Bacterial Spine Infections in Adults: Evaluation and Management

Predictive Factors of Cloxacillin Susceptibility in Primary Bacterial Spinal Infection

STUDY DESIGN

Prognostic study.

OBJECTIVES

The objective of this study is to identify predictive factors for cloxacillin susceptibility in spinal infections.

METHODS

A retrospective analysis was conducted using data from January 1, 1997, to December 31, 2021. The study included patients presenting with back pain and either a positive bacterial culture from the spine or radiological evidence of spinal infection (spondylodiscitis and/or epidural abscess) along with positive bacterial blood culture.

RESULTS

Among 171 patients (127 males, 44 females), 53.2% had Staphylococcus isolates, with 40.4% showing cloxacillin resistance. Lower globulin levels (<33.5 g/L), recent hospitalization within 90 days, and residence in an old age home predicted gram-positive bacteria with cloxacillin resistance and gram-negative bacteria as causative organisms (P<.05). The 30-day and 1-year all-cause mortality rates were 0% and 8.2%, respectively. Higher red cell distribution width (RDW >16.1%) and Charlson comorbidity index (CCI) scores predicted 1-year all-cause mortality (P<.05). Intensive care unit admission was required for 9.9% of patients.

CONCLUSIONS

This study identified predictive factors for spinal infection by gram-positive bacteria with cloxacillin resistance and gram-negative bacteria. Patients with lower globulin levels (<33.5 g/L), recent hospitalization within 90 days, or residency in an old age home upon admission should avoid standalone cloxacillin therapy and consider antibiotics with gram-negative coverage. Higher RDW (>16.1%) and CCI scores were associated with increased 1-year all-cause mortality. These findings contribute to treatment decision-making and improving patient outcomes in spinal infections.

The IFSD Score-A Practical Prognostic Model for Invasive Fungal Spondylodiscitis

Objectives: Invasive fungal spondylodiscitis (IFSD) is rare and could be lethal in certain circumstances. The previous literature revealed limited data concerning its outcomes. This study aimed to establish a risk-scoring system to predict the one-year mortality rate of this disease. Methods: A total of 53 patients from a multi-centered database in Taiwan were included in this study. All the clinicopathological and laboratory data were retrospectively analyzed. Variables strongly related to one-year mortality were identified using a multivariate Cox proportional hazards model. A receiver operating characteristic (ROC) curve was used to express the performance of our IFSD scoring model. Results: Five strong predictors were included in the IFSD score: predisposing immunocompromised state, the initial presentation of either radiculopathy or myelopathy, initial laboratory findings of WBC > 12.0 or <0.4 103/µL, hemoglobin < 8 g/dL, and evidence of candidemia. One-year mortality rates for patients with IFSD scores of 0, 1, 2, 3, and 4 were 0%, 16.7%, 56.3%, 72.7%, and 100%, respectively. The area under the curve of the ROC curve was 0.823. Conclusions: We developed a practical scoring model with easily obtained demographic, clinical, and laboratory parameters to predict the probability of one-year mortality in patients with IFSD. However, more large-scale and international validations would be necessary before this scoring model is commonly used.

Antibiotic use in spine surgery: A narrative review based in principles of antibiotic stewardship

Background

A growing emphasis on antibiotic stewardship has led to extensive literature regarding antibiotic use in spine surgery for surgical prophylaxis and the treatment of spinal infections.

Purpose

This article aims to review principles of antibiotic stewardship, evidence-based guidelines for surgical prophylaxis and ways to optimize antibiotics use in the treatment of spinal infections.

Methods

A narrative review of several society guidelines and spine surgery literature was conducted.

Results

Antibiotic stewardship in spine surgery requires multidisciplinary investment and consistent evaluation of antibiotic use for drug selection, dose, duration, drug-route, and de-escalation. Developing effective surgical prophylaxis regimens is a key strategy in reducing the burden of antibiotic resistance. For treatment of primary spinal infection, the diagnostic work-up is vital in tailoring effective antibiotic therapy. The future of antibiotics in spine surgery will be highly influenced by improving surgical technique and evidence regarding the role of bacteria in the pathogenesis of degenerative spinal pathology.

Conclusions

Incorporating evidence-based guidelines into regular practice will serve to limit the development of resistance while preventing morbidity from spinal infection. Further research should be conducted to provide more evidence for surgical site infection prevention and treatment of spinal infections.

Laboratory diagnostics for primary spinal infections in pediatric and adult populations: a narrative review

Primary spinal infection (PSI) is a generic term covering a heterogeneous group of infections that can affect the vertebral body, intervertebral disks, the content of the medullary cavity, and adjacent paraspinal tissues. Patients' characteristics can vary significantly, notably according to their age, and some of these characteristics undoubtedly play a primordial role in the occurrence of a PSI and in the type of offending pathogen. Before approaching the subject of laboratory diagnostics, it is essential to define the characteristics of the patient and their infection, which can then guide the physician toward specific diagnostic approaches. This review critically examined the roles and usefulness of traditional and modern laboratory diagnostics in supporting clinicians' decision-making in cases of pediatric and adult primary spinal infection (PSI). It appears impossible to compare PSIs in children and adults, whether from an epidemiological, clinical, bacteriological, or biological perspective. The recipients are really too different, and the responsible germs are closely correlated to their age. Secondly, the interpretation of traditional laboratory blood tests appears to contribute little guidance for clinicians attempting to diagnose a PSI. Biopsy or needle aspiration for bacterial identification remains a controversial subject, as the success rates of these procedures for identifying causative organisms are relatively uncertain in pediatric populations.Using nucleic acid amplification assays (NAAAs) on biopsy samples has been demonstrated to be more sensitive than conventional cultures for diagnosing PSI. Recent advances in next-generation sequencing (NGS) are particularly interesting for establishing a microbiological diagnosis of a PSI when standard cultures and NAAAs have failed to detect the culprit. We can even imagine that plasma metagenomic NGS using plasma (known as "liquid biopsy") is a diagnostic approach that can detect not only pathogens circulating in the bloodstream but also those causing focal infections, and thus eliminate the need for source sample collection using costly invasive surgical procedures.

Advances in diagnosis and management of atypical spinal infections: A comprehensive review

Atypical spinal infections (ASIs) of the spine are a challenging pathology to management with potentially devastating morbidity and mortality. To identify patients with atypical spinal infections, it is important to recognize the often insidious clinical and radiographic presentations, in the setting of indolent and smoldering organism growth. Trending of inflammatory markers, and culturing of organisms, is essential. Once identified, the spinal infection should be treated with antibiotics and possibly various surgical interventions including decompression and possible fusion depending on spine structural integrity and stability. Early diagnosis of ASIs and immediate treatment of debilitating conditions, such as epidural abscess, correlate with fewer neurological deficits and a shorter duration of medical treatment. There have been great advances in surgical interventions and spinal fusion techniques for patients with spinal infection. Overall, ASIs remain a perplexing pathology that could be successfully treated with early diagnosis and immediate, appropriate medical, and surgical management.

Clinical characteristics of native vertebral osteomyelitis in patients with history of acupuncture

BACKGROUND

Considering that vertebral osteomyelitis (VO) can occur via various routes, it can be predicted that clinical characteristics may vary depending on the route of infection or risk factors of the disease. In this study, differences in clinical characteristics, causative pathogens, clinical features and prognosis were investigated in patients of native vertebral osteomyelitis with history of acupuncture.

METHODS

This retrospective study was conducted at Kyung Hee University Hospital at Gangdong, Seoul. We extracted data of patients diagnosed with VO from May 2006 to February 2021 using an electronic database. Data on demography, clinical presentation, treatment, causative organisms and clinical outcomes were identified and compared according to the history of acupuncture.

RESULTS

A total of 100 patients with VO were reviewed, among which 34 patients had a history of acupuncture prior to the diagnosis of VO. The frequency of Gram-positive cocci (GPC) was significantly higher in the acupuncture group than in the non-acupuncture group (p = 0.016). Abscess was observed more frequently in the acupuncture group than in the non-acupuncture group (p = 0.01). There was no difference in neurological sequelae and recurrence between the two groups. There was no difference in mortality between the two groups. (p = 0.098) CONCLUSION: This study suggests that confirming a history of acupuncture may help predict the pathogen or clinical characteristics of the disease. If the patient has a history of acupuncture, GPC can be considered as the causative organism, and the findings that abscesses and surgical treatment are more common may be helpful in evaluating patients.

Health Care Utilization and Associated Economic Burden of Postoperative Surgical Site Infection after Spinal Surgery with Follow-Up of 24 Months

BACKGROUND

 Surgical site infection (SSI) may lead to vertebral osteomyelitis, diskitis, paraspinal musculoskeletal infection, and abscess, and remains a significant concern in postoperative management of spinal surgery. SSI is associated with greater postoperative morbidity and increased health care payments.

METHODS

 We conducted a retrospective analysis using MarketScan to identify health care utilization payments and risk factors associated with SSI that occurs postoperatively. Known patient- or procedure-related risk factors were searched across those receiving spine surgery who developed postoperative infection.

RESULTS

 A total of 33,061 patients who developed infection after spinal surgery were identified in Marketscan. Overall payments at 6 months, including index hospitalization for those with infection, were $53,573 and $46,985 for the cohort with no infection. At 24 months, the infection group had overall payments of $83,280 and $66,221 for no infection. Risk factors with largest effect size most likely to contribute to infection versus no infection were depression (4.6%), diabetes (3.7), anemia (3.3%), two or more levels (2.8%), tobacco use (2.2%), trauma (2.1%), neoplasm (1.8%), congestive heart failure (1.3%), instrumentation (1.1%), renal failure (0.9%), intravenous drug use (0.8%), and malnutrition (0.5%).

CONCLUSIONS

 SSIs were associated with significant health care utilization payments at 24 months of follow-up. The following clinical and procedural risk factors appear to be predictive of postoperative SSI: depression, diabetes, anemia, two or more levels, tobacco use, trauma, neoplasm, congestive heart failure, instrumentation, renal failure, intravenous drug use, and malnutrition. Interpretation of modifiable and nonmodifiable risk factors for infection informs surgeons of expected postoperative course and preoperative risk for this most common and deleterious postoperative complication to spinal surgery.

The Golden Grapes of Wrath - Staphylococcus aureus Bacteremia: A Clinical Review

Staphylococcus aureus bacteremia is common and associated with fatality rates approximating 25%. We provide a brief overview of S. aureus bacteremia from a clinical and microbiological lens and review the relevant evidence and literature gaps in its management. Using a case-based approach, evidence and clinical judgement are meshed to highlight and justify the 5 core interventions that ought to be performed for all cases of S. aureus bacteremia: 1) appropriate anti-staphylococcal therapy, 2) screening echocardiography, 3) assessment for metastatic phenomena and source control, 4) decision on duration of antimicrobial therapy, and 5) Infectious Diseases consultation.

Imaging in the Diagnosis of Nonspecific Pyogenic Spondylodiskitis

The prevalence of nonspecific pyogenic spondylodiskitis, associated with both a high morbidity and a high mortality, has increased in the last few decades. The diagnosis is often delayed because of the nonspecific clinical manifestation at the early stage. The reliability of radiographs is limited, particularly in early stage after the onset of infection. Computed tomography (CT) can reliably assess the bony condition with the possibility of spatial visualization. Contrast enhancement supports the detection of affected soft tissue. Magnetic resonance imaging (MRI) continues to be the gold standard in the diagnosis of spondylodiskitis. Sophisticated investigation protocols supported by gadolinium enhancement secure the diagnosis. MRI has a high resolution without radiation exposure. Different nuclear investigation techniques extend the diagnostic options. Reports of 18F-fluorodeoxyglucose-positron emission tomography (18-FDG-PET) are particularly promising to confirm the diagnosis. The drawback of the reduced image quality with respect to detailed anatomical information can be overcome by a combined simultaneous acquisition of CT or MRI. With respect to one of the greatest challenges, the differentiation between degenerative changes (Modic type 1) and infection at an early stage using differentiated MRI protocols and FDG-PET is promising. This overview presents a concise state-of-the-art look at radiologic investigations in case of suspected nonspecific pyogenic spondylodiskitis with the focus on a pragmatic approach.

Evaluation of the metagenomic next-generation sequencing performance in pathogenic detection in patients with spinal infection

Spinal infection is a rarely occurred pathology, whose diagnosis remains a major challenge due to the low sensitivity of culturing techniques. Metagenomic next-generation sequencing (mNGS) is a novel approach to identify the pathogenic organisms in infectious diseases. In this study, mNGS technology was adopted for pathogenic detection in spinal infection from the tissue and pus samples. Additionally, the diagnostic performance of mNGS for spinal infection was evaluated, by comparing it with that of the conventional microbial culture, with the histopathological results as the gold standard. Overall, 56 samples from 38 patients were enrolled for mNGS testing, and 69 samples were included for microbial culture. 30 patients (78.95%) were identified to be positive by the mNGS method, which was higher than that of microbial culture (17, 44.74%). The sensitivity and specificity of mNGS with pus samples were 84.2% and 100.0%, respectively, which outperformed those of microbial culture (42.1% and 100.0%). The pathogen identification results were applied to medication guidance, and all 38 patients experienced favorable outcomes at three months, followed-up post-treatment, without any adverse effects. These findings proved that mNGS was superior to microbial culture in pathogenic identification of the spinal infection, thereby showing great promise in guiding drug administration and improving clinical outcomes.

Spinal Tumors: Diagnosis and Treatment

Tumors that present in or around the spine can be challenging to diagnose and treat. A proper workup involves a complete history and physical examination, appropriate staging studies, appropriate imaging of the entire spine, and a tissue biopsy. The biopsy defines the lesion and guides treatment, but in some rare instances, rapid neurological decline may lead to urgent or emergent surgery before it can be analyzed. "Enneking-appropriate" margins should remain the goal for primary tumors while adequate debulking/separation/stabilization are often the goals in metastatic disease. Primary tumors of the spine are rare and often complex tumors to operate on-achieving Enneking-appropriate margins provides the greatest chance of survival while decreasing the chance of local recurrence. Metastatic tumors of the spine are increasingly more common, and timing of surgery must be considered within the greater framework of the patient and the patient's disease, deficits, stability, and other treatments available. The specific tumor type will dictate what other multidisciplinary approaches are available, allowing for chemotherapy and radiation as needed.

The Impact of Corticosteroid Injection Timing on Infection Rates Following Spine Surgery: A Systematic Review and Meta-Analysis

STUDY DESIGN/SETTING

Systematic review/meta-analysis.

OBJECTIVES

The objective of this review was to assess how the risk of infection following lumbar spine surgery varies as a function of the timing of preoperative corticosteroid spinal injections (CSIs).

METHODS

A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. PubMed and EMBASE databases were searched and data was pooled for meta-analysis.

RESULTS

Six studies were identified for inclusion. Two (33.3%) demonstrated a significant relationship between the timing of preoperative CSIs and the risk of postoperative infection, while 4 (66.7%) demonstrated no impact. A total of 2.5% (110/4,448) of patients who underwent CSI <1 month before surgery experienced a postoperative infection, as compared to 1.2% (1,466/120, 943) of controls, which was statistically significant (RR = 1.986 95% CI 1.202-3.282 P = 0.007). A total of 1.6% (25/1,600) of patients who underwent CSI 0-3 months before surgery experienced a postoperative infection, as compared to 1.6% (201/12, 845) of controls (RR = 0.887 95% CI 0.586-1.341, P = 0.569). A total of 1.1% (199/17 870) of patients who underwent CSI 3-6 months before surgery experienced a postoperative infection, as compared to 1.3% (1,382/102, 572) of controls (RR = 1.053 95% CI 0.704-1.575, P = 0.802). Differences in infection risk for 0-3 months and 3-6 months were not statistically significant.

CONCLUSIONS

CSIs <1 month prior to lumbar spine surgery are a significant risk factor for infection, while CSIs beyond that point showed no such association. Surgeons should consider avoiding CSIs <1 month of the use of CSIs of the spine.

The effectiveness of percutaneous endoscopic lumbar discectomy combined with external lumbar drainage in the treatment of intervertebral infections

Objective

To analyze the effect of percutaneous endoscopic lumbar discectomy in treating lumbar intervertebral infections.

Methods

A total of 13 patients with lumbar intervertebral infections who underwent percutaneous endoscopic lumbar discectomy combined with external drainage between November 2016 and December 2019 were enrolled in the present study. After the operation, sensitive antibiotics were used based on the results of the bacterial culture. If no pathogens were detected in the biopsy culture of the infected tissues, empirical antibiotics were administrated to these patients. The clinical efficacy was evaluated by using a visual analog scale (VAS), Japanese Orthopaedic Association (JOA), Oswestry Disability Index (ODI), and standard Macnab's evaluation. Postoperative computed tomography (CT) and MRI were also used to evaluate clinical efficacy.

Results

The follow-up time was 10–18 months, and the average time was (13.69 ± 2.63) months. Causative bacteria were isolated in 7 of 13 infected tissue biopsy cultures. Systemic antibiotics and anti-tuberculous chemotherapy were administered according to sensitivity studies for identified. There were no pathogens isolated from the other six patients. Empiric antibiotics were administrated in these patients. One week after the operation, WBC, a fractional fraction of medium granulocytes, ESR and CRP were significantly lower compared to before the operation (all P < 0.05). At the last follow-up visit, the above-mentioned markers were all within normal range, which differed compared to the pre-operative data (P < 0.05). The VAS and ODI of the patients at 1 week and 3 months after operation were significantly lower compared to preoperative data (all P < 0.05). During the last follow-up visit, seven patients were excellent, five were good, and one was poor according to standard Macnab's evaluation. No serious complications were recorded.

Conclusions

Percutaneous lumbar discectomy combined with external drainage resulted as an effective method for treating lumbar intervertebral infections and was associated with fewer injuries, less pain, low cost, and low recurrence rate.

Does Operative Management of Epidural Abscesses Increase Healthcare Expenditures up to 1 Year After Treatment?

BACKGROUND

The incidence of spinal epidural abscesses is increasing. What is more, they are associated with high rates of morbidity and mortality. Advances in diagnostic imaging and antibiotic therapies have made earlier diagnosis and nonoperative management feasible in appropriately selected patients. Nonoperative treatment also has the advantage of lower immediate healthcare charges; however, it is unknown whether initial nonoperative care leads to higher healthcare charges long term.

QUESTIONS/PURPOSES

(1) Does operative intervention generate higher charges than nonoperative treatment over the course of 1 year after the initial treatment of spinal epidural abscesses? (2) Does the treatment of spinal epidural abscesses in people who actively use intravenous drugs generate higher charges than management in people who do not?

METHODS

This retrospective comparative study at two tertiary academic centers compared adult patients with spinal epidural abscesses treated operatively and nonoperatively from January 2016 through December 2017. Ninety-five patients were identified, with four excluded for lack of billing data and one excluded for concomitant intracranial abscess. Indications for operative management included new or progressive motor deficit, lack of response to nonoperative treatment including persistent or progressive systemic illness, or initial sepsis requiring urgent source control. Of the included patients, 52% (47 of 90) received operative treatment with no differences in age, gender, BMI, and Charlson comorbidity index between groups, nor any difference in 30-day all-cause readmission rate, 1-year reoperation rate, or 2-year mortality. Furthermore, 29% (26 of 90) of patients actively used intravenous drugs and were younger, with a lower BMI and lower Charlson comorbidity index, with no differences in 30-day all-cause readmission rate, 1-year reoperation rate, or 2-year mortality. Cumulative charges at the index hospital discharge and 90 days and 1 year after discharge were compared based on operative or nonoperative management and secondarily by intravenous drug use status. Medical records, laboratory results, and hospital billing data were reviewed for data extraction. Demographic factors including age, gender, region of abscess, intravenous drug use, and comorbidities were extracted, along with clinical factors such as symptoms and ambulatory function at presentation, spinal instability, intensive care unit admission, and complications. The primary outcome was charges associated with care at the index hospital discharge and 90 days and 1 year after discharge. All covariates extracted were included in this analysis using negative binomial regression that accounted for confounders and the nonparametric nature of charge data. Results are presented as an incidence rate ratio with 95% confidence intervals.

RESULTS

After adjusting for demographic and clinical variables such as age, gender, BMI, ambulatory status, presence of mechanical instability, and intensive care unit admission among others, we found higher charges for the group treated with surgery compared with those treated nonoperatively at the index admission (incidence rate ratio [IRR] 1.62 [95% CI 1.35 to 1.94]; p < 0.001) and at 1 year (IRR 1.36 [95% CI 1.10 to 1.68]; p = 0.004). Adjusted analysis also showed that active intravenous drug use was also associated with higher charges at the index admission (IRR 1.57 [95% CI 1.16 to 2.14]; p = 0.004) but no difference at 1 year (IRR 1.11 [95% CI 0.79 to 1.57]; p = 0.55).

CONCLUSION

Multidisciplinary teams caring for patients with spinal epidural abscesses should understand that the decreased charges associated with selecting nonoperative management during the index admission persist at 1 year with no difference in 30-day readmission rates, 1-year reoperation rates, or 2-year mortality. On the other hand, patients with active intravenous drug use have higher index admission charges that do not persist at 1 year, with no difference in 30-day readmission rates, 1-year reoperation rates, or 2-year mortality. These results suggest possible economic benefit to nonoperative management of epidural abscesses without increases in readmission or mortality rates, further tipping the scale in an evolving framework of clinical decision-making. Future studies should investigate if these economic implications are mirrored on the patient-facing side to determine whether any financial burden is shifted onto patients and their families in nonoperative management.

LEVEL OF EVIDENCE

Level III, therapeutic study.

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.

Spinal endoscopy: evidence, techniques, global trends, and future projections

The utilization of indirect visualization during procedures has been increasingly replacing traditional forms of direct visualization across many different surgical specialties. The adoption of arthroscopy, using small cameras placed inside joints, has transformed musculoskeletal care over the last several decades, allowing surgeons to provide the same anatomic solutions with less tissue dissection, resulting in lower requirements for inpatient care, reduced costs, and expedited recovery.  For a variety of reasons, spine surgery has lagged behind other specialties in the adoption of indirect visualization.  Nonetheless, patient demand for less invasive spine procedures and surgeon drive to provide these solutions and improve care quality has driven global adoption of spinal endoscopy.  There are numerous endoscopic platforms and techniques currently utilized, and these systems are rapidly evolving.  Additionally, the variance in technology and health system incentives across the globe has generated tremendous regional heterogeneity in the utilization of spinal endoscopic procedures.  We present a consolidated review, including the background, evidence, techniques, and trends in spinal endoscopy, so that clinicians can gain a deeper understanding of this rapidly evolving domain of spinal healthcare.

MORPHOLOGICAL ASPECT OF PYOGENIC SPINAL EPIDURAL ABSCESSES. PART I

ABSTRACT Background: Pyogenic Spinal Epidural Abscess (PSEA) is difficult to diagnose and can have devastating consequences. Magnetic Resonance Imaging (MRI) has high sensitivity and specificity, which are further increased with the use of contrast. There are several classifications of vertebral infectious processes, with emphasis on spondylodiscitis. Objective: To analyze the morphological parameters and their reproducibility; and to analyze different resonance imaging sequences. Methods: Using an image database, a morphological classification of PSEA was planned, with five parameters: Region (R), indicating the upper and lower limits of the abscess; Location (U), indicating whether the abscess is anterior or posterior within the canal; Compromise (C), meningeal or content of the structures; Association (A), discitis, osteomyelitis or both; and Perivertebral (P), anterior, lateral or posterior extravertebral abscess. The first three parameters give an idea of the volume of the PSEA, while the last two give the related infectious foci. Thirty-five cases were analyzed using Kappa’s coefficient. Results: The global intra- and interobserver reproducibility was Kappa 0.81. The results for each parameter were as follows: R=0.95, U=0.92, C=0.66, A=0.70 and P=0.80. The first three give a notion of volume and the last two relate to the presence of vertebral infectious foci outside the canal. T2 weighted MRI with contrast was found to be the most effective imaging sequence. Conclusion: The morphological classification is simple to use, with excellent reproducibility. The parameters with the highest reproducibility were region and location, with values >0.92. The addition of gadolinium contrast increased the sensitivity of the diagnosis; the use of sagittal and axial images in T2-MRI was the most sensitive imaging sequence. Evidence Level III; Original.

Predilection for developing a hematogenous orthopaedic implant-associated infection in older versus younger mice

Background

The pathogenesis of hematogenous orthopaedic implant-associated infections (HOIAI) remains largely unknown, with little understanding of the influence of the physis on bacterial seeding. Since the growth velocity in the physis of long bones decreases during aging, we sought to evaluate the role of the physis on influencing the development of Staphylococcus aureus HOIAI in a mouse model comparing younger versus older mice.

Methods

In a mouse model of HOIAI, a sterile Kirschner wire was inserted retrograde into the distal femur of younger (5–8-week-old) and older (14–21-week-old) mice. After a 3-week convalescent period, a bioluminescent Staphylococcus aureus strain was inoculated intravenously. Bacterial dissemination to operative and non-operative legs was monitored longitudinally in vivo for 4 weeks, followed by ex vivo bacterial enumeration and X-ray analysis.

Results

In vivo bioluminescence imaging and ex vivo CFU enumeration of the bone/joint tissue demonstrated that older mice had a strong predilection for developing a hematogenous infection in the operative legs but not the non-operative legs. In contrast, this predilection was less apparent in younger mice as the infection occurred at a similar rate in both the operative and non-operative legs. X-ray imaging revealed that the operative legs of younger mice had decreased femoral length, likely due to the surgical and/or infectious insult to the more active physis, which was not observed in older mice. Both age groups demonstrated substantial reactive bone changes in the operative leg due to infection.

Conclusions

The presence of an implant was an important determinant for developing a hematogenous orthopaedic infection in older but not younger mice, whereas younger mice had a similar predilection for developing periarticular infection whether or not an implant was present. On a clinical scale, diagnosing HOIAI may be difficult particularly in at-risk patients with limited examination or other data points. Understanding the influence of age on developing HOIAI may guide clinical surveillance and decision-making in at-risk patients.

Spinal Tuberculosis Secondary to Intravesical Bacille Calmette-Guerin Treatment for Bladder Cancer

Intravesical administration of bacille Calmette-Guérin (BCG) is an important component of the gold standard in treating non-muscle invasive bladder cancer (NMIBC). However, complications of this treatment include infections caused by the dissemination of Mycobacterium bovis. We present a case of a 62-year-old man who had been treated with intravesical BCG for bladder cancer and developed an M. bovis infection of his vertebral column. About four months after completing the BCG treatment, he developed an acute onset of severe upper thoracic radicular back pain, with radiation anteriorly to his sternum. Examination revealed the presence of early myelopathy. After other causes were ruled out, he was diagnosed with the infection four months later. He was investigated for the pain, with resulting imaging identifying an erosive ventral epidural mass at the T4-T5 levels causing cord compression. The patient underwent a transthoracic procedure to evacuate the paraspinal mass lesion and obtain a diagnostic biopsy, followed by a posterolateral decompression of the lesion and posterior instrumented stabilization. Pathology resulted in the identification of a granuloma with a single acid-fast bacillus (AFB) from the paraspinal abscess, thus being diagnostic of a mycobacterial granuloma with paraspinal involvement. We subsequently performed an extensive review of current literature, looking at articles on spinal osteomyelitis following intravesical BCG treatment of bladder cancer. We identified 26 documented cases in English literature. We present our case report with a good outcome at 24 months, resolving with appropriate chemotherapy. Additionally, we completed a systematic review of the literature and discuss this infrequent iatrogenic pathology. Our report reveals the good response to targeted therapy in the case of osteomyelitis at other skeletal sites and that practitioners caring for these patients maintain a high degree of suspicion in the workup of these patients. Early identification and treatment can appropriately treat osteomyelitis with good long-term outcomes.

Defining Disc Biopsy Timing in Relation to Blood Culture Results for Inpatients with Suspected Discitis-Osteomyelitis

PURPOSE

To determine optimal timing of biopsy for suspected discitis-osteomyelitis (DOM) with respect to preliminary blood culture results and the effect of biopsy timing on hospital length of stay (LOS).

MATERIALS AND METHODS

This retrospective study reviewed disc/vertebral biopsies for suspected DOM performed between 2010 and 2018. A total of 107 disc/vertebral biopsies were performed on 96 inpatients (mean ± SD age 57.9 ± 14.5 years, 68 men/28 women) for suspected DOM, and 100 cases of DOM were clinically confirmed and treated. Descriptive and regression statistics were performed with LOS as the primary outcome.

RESULTS

Of disc biopsies in clinically confirmed cases, 68% were positive; 20% of all biopsies had preliminary positive blood cultures after 2 hospital days. There was no difference in LOS between cases with biopsy performed ≤ 2 days after blood culture and cases with biopsy performed > 2 days after blood culture (P = .40). Regression analysis showed no association between positive biopsy results and sepsis, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), or C-reactive protein (CRP). Biopsy yield was not significantly decreased in patients previously taking antibiotics (P = .09).

CONCLUSIONS

Waiting 2 days for preliminary blood culture results could avoid disc/vertebral biopsy in 20% of patients and does not significantly impact hospital LOS. Additionally, clinical factors (sepsis, WBC count, CRP, and ESR) do not have predictive value for positive disc biopsy results.

Risk factors for residual neurologic deficits after surgical treatment for epidural abscess in the thoracic or lumbar spine

BACKGROUND CONTEXT

Spinal epidural abscess (SEA) can cause neurologic deficits and needs urgent surgical intervention. Many clinical factors had been proposed to predict surgical outcomes in patients with SEA, but the predictive radiographic risk factors for residual neurologic deficits were not addressed sufficiently.

PURPOSE

To analyze the clinical and radiographic risk factors for residual neurologic deficit in patients with SEA after surgical intervention of the thoracic or lumbar spine.

STUDY DESIGN/SETTING

A retrospective consecutive case series.

PATIENT SAMPLE

From January 2005 through December 2014, 53 patients with primary SEA, confirmed by culture or histopathology, in the thoracic or lumbar spine who underwent posterior-only approach surgery at our hospital.

OUTCOME MEASURES

Neurologic status was assessed using the Frankel grading system preoperatively, postoperatively, and at final follow-up.

METHODS

The patients were allocated into two groups based on the presence of postoperative residual neurologic deficits. Patients' demographic, clinical, and factors based on magnetic resonance imaging (MRI) were analyzed for their influence on residual neurologic deficits. Clinical factors included age, sex, diabetes, comorbidities, pathogens, affected spinal levels, the interval between onset of symptoms to surgery, preoperative neurologic status, presence of cauda equina syndrome, and surgical procedures. MRI factors included the distribution of abscesses within the spinal canal, presence of ring enhancement, presence of paravertebral abscess or psoas abscess, canal compromise anteroposterior (AP) ratio and cross-sectional area ratio, abscess length, and abscess thickness.

RESULTS

Thirty-five of the 53 patients (66%) had preoperative neurologic deficits, and 21 of 53 patients (40%) had postoperative residual neurologic deficits. Patients' neurologic status improved significantly after the surgery (p<.001). Risk factors including age, diabetes, cauda equina syndrome, presence of anterior with posterior (A+P) dural abscess, canal compromise AP ratio, cross-sectional area ratio, abscess length, and abscess thickness were significantly correlated with postoperative residual neurologic deficits. In multivariate logistic regression analysis, age ≥70 years, preoperative cauda equina syndrome, abscess length ≥5.5 cm and abscess thickness ≥0.8 cm were the four most significant factors related to residual neurologic deficits.

CONCLUSIONS

In patients with SEA of the thoracic and lumbar spine, age ≥70 years, preoperative cauda equina syndrome, abscess length ≥5.5 cm and abscess thickness ≥0.8 cm were the most significant preoperative risk factors for residual neurologic deficits after surgery.

Lumbar Discitis and Osteomyelitis After a Spinal Stem Cell Injection?: A Case Report and Literature Review

CASE

A 32-year-old man developed lumbar discitis and osteomyelitis after receiving a cell-based injection for the treatment of degenerative disc disease. Initial cultures were negative, but he continued to worsen, and a repeat set of cultures was taken. On day 10, Cutibacterium acnes was isolated. He was then successfully treated with 12 weeks of intravenous antibiotics.

CONCLUSIONS

There is minimal regulation on the preparation or administration of cell-based interventions. It is important to consider slow growing organisms such as C. acnes in patients presenting with spinal infection with insidious onset after these treatments.

Sensitivity of C-reactive protein cut-off values for pyogenic spinal infection in the emergency department

OBJECTIVES

The aim of this study was to describe the sensitivity of various C-reactive protein (CRP) cut-off values to identify patients requiring magnetic resonance imaging evaluation for pyogenic spinal infection among emergency department (ED) adults presenting with neck or back pain.

METHODS

We prospectively enrolled a convenience series of adults presenting to a community ED with neck or back pain in whom ED providers had concern for pyogenic spinal infection in a derivation cohort from 2004 to 2010 and a validation cohort from 2010 to 2018. The validation cohort included only patients with pyogenic spinal infection. We analysed diagnostic test characteristics of various CRP cut-off values.

RESULTS

We enrolled 232 patients and analysed 201 patients. The median age was 55 years, 43.8% were male, 4.0% had history of intravenous drug use, and 20.9% had recent spinal surgery. In the derivation cohort, 38 (23.9%) of 159 patients had pyogenic spinal infection. Derivation sensitivity and specificity of CRP cut-off values were > 3.5 mg/L (100%, 24.8%), > 10 mg/L (100%, 41.3%), > 30 mg/L (100%, 61.2%), and > 50 mg/L (89.5%, 69.4%). Validation sensitivities of CRP cut-off values were > 3.5 mg/L (97.6%), > 10 mg/L (97.6%), > 30 mg/L (90.4%), and > 50 mg/L (85.7%).

CONCLUSIONS

CRP cut-offs beyond the upper limit of normal had high sensitivity for pyogenic spinal infection in this adult ED population. Elevated CRP cut-off values of 10 mg/L and 30 mg/L require validation in other settings.

Injection Drug Use in Patients With Spinal Epidural Abscess: Nationwide Data, 2000 to 2013

STUDY DESIGN

Retrospective review of the Healthcare Cost and Utilization Project National Inpatient Sample, 2000 to 2013.

OBJECTIVE

To determine the proportion of spinal epidural abscess (SEA) cases that were related to injection drug use (IDU) and to compare length of stay, leaving against medical advice, paralysis, cauda equina syndrome, radiculitis, and in-hospital mortality between SEA cases with and without IDU.

SUMMARY OF BACKGROUND DATA

The US opioid epidemic impacts all aspects of healthcare, including spinal surgeons. Although injection drug use (IDU) is a risk factor for spinal epidural abscess (SEA), IDU among SEA patients and its effect on clinical outcomes is not well understood.

METHODS

Cases aged 15 to 64 with principal diagnosis of SEA were classified as IDU-related (IDU-SEA) or non-IDU-related (non-IDU-SEA) using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for illicit drug use and hepatitis C. We determined the proportion of SEA patients with IDU and compared length of stay, leaving against medical advice, paralysis, cauda equina syndrome, radiculitis, and in-hospital mortality between IDU-SEA and non-IDU-SEA patients.

RESULTS

From 2000 to 2013, there were 20,425 admissions with a principal diagnosis of SEA (95% confidence interval (CI), 19,281-21,568); 19.1% were associated with IDU (95% CI, 17.7%-20.5%). The proportion of white IDU-SEA cases increased by 2.4 percentage points annually (95% CI, 1.4-3.4). After adjusting for age, sex, and race, IDU-SEA patients stayed a mean of 6.7 more days in the hospital (95% CI, 5.1-8.2) and were 4.8 times more likely to leave against medical advice (95% CI, 2.9-8.0). Mean hospital charges for IDU-SEA patients were $31,603 higher (95% CI: $20,721-$42,485). Patients with IDU-SEA were less likely to have cauda equina syndrome (adjusted odds ratio, 0.48, 95% CI, 0.26-0.87).

CONCLUSION

IDU-SEA patients stay in the hospital longer and more often leave against medical advice. Providers and hospitals may benefit from exploring how to better facilitate completion of inpatient treatment and achieve superior outcomes.

LEVEL OF EVIDENCE

3.

Vague neck pain following a gastrointestinal procedure: a rare case presentation of vertebral osteomyelitis and cervical epidural abscess

INTRODUCTION

Vertebral osteomyelitis (VO), spondylodiscitis, and spinal epidural abscesses (SEA) are infectious and inflammatory processes impacting the spine that cause major morbidity and mortality. They require prolonged hospital stays with expensive treatment regimens. Along with acute management, studies have provided evidence highlighting poor long-term outcomes. VO accounts for ~2% of all osteomyelitis. Recent data have illustrated an increase in incidence to 5.4 per 100,000 person years. The majority of patients that present with SEA and VO typically have some combination of back pain, fevers, and neurological deficits.

CASE PRESENTATION

A 55-year-old woman with known history of hypertension and hyperlipidemia, status-post endoscopic repair of a Zenker's Diverticulum 3 weeks prior, presented to our outpatient clinic with a 2-week history of axial cervical spine pain as well as left sided scapular and deltoid pain. Further questioning and exam revealed no neurologic deficits or fever. As pain persisted and she did not respond to treatment, further imaging was performed. She was found to have cervical discitis, osteomyelitis, and a cervical epidural abscess.

DISCUSSION

Patients presenting with VO/SEA typically have spine pain with some other associated symptoms of spinal cord compression or fevers, making this a rare presentation. The urgency for discovery because of the need for emergent operative intervention is evident by the documented complications associated with a delay in diagnosis. This case report emphasizes the importance of always keeping VO/SEA on the differential for cervical spine pain even with lack of associated symptoms, in order to optimize patient care.

Consensus on the Role of Antibiotic Use in SSI Following Spinal Surgery

In July of 2018, the Second International Consensus Meeting (ICM) on Musculoskeletal Infection convened in Philadelphia, PA was held to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 17 focused on the use of antibiotics in spine surgery, for which this article provides the recommendations, voting results, and rationales.

Current Strategies for Reconstruction of Soft Tissue Defects of the Spine

Spinal surgery has been revolutionized by advances in instrumentation, bone graft substitutes, and perioperative care. Extensive dissection, creation of large areas of dead space, and the use of instrumentation in compromised patients, however, predisposes to high rates of wound complications. Postoperative wound complications in patients undergoing complex spinal surgery can have devastating sequelae, including hardware exposure, meningitis, and unplanned reoperation. Recognition of high-risk patients and prediction of wound closure difficulties, combined with preemptive reconstructive surgical strategies may prevent complications. The purpose of this review is to discuss the principles of spine wound management and provide a synopsis of the soft tissue reconstructive strategies utilized in spinal surgery. We review the senior author's preferred reconstructive algorithm for the management of these complex wounds, in addition to outcomes data relating to the timing of reconstructive surgery.

Epidural Abscess Caused by Gas-Producing Clostridium Septicum: A Case Report

CASE

Few cases have reported Clostridium species of bacteria as a source for vertebral osteomyelitis and epidural abscesses. The subspecies of Clostridium septicum has not been described as a cause. This case describes a 69-year-old man who hematogenously spread C. septicum without associated malignancy, subsequently failed conservative management in the form of intravenous antibiotics, and was definitively treated with surgical intervention through a minimally invasive approach.

CONCLUSIONS

An epidural abscess occurring in a surgically naive patient is a rare phenomenon. An epidural abscess caused by C. septicum is even rarer. Appropriate imaging, early recognition, and surgical debridement can lead to a favorable outcome.

Continuous Epidural Irrigation and Drainage Combined with Posterior Debridement and Posterior Lumbar Inter-Body Fusion for the Management of Single-Segment Lumbar Pyogenic Spondylodiscitis

Purpose: To observe the clinical curative effect of continuous epidural irrigation combined with posterior debridement and posterior lumbar inter-body fusion with instrumentation for the therapy of single-segment lumbar pyogenic spongdylodiscitis. Methods: From June 2010 to November 2013, surgical treatment was performed in 18 patients with pyogenic spondylodiscitis. The surgical indications were progressive biomechanical instability, epidural abscesses, deterioration of neurologic status, and intractable back pain. All these patients received posterior decompression with posterior instrumentation, debridement of infected tissue, and inter-body fusion. Visual Analogue Scale (VAS) scores were used to assess clinical outcomes. The neural function was evaluated by the Frankel grading system. Laboratory and radiologic results were recorded during clinical follow-up for at least one year. Results: The average follow-up period was 18 months after the operation. The VAS scores decreased from an average of 7.1 points before the procedure to 2.6 points after operation. The neurologic deficits of all the patients were recovered to Frankel grade E. All of the examined laboratory parameters were normalized gradually. Imaging-documented fusion was achieved in each patient, and no implants failure was noted. No patients showed any evidence of recurrence or persistence of infection. Conclusion: In carefully selected patients, single-segment lumbar pyogenic spondylodiscitis can be cured successfully with continuous epidural irrigation and drainage combined with posterior debridement and posterior lumbar inter-body fusion. Instrumentation could provide immediate stability and reconstruction of the spine column, and the presence of instrumentation did not result in any persistence or recurrence of infection. Continuous epidural irrigation and drainage is an effective method facilitating the elimination of residual infection.

Mycobacteriumabscessus-associated vertebral osteomyelitis in an immunocompetent patient: a rare case report and literature review

Introduction

Vertebral osteomyelitis (VO) is an uncommon infection with Staphylococcus aureus as the most commonly implicated organism. VO caused by nontuberculous mycobacteria (NTM) such as Mycobacteriumabscessus (M. abscesscus) is exceedingly rare with only eight cases reported in literature.

Case presentation

We report a rare case of an 82-year-old male with a remote history of trauma who was diagnosed with NTM vertebral osteomyelitis. The patient initially underwent a vertebroplasty of T12 and kyphoplasty of L1 for pathologic compression fractures. Subsequent cultures revealed M. abscessus. The patient further underwent an anterior T12-L2 corpectomy and debridement with instrumented fusion, as well as a posterior T9-L4 instrumentation and fusion. He received multi-agent antibiotic therapy; however, was ultimately unable to tolerate the aggressive treatment regimen and his prolonged postoperative course.

Discussion

Nontuberculous mycobacteria vertebral osteomyelitis is exceedingly rare. NTM vertebral osteomyelitis is challenging to treat. Surgical management plays a limited role in early VO, but is the mainstay treatment in chronic VO. Early recognition of the condition and shared patient management with multidisciplinary teams is key to successfully treating cases of NTM VO.

Neurological Outcomes After Surgical or Conservative Management of Spontaneous Spinal Epidural Abscesses: A Systematic Review and Meta-Analysis of Data From 1980 Through 2016

STUDY DESIGN

This is a meta-analysis.

OBJECTIVE

Perform a systematic review and quantitative meta-analysis of neurological outcomes from all available spinal epidural abscess (SEA) literature published between 1980 and 2016.

SUMMARY OF BACKGROUND DATA

Current literature on SEAs lacks large-scale data characterizing prognostic factors and surgical indications.

MATERIALS AND METHODS

PubMed was queried for studies reporting neurological outcomes from patients undergoing conservative or surgical management for spontaneous SEA. Inclusion criteria included outcomes data measured ≥6 months after presentation, ≥10 human subjects, and diagnosis by magnetic resonance imaging or Computed tomography-myelogram. Where available, demographic data, abscess location, comorbidities, pretreatment neurological deficits, treatment methods, bacterial speciation, and complications were extracted from each study. Potential outcome predictors represented by continuous variables were compared using student t test and categorical variables were compared using the Pearson χ test. Variables identified as potentially associated with outcome (P≤0.05) were subjected to meta-analysis using Cochran-Mantel-Haenszel testing to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

In total, 808 patients were analyzed from 20 studies that met inclusion criteria. 456 (56.3%) patients were treated with surgery and antibiotics, and 353 (43.7%) patients were managed with antibiotics alone. Neither surgical intervention (OR=1.01, 95% CI=0.40-2.59), lumbosacral location (OR=1.51, 95% CI=0.23-9.79), nor neurological deficit on presentation (OR=0.88, 95% CI=0.40-1.92) were significantly associated with good (stable or improved) or bad (worsened) neurological outcome, whereas delayed surgery was significantly associated with bad outcome (OR=0.01, 95% CI=0.02-0.62) and cervicothoracic location approached significance for predicting bad outcome (OR=0.41, 95% CI=0.15-1.09).

CONCLUSIONS

Current literature does not definitively support or oppose surgical intervention in all SEA cases. Therefore, until better evidence exists, the decision to operate must be made on an individual case-by-case basis with the goals of preventing neurological decline, obtaining source control after failed conservative treatment, or restoring spinal stability.

Outcomes of decompression and fusion for treatment of spinal infection

OBJECTIVE

Spine infection including vertebral osteomyelitis, discitis, paraspinal musculoskeletal infection, and spinal abscess refractory to medical management poses significant challenges to the treating physician. Surgical management is often required in patients suffering neurological deficits or spinal deformity with significant pain. To date, best practices have not been elucidated for the optimization of health outcomes and resource utilization in the setting of surgical intervention for spinal infection. The authors conducted the present study to assess the magnitude of reoperation rates in both fusion and nonfusion groups as well as overall health resource utilization following surgical decompression for spine infection.

METHODS

The authors performed an analysis using MarketScan (2001–2015) to identify health outcomes and healthcare utilization metrics of spine infection following surgical intervention with decompression alone or combined with fusion. Adult patients underwent surgical management for primary or secondary spinal infection and were followed up for at least 12 months postoperatively. Assessed outcomes included reoperation, healthcare utilization and payment at the index hospitalization and within 12 months after discharge, postoperative complications, and infection recurrence.

RESULTS

A total of 2662 patients in the database were eligible for inclusion in this study. Rehospitalization for infection was observed in 3.99% of patients who had undergone fusion and in 11.25% of those treated with decompression alone. Reoperation was needed in 12.7% of the patients without fusion and 8.16% of those with fusion. Complications within 30 days were more common in the nonfusion group (24.64%) than in the fusion group (16.49%). Overall postoperative payments after 12 months totaled $33,137 for the nonfusion group and $23,426 for the fusion group.

CONCLUSIONS

In this large cohort study with a 12-month follow-up, the recurrence of infection, reoperation rates, and complications were higher in patients treated with decompression alone than in those treated with decompression plus fusion. These findings along with imaging characteristics, disease severity, extent of bony resection, and the presence of instability may help surgeons decide whether to include fusion at the time of initial surgery. Further studies that control for selection bias in appropriately matched cohorts are necessary to determine the additive benefits of fusion in spinal infection management.

Emerging Infectious Diseases

Emerging infectious diseases (EIDs) including novel avian influenza viruses or even recently reported Zika virus (ZIKV) have drawn great attentions globally. The application of modern diagnostic technologies is expected to increase. Imaging plays a key role on diagnosis and prognosis assessment in patients with EID.

Weighted spectral reconstruction method for discrimination of bacterial species with low signal-to-noise ratio Raman measurements

Raman spectroscopy is a label-free and non-destructive spectroscopic technique that has been explored for bacterial identification. However, noise often interferes with the interesting Raman peaks because the Raman signal is inherently weak, especially for bacterial samples. Although this problem can be solved by increasing the exposure time or the power of the excitation laser, a longer acquisition time is required or the risk of sample damage is increased. In contrast, short exposure time and low laser power often lead to inadequate acquisition of Raman scattering, in which the Raman spectra with low signal-to-noise ratio (SNR) is difficult to be further analyzed. In order to quickly and accurately characterize biological samples by using low SNR Raman measurements, a weighted spectral reconstruction based method was developed and tested on Raman spectra with low SNR from 20 bacterial samples of two species. Principal component analysis followed by support vector machine was applied on the reference Raman spectra and the spectra recovered from the low SNR Raman measurements by the proposed method, the traditional spectral reconstruction method, and four other commonly used de-noising methods for the discrimination of bacterial species. The results showed that a classification accuracy of 90% was achieved based on our method, which was comparable to that of the reference Raman spectra and showed significant advantages over other spectral recovery methods. Therefore, the weighted spectral reconstruction method can preserve the most biochemical information for the bacterial species' identification while removing the noise from the low SNR Raman spectra, in which the advantages of lesser sample damage and shorter acquisition time would promote wider biomedical applications of Raman spectroscopy.

Raman spectra recovered from low SNR Raman measurements by weighted spectral reconstruction method show excellent preservation of information about bacterial identification.

Unilateral percutaneous endoscopic debridement and drainage for lumbar infectious spondylitis

BACKGROUND

The treatment of lumbar infectious spondylitis is controversial. In this study, we attempted to demonstrate that unilateral percutaneous endoscopic debridement with physiologic saline and negative pressure drainage postoperatively may achieve a satisfactory result in lumbar infectious spondylitis.

METHODS

We retrospectively analyzed 17 patients with lumbar infectious spondylitis who underwent percutaneous endoscopic debridement and drainage (PEDD) through a posterolateral transforaminal approach. Each biopsy specimen was submitted without delay after surgery and examined for microorganisms and evaluated histopathologically. Patients were assessed by careful physical examination, MacNab criteria, Oswestry Disability Index (ODI), visual analog scale (VAS), regular serological tests, imaging studies for clinical function, and patient satisfaction.

RESULTS

Of the 17 patients, 14 (82.4%) had satisfactory relief of their back pain according to MacNab criteria at 1 week after PEDD. Three patients (17.6%) who had advanced infections with multilevel involvement and paraspinal abscesses underwent anterior debridement and autograft interbody fusion with instrumentation within 2 weeks. However, there were no other severe surgery-related complications. Causative bacteria were identified in most cases, and Staphylococcus aureus was the most prevalent strain.

CONCLUSIONS

Unilateral PEDD with physiological saline or empirical antibiotics did not disrupt lumbar stability and avoided the important intraspinal structures such as the dural sac and nerve roots. It not only had a high rate of identification of the causative pathogen, but also provided effective infection control and pain relief. PEDD may be a useful technique for treatment of lumbar infectious spondylodiscitis patients who have no severe deformities and are unable to undergo the conventional anterior surgery due to poor health or advanced age.

Epidemiology and Outcomes of Infectious Spondylodiscitis in Hemodialysis Patients

STUDY DESIGN

A retrospective study of patients who were hospitalized for infectious spondylodiscitis over a 13-year period.

OBJECTIVE

To elucidate the epidemiology and prognostic factors of infectious spondylodiscitis in hemodialysis (HD) patients and to identify the impact of HD on infectious spondylodiscitis.

SUMMARY OF BACKGROUND DATA

Only a few case studies of infectious spondylodiscitis in HD patients can be found in the literature. Reports of prognostic factors are limited and patients' outcomes have not been well described.

METHODS

The cases of 1402 patients who were hospitalized for infectious spondylodiscitis over a 13-year period were retrospectively reviewed. Of these, 102 patients on maintenance HD were enrolled in this study. Cox proportional hazard model was used to evaluate the risk factors of mortality and recurrence.

RESULTS

The 102 enrolled patients had an average age 63.3 ± 11.2 years old and male-to-female ratio of 1:1.04. Back pain was present in 75.5% of patients and the most commonly infected site was the lumbosacral spine. Infection associated with vascular access was identified in 31.4% of patients. The prevalence of dialysis via central venous catheters was higher than prevalent HD patients. Methicillin-resistant Staphylococcus aureus was the most common pathogen, followed coagulase-negative staphylococci. The patients' in-hospital survival rate was 82.4%; their vascular access survival rate was 75.5%; their 1-year survival rate was 78.4%, and their 1-year recurrence rate was 20.2%. Congestive heart failure was associated with an increased 1-year mortality. Other variables exhibited no significant relationship with patients' in-hospital mortality, 1-year mortality or recurrence.

CONCLUSION

The characteristics and outcomes of infectious spondylodiscitis in HD patients were elucidated. Most of the demographic and clinical variables, evaluated upon admission, did not predict mortality or recurrence.

LEVEL OF EVIDENCE

3.

Anterior versus posterior surgical approach for lumbosacral tuberculosis

Objective

To compare two different approaches for the treatment of lumbosacral tuberculosis.

Patients and Methods

In total, 115 patients who were surgically treated in our department from July 2010 to July 2014 were included in this retrospective study. They were divided into the anterior and posterior approach groups. Intraoperative hemorrhage; the surgery time; the Cobb angle preoperatively, postoperatively, and at the follow-up visit (2 years postoperatively); visual analog scale (VAS) pain scores before and after surgery; and Oswestry Disability Index (ODI) scores before and after surgery were compared between the two groups.

Results

The Cobb angle and VAS and ODI scores were significantly improved in both groups after surgery. Significant differences were found in the operation time, intraoperative hemorrhage, Cobb angle correction, and loss of correction at the last follow-up. No significant differences were found in the VAS and ODI scores between the groups.

Conclusions

The posterior approach is superior to the anterior approach with respect to the surgery time, intraoperative hemorrhage, and Cobb angle postoperatively and at the last follow-up. When both approaches can be carried out for a patient with lumbosacral tuberculosis, the posterior approach should be favored over the anterior approach.

Bone and joint infection

Bone and joint infections include septic arthritis, prosthetic joint infections, osteomyelitis, spinal infections (discitis, vertebral osteomyelitis and epidural abscess) and diabetic foot osteomyelitis. All of these may present through the acute medical take. This article discusses the pathogenesis of infection and highlights the importance of taking a careful history and fully examining the patient. It also emphasises the importance of early surgical intervention in many cases. Consideration of alternative diagnoses, appropriate imaging and high-quality microbiological sampling is important to allow appropriate and targeted antimicrobial therapy. This article makes some suggestions as to empiric antibiotic choice; however, therapy should be guided by local antimicrobial policies and infection specialists. Involvement of a multidisciplinary team is essential for optimal outcomes.

Spondylodiscitis: Diagnosis and Treatment Options

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

First report on treating spontaneous infectious spondylodiscitis of lumbar spine with posterior debridement, posterior instrumentation and an injectable calcium sulfate/hydroxyapatite composite eluting gentamicin: a case report

Background

Spontaneous infectious spondylodiscitis is a rare, but serious disease with the risk of progressive neurological impairment. The surgical approach to spontaneous infectious spondylodiscitis is in most cases an anterior debridement and fusion, often in staged surgeries. Here we report a case of single-stage posterior debridement and posterior instrumented fusion in combination with an injectable calcium sulfate/hydroxyapatite composite eluting gentamicin.

Case presentation

A 59-year-old Caucasian man presented with a 6-week history of lumbar pain without sensory or motor disorders of his lower extremities. A magnetic resonance imaging scan of his lumbar spine in T2-weighted sequences showed a high signal of the intervertebral disc L4/L5 and in T1-weighted sequences an epidural abscess at the posterior wall of L4. Additional computed tomography imaging revealed osteolytic destruction of the base plate of L4 and the upper plate of L5. Antibiotic therapy was started with intravenous ciprofloxacin and clindamycin. We performed a posterior debridement via a minimally invasive approach, a posterior percutaneous stabilization using transpedicular screw-rod instrumentation and filled the intervertebral space with an injectable calcium sulfate/hydroxyapatite composite which elutes a high concentration of gentamicin. The patient’s lower back pain improved quickly after surgery and no recurrence of infection has been noticed during the 1-year follow-up. Computed tomography at 11 months shows complete bony fusion of L4 and L5.

Conclusions

An injectable calcium sulfate/hydroxyapatite composite releasing a high level of gentamicin can support the surgical treatment of spondylodiscitis in combination with posterior debridement and transpedicular screw-rod instrumentation.

Mesh cage for treatment of hematogenous spondylitis and spondylodiskitis. How safe and successful is its use in acute and chronic complicated cases? A systematic review of literature over a decade

BACKGROUND

Surgical treatment of hematogenous pyogenic spondylitis and spondylodiskitis includes anterior debridement, stabilization, and fusion. Titanium mesh cage (TMC) has been advocated to immediately correct deformity and eradicate infection with low recurrence rates. There are no comprehensive reviews on TMC.

PURPOSE

To evaluate recorded information regarding surgical outcome with the use of TMC for treating patients with pyogenic spinal infection.

STUDY DESIGN

Comprehensive review.

METHODS

The terms "titanium cage", "spine", "infection" were searched. A total of 486 peer-reviewed papers published from 2002 to 2012 were obtained from PubMed search. Fifteen Level IV articles with 363 patients were enrolled for consideration. Finally, 192 (53 %) patients who received TMC were eligible and included in this review. Age, comorbidities, indications for surgery, abscess formation, time lapsed between symptoms initiation and surgery, microbiology, radiological spine restoration, neurological outcome, and complications following surgery are evaluated.

RESULTS

The average age at the index surgery was 57 years, range 15-85 years. The reported time lapsed from symptoms presentation to diagnosis varied significantly from 1 week to 2 years. On admission, there reported paravertebral and/or epidural abscess in 48 % and neurological impairment in 51 % of the patients. One hundred and seventy-seven comorbidities were recorded in 192 patients. Bone biopsy and culture revealed gram (+) bacteria in 71 %, gram (-) in 24 %, and multiple bacteria in 1 %, while it was negative in 3.1 % of the patients. TMC was most commonly (49 %) implanted in the lumbar spine. The follow-up observation following surgery averaged 26 months, range 10-116 months. Most of the studies reported decrease in segmental kyphosis and neurological improvement in incomplete lesions postoperatively. TMC was primarily revised for early dislodgment or cage misplacement in 3.2 % of the patients. Infection recurrence was recorded in two patients (1.3 %), but revision surgery needed in one (0.65 %) patient. Mortality was reported in 5.8 % of the patients.

CONCLUSIONS

TMC offers an advantageous and safe technique for spinal debridement and fusion for hematogenous spinal infection. TMC safeguarded medium-term spinal stability with low infection recurrence rates, which were independent form causative pathogen, age, and comorbidities.