Diagnosis Of Musculoskeletal Infections Research Articles

Use of intra-operative fluorescence imaging in periprosthetic joint infection: State of the art and future perspectives.

In periprosthetic joint infections (PJIs), the surgeon's role becomes pivotal in addressing the infection locally, necessitating the surgical removal of infected and necrotic tissue. Opportunity to enhance the visualization of infected tissue during surgery could represent a game-changing innovation. The aim of this narrative review is to delineate the application of intraoperative fluorescence imaging for targeting infected tissues in PJIs. A systematic review, adhering to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, was carried out. The search included multiple online database; MEDLINE, Scopus, and Web of Science. For data extraction the following were evaluated: (i) diagnosis of musculoskeletal infection; (ii) use of intraoperative fluorescence imaging; (iii) infected or necrotic tissues as target. Initially, 116 studies were identified through online database searches and reference investigations. The search was narrowed down to a final list of 5 papers for in-depth analysis at the full-text level. Subsequently, 2 studies were included in the review. The study included a total of 13 patients, focusing on cases of fracture-related infections of the lower limbs. The primary and crucial role for orthopedic surgeons in PJIs is the surgical debridement and precise removal of necrotic and infected tissue. Technologies that enable clear and accurate visualization of the tissue to be removed can enhance the eradication of infections, thereby promoting healing. A promising avenue for the future involves the potential application of intraoperative fluorescence imaging in pursuit of this objective.

Procalcitonin Role in Musculoskeletal Infection: A Comparative Prospective Study

Early diagnosis of musculoskeletal infections is of vital importance to avoid devastating complications. There is no single laboratory marker which is sensitive and specific in diagnosing these infections accurately. White blood cell count, erythrocyte sedimentation rate and C-reactive protein are not specific as they can also be elevated in conditions other than bacterial infections. Materials Culture and sensitivity is not a true gold standard due to its varied positivity rates. Serum Procalcitonin (PCT) is one of the new laboratory markers for pyogenic infections. The objective of this study is to assess the value of PCT in diagnosis of soft tissue, bone and joint infections. Patients and Methods: Patients of all age groups (seventy-four patients) with diagnosis of musculoskeletal infection are prospectively included in this study. All patients were subjected to White blood cell count, erythrocyte sedimentation rate, C-reactive protein and serum Procalcitonin measurements. Healthy non infected outpatient group (twenty-two patients) taken as a control group and underwent the same evaluation steps as the study group. Results: The study group showed mean Procalcitonin levels of 1.3 ng/ml. Procalcitonin, at 0.5 ng/ml, was (42.6%) sensitive and (95.5%) specific in diagnosing of musculoskeletal infections with (positive predictive value of 87.5% and negative predictive value of 48.3%) and (positive likelihood ratio of 9.3 and negative likelihood ratio of 0.6). Conclusion: Serum Procalcitonin, at a cut – off of 0.5 ng/ml, is a specific but not sensitive marker in the diagnosis of musculoskeletal infections, and it can be used effectively to rule in the diagnosis of infection but not to rule out it.

Role of Nuclear Medicine in the diagnosis of musculoskeletal infection: a review

Inflammatory and infectious osteoarticular diseases can cause serious consequences for the patient if they are not diagnosed on time. In the last decades, different modalities of nuclear medicine have allowed to study the physiopathology of these processes, and nowadays, they play an important role in diagnosis, characterization and monitoring of musculoskeletal infectious diseases. Therefore, it is essential that every nuclear medicine physician have a vision of the advantages and disadvantages of each method and know how to use them correctly in the diagnosis of the patient. This article highlights the role of nuclear medicine in standardizing the diagnostic approach in patients with infectious/inflammatory diseases, in particular in peripheral osteomyelitis, septic arthritis, prosthetic joint infections, infected diabetic foot and spinal infections. The authors reveal the role of the most common radionuclides tests, with their advantages and clinical indications, to achieve an adequate diagnosis of infection and inflammation.

Hybrid imaging of musculoskeletal infections.

This review article highlights the role of radiological and nuclear medicine techniques in diagnosis of musculoskeletal infections with particular regard to hybrid imaging of osteomyelitis, prosthetic joint infections, sternal infections and spine infections. Authors conclude on the complementary role of the several techniques with indications for an appropriate diagnostic flow chart, in the light of the recent European Association of Nuclear Medicine guidelines on infection.

Molecular imaging in musculoskeletal infections with 99mTc-UBI 29-41 SPECT/CT

ObjectiveTo determine the added value of CT over planar and SPECT-only imaging in the diagnosis of musculoskeletal infection using 99mTc-UBI 29-4.Materials and methods184 patients with suspected musculoskeletal infection who underwent planar and SPECT/CT imaging with 99mTc-UBI 29-41 were included. Planar, SPECT-only and SPECT/CT images were reviewed by two independent analysts for presence of bone or soft tissue infection. Final diagnosis was confirmed with tissue cultures, surgery/histology or clinical follow-up.Results99mTc-UBI 29-41 was true positive in 105/184 patients and true negative in 65/184 patients. When differentiating between soft tissue and bone infection, planar + SPECT-only imaging had a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 95.0, 74.3, 84.8, 91.3 and 86.9%, respectively, versus 99.0, 94.5, 92.5, 98.5 and 94.5% for SPECT/CT. SPECT/CT resulted in a change in reviewers’ confidence in the final diagnosis in 91/184 patients. Inter-observer agreement was better with SPECT/CT compared with planar + SPECT imaging (kappa 0.87, 95% CI 0.71–0.85 versus kappa 0.81, 95% CI 0.58–0.75).ConclusionAddition of CT to planar and SPECT-only imaging led to an increase in diagnostic performance and an improvement in reviewers’ confidence and inter-observer agreement in differentiating bone from soft tissue infection.

A striking case of florid multifacial soft-tissue infection on an FDG-PET scan

Background: A 24-year-old male had a road traffic accident in which he sustained a crush injury to his right lower leg and a compound fracture of the right femur, which were respectively treated with below knee amputation and metallic nailing of the right femur. The patient presented to the outpatient clinic 7 years later with 1-month history of pain and swelling of the right thigh; however, he didn’t report any fever. An FDG-PET scan was prescribed to rule out infection. Procedure: 18F-flourodeoxyglucose (329 MBq) was injected intravenously and PET/CT imaging performed after 60 minutes on a PET/CT camera (GE 710). A CT scan without oral or intravenous contrast, without breath holding, was acquired at low mA level for attenuation correction and localization purposes only. Arms were held up. Subsequently PET images from vertex to toe were obtained. PET, CT and fused images were reconstructed in the transaxial, coronal and sagittal axes (Figure 1). Findings: The PET/CT scan images show extensive accumulation of FDGavid fluid in the right thigh starting from the level above the nail in the mid gluteal region. Focal uptake is seen in the soft-tissue above the femoral neck with the high FDG uptake (SUVmax 12.7). There is FDG-avid fluid surrounding the intramedullary nail (SUVmax 3.8 to 5.9). The PET/CT scan shows extensive hypermetabolic fluid uptake in the right thigh in different soft-tissue regions including: 1) subcutaneously in the lateral aspect of the right thigh, 2) from mid to lower right thigh (SUVmax 12.6), 3) intrafacial, 4) sub-facial, 5) intraseptal, 6) inter and intramuscular (SUVmax 9 to 15.5). See Figures 1-3. Conclusion: The PET/CT scan findings were consistent with multiple hypermetabolic abscesses at different soft-tissue levels in the right thigh. There was however no evidence of osteomyelitis seen. Comments: Hybrid positron emission tomography/computed tomography (PET/CT) with the glucose analogue, 18F-fluoro-2- deoxyglucose (18F-FDG), is being increasingly used for the diagnosis of musculoskeletal infection. Activated granulocytes present at sites of infection/inflammation use glucose as an energy source and avidly take up FDG, which is transported into the cells and phosphorylated by hexokinase to 18F-fluoro2-deoxyglucose-6- phosphate, that is not further metabolized. Increased cellular metabolism in the activated inflammatory cells results in an increased expression of glucose transporter (GLUT) proteins by these cells, which coupled with an increase in the affinity for glucose by the glucose transporters secondary to the effects of cytokines and growth factors, results in high FDG uptake at sites of infection/ inflammation [1, 2]. This striking case of florid and extensive soft-tissue infection in the right thigh 7 years post surgery demonstrates the effectiveness of this new infection imaging modality in the non-invasive diagnosis of infection. The combination of PET and CT provides complementary information at a higher resolution and sensitivity as compared with singlephoton emitting radionuclides. FDG-PET technique demonstrates the metabolic changes that occur earlier compared to the anatomical changes seen by CT or MRI alone. The high metabolic activity of infective abscesses due to a high degree of FDG avidity coupled with structural CT changes of infection facilitates rapid interpretation of both the severity and the extent of infection and helps delineate osseous from soft-tissue involvement. The PET/ CT scan in this case showed multiple hypermetabolic areas which were precisely localized to the soft-tissue and showed no bone involvement. The findings are extremely helpful in determining and instituting the appropriate treatment and also useful for monitoring the therapeutic efficacy.

Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

The incremental value of gadolinium in the diagnosis of musculoskeletal infection by MRI is controversial. To compare diagnostic utility of noncontrast with contrast MRI in the evaluation of pediatric musculoskeletal infections. We reviewed 90 gadolinium-enhanced MRIs in children with suspected musculoskeletal infection. Noncontrast and contrast MRI scans were evaluated to determine sensitivity and specificity in the diagnosis of musculoskeletal infection and identification of abscesses. Pre- and post-contrast diagnosis of osteomyelitis sensitivity was 89% and 91% (P = 1.00) and specificity was 96% and 96% (P = 1.00), respectively; septic arthritis sensitivity was 50% and 67% (P = 1.00) and specificity was 98% and 98% (P = 1.00), respectively; cellulitis/myositis sensitivity was 100% and 100% (P = 1.00) and specificity was 84% and 88% (P = 0.59), respectively; abscess for the total group was 22 (24.4%) and 42 (46.6%), respectively (P < 0.0001). Abscesses identified only on contrast sequences led to intervention in eight additional children. No child with a final diagnosis of infection had a normal pre-contrast study. Intravenous gadolinium should not be routinely administered in the imaging work-up of nonspinal musculoskeletal infections, particularly when pre-contrast images are normal. However, gadolinium contrast significantly increases the detection of abscesses, particularly small ones that might not require surgical intervention.

Papers Presented at the 2008 Meeting of the Musculoskeletal Infection Society: Editorial Comment

Surgical site infections after orthopaedic surgery are a source of considerable postoperative morbidity and mortality and are associated with increased rehospitalization and higher healthcare expenditures. Patients with surgical site infections may develop greater physical limitations that lead to reductions in health-related quality of life, particularly if they require reoperation and/or removal of an orthopaedic implant such as a joint prosthesis. While much of the science of infection prevention and treatment has yet to be explored, there has been substantial progress in improving methods for addressing surgical site infections. The 18th annual meeting of the Musculoskeletal Infection Society of North America was held in August 2008 at Lake Tahoe, California. In this issue, CORR features papers presented at the annual session. Three themes emerge from the series of papers—prevention, diagnosis, and treatment of musculoskeletal infection. Several papers focus on prevention by presenting risk factors associated with the development of surgical site infections, including modifiable risk factors. These modifiable risk factors, such as diabetes, can be improved by patients and physicians prior to orthopaedic surgery to decrease the risk of surgical site infection in the individual patient. The utility of specific preoperative preventive measures such as different types of barrier preparations were also discussed, as were the effect of the attachment of antibiotics to prostheses to reduce the risk of surgical site infection on the topography of titanium alloy surfaces. The increasing use of ingrowth prostheses that do not allow for antibiotic impregnated cement makes this an important issue for future basic science and translational research. Regarding the diagnosis of musculoskeletal infection, the utility of MRI to improve preoperative planning in patients with musculoskeletal infections was reviewed. More work in this area relating to the cost effectiveness of the approach is warranted. The majority of the papers presented at the annual session discussed the treatment of infection, with the focus on implant-related infection. Topics range from the basic science of local antibiotic delivery to the clinical experience of major limb amputations due to uncontrolled infection. Also addressed were important specific topics relating to the reasons for unexpected hospital readmission following discharge after treatment of musculoskeletal infection, and the increasing threat of antimicrobial resistance among organisms causing musculoskeletal infection. In this era of optimization of patient safety and infection prevention, addressing the problem of surgical site infections begins with careful patient selection and preoperative improvement in modifiable risk factors, proper surgical technique with meticulous environmental control, and heightened awareness for effective surveillance. Once diagnosed, successful treatment of musculoskeletal infection requires a team approach that employs evidence-based practices whenever possible. It is through dialogue—between orthopaedists, infectious disease specialists, and basic scientists—that we advance our understanding of musculoskeletal infection, its prevention, diagnosis, and treatment. We hope you enjoy and learn from the articles in the symposium as we did upon hearing them presented at the annual session in 2008. We invite you to join us for our 2009 annual meeting.

Radionuclide Imaging of Musculoskeletal Infection: Conventional Agents

The diagnosis of musculoskeletal infection can be clinically challenging, and radionuclide imaging is often performed as part of the diagnostic workup. Conventional studies include bone scan, gallium imaging, and labeled leukocyte imaging. No single test is equally efficacious in all situations, and thus the procedure(s) performed should be optimized for the individual patient. Three-phase bone imaging, readily available and relatively inexpensive, is very accurate in unviolated bone. In the setting of underlying osseous abnormalities, however, the specificity of the test decreases. Four-phase bone, sequential bone/gallium, and labeled leukocyte imaging all have been used in an effort to enhance specificity. Labeled leukocyte imaging is the radionuclide procedure of choice for diagnosing so-called complicating osteomyelitis such as infected joint prostheses, diabetic pedal osteomyelitis, and infection of the neuropathic joint. To maximize the accuracy of the study, complementary bone marrow imaging often must be performed. Labeled leukocyte imaging is of limited value in spinal osteomyelitis, however, because this entity often presents as a nonspecific photopenic defect on white cell studies. The conventional radionuclide study for evaluating spinal osteomyelitis is gallium imaging, which should be performed regardless of the findings on a contemporaneous bone scan. The reasons for this are as follows: Gallium improves the specificity of the bone scan; gallium detects accompanying soft tissue infection, whereas the bone scan does not, and gallium may be more sensitive than the bone scan in elderly patients.

Molecular diagnostics for the detection of musculoskeletal infection.

The last decade has seen the crossover of basic molecular research techniques toward clinical application. The use of molecular diagnostics originally was driven by the desire to identify unculturable or fastidious pathogens. Success in this setting has led to new applications aimed at identifying organisms involved in musculoskeletal infection. Recently, polymerase chain reaction techniques have been investigated as to their efficacy in diagnosing septic arthritis and periprosthetic infection. This paper will offer an introduction to molecular diagnostics, a brief review of several techniques, and update their status in the diagnosis of musculoskeletal infection.

Musculoskeletal infections of the extremities; Ultrasound features

To show the value of US in diagnosis of musculoskeletal infections at their earliest stages, when conventional radiographs are usually normal or show only a nonspecific soft tissue swelling.

Imaging in the diagnosis of musculoskeletal infections in children

Imaging in the diagnosis of musculoskeletal infections in children

Diagnosis of musculoskeletal infection using combined In-111 labeled leukocyte and Tc-99m SC marrow imaging.

Seventy-three patients with various underlying disorders that could potentially alter distribution of bone marrow underwent In-111 labeled autologous leukocyte and Tc-99m SC marrow imaging to exclude musculoskeletal infection. There were 22 cases of infection among the 73 patients studied. When interpreted in isolation, labeled leukocyte images were considered positive for infection when uptake of labeled cells in the region of interest exceeded uptake in the corresponding contralateral side. The sensitivity, specificity, and accuracy of the study using this criterion were 86%, 12%, and 34%, respectively. When interpreted in conjunction with sulfur colloid marrow images, studies were considered positive for infection when uptake in the region of interest on leukocyte and marrow images was spatially incongruent. The sensitivity, specificity, and accuracy of this dual tracer modality were 100%, 94%, and 96%, respectively. Three patients with infection and abnormal leukocyte/marrow images underwent repeat imaging after appropriate therapy. Images were interpreted as normal in two of them; both were infection free at subsequent surgery. Images of the third patient were interpreted as consistent with persistent infection, and operative cultures grew out Staphylococcus aureus. In summary, combined leukocyte/marrow imaging is a highly accurate method for diagnosing musculoskeletal infection and overcomes certain inherent limitations of labeled leukocyte imaging alone.

Detection of Soft-Tissue and Skeletal Infections with Ultra Low-Field (0.02 T) Mr Imaging

To evaluate the use of ultra low-field (0.02 T) magnetic resonance (MR) imaging in the diagnosis of musculoskeletal infection, MR examinations with T2 weighted sequences were performed in 61 patients thought to be suffering from one of four major diagnostic categories: Soft-tissue abscesses (n = 22), osteomyelitis (n = 21), septic arthritis (n = 9) and spondylitis (n = 9). Infection was confirmed for 37 of these 61 patients. The verified abscesses, arthritis, spondylitis and acute osteomyelitis could be detected by 0.02 T MR. The sensitivity was poor in cases of chronic osteomyelitis. There was one false positive finding in a patient with a possible soft tissue infection. The 0.02 T MR examination failed four times. Two patients were too heavy and another 2 patients had magnetic material in or near the scanning field. Compared with computed tomography and isotope scanning, 0.02 T MR proved a little more informative, but without any statistical significance.