The impact of antibiotic pre-treatment on diagnostic yield of CT-guided biopsy for spondylodiscitis: A multi-centre retrospective study and meta-analysis

Diagnostic accuracy of fluorine-18 fluorodeoxyglucose positron emission tomography for suspected primary and postoperative pyogenic spondylitis

OBJECTIVE

Fluorine-18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) and PET/CT have been suggested for confirming or excluding musculoskeletal infection but the diagnostic value of this tool for pyogenic spondylitis remains to be confirmed. This meta-analysis was performed to verify the accuracy of ¹⁸F-FDG PET and PET/CT in diagnosing suspected pyogenic spondylitis by performing a systematic review and meta-analysis.

METHODS

We conducted a comprehensive literature search of PubMed, Embase and Cochrane Library to retrieve diagnostic accuracy studies in which suspected pyogenic spondylitis was assessed with ¹⁸F-FDG PET or PET/CT. The pooled sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR), summarized receiver operating characteristic curve (sROC) and the area under the sROC (AUC) were calculated by using Stata software.

RESULTS

A total of 18 eligible studies (660 patients) with suspected pyogenic spondylitis were included in the quantitative analysis. ¹⁸F-FDG PET and PET/CT illustrated relatively high sensitivity (0.91, 95% CI: 0.84-0.95) and specificity (0.90, 95% CI: 0.79-0.95) for the diagnosis of pyogenic spondylitis. The pooled DOR and AUC were 86.00 (95% CI, 31.00-240.00) and 0.96 (95% CI, 0.94-0.97), respectively. For diagnosing pyogenic spondylitis without previous spine surgery, the pooled sensitivity, specificity, DOR and AUC were 0.93 (95% CI, 0.85-0.97), 0.91 (95% CI, 0.77-0.97), 136 (95% CI, 35-530) and 0.97 (95% CI, 0.95-0.98), respectively. For diagnosing postoperative pyogenic spondylitis, the pooled sensitivity, specificity, DOR and AUC were 0.85 (95% CI, 0.71 to 0.93), 0.87 (95% CI, 0.66 to 0.96), 38 (95% CI, 9 to 167) and 0.92 (95% CI, 0.89 to 0.94), respectively.

CONCLUSION

¹⁸F-FDG PET and PET/CT presented satisfactory accuracy for diagnosing pyogenic spondylitis. The diagnostic effect of this nuclear imaging method for pyogenic spondylitis without previous spine surgery seems to be better than that for the postoperative ones. However, whether ¹⁸F-FDG PET and PET/CT could become a routine in patients with suspected pyogenic spondylitis remains to be confirmed.

LEVEL OF EVIDENCE

Level I evidence, a summary of meta-analysis.

Factors Impacting the Yield of Image-Guided Biopsy in Native Vertebral Osteomyelitis: A 10-Year Retrospective Study

Background

Image-guided biopsies in patients with suspected native vertebral osteomyelitis (NVO) are recommended to establish the microbiological diagnosis and guide antibiotic therapy. Despite recent advances, the microbiological yield of this procedure remains between 48% and 52%. A better understanding of factors associated with this low yield may lead to improved microbiological diagnosis.

Methods

We retrospectively identified patients with suspected NVO undergoing image-guided biopsies from January 2011 to June 2021 at our institution. Two hundred nine patients undergoing 248 percutaneous biopsies were included. Demographic data, biopsy and microbiologic techniques, clinical characteristics, and antibiotic use were collected. Multivariable logistic regression analysis was conducted to determine factors associated with microbiological yield.

Results

A total of 110 of 209 (52.6%) initial image-guided biopsies revealed positive microbiological results. This number increased to 121 of 209 (57.9%) when repeat image-guided biopsies were included. In multivariable analysis, aspiration of fluid was associated with a 3-fold increased odds of yielding a positive result (odds ratio [OR], 3.13; 95% confidence interval [CI], 1.39-7.04; P = .006), whereas prior antibiotic use was associated with a 3-fold decreased yield (OR, 0.32; 95% CI, .16-.65; P = .002). A univariate subgroup analysis revealed a significant association between the length of the antibiotic-free period and microbiological yield, with the lowest rates of pathogen detection at 0-3 days and higher rates as duration increased (P = .017).

Conclusions

Prior antibiotic use in patients with suspected NVO was associated with a decrease in the microbiological yield of image-guided biopsies. An antibiotic-free period of at least 4 days is suggested to maximize yield. Successful fluid aspiration during the procedure also increases microbiological yield.

Treatment of Refractory Multilevel Thoracic Spondylodiscitis Using Ultra-Minimally Invasive Endoscopic Approach for Debridement and Drainage: A Technical Note, Intraoperative Video, and Literature Review

OBJECTIVE/BACKGROUND

Spondylodiscitis is an infection of the spinal column which can result in pain, deformity, instability, and/or neurologic deficits. When surgical treatment is required for thoracic spondylodiscitis, invasive open approaches are often utilized due to the ventral location of the pathology.

METHODS

We describe the use of a spinal endoscope to perform drainage and debridement of infected tissue through a transforaminal/intradiscal approach in a patient with multilevel thoracic spondylodiscitis refractory to antibiotic therapy. Illustrative videos are provided, as well as a review of the relevant literature.

RESULTS

A total of 188 patients were included in the systematic review. The mean positive reported culture rate was 76% (117/154 patients). The mean preoperative visual analog scale score was 6.8 (n = 114), and the mean postoperative visual analog scale score was 1.8 at 1 week postoperatively (n = 56) and 1.01 at the final follow-up (n = 114). The most common surgical approach was transforaminal/intradiscal (103/188 patients, 54.8%). The mean reoperation rate was 9.1%. The mean complication rate was 5.25%, with complications including increased transient radicular pain, infection, hardware failure, and new unspecified neurological deficits.

CONCLUSION

This case and those highlighted in our literature review demonstrate that endoscopic treatment for thoracic spondylodiscitis is a viable alternative to traditional open surgery in many cases.

Utility of disc space aspirate cell counts and differentials in the diagnosis of native vertebral osteomyelitis

Background: Aspiration of intervertebral disc space is often done to confirm the diagnosis of native vertebral osteomyelitis. A study has not been done examining the utility of cell counts and differentials of the aspirated fluid in diagnosing native vertebral osteomyelitis (NVO). Methods: In this feasibility study, we prospectively enrolled patients with a suspected diagnosis of NVO referred to the Division of Neuroradiology for image-guided needle aspiration of the intervertebral disc. In this study, manual cell count was done on the aspirated fluid, followed by a differential cytospin technique and touch prep. We obtained demographic, lab, and microbiologic data and used the receiver operating curve (ROC) for statistical analysis. Results: Over 12 months, we performed 17 aspirates on 14 patients. The median age was 70.5 years (range: 45-77). The median manual cell count on the aspirated fluid was 52 cells  µ L - 1 (range: 0-6656), the median neutrophil percentage on the touch prep slide was 73 % (range: 5 %-100 %), and the median neutrophil percentage on the cytospin slide was 82 % (range: 0 %-100 %). Routine bacterial cultures were positive in five cases, and the 16S ribosomal RNA gene polymerase chain reaction was positive in two cases. The optimal cutoff for a cell count of 104 total nucleated cells offered a sensitivity and specificity of 86 %, and a neutrophil cutoff of 83 % was associated with a 71 % sensitivity and specificity. Conclusion: An image-guided aspirated specimen leukocyte differential of ≥ 83  % neutrophils or a leukocyte count of ≥ 104   µ L - 1 was a sensitive and specific test for diagnosing patients with suspected NVO. Additionally, more extensive studies are warranted to confirm the findings.

Diagnosis of vertebral osteomyelitis

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