMI (p < 0.001) and a significantly different clinical profile. There was a significant difference in positive open biopsy when separated by IVDU status (p = 0.025).

CONCLUSION

CTB was associated with significantly reduced cost of hospitalization and LOS compared to non-CTB. IVDU patients with osteodiscitis have significantly different clinical profiles than non-IVDU that may impact diagnosis and treatment. Further work is indicated to elucidate causes of these differences to provide high value care to patients with osteodiscitis.

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.

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.

Posterior stabilisation without formal debridement for the treatment of non-tuberculous pyogenic spinal infection in frail and debilitated population - A systematic review and meta-analysis

Non-tuberculous pyogenic spinal infection (PSI) incorporates a variety of different clinical conditions. Surgical interventions may be necessary for severe cases where there is evidence of spinal instability or neurological compromise. The primary surgical procedure, for late-stage PSI, focuses on the anterior approach with aggressive debridement of the infected tissue regions. An alternative treatment method that employs a posterior approach without any formal debridement, is seen as controversial. To the best of our knowledge, few case series and no systematic reviews are assessing the value of this posterior technique. We aim to evaluate the effectiveness of the posterior approach without formal debridement and the associated clinical outcomes, for PSI cases requiring surgical intervention. Several databases including MEDLINE, NHS Evidence, and the Cochrane database were searched from the date of creation of each database to December 16, 2019. A selection of the keywords used includes: "posterior approach", "debridement" and "discitis". Studies were excluded if they involved the anterior approach, carried out formal debridement, or were tuberculous spinal infection cases. We accepted any study type which included adult patients, with spinal infection at any level of the vertebral column. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were used to follow standard systematic review structure. The main clinical outcomes evaluated include pain, neurological recovery (Frankel Grading System, FGS) post-operative complications, and functional outcomes (Kirkaldy-Willis Criteria and Spine Tango Combined Outcome Measure Index, COMI). Post-surgical neurological improvement was demonstrated with a mean FGS improvement of 1.12 in 102 patients over the included four articles. Post-operative neurological function was found to be improved at a statistically significant level when a random-effects model was applied, with the effect size found to be at 0.68 (p < 0.001). Pain level was improved significantly postoperatively. There were also enhanced functional outcomes post-intervention when the Kirkaldy-Willis criteria and COMI scores were assessed in certain studies. Within the limit of the available literature, our results showed that the posterior approach with posterior stabilisation without formal debridement can result in successful infection resolution, improved pain scores and neurological outcomes. However, Larger series with longer follow-up duration is strongly recommended.

Surgical Management of Thoracic Osteomyelitis due to Escherichia Coli Sepsis

Case Report. Escherichia coli is a rare cause of vertebral osteomyelitis. It is more common in adults and males. We present a case of an immunocompetent adult male presenting with a several month history of progressive systemic symptoms and subsequent neurologic compromise. We discuss the neurosurgical evaluation of a patient with a progressive vertebral osteomyelitis and treatment options. Surgical debridement and spinal stabilization were performed and confirmed the diagnosis. The patient successfully completed a prolonged antimicrobial therapy course. The patient made a complete neurologic recovery. We discuss the presentation of a patient with Escherichia coli vertebral osteomyelitis and the successful surgical management.

De novo methicillin-resistant Staphylococcus aureus vs. methicillin-sensitive Staphylococcus aureus infections of the spine, similar clinical outcome, despite more severe presentation in surgical patients

Vertebral osteomyelitis (VO) is a severe infection of the vertebral body and the adjacent disc space, where Staphylococcus aureus is most commonly isolated. The objective of this retrospective study was to determine risk factors for and compare outcome differences between de novo methicillin-resistant Staphylococcus aureus (MRSA) VO and methicillin-sensitive Staphylococcus aureus (MSSA) VO. A retrospective cohort study was performed by review of the electronic medical records of 4541 consecutive spine surgery patients. Among these 37 underwent surgical treatment of de novo MRSA and MSSA spinal infections. Patient demographics, pre- and postoperative neurological status (ASIA impairment score), surgical treatment, inflammatory laboratory values, nutritional status, comorbidities, antibiotics, hospital stay, ICU stay, reoperation, readmission, and complications were collected. A minimum follow-up (FU) of 12 months was required. Among the 37 patients with de novo VO, 19 were MRSA and 18 were MSSA. Mean age was 52.4 and 52.9 years in the MRSA and MSSA groups, respectively. Neurological deficits were found in 53% of patients with MRSA infection and in 17% of the patients with MSSA infection, which was statistically significant (p < 0.05). Chronic renal insufficiency and malnutrition were found to be significant risk factors for MRSA VO. Preoperative albumin was significantly lower in the MRSA group (p < 0.05). Patients suffering from spinal infection with chronic renal insufficiency and malnutrition should be watched more carefully for MRSA. The MRSA group did not show a significant difference with regard to final clinical outcome despite more severe presentation.

Predictive factors for positive disco-vertebral biopsy culture in pyogenic vertebral osteomyelitis, and impact of fluoroscopic versus scanographic guidance

Background

The aims of this study were to identify the predictive factors for microbiological diagnosis through disco-vertebral biopsy (DVB) in patients with pyogenic vertebral osteomyelitis (PVO) and negative blood cultures, and compare the performance of DVB under fluoroscopic versus scanographic guidance.

Methods

We performed a cohort study comparing positive and negative DVB among patients with PVO. All cases of PVO undergoing a DVB for microbiological diagnosis in our center were retrospectively reviewed. Infections due to Mycobacterium tuberculosis, infections on foreign device, and non-septic diseases were excluded. Anamnestic, clinical, biological, microbiological, as well as radiological data were collected from medical charts thanks to a standardized data set.

Results

A total of 111 patients were screened; 88 patients were included. Microbiological cultures were positive in 53/88 (60.2%) patients. A thickening of the paravertebral tissue ≥10 mm on magnetic resonance imaging (MRI) in axial MR scans was a predictive factor of DVB microbiological positivity (52.4% vs. 13.3%; p = 0.006; OR = 5.4). Overall, 51 DVB were performed under fluoroscopic guidance and 37 under scanographic guidance. Considering lumbar DVB, 25/36 (69.4%) of cases yielded positive results under fluoroscopic guidance versus 5/15 (33.3%) under scanographic guidance (p = 0.02; OR = 4.4). No adverse event linked to DVB was notified.

Conclusion

Every patient with PVO and negative blood cultures should undergo a DVB. A thickening of the paravertebral tissue ≥10 mm on MRI is associated with a higher rate of positive DVB culture. A lumbar DVB under fluoroscopic guidance is more sensitive than under scanographic guidance to identify the micro-organism involved.

Pyogenic spondylodiscitis of the lumbar spine related to anastomotic fistula after surgery for esophageal cancer: a case report

Background

Pyogenic spondylodiscitis is an extremely rare complication of esophagectomy for esophageal cancer.

Case presentation

A 70-year-old Japanese man, with a previous medical history of type 2 diabetes mellitus, coronary artery disease, and laryngeal cancer, received neoadjuvant chemotherapy and underwent thoracoscopic esophagectomy with gastric tube reconstruction for advanced esophageal cancer. Cervical esophagogastrostomy with circular-stapled end-to-side anastomosis was performed. However, partial necrosis in the gastric tube developed to form refractory anastomotic fistula. Two months after the initial surgery, debridement and free jejunal transfer reconstruction with the pectoralis major muscle flap were performed. Although the postoperative course of the second surgery was uneventful, the patient complained of severe lower back pain and fever. The patient was diagnosed with pyogenic spondylodiscitis according to the results of the magnetic resonance imaging. Enterobacter cloacae were isolated from the arterial blood culture. Sensitive antibiotics were administered continuously, and the patient required to use a lumbar corset for 2 months. Subsequently, his physiological signs and symptoms had completely disappeared.

Conclusion

To the best of our knowledge, this case study is the first study that reported pyogenic spondylodiscitis of the lumbar spine, a complication of cervical anastomotic fistula after surgery for advanced esophageal cancer.

How is the microbial diagnosis of bacterial vertebral osteomyelitis performed? An 11-year retrospective study

Vertebral osteomyelitis (VOM) is often diagnosed with delays, resulting in poorer outcomes. Microbial documentation is particularly challenging and obtained using blood cultures (BCs) and vertebral biopsies (VBs; CT-guided or surgical). We retrospectively analysed VOM cases in a tertiary reference centre between 2004 and 2015, focusing on how and how quickly microbiological diagnosis was performed. Among 220 VOM, 88.2% had documentation, including Gram-positive cocci (GPC) (70.6%), Gram-negative rods (GNR) (9.3%), anaerobes (3.6%), polybacterial infections (6.7%) and tuberculosis (9.8%). BCs were performed in 98.2% and positive in 59.3%, identifying most GPC (80.3%) and half of GNR (54.6%). VBs were performed in fewer cases (37.7%), but were more frequently positive (68.8% for CT-guided and 81.0% for surgical biopsies). They documented all anaerobes (100.0%), most M. tuberculosis (84.2%) and polybacterial infections (76.9%), and GNR (45.4%). Extra-vertebral samples highly contributed to tuberculosis diagnosis (52.6%, and 15.8% as the only positive sample). Documentations most often followed radiological diagnosis (53.4%). They were obtained earlier by BCs than by VB after first clinical symptoms (median of 14 versus 51 days). Antibiotic treatments were mostly initiated after samplings (88.0%). BCs allow the documentation of most VOM and should be performed without delay in case of clinical or radiological suspicion; however, they may miss 1 out of 5 GPC and 1 out of 2 GNR. VBs have a higher positivity rate and should be rapidly performed if negative BCs. It is likely that delayed and missed diagnoses result from the insufficient use of VB.

Safety and efficacy of percutaneous instrumentation combined with antibiotic treatment in spondylodiscitis

BACKGROUND

Patients with spondylodiscitis are treated with antibiotics and braces for 6 to 12 weeks. Braces aim to decrease pain and prevent kyphotic deformity due to vertebral body collapse. Percutaneous instrumentation could be an alternative to influence pain and patient's autonomy.

PURPOSE

The purpose of this study was to analyze back pain, quality of life, sagittal deformity, and complications after percutaneous instrumentation in spondylodiscitis.

PATIENTS AND METHODS

VAS for back pain, EQ-5D, radiographic sagittal index were assessed retrospectively for 28 patients who had a standardized follow-up at 5 days, 6 weeks, 3 months, 1 and 2 years. Probabilities>0.95 indicated significant changes (Bayesian model).

RESULTS

VAS was 7.0 preoperatively, 3.2 (day 5), 2.2 (6 weeks), 1.9 (3 months), 1.6 (1 year), 1.4 (2 years): probabilities>0.95 within 6 weeks. EQ-5D was 0.229 preoperatively, 0.563 (6 weeks), 0.687 (3 months), 0.755 (1 year), 0.787 (2 years): probabilities>0.95 within 1 year. Sagittal index was 15.1° preoperatively, 9.6° postoperatively: probability>0.95. Inter-body fusion was: complete 60.7%, partial 17.9%, and nonunion 21.4%. Antibiotic treatment was stopped at 6 weeks in 82.1%, at 3 months in 17.9%, without septic complication.

CONCLUSION

Percutaneous instrumentation improved pain control, quality of life and prevented kyphosis. Antibiotic treatment was not influenced. Septic complications were not observed.

LEVEL OF EVIDENCE

IV.

Comparison of Percutaneous Endoscopic Surgery and Traditional Anterior Open Surgery for Treating Lumbar Infectious Spondylitis

Minimally invasive surgery is becoming popular for treating spinal disorders. The advantages of percutaneous endoscopic debridement and drainage (PEDD) for infectious spondylitis include direct observation of the lesion, direct pus drainage, and earlier pain relief. We retrospectively reviewed 37 patients who underwent PEDD and 31 who underwent traditional anterior open debridement and interbody fusion with bone grafting from 2004 to 2012. The causative organisms were isolated from 30 patients (81.1%) following PEDD, and from 25 patients (80.6%) following open surgery (p = 0.48). Staphylococcus aureus was the most common pathogen (38.2%). In the PEDD group, blood loss (<50 mL versus 585 ± 428 mL, p < 0.001) was significantly lesser and the duration of hospitalization (24.4 ± 12.5 days versus 31.5 ± 14.6 days, p = 0.03) was shorter than that in the open surgery group. Serologically, there were significantly faster C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) normalization rates in the PEDD group (p < 0.001, p = 0.009, respectively). In the two-year follow-up radiographs, 26 out of 30 (86.7%) open surgery patients showed bony fusions of the infected segments. On the contrary, sclerotic change of the destructive endplates was observed and the motion of infected spinal segments was still preserved in the PEDD group. There was no significant difference in the change of sagittal profile, including primary correction gain, correction loss, and actual correction gain/loss. PEDD is an effective alternative option and should be considered prior to traditional extensive spinal surgery—particularly for patients with early-stage spinal infection or serious complicated medical conditions.

Management of Pyogenic Spinal Infection, review of literature

Objective

To evaluate the available evidence for the management of Pyogenic Spinal Infection (PSI).

Methods and results

A comprehensive search for the relevant literature published between 1990 and 2018 to evaluate the management of PSI was conducted.Nonoperative management of carefully selected patients for an adequate duration of antibiotics can result in satisfactory outcomes with low recurrence rate. When there is an indication for surgery, posterior approach, with or without debridement of infected tissue reported to be associated with good outcomes.

Conclusion

Studies with larger sample sizes and longer duration of follow up are recommended to formulate more comprehensive evidence.

SPONDYLODISCITIS INVESTIGATION AND THERAPEUTIC PROTOCOL: NEUROSURGERY SERVICE RESULTS

ABSTRACT Objective: Spondylodiscitis is still a frequent pathology among neurosurgical services, and its correct treatment involves infectious, neurological and orthopedic goals. The authors describe the protocol and report the diagnostic and therapeutic results after its implementation. Methods: A prospective prognostic study (Level I) including patients with primary spondylodiscitis treated in the Neurosurgical Service of Cristo Redentor Hospital from January 2014 to March 2018. Demographic, spine, infectious and treatment-related variables were analyzed. The numerical variables are presented as mean and standard deviation or median and interquartile range (according to their parametricity), and are compared by the student's t-Test or Mann-Whitney U Test, respectively. Results: Thirty seven patients were included. The sexes were evenly distributed, with predominantly Caucasians, and a mean age of 56.89 ±15.33. Hypertension and type 2 diabetes were the most frequent comorbidities. Vertebral lumbar level was the most involved segment. Pathogens were identified in 34 cases (91%), with Staphylococcus aureus being the most prevalent, followed by Koch Bacilli. Inflammatory markers are higher in pyogenic infections at hospital admission, but lower at hospital discharge when compared to tuberculous discitis (p<0.01). Mean hospital stay was higher in the pyogenic group. Conclusion: The protocol described has a high diagnostic level of the pathogen, with cure of infection and satisfactory neurologic outcome in all cases. Level of Evidence I, Diagnostic Studies - Investigating a Diagnostic Test.

Analysis of infectious spondylodiscitis: 7-years data

Objective:

Infectious spondylodiscitis (SD) is an infectious disease that is rare and difficult to diagnose due to its non-specific clinical features. In this study, we aimed to describe the clinical and diagnostic features of infectious spondylodiscitis.

Methods:

All patients who were diagnosed with SD at our hospital during a 7-year period from January 1, 2011 through December 31, 2017 were included in the study. Spondylodiscitis is divided into the following three types: pyogenic, tuberculous, and brucellar. Clinical and laboratory data were collected retrospectively from the medical records of the patients.

Results:

Of the 118 patients, 66 (55.9%) were female, 81 (68.6%) had pyogenic SD (PSD), 21 (17.8%) had tuberculous SD (TSD), and 16 (13.6%) had brucellar SD (BSD). The mean age was 59.3 ± 14.6 years. Leucocytosis was significantly higher in patients with PSD (p=0.01) than in patients with other types of SD. Thoracic involvement (47.6%) was significantly higher in patients with TSD (p=0.005) than in other patients. Sacral involvement (12.5%) was significantly higher in patients with BSD (p=0.01) than in other patients. Paravertebral abscess formation (42.8%) occurred most frequently in patients with TSD. Microbiologic agents were defined in 50% (18/36) of the surgical specimens and in 12.5% of the fine needle aspiration biopsy (FNAB) specimens. Staphylococcus aureus was the most common microbiological agent in patients with PSD. Spinal surgery was defined as a risk factor for PSD (p = 0.0001). Binary logistic regression analysis revealed that female gender, thoracic involvement and night sweats were the predictive markers for TSD (OR 4.5 [95% CI 1.3-15.3] and OR 5 [95% CI 1.7-14.6]).

Conclusion:

PSD is the most frequent form of SD. Leucocytosis is most common in patients with PSD. Thoracic involvement and paraspinal abscess were prominent in patients with TSD. Sacral involvement was most common in patients with BSD. Thoracic involvement, female gender and night sweats were the predictive markers for TSD. The microbiological culture positivity rate was higher in surgical specimens compared to FNAB specimens. The need for surgical treatment was most common in patients with TSD.

Cervical Spine Osteomyelitis: A Systematic Review of Instrumented Fusion in the Modern Era

OBJECTIVE

For cases of cervical osteomyelitis that require surgery, concern has continued regarding instrumentation owing to the potential for bacterial seeding of the hardware. We performed a systematic review of the current data.

METHODS

A search was performed using Medline, Embase, and Ovid for articles using the keywords "cervical osteomyelitis/spondylodiscitis" and "fusion" or "instrumentation" reported from 1980 to 2017. Prospective or retrospective studies describing ≥2 patients with cervical osteomyelitis were included in the analysis; non-English reports were excluded. Individual patients were excluded from the final analysis if they had previously undergone spinal instrumentation.

RESULTS

A total of 239 patients from 24 studies met our criteria. Surgical approaches were classified as anterior-only, combined anteroposterior, and posterior-only for 64.8%, 31.9%, and 3.3% of the patients respectively. Of the patients treated using an anterior-only approach, 76.5% had received anterior plating and 85.3%, a cage or spacer implants. Of the patients who had undergone combined approaches, 85.1% underwent circumferential fixation and 14.9%, anterior debridement with posterior instrumentation. The follow-up period ranged from 6 weeks to 11 years (mean, 31.0 months). All the studies reporting the fusion rates, except for 1, reported a 100% fusion rate. The reported rates of pain improvement and neurologic recovery were favorable. The incidence of hardware failure and wound complications was 4.6% and 4.0%, respectively.

CONCLUSIONS

Despite placing instrumentation during active infection, the rates of hardware failure and wound complications were comparable to those of elective cervical spine procedures. These results suggest that surgical intervention with instrumentation is a safe treatment option for patients with cervical spine osteomyelitis.

Diagnosis and management of spinal infections

The number of spinal infections has been increasing due to aging populations and larger numbers of immunocompromised hosts and intravenous drug users. Magnetic resonance imaging is a useful tool for the early diagnosis of spinal infections, and can yield positive findings just 3-5 days after disease onset. Before antibiotic administration, cultures must be initiated from blood and from specimens collected from the locus of infection. Based on the pathogens identified by culture, appropriate antibiotics should be selected with careful consideration of antimicrobial susceptibility and spinal tissue penetration. Antibiotic treatment of spinal infections should be continued for longer than for most other types of infections, although the optimal duration remains unknown. The indications for surgical treatment include progressive neurologic deficits, progressive deformity, spinal instability, persistent or recurrent infection, and unbearable pain. In most patients with spinal infection, the gold standard surgical treatment is anterior radical debridement followed by autologous strut bone grafting. The addition of posterior instrumentation has recently become popular. This procedure may be performed alone as an alternative surgical option in patients in poor condition, and if it dramatically reduces pain, subsequent observation may be reasonable. If progressive deformity is observed or pain relief is inadequate after posterior instrumentation, additional anterior debridement and bone grafting should be scheduled.

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

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.

Typhoid spondylodiscitis mimicking tuberculosis in a teenage girl

Salmonella Typhi cause a broad spectrum of human illnesses like gastroenteritis, typhoid fever, and bacteremia. It has also been recognized as a causative organism of osteomyelitis for more than a century but the incidence appears to be uncommon. Microbiological workup plays important role in the diagnosis of Typhoid spondylodiscitis as most of the time it mimics tuberculosis and misguide the clinician, especially in the developing world. Here, we reported an uncommon case of lumbar spondylodiscitis by Salmonella Typhi in an immunocompetent teenager, with the help of clinical, microbiological and radiological evidence. The case was managed conservatively after posterior spinal stabilization.

Predictive Value of C-Reactive Protein (CRP) in Identifying Fatal Outcome and Deep Infections in Staphylococcus aureus Bacteremia

Introduction

Clear cut-off levels could aid clinicians in identifying patients with a risk of fatal outcomes or complications such as deep infection foci in Staphylococcus aureus bacteremia (SAB). Cut-off levels for widely used clinical follow-up parameters including serum C-reactive protein (CRP) levels and white blood cell counts (WBC) have not been previously studied.

Methods

430 adult SAB patients in Finland took part in prospective multicentre study in which their CRP levels and WBC counts were measured on the day of the positive blood culture, every other day during the first week, twice a week during hospitalization and at 30 days. Receiver operating characteristic (ROC) analysis was used to evaluate the prognostic value of CRP and WBC on the day of the positive blood culture and at days 4, 7, and 14 in predicting mortality and the presence of deep infections at 30 days. Adjusted hazard ratios (HR) for CRP level and WBC count cut-off values for mortality were calculated by the Cox regression analysis and adjusted odds ratios (OR) for cut-off values to predict the presence of deep infection by the binary logistic regression analysis.

Results

The succumbing patients could be distinguished from the survivors, starting on day 4 after the positive blood culture, by higher CRP levels. Cut-off values of CRP for day 30 mortality in adjusted analysis, that significantly predicted fatal outcome were at day 4 CRP >103 mg/L with sensitivity of 77%, specificity of 55%, and HR of 3.5 (95% CI, 1.2–10.3; p = 0.024), at day 14 CRP >61 mg/L with a sensitivity of 82%, specificity of 80% and HR of 3.6 (95% CI, 1.1–10.3; p<0.039) and cut-off value of WBC at day 14 >8.6 x10⁹/L was prognostic with sensitivity of 77%, specificity of 78% and HR of 8.2 (95% CI, 2.9–23.1; p<0.0001). Cut-off values for deep infection in adjusted analysis were on the day of the positive blood culture CRP >108 mg/L with sensitivity of 77%, specificity of 60%, and HR of 2.6 (95% CI, 1.3–4.9; p = 0.005) and at day 14 CRP >22 mg/L with sensitivity of 59%, specificity of 68%, and HR of 3.9 (95% CI, 1.6–9.5; p = 0.003). The lack of decline of CRP in 14 days or during the second week were neither prognostic nor markers of deep infection focus.

Conclusions

CRP levels have potential for the early identification of SAB patients with a greater risk for death and deep infections.

Does Pathogen Identification Influence the Clinical Outcomes in Patients With Pyogenic Spinal Infections?

STUDY DESIGN

Retrospective study.

OBJECTIVE

To study the clinical outcomes of patients suffering from pyogenic spinal infections (PSI), by comparing the outcomes of patients with an identified microbiological agent with those of patients without an identified pathogen.

SUMMARY OF BACKGROUND DATA

PSI is associated with significant risks for morbidity and mortality. Specific antibiotic treatment has been considered a key to successful medical treatment; however, clinicians frequently treat patients with PSI without an identified agent. A paucity of data is available comparing the clinical outcomes of patients with or without an identified pathogen.

MATERIALS AND METHODS

The records of 97 consecutive patients discharged from a University Hospital with the diagnosis of PSI during a 14-year period were retrospectively reviewed. Patients' demographics, etiological agent, comorbidities, site of infection, white blood cell count, erythrocyte sedimentation rate, C-reactive protein at the time of presentation, neurological impairment, length of hospital stay, and mortality were registered to compare the clinical outcomes of patients with an identified pathogen with those of patients without an identified agent.

RESULTS

The causative organism was identified in 74 patients (76.3%). Patients with microbiological diagnosis were younger, and a larger percentage of them exhibited elevated C-reactive protein value; however, they were not different from those without an identified agent in terms of sex, site of infection, comorbidities, and the presence of a concomitant infection. Our study could not demonstrate different neurological outcomes, length of stay, or mortality rates among the 2 groups.

CONCLUSIONS

In a large series of patients with PSI, we did not demonstrate differences in clinical outcomes using empirical antibiotics in patients without an identified pathogen compared with patients with an identified microbiological agent receiving specific antibiotics. Future prospective multicenter studies should be conducted to obtain an answer to this important clinical question.

Differential diagnosis between tuberculous spondylodiscitis and pyogenic spontaneous spondylodiscitis: a multicenter descriptive and comparative study

BACKGROUND CONTEXT

Although tuberculous and pyogenic spondylodiscitis are common causes of spinal infections, their protean manifestation complicates differential diagnosis.

PURPOSE

The clinical, laboratory, and radiologic characteristics of tuberculous and pyogenic spontaneous spondylodiscitis were compared in this study.

STUDY DESIGN

This multicenter retrospective study was conducted in 11 teaching hospitals in the Republic of Korea from January 2011 to December 2013.

PATIENT SAMPLE

Study subjects included adult patients (≥18 years) diagnosed with tuberculous (n=60) or pyogenic (n=117) spontaneous spondylodiscitis.

OUTCOME MEASURES

Risk factors for tuberculous spondylodiscitis were determined, and their predictive performance was evaluated.

METHODS

Multivariate logistic regression analysis was performed to determine predictors independently associated with tuberculous spondylodiscitis. Receiver-operating characteristic curve analysis using the presence or absence of risk factors was used to generate a risk index to identify patients with increased probability of tuberculous spondylodiscitis.

RESULTS

Of 177 patients, multivariate logistic regression analysis showed that patients with tuberculous spondylodiscitis (n=60) were more frequently women, with increased nonlumbar spinal involvement and associated non-spinal lesions, delayed diagnosis, higher serum albumin levels, reduced white blood cell counts, and lower C-reactive protein and procalcitonin levels. Among 117 patients with pyogenic spondylodiscitis, the most frequent causative microorganism was Staphylococcus aureus (64.1%). The mean diagnostic delay was significantly shorter, which may reflect higher clinical expression leading to earlier diagnosis. A combination of clinical data and biomarkers had better predictive value for differential diagnosis compared with biomarkers alone, with an area under the curve of 0.93, and sensitivity, specificity, and positive and negative predictive values of 95.0%, 79.5%, 70.4%, and 96.9%, respectively.

CONCLUSIONS

This study provides guidance for clinicians to predict the causative organisms of spondylodiscitis in uncertain situations and before culture or pathologic examinations. Clinical data and single biomarkers combined can be useful for differential diagnoses between tuberculous and pyogenic spondylodiscitis.

Extreme lateral interbody fusion with posterior instrumentation for spondylodiscitis

The purpose of this study was to evaluate our initial experience utilizing extreme lateral interbody fusion (XLIF; NuVasive, San Diego, CA, USA) with percutaneous posterior instrumentation to treat 11 spondylodiscitis patients between January 2011 and February 2014. Although medical management is the first line treatment for spondylodiscitis, many patients fail antibiotic therapy and bracing, or present with instability, neurologic deficits, or sepsis, requiring operative debridement and stabilization. High rates of fusion and infection clearance have been reported with anterior lumbar interbody fusion (ALIF), but this approach requires a morbid exposure, associated with non-trivial rates of vascular and peritoneal complications. XLIF is an increasingly popular interbody fusion technique which utilizes a fast and minimally invasive approach, sparing the anterior longitudinal ligament, and allowing sufficient visualization of the intervertebral discs and bodies to debride and place a large, lordotic cage. The outcome measures for this study included lumbar lordosis, sagittal balance, subsidence, fusion, pain, neurological deficit, and microbiology/laboratory evidence of infection. The mean follow-up time was 9.3 months. All patients had improvements in pain and neurological symptoms. The mean lordosis change was 11.0°, from 23.1° preoperatively to 34.0° postoperatively. Fusion was confirmed with CT scans in five of six patients. At the last follow-up, all patients had normalization of inflammatory markers, no symptoms of infection, and none required repeat surgical treatment for spondylodiscitis. XLIF with percutaneous posterior instrumentation is a minimally invasive technique with reduced morbidity for lumbar spine fusion which affords adequate exposure to the vertebral bodies and discs to aggressively debride necrotic and infected tissue. This study suggests that XLIF may be a safe and effective alternative to ALIF for the treatment of spondylodiscitis.

Changing trends in the epidemiology of vertebral osteomyelitis in Marseille, France

The incidence and significant morbidity of vertebral osteomyelitis are increasing despite the progress of diagnosis competences. Among the 50 cases of vertebral osteomyelitis managed in our centers over the past 5 years, 84% of the cases were in men. The mean age was 55 years. Sixty-two percent of patients had comorbidities and risk factors: diabetes mellitus (24%), malignancy (16%), intravenous drug use (10%) and alcoholism (4%). A source of infection was identified in 66% of cases, including postvertebral surgery infection (18%) and hematogenous infection (48%). The mean time to diagnosis was 36 days. Back pain were occurred in 90% of cases, fever (70%), neurologic deficits (40%), epidural abscesses (32%), completed vertebral bone destruction (26%) and psoas abscess (12%). A single organism was isolated in 92% of cases. Gram-positive bacteria were identified in 76% of cases, while Gram-negative bacilli (GNB) were found in 18% of cases. The presence of GNB was significantly associated with malignancy (p 0.041). The mean duration of antibiotic therapy was 123 days. Surgical treatment was performed in 41 cases: spinal stabilization (26%), drainage of abscesses (32%) and relief of compression (40%). Residual pain was found in 24% of cases, and neurologic sequelae in 22%. Cervical or thoracic localization was a risk factor for neurologic compromise (p 0.042). The epidemiology of vertebral osteomyelitis has changed; an increase in malignancy that was significantly associated with vertebral osteomyelitis due to GNB has been observed. Our study shows that the rate of neurologic complications remains high despite improved diagnostic capabilities and optimal treatment.

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.

Diagnosis and management of primary pyogenic spinal infections in intravenous recreational drug users

OBJECT

Primary spine infection secondary to intravenous drug abuse (IVDA) is a difficult clinical entity encountered by spine surgeons and infectious disease specialists. Patients tend to be noncompliant with the treatment and follow-up, and some continue to use IV recreational drugs even after the diagnosis of spine infection. The authors undertook this study to analyze the presentation, etiology, demographic characteristics, treatment, and outcome of primary pyogenic spinal infection in patients with IVDA as the major risk factor.

METHODS

The medical records, radiology imaging, and laboratory results (white blood cell count, inflammatory markers, bacteriology cultures) of all patients with pyogenic spine infection and history of IVDA presenting to a tertiary care center from August 2005 through December 2013 were retrospectively reviewed. The department of neurosurgery database and the hospital electronic medical records of University Hospital in San Antonio were used to identify the cohort for our study.

RESULTS

A total of 164 patients with spinal infection were evaluated during the study period; 102 of these patients had a history of IVDA. Their average age was 45.4 years, and only 14 (13.7%) were women. The mean laboratory values at presentation included a white blood cell count of 11.1 × 10(3) cells/μl (range 0.5-32 × 10(3) cells/μl), erythrocyte sedimentation rate (ESR) of 74 mm/hr (range 9.9-140 mm/hr), and C-reactive protein (CRP) level of 67 mg/L (range 0.1-327 mg/L). Twenty-six patients (25.4%) had an associated epidural abscess. The most common organism isolated from cultures of the bone and/or blood was methicillin-sensitive Staphylococcus aureus (MSSA), which was found in 37 cases. A close second was methicillin-resistant S. aureus (MRSA), found in 23 cases. The most commonly involved region was the lumbar spine (24 cases [57.8%]), and most patients (69.6%) had involvement of only a single level. Eighty patients were initially treated with long-term IV antibiotic therapy, and only 22 underwent surgical intervention (24 procedures). Of the latter group, 8 patients underwent laminectomy alone while 16 required some type of instrumented stabilization. Of the patients requiring stabilization procedures, 2 (12.5%) required reoperation with extension of their surgical constructs to other levels. The average follow-up was 29.7 weeks (range 6 weeks to 3 years).

CONCLUSIONS

Diagnosis and management of spinal infection in patients with a history of IVDA is challenging. The data from this study show that initial laboratory values are difficult to interpret given that only a minority of these patients present with leukocytosis. Back pain was the only reliable predictor of spine infection. The authors' experience indicates that the majority of patients with spine infection and a history of IVDA can be successfully treated with IV antibiotic therapy alone.

Risk factors for the development of deformity in patients with spinal infection

OBJECT

Bacterial spinal infections are infrequent but may lead to significant morbidity and death. Apart from neurological complications, infections may also lead to bone destruction resulting in deformity of the spine. However, the incidence of spinal deformities and risk factors is not well characterized in the literature.

METHODS

A retrospective cohort study was conducted using electronic medical records at a single institution. All patients were over 18 years of age and had a clinically and radiologically documented spinal infection that was treated surgically during the period 2006-2013. Infections were classified according to anatomical location including disc, bone, and/or epidural space. Deformities included kyphosis and/or subluxation. The authors analyzed risk factors for developing at least 1 deformity between the time of infection and operation using the Fisher exact test and chi-square test. Change in visual analog scale (VAS) scores preoperatively versus postoperatively was also analyzed using the paired t-test.

RESULTS

The study included 48 patients. The most common types of spinal infections were osteomyelitis and discitis (31%); osteomyelitis, discitis, and spinal epidural abscess (SEA; 27%); SEA only (15%); and osteomyelitis only (13%). Overall, 21 (44%) of 48 patients developed a spinal deformity. Anatomical location of infection (bone and/or disc and/or epidural space) was significantly associated with development of deformity (p < 0.001). In particular, patients with SEA had lower odds of deformity compared with patients without SEA (odds ratio 0.2, 95% confidence interval 0.05-0.9; p < 0.001). No other factor was significantly associated with deformity. Pain measured by VAS score tended to improve by a mean of 1.7 ± 2.7 points (p < 0.001) when comparing preoperative to postoperative scores.

CONCLUSIONS

In this cohort of patients, 44% developed at least 1 deformity, predominantly kyphosis. The only variable significantly associated with deformity was infection location. Patients with SEA alone demonstrated lower odds of developing a deformity compared with patients without SEA. Other analyzed variables, including age, body mass index, time from initial diagnosis to surgery, and comorbidities, were not found to be associated with development of deformity. Surgical intervention resulted in pain improvement.

Factors influencing culture positivity in pyogenic vertebral osteomyelitis patients with prior antibiotic exposure

We conducted a retrospective cohort study to evaluate factors influencing tissue culture positivity in patients with pyogenic vertebral osteomyelitis exposed to antibiotics before diagnosis. Tissue culture was positive in 48.3% (28/58) of the patients, and the median antibiotic-free period was 1.5 days (range, 0.7 to 5.7 days). In a multivariate analysis, a higher C-reactive protein (CRP) level (adjusted odds ratio [aOR], 1.18; 95% confidence interval, 1.07 to 1.29) and open surgical biopsy (aOR, 6.33; 95% confidence interval, 1.12 to 35.86) were associated with tissue culture positivity.

Infectious spondylodiscitis: has there been any evolution in the diagnostic and treatment outcomes?

Objective: To evaluate the clinical and radiological results of treatment of patients with spondylodiscitis. Methods: Imaging exams used in this study were plain radiographs and magnetic resonance imaging of the spine. Results: Data from 33 patients, 10 (30.3%) females and 23 (69.7%) males were evaluated. The average time to diagnosis was four months and 28 days (SD &#177; 1 month and 28 days) and 19 patients (57.5%) presented neurological deficit. Surgical treatment was performed in 22 patients (66.6%) and three patients (9.1%) had complications from the surgery. Conclusions: Despite technological advances in complementary exams, early diagnosis of spondylodiscitis remains a challenge. However, drug treatment associated with surgery shows good results.

Surgical treatment for pyogenic vertebral osteomyelitis using iodine-supported spinal instruments: initial case series of 14 patients

Reports have detailed the increasing use of spinal instrumentation in the treatment of pyogenic vertebral osteomyelitis, with the aims of achieving a lower pseudoarthrosis rate and restoring spinal alignment. However, controversy remains over the use of instrumentation in the presence of active infection because of concerns about increased bacterial adherence and biofilm formation on the metallic implant surface. Fourteen consecutive patients were followed who were diagnosed as having pyogenic vertebral osteomyelitis and underwent surgery with spinal instrumentation with iodine-containing surfaces that could be directly supported to existing titanium implants. Bone-cage interfaces and implant-related complications after surgery were evaluated. The white blood cell (WBC) count and C-reactive protein (CRP) level were analyzed during the follow-up period. To confirm the influence of iodine release from the implant, thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were also examined. The infection subsided in all 14 patients. Both WBC counts and CRP levels returned to normal ranges by the final follow-up. One patient showed a lucent area around the screw and two patients showed lucencies inside the cage. However, no cage dislocations, cage migrations, or screw pull-outs were noted, and all patients' FT3, FT4, and TSH levels were within normal ranges during the follow-up period. We demonstrated the efficacy of iodine-supported titanium implants in the management of pyogenic vertebral osteomyelitis. No cytotoxicity or adverse effects were noted in this series.

Use of permanently placed metal expandable cages for vertebral body reconstruction in the surgical treatment of spondylodiscitis

This is a retrospective study of 15 patients treated for spondylodiscitis with implanted metal cages. The purpose of this study is to investigate the outcomes of patients treated with permanently placed metal hardware in vertebral body reconstruction for spondylodiscitis. The use of metal implants in the face of infection has classically been discouraged in orthopedic literature because of the ability of bacteria to form biofilms on metal surfaces. Traditional treatment of spondylodiscitis has been aggressive debridement followed by reconstruction with bone grafts. Expandable metallic cages made reconstruction of these defects significantly easier. However, concern exists that metallic implants affect the resolution of infection. A search of the authors' patient database from 2005 to 2009 revealed 21 patients with spondylodiscitis treated with anterior debridement and reconstruction with an expandable metallic cage. Fourteen patients (15 cases) had sufficient documented clinical follow-up and were available for review. Resolution of infection was determined by evaluating symptoms, laboratory data, and final radiographic result. Of the 15 cases, all had clinical resolution of infection with an average follow-up time of 25 months. An average loss of 1.9° of correction was observed when comparing final follow-up radiographs with initial postoperative radiographs. Radiograph review revealed no extensive osteolysis around the hardware or progressive collapse. These results suggest that the use of expandable metal cages maintains alignment while not perpetuating infection. The spine appears to provide a unique environment that permits the use of metal implants in the setting of infection.

Surgical treatment of lumbar spondylodiscitis: a comparison of two methods

PURPOSE

This study evaluates two basic hypotheses: (1) the risk of an isolated dorsal approach to ventral lumbar spondylodiscitis based on clinical and radiographic results and (2) the risk of anterior radical debridement due to using a titanium implant in the site of bone infection.

METHODS

Group A consisting of 23 patients was treated only by a dorsal transmuscular approach and group B consisting of eight patients was treated by two-stage posteroanterior surgery. Both evaluated groups were assessed before surgery, six weeks and one year after surgery with the Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) and Kirkaldy-Willis functional criteria. To evaluate the sagittal balance restoration, measurement by the Cobb modified angle of the affected segment was performed.

RESULTS

Differences (p < 0.001) in group A were found between JOA values before surgery (average 9.30) and at six weeks after surgery (average 11.82) and 12 months after surgery (13.27) and VAS differences before surgery (average 7.39), six weeks after surgery (average 3.82) and 12 months after surgery (average 2.36) in group A. According to the Kirkaldy-Willis functional criteria, 11 patients were evaluated as excellent, nine patients as good and two patients as poor. The values of the JOA score in group B showed an improvement compared with the JOA values before surgery (average 9.38) at six weeks after surgery (average 11.75) and 12 months after surgery (average 13.63), and the VAS score before surgery (average 7.38) was found to have improved six weeks after surgery (average 4.63) and 12 months after surgery (average 2.25). The functional evaluation according to the Kirkaldy-Willis functional criteria assessed three patients as excellent, four patients as good and one patient as fair. Radiographic examinations of group A revealed the following findings before surgery (average 1.75), six months after surgery (average -3.73) and 12 months after surgery (average -0.79) and in group B before surgery (average 3.71), six weeks after surgery (average -8.21) and 12 months after surgery (average -6.45).

CONCLUSIONS

The results demonstrate the minimum serious surgical complications and greater loss of sagittal balance without clinical correlation in group A. We did not find any relapse or persistence of the infection in the post-operative period in group B.

Is switching to an oral antibiotic regimen safe after 2 weeks of intravenous treatment for primary bacterial vertebral osteomyelitis?

Background

Vertebral osteomyelitis (VO) may lead to disabling neurologic complications. Little evidence exists on optimal antibiotic management.

Methods

All patients with primary, non-implant VO, admitted from 2000–2010 were retrospectively analyzed. Patients with endocarditis, immunodeficiency, vertebral implants and surgical site infection following spine surgery were excluded. Persistence of clinical or laboratory signs of inflammation at 1 year were defined as treatment failure. Logistic regression was used to estimate the odds ratios (OR) of switch to an oral regimen after 2 weeks.

Results

Median antibiotic treatment was 8.1 weeks in 61 identified patients. Switch to oral antibiotics was performed in 72% of patients after a median intravenous therapy of 2.7 weeks. Switch to oral therapy was already performed after two weeks in 34% of the patients. A lower CRP at 2 weeks was the only independent predictor for switch to oral therapy (OR 0.7, 95% confidence interval 0.5-0.9, p = 0.041, per 10 mg/l increase). Staphylococcus aureus was the most frequently isolated microorganism (21%). Indications for surgery, other than biopsy, included debridement with drainage of epidural or paravertebral abscess (26 patients; 42%), and CT - guided drainage (3 patients).

During the follow-up, no recurrences were observed but 2 patients died of other reasons than VO, i.e. the 1 year intention to treat success rate was 97%.

Conclusions

Cure rates for non-implant VO were very high with partly short intravenous and overall antibiotic therapy. Switching to an oral antibiotic regimen after two weeks intravenous treatment may be safe, provided that CRP has decreased and epidural or paravertebral abscesses of significant size have been drained.

Comparison of pyogenic spondylitis and tuberculous spondylitis

Pyogenic spondylitis and tuberculous spondylitis are common causes of spinal infection. It is difficult to differentiate tuberculous spondylitis and pyogenic spondylitis clinically and radiologically. Recently magnetic resonance imaging has been reported to be beneficial for early diagnosis and differential diagnosis of the spondylitis, and is being used extensively for diagnosis. However, the diagnosis must be considered in combination with corresponding changes in clinical manifestations, radiological findings, blood and tissue cultures and histopathological findings. Conservative treatments, including antimicrobial medications, are started initially. Surgical treatments, which include anterior or posterior approach, single-stage or two-stage surgery, with or without instrumentation, may be performed as indicated.

Surgical management of pyogenic discitis of lumbar region

Study Design

Retrospective review of patients who had pyogenic discitis and were managed surgically.

Purpose

To analyze the bacteriology, pathology, management and outcome of pyogenic discitis of the lumbar region treated surgically.

Overview of Literature

Surgical management of pyogenic discitis is still an infrequently used modality of treatment.

Methods

A total of 42 patients comprised of 33 males and 9 females who had pyogenic discitis with a mean age of 51.61 years (range, 16-75 years) were included in this study. All the cases were confirmed as having pyogenic discitis by pus culture report and histopathological examination. The mean follow-up period was 41.9 months.

Results

Debridement and posterior lumbar interbody fusion with autologous iliac bone graft was done in all cases. Thirteen (30.95%) patients had other medical co-morbidities. Five cases had a previous operation of the spine, and three cases had a history of vertebral fracture. Three patients were operated for gynaecological problems, and four cases had a history of urological surgery. L4-5 level was the most frequent site of pyogenic discitis. The most common bacterium isolated was Staphylococcus aureus (S. aureus). Radiologically good fusion was seen in the majority of patients.

Conclusions

Pyogenic discitis should be suspected in people having pain and local tenderness in the spinal region with a rise in inflammatory parameters in blood. The most common bacterium was S. aureus, but there were still a greater number of patients infected with other types of bacteria. Therefore, antibiotics therapy should be started only after isolating the bacteria and making the culture sensitivity report.

Central Nervous System Infections

Central nervous system (CNS) infections—i.e., infections involving the brain (cerebrum and cerebellum), spinal cord, optic nerves, and their covering membranes—are medical emergencies that are associated with substantial morbidity, mortality, or long-term sequelae that may have catastrophic implications for the quality of life of affected individuals. Acute CNS infections that warrant neurointensive care (ICU) admission fall broadly into three categories—meningitis, encephalitis, and abscesses—and generally result from blood-borne spread of the respective microorganisms. Other causes of CNS infections include head trauma resulting in fractures at the base of the skull or the cribriform plate that can lead to an opening between the CNS and the sinuses, mastoid, the middle ear, or the nasopharynx. Extrinsic contamination of the CNS can occur intraoperatively during neurosurgical procedures. Also, implanted medical devices or adjunct hardware (e.g., shunts, ventriculostomies, or external drainage tubes) and congenital malformations (e.g., spina bifida or sinus tracts) can become colonized and serve as sources or foci of infection. Viruses, such as rabies, herpes simplex virus, or polioviruses, can spread to the CNS via intraneural pathways resulting in encephalitis. If infection occurs at sites (e.g., middle ear or mastoid) contiguous with the CNS, infection may spread directly into the CNS causing brain abscesses; alternatively, the organism may reach the CNS indirectly via venous drainage or the sheaths of cranial and spinal nerves. Abscesses also may become localized in the subdural or epidural spaces. Meningitis results if bacteria spread directly from an abscess to the subarachnoid space. CNS abscesses may be a result of pyogenic meningitis or from septic emboli associated with endocarditis, lung abscess, or other serious purulent infections. Breaches of the blood–brain barrier (BBB) can result in CNS infections. Causes of such breaches include damage (e.g., microhemorrhage or necrosis of surrounding tissue) to the BBB; mechanical obstruction of microvessels by parasitized red blood cells, leukocytes, or platelets; overproduction of cytokines that degrade tight junction proteins; or microbe-specific interactions with the BBB that facilitate transcellular passage of the microorganism. The microorganisms that cause CNS infections include a wide range of bacteria, mycobacteria, yeasts, fungi, viruses, spirochaetes (e.g., neurosyphilis), and parasites (e.g., cerebral malaria and strongyloidiasis). The clinical picture of the various infections can be nonspecific or characterized by distinct, recognizable clinical syndromes. At some juncture, individuals with severe acute CNS infections require critical care management that warrants neuro-ICU admission. The implications for CNS infections are serious and complex and include the increased human and material resources necessary to manage very sick patients, the difficulties in triaging patients with vague or mild symptoms, and ascertaining the precise cause and degree of CNS involvement at the time of admission to the neuro-ICU. This chapter addresses a wide range of severe CNS infections that are better managed in the neuro-ICU. Topics covered include the medical epidemiology of the respective CNS infection; discussions of the relevant neuroanatomy and blood supply (essential for understanding the pathogenesis of CNS infections) and pathophysiology; symptoms and signs; diagnostic procedures, including essential neuroimaging studies; therapeutic options, including empirical therapy where indicated; and the perennial issue of the utility and effectiveness of steroid therapy for certain CNS infections. Finally, therapeutic options and alternatives are discussed, including the choices of antimicrobial agents best able to cross the BBB, supportive therapy, and prognosis.

The management gram-negative bacterial haematogenous vertebral osteomyelitis: a case series of diagnosis, treatment and therapeutic outcomes

PURPOSE

The incidence of gram-negative bacterial haematogenous vertebral osteomyelitis (GNB HVO) is increasing. We performed a retrospective cohort study of patients with this type of infection in an effort to gain an improved understanding of the current clinical presentation, management and outcome.

METHODS

Between May 2007 and May 2010, all patients, over the age of 18 years, suffering from GNB HVO were identified and their microbiological diagnoses were evaluated.

RESULTS

This study identified seventy-nine patients with haematogenous vertebral osteomyelitis (HVO). Of these seventy-nine patients, 10 patients (12.66%) had Gram-negative organisms isolated. These organisms included Escherichia coli (4), Pseudomonas aeruginosa (3), Klebsiella pneumonia (1), Haemophilus influenza (1) and Enterobacter cloacae (1). Eight patients were successfully treated with antibiotics and/or surgery. Of the eight patients whose HVO was cured, five had Ciprofloxacin as part of their definitive antibiotic regime.

CONCLUSION

The treatment of GNB HVO is often challenging because of unpredictable resistance patterns and limited published data on effective treatment regimens. Our study has highlighted the need for prompt microbiological sampling and initiation of early appropriate antibiotic regime. The most effective treatment for GNB HVO was with oral Ciprofloxacin over a period of 6-8 weeks.

[Pyogenic spondylodiscitis: therapy algorithm and a new classification for therapeutic decision-making]

The incidence of pyogenic spondylodiscitis is low but has been steadily increasing in recent years. To date there has been no consensus concerning selection of the appropriate treatment, management and strategies and the recommendations for an operative strategy are still a highly controversial issue. In the literature a few statements have been published concerning therapeutic decision-making in pyogenic spondylodiscitis. The classification given in this article is based on clinical experience and retrospective data analysis considering the degree of segmental bony destruction, grade of kyphosis and instability, epidural involvement of the disease and neurological deficits, which are pivotal for therapeutic decision-making. The therapeutic procedure can be defined based on this classification.

Surgical results of long posterior fixation with short fusion in the treatment of pyogenic spondylodiscitis of the thoracic and lumbar spine: a retrospective study

STUDY DESIGN

A single-institution, single-surgeon retrospective review.

OBJECTIVE

To evaluate the clinical results of long posterior instrumentation with short posterior or posterolateral fusion for pyogenic spondylodiscitis of the thoracic and lumbar spine retrospectively.

SUMMARY OF BACKGROUND DATA

There are controversies concerning the optimal treatment for pyogenic spondylodiscitis, in terms of approach, grafting, and instrumentation. Reports of long posterior fixation with short fusion without debridement of infected tissue for pyogenic spondylodiscitis are rare.

METHODS

From June 1997 to June 2007, 48 patients with pyogenic spondylodiscitis were treated. The indications for surgery were neurological compromise, significant vertebral body destruction with kyphosis and segmental instability, failure of medical treatment, and the need for tissue diagnosis. All patients received long posterior instrumentation with or without posterior decompression, depending on whether the patients had neurological deficit. During operation, no debridement of infected tissue was done. Clinical outcomes were assessed using the criteria of Kirkaldy-Willis and the visual analogue scale for pain. The neurological outcome was graded using Frankel grading system. Segmental kyphotic angle and fusion were recorded and analyzed.

RESULTS

The average follow-up time was 64 months. The visual analogue scale scores improved from an average of 7.2 before surgery to 2.2 after surgery. Twenty-eight patients with initial neurological impairment had an average improvement of 1.03 grades, using the Frankel grading system, at the final follow-up. The segmental kyphotic deformity improved by an average of 8.5° immediately after operation and lost an average correction of 3.0° at the final follow-up. No relapse of infection was found among these 48 patients.

CONCLUSION

The posterior approach with long segmental fixation and short posterior or posterolateral fusion without debridement of the infected tissue was effective for pyogenic spondylodiscitis of the thoracic and lumbar spine.

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.

Pyogenic spondylodiscitis after transoral surgery for oropharyngeal cancer

We report the case of a patient with pyogenic spondylodiscitis after transoral surgery for oropharyngeal cancer. The patient was a 66-year-old man with a history of hepatic cell carcinoma, alcoholic cirrhosis, and chronic pancreatitis. The tumor was resected via a transoral approach with concurrent bilateral elective neck dissections. Although the initial postoperative course was uneventful, the patient experienced severe cervical pain because of which he revisited the hospital. The patient was diagnosed with pyogenic spondylodiscitis, according to the results of magnetic resonance imaging. Continuous treatment with parenteral antibiotics and a cervical brace was required for 2 months before all his symptoms and signs diminished. To the best of our knowledge, this is the first reported case of pyogenic spondylodiscitis as a complication of transoral resection for head and neck cancer.

Posterior interbody grafting and instrumentation for spondylodiscitis

PURPOSE

To report outcomes of 7 patients with bacterial spondylodiscitis treated through a posterior approach.

METHODS

Five men and 2 women aged 40 to 80 years underwent one-stage posterior interbody debridement and instrumentation for single-segment bacterial spondylodiscitis of lumbar (n=5) or thoracic (n=2) vertebrae. The Oswestry Disability Score, the Frankel classification, the Cobb angle, and the visual analogue scale (VAS) for pain as well as bone union on radiographs were assessed.

RESULTS

Patients were followed up for 19 to 36 months. None had relapses or complications. Postoperatively, 5 patients had no pain or used analgesics only occasionally; their VAS scores varied from 0 to 20. The remaining 2 patients had residual symptoms and received regular peripheral pain medication and opiates; their VAS scores ranged from 30 to 50. The mean Oswestry Disability Score improved to 21 (range, 12-38). The mean Cobb angle improved from 13.1 to 11.1 degrees. The segments were probably fused in 5 patients and questionable in 2.

CONCLUSION

Posterior debridement and instrumentation was adequate for single-segment spondylodiscitis and achieved good outcomes.

Postoperative disc space infection after discectomy: a report on thirty-five patients

PURPOSE

The focus of this study was to analyse the patient with disc space infection and the need for re-exploration.

METHOD

Thirty-five patients were analysed within the period from April 1992 and May 2011. The diagnosis was confirmed by the cardinal clinical features, raised erythrocyte sedimentation rate [ESR], raised C-reactive protein and MRI findings. All received 500-mg intravenous amikacin and one gram ceftriaxone at the time of anaesthetic induction and six hours after surgery.

RESULTS

Age range was between 25-62 years. The appearance of symptoms was between four days and three weeks. Nine patients had silent chronic urinary tract infection. Twenty-nine patients had re-exploration while the others did well on conservative treatment. Neurological deficit was not recorded. All recovered well within six to nine months.

CONCLUSION

Re-exploration is recommended if no response is achieved after four day's conservative treatment for or if the patient's condition is critical.

Microbiologically and clinically diagnosed vertebral osteomyelitis: impact of prior antibiotic exposure

We retrospectively reviewed medical records to identify the factors that affect the results of culture in patients with pyogenic vertebral osteomyelitis. In multivariate analysis, the presence of paravertebral abscess was associated with positive results of microbiologic culture. Prior antibiotic exposure, especially of longer duration, was strongly associated with negative results.