Hematogenous pyogenic spinal infection: current perceptions

PET/CT and SPECT/CT for Infection in Joints and Bones: An Overview and Future Directions

Infections of the bones and joints, if misdiagnosed, may result in serious morbidity and even mortality. A prompt diagnosis followed by appropriate management may reduce the socioeconomic impact of bone and joint infections. Morphologic imaging such as ultrasound and plain radiographs form the first line investigations, however, in early infections findings may be negative or nonspecific. Nuclear medicine imaging techniques play a complementary role to morphologic imaging in the diagnosis of bone and joint infections. The availability of hybrid systems (SPECT/CT, SPECT/MRI, PET/CT or PET/MRI) offers improved specificity with ability to assess the extent of infection. Bone scans are useful as a gatekeeper wherein negative scans rule out sepsis with a good accuracy, however positive scans are nondiagnostic and more specific tracers should be considered. These include the use of labeled white blood cells and antigranulocyte antibodies. Various qualitative and quantitative interpretation criteria have been suggested to improve the specificity of the scans. PET has better image resolution and 18F-FDG is the major tracer for PET imaging with applications in oncology and inflammatory/infective disorders. It has demonstrated improved sensitivity over the SPECT based tracers, however, still suffers from lack of specificity. 18F-FDG PET has been used to monitor therapy in bone and joint infections. Other less studied, noncommercialized SPECT and PET tracers such as 111In-Biotin, 99mTc-Ubiquicidin, 18F-Na-Fluoride, 18F-labeled white blood cells and 124I-Fialuridine to name a few have shown great promise, however, their role in various bone and joint infections has not been established. Hybrid imaging with PET or PET/MRI offers huge potential for improving diagnostics in infections of the joints and bones.

Thoracic spine infection caused by Pseudomonas fluorescens: A case report and review of literature

BACKGROUND

The clinical incidence of spinal infection is gradually increasing, and its onset is insidious, easily leading to missed diagnosis and misdiagnosis, which may lead to serious complications such as nervous system dysfunction, spinal instability and/or deformity, and cause a huge burden on society and families. Early identification of the causative agent and precision medicine will greatly reduce the suffering of patients. At present, the main pathogenic bacteria that cause spinal infection are Staphylococcus aureus, Streptococcus, Pneumococcus, Escherichia coli, and Klebsiella. There are no reports of spinal infection caused by Pseudomonas fluorescens.

CASE SUMMARY

We report a 32-year-old female patient with spinal infection. She presented with flank pain, initially thought to be bone metastases or bone tuberculosis, and had a family background of tumors. Her clinical features and changes in imaging and laboratory tests led to the suspicion of thoracic spine infection. Histopathology of the lesion showed inflammation, tissue culture of the lesion was negative several times, and the possible pathogen - Pseudomonas fluorescens was found after gene sequencing of the lesion. The patient recovered completely after a full course of antibiotic treatment.

CONCLUSION

This report increases the range of pathogens involved in spinal infections, highlights the unique advantages of gene sequencing technology in difficult-to-diagnose diseases, and validates conservative treatment with a full course of antibiotics for spinal infections without complications.

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.

V, Prasad P, Leasure J, Stepansky F, Piple A, Kondrashov D. Pyogenic spinal infections warrant a total spine MRI

Study design: retrospective case series. Objective: the presenting clinical symptoms of spinal infections are often nonspecific and a delay in diagnosis can lead to adverse patient outcomes. The morbidity and mortality of patients with multifocal spinal infections is significantly higher compared to unifocal infections. The purpose of the current study was to analyse the risk factors for multifocal spinal infections. Methods: we conducted a retrospective review of all pyogenic non-tuberculous spinal infections treated surgically at a single tertiary care medical center from 2006-2020. The medical records, imaging studies, and laboratory data of 43 patients during this time period were reviewed and analysed after receiving Institutional Review Board approval. Univariate and multivariate analyses were performed to identify factors associated with a multifocal spinal infection. Results: 15 patients (35 %) had multifocal infections. In univariate analysis, there was a significant association with chronic kidney disease ( p = 0.040 ), gender ( p = 0.003 ), a white blood cell count ( p = 0.011 ), and cervical ( p < 0.001 ) or thoracic ( p < 0 .001) involvement. In multivariate analysis, both cervical and thoracic involvement remained statistically significant ( p = 0.001 and p < 0.001 , respectively). Conclusions: patients with infections in the thoracic or cervical region are more likely to have a multifocal infection. Multifocal pyogenic spinal infections remain a common entity and a total spine MRI should be performed to aid in prompt diagnosis.

Chronological Analysis of Primary Cervical Spine Infection: A Single-Center Analysis of 59 Patients over Three Decades (1992–2018)

Primary cervical spine infections progress quickly and cause neurological impairment at an early stage. Despite their clinical significance, few studies have investigated primary cervical spine infections, owing to the rarity of the condition. This study analyzed the characteristics of 59 patients treated for primary cervical spine infections between 1992 and 2018 at our hospital. Clinical and radiological analyses were conducted. Moreover, a comparative analysis was performed, incorporating each patient’s underlying disease, mortality and complications, and treatment results. Comparison between groups based on the chronological period (1992–2000, 2001–2009, and 2010–2018) revealed that the mean age of onset has increased significantly in recent years. The rate of neurological impairment, duration of antibiotic use, and frequency of underlying disease increased significantly with time. No significant differences among groups were observed in the hematological and microbiological analyses. The incidence rate of epidural abscess and multisegmental infection increased significantly in recent years. There was no statistically significant difference in the complication and mortality rates, according to the time period. We think that prompt diagnosis and appropriate treatment are necessary, considering the current trends in primary cervical spine infection.

Whole-Spine Magnetic Resonance Imaging: A Review of Suggested Indications

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The spinal column has a propensity for lesions to manifest in a multifocal manner, and identification of the lesions can be difficult.

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When used to image the spine, magnetic resonance imaging (MRI) most accurately identifies the presence and location of lesions, guiding the treatment plan and preventing potentially devastating complications that are known to be associated with unidentified lesions.

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Certain conditions clearly warrant evaluation with whole-spine MRI, whereas the use of whole-spine MRI with other conditions is more controversial.

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We suggest whole-spine MRI when evaluating and treating any spinal infection, lumbar stenosis with upper motor neuron signs, ankylosing disorders of the spine with concern for fracture, congenital scoliosis undergoing surgical correction, and metastatic spinal tumors.

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Use of whole-spine MRI in patients with idiopathic scoliosis and acute spinal trauma remains controversial.

Minimally invasive posterior fixation and anterior debridement-fusion for thoracolumbar spondylodiscitis: A 40-case series and review of the literature

INTRODUCTION

Pyogenic spondylodiscitis is a rare disease, but incidence is increasing. Reported failure rates following conservative management range from 12% to 18%. The purpose of this study was to determine the safety and efficacy of posterior percutaneous pedicle screw fixation combined with anterior debridement and fusion (ADF) for infective spondylodiscitis in the thoracic and/or lumbar spine.

METHODS

The retrospective study cohort comprised all patients without neurological deficit who underwent minimally invasive posterior and anterior surgery between April 2008 and April 2016 for thoracic and/or lumbar spondylodiscitis.

RESULTS

Forty patients were eligible (16 female: 40%). The lumbar region was affected in 31 cases (77.5%). Source of infection was identified in only 22 cases (55%) and bacteriological identification was obtained in 32 cases (80%). Mean hospital stay was 14.8 days (range, 6-39 days). Complete recovery was achieved in 39 patients (97.5%) at 3 months' follow-up. Mean preoperative local kyphosis angle was 16.1^o, versus 14^o at 1-year (P>0.05). 36 patients (90%) had at least 1 year's follow-up, and fusion was obtained for all these cases.

CONCLUSION

Two-stage minimally invasive surgery is effective and safe for the treatment of single or two-level thoracolumbar spondylodiscitis. It could be an alternative to conventional open surgery or conservative treatment.

Cervical alignment after single-level anterior cervical corpectomy and fusion using autologous bone graft without spinal instrumentation for cervical pyogenic spondylitis

BACKGROUND

Subsidence in anterior cervical corpectomy and fusion (ACCF) for cervical degenerative disease (CDD) are constantly observed during the postoperative course. Although kyphotic change of cervical alignment occurred frequently in cervical pyogenic spondylitis (CPS) postoperatively, studies on the postoperative change in segmental angle for CPS are limited. This study aimed to analyze cervical alignment after single-level ACCF using autologous bone graft without spinal instrumentation for CPS compared with that for CDD.

METHODS

Six patients underwent single-level ACCF using autologous bone graft without spinal instrumentation for CPS. The control group included 18 age-matched patients who underwent single-level ACCF using autologous bone graft for CDD without spinal instrumentation for the same duration. Cervical and lateral plain radiographs and computed tomography scans were taken. The Frankel classification was used to assess the neurological status preoperatively, postoperatively, and at 2-year follow-up for CPS.

RESULTS

At 2-year follow-up, the average segmental angle at the fusion level was - 12.2° ± 6.9° for CPS and - 5.2° ± 7.6° for CDD (p = 0.04). Changes in segmental angle at the fusion level were - 7.2 ± 9.0° for CPS and - 1.1° ± 7.1° for CDD (p = 0.02). At 2-year follow-up, the average anterior segmental fusion height was 23.4 ± 1.7 mm for CPS and 29.1 ± 5.1 mm for CDD (p < 0.001). At 2-year follow-up, bone fusion in the CPS group was classified as grade 5 (complete fusion) in 4 patients (66.7%) and grade 4 (probable fusion) in 2 (33.3%). In the CDD group, it was grade 5 in 13 patients (72.2%) and grade 4 in 5 patients (27.8%). Overall, both groups achieved 100% bone fusion rate. The Frankel classification in all CPS cases improved or leveled off.

CONCLUSION

Progression of segmental kyphosis angle and subsidence of graft bone were observed postoperatively on all CPS cases. However, the neurological recovery and bone union were satisfactory.

High Prevalence of Multifocal Spine Infections Involving the Cervical and Thoracic Regions: A Case for Imaging the Entire Spine

Objective

Pyogenic spinal infections account for 2%–4% of orthopaedic infections. They are often difficult to diagnose, resulting in a delay in diagnosis. Risk factors for orthopaedic and spinal infection are well-documented in the literature, yet there is a paucity of studies examining risk factors specifically for multifocal spinal infections. The objective of this study was to identify predictors of multifocal spinal infections in comparison to unifocal spinal infections.

Methods

The medical records, imaging studies, and bacteriology data of 20 patients treated surgically for pyogenic spinal infection over 6 years at a tertiary referral center were reviewed and analyzed after receiving Institutional Review Board approval. Univariate and multivariate analyses were performed to identify factors associated with a multifocal spinal infection.

Results

Seven patients (35%) had multifocal infections. Three were bifocal, and 4 were trifocal. Patients with surgically treated cervical or thoracic spinal infections had a high rate of concomitant multifocal spinal infections (71% and 83%, respectively). Other potential predictors (e.g., patient age, body mass index, magnetic resonance image findings, etc.) did not reach statistical significance. Each of the multifocal infections involved the lumbar spine.

Conclusion

In this study, the spinal region was the only statistically significant risk factor for multifocal infection. Patients who are diagnosed with a spinal infection that requires operative treatment should have their entire spine evaluated with magnetic resonance imaging to detect multifocal involvement promptly.

Calcium Pyrophosphate Deposition Disease Involving a Lumbar Facet Joint Following Urinary Tract Infection

A 75-year-old woman was admitted with urosepsis due to Escherichia coli infection. After improvement with a ureteral stent and antimicrobial agent, she complained of back pain and showed elevated inflammation marker levels. Arthralgia and arthritis of multiple peripheral joints were noted, and radiography indicated cartilage calcification. Magnetic resonance imaging revealed lumbar facet joint effusion. Her symptoms improved with nonsteroidal anti-inflammatory drug administration. Thus, she was diagnosed with calcium pyrophosphate deposition (CPPD)-related facet joint arthritis (FJA) rather than infectious FJA. CPPD-related FJA is an important differential diagnosis in elderly individuals with a risk of CPPD disease who complain of back pain.

Adjacent level spondylodiscitis in a patient with thoracic spondylodiscitis: A case report and review of the literature

INTRODUCTION

Adjacent level spondylodiscitis (ALS) after primary surgery for thoracic spondylodiscitis is a very rare condition.

CASE REPORT

We report the case of a 76-year-old man with this pathology. A first posterior minimally invasive approach combined with anterior approach to the thoracic spine was safely performed for thoracic spondylodiscitis. More than a year later, exploration of recurrent symptoms with ¹⁸FDG PET scan helped to diagnose ALS. Further surgery was performed. At 3-year follow-up examination showed no recurrence of the infection.

DISCUSSION

ALS should be suspected during recurrent symptoms after spinal fusion surgery. Evaluation should be based on the results of ¹⁸FDG PET scan and surgery.

CONCLUSION

Bacterial and histopathological analyses combined with an increase of spine fixation and adapted antimicrobial therapy are a safe management for ALS.

Cervical spondylodiscitis following an invasive procedure on the neopharynx after circumferential pharyngolaryngectomy: a retrospective case series

PURPOSE

To highlight cervical spondylodiscitis as an infrequent complication following an invasive procedure on the neopharynx in patients previously treated with circumferential pharyngolaryngectomy with pectoralis major myocutaneous flap reconstruction.

METHODS

Patients diagnosed with cervical spondylodiscitis after circumferential pharyngolaryngectomy between 2001 and 2013 were retrospectively studied using a questionnaire sent to the French head and neck tumour study group. Medical history; tumour management; clinical symptoms; biological, microbiological and imaging results; and management of the infection were collected for each patient.

RESULTS

Six men aged 51-66 years were diagnosed with spondylodiscitis on average 5.6 years after circumferential pharyngolaryngectomy, and a mean 2 months following an invasive procedure on the neopharynx (oesophageal dilatation, phonatory prosthesis insertion). The patients presented with cervical pain and increased CRP level. MRI showed epidural abscess and communication between the pharynx and vertebral bodies in most cases. Microbiological samples yielded bacteria from the pharynx flora. Infection was managed using antibiotics adjusted according to the culture results and spinal immobilisation for duration of 6-12 weeks. No surgical treatment was required. During follow-up, no patient experienced recurrence or residual disability.

CONCLUSIONS

Cervical spondylodiscitis is a rare but potentially severe complication following an invasive procedure on the neopharynx after circumferential pharyngolaryngectomy. Therefore, the onset of nonspecific symptoms should not be overlooked, and MRI must be performed if infection is suspected. Microbiological confirmation is critical in optimising treatment, which should be aggressive, even if overall prognosis seems to be good.

Cervical pyogenic spinal infections: are they more severe diseases than infections in other vertebral locations?

PURPOSE

Cervical spine pyogenic infections are unusual compared to other vertebral segments, but they can be associated to worse clinical outcomes. We compared all patients with cervical spine pyogenic infections to those with thoracolumbar involvement in terms of epidemiology, prognostic factors and clinical outcomes.

METHODS

We retrospectively reviewed all patients discharged from our institution with diagnosis of pyogenic spinal infections (PSI) during a 14-year period. Patients' demographics, etiologic agent, co-morbidities, site of infection, white blood cell count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) at time of presentation, neurological impairment and mortality were registered to compare clinical outcomes of patients with PSI affecting the cervical spine and other segments.

RESULTS

We studied 102 patients with PSI. Nineteen (18.6 %) had cervical involvement; 73.7 % of them were males, with a mean age of 65.22 years. 89.7 % of them presented spondylodiscitis; 12 patients (63.2 %) exhibited a one segment involvement (C5-C6 being the most common), and 11 patients presented an epidural abscess. Thirteen patients (68.4 %) exhibited neurological deficit. Seventeen patients (89.5 %) presented elevated ESR and CRP, while 12 patients (63.2 %) exhibited leukocytosis. The causative organism was identified in 17 patients (89.5 %). Despite similar baseline characteristics, compared to PSI in other locations, patients with cervical PSI presented significantly more neurological involvement (68.4 vs. 41 %; p = 0.03), they more often required surgical treatment (84.2 vs. 46.3 %; p < 0.01), and they had and increased mortality (21.1 % compared to 3.6 %; p = 0.02).

CONCLUSION

An early diagnosis and prompt treatment should be the goal treating cervical PSI, considering the potential devastating complications and increased mortality.

Spinal infection: state of the art and management algorithm

INTRODUCTION

Spinal infection is a rare pathology although a concerning rising incidence has been observed in recent years. This increase might reflect a progressively more susceptible population but also the availability of increased diagnostic accuracy. Yet, even with improved diagnosis tools and procedures, the delay in diagnosis remains an important issue. This review aims to highlight the importance of a methodological attitude towards accurate and prompt diagnosis using an algorithm to aid on spinal infection management.

METHODS

Appropriate literature on spinal infection was selected using databases from the US National Library of Medicine and the National Institutes of Health.

RESULTS

Literature reveals that histopathological analysis of infected tissues is a paramount for diagnosis and must be performed routinely. Antibiotic therapy is transversal to both conservative and surgical approaches and must be initiated after etiological diagnosis. Indications for surgical treatment include neurological deficits or sepsis, spine instability and/or deformity, presence of epidural abscess and upon failure of conservative treatment.

CONCLUSIONS

A methodological assessment could lead to diagnosis effectiveness of spinal infection. Towards this, we present a management algorithm based on literature findings.