Pyogenic sacroiliitis: diagnosis, management and clinical outcome

Infectious sacroiliitis: MRI- and CT-based assessment of disease extent, complications, and anatomic correlation

OBJECTIVE

To describe the frequency of MR and CT features of infectious sacroiliitis (ISI) and assess its extent and complications MATERIALS AND METHODS: This retrospective study included patients with ISI who were evaluated between 2008 and 2021 in a single center. Two radiologists reviewed MRI and CT images to determine the anatomical distribution (unilateral/bilateral, iliac/sacral bone, proximal/middle/distal), severity (bone marrow edema [BME]/periostitis/erosions), concurrent infection (vertebral/nonvertebral), and complications (abscess/probable adjacent osteomyelitis/cavitation/devitalized areas/sequestrum/pelvic venous thrombosis) of ISI. Interobserver reproducibility was assessed. Correlation analysis evaluated the effect of the causative microorganism on severity. Two human bodies were dissected to outline possible ways that ISI can spread.

RESULTS

Forty patients with ISI (40 years ± 22; 26 women) were evaluated. Ten patients had bilateral ISI. Concurrent vertebral infection was associated in 15% of cases. Reproducibility of sacral BME, periostitis, and reactive locoregional abnormalities was perfect (κ = 1). Reproducibility was low for erosion count (κ = 0.52[0.52-0.82]) and periarticular osteopenia (κ = 0.50[0.18-0.82]). Inflammatory changes were BME (42/42 joints), muscle edema (38/42), and severe periostitis along the ilium (33/37). Destructive structural changes occurred with confluent erosions (iliac, 20/48; sacral, 13/48), sequestrum (20/48), and cavitation (12/48). Complications occurred in 75% of cases, including periarticular abscesses (n = 30/47), probable adjacent osteomyelitis (n = 16/37), and pelvic thrombophlebitis (n = 3). Tuberculous ISI (6/40) correlated with sclerosis (rs = 0.45[0.16; 0.67]; p < 10-2) and bone devitalization (rs = 0.38[0.16; 0.67]; p = .02). The anatomical study highlighted the shared venous vascularization of sacroiliac joints, pelvic organs, and mobile spine.

CONCLUSION

Complications of ISI are frequent, including abscesses, adjacent osteomyelitis, and periostitis. ISI had bilateral involvement nonrarely and is commonly associated with another spinal infection.

Imaging of Sacroiliac Joints

The central role of imaging in diagnosing disorders affecting the sacroiliac joints (SIJs) necessitates a comprehensive understanding of the advantages, limitations, and potential pitfalls of the imaging techniques that can be used. In this article, the anatomy and biomechanics of SIJs are exposed, outlining their unique features, particularly the division into anteroinferior cartilaginous and postero-superior ligamentous parts. Overall, the goal of this article is to offer a comprehensive understanding of imaging techniques, anatomic complexity, and diagnostic considerations relevant to SIJs disorders, facilitating accurate diagnosis and patient management in clinical practice and research.

Imaging of Sacroiliac Pain: The Current State-of-the-Art

Pain in the sacroiliac (SI) region is a common clinical manifestation, often caused by diseases involving the SI joints. This is typically due to inflammation or degenerative changes, while infections or cancer are less frequent causes. The SI joint is challenging to image accurately because of its distinct anatomical characteristics. For an accurate diagnosis, conventional radiography often needs to be supplemented with more precise methods such as magnetic resonance imaging (MRI) or computed tomography (CT). Sacroiliitis, a common presenting feature of axial spondyloarthritis (axial SpA), manifests as bone marrow edema, erosions, sclerosis, and joint space narrowing. Septic sacroiliitis and repetitive stress injuries in sports can also cause changes resembling inflammatory sacroiliitis. Other conditions, such as osteitis condensans ilii (OCI), can mimic the radiologic characteristics of sacroiliitis. Inflammatory lesions are diagnosed by concurrent erosions, hyperostosis, and ankylosis. Ligament ossifications or mechanical stress can also result in arthritic disorders. Determining the exact diagnosis can be aided by the distribution of the lesions. Inflammatory lesions can affect any part of the articulation, including the inferior and posterior portions. Mechanical lesions, such as those seen in OCI, often occur in the anterior middle region of the joint. In cases of idiopathic skeletal hyperostosis, ligament ossification is found at the joint borders. This pictorial essay describes common SI joint problems, illustrated with multimodal imaging data. We, also, discuss strategies for selecting the best imaging modalities, along with imaging pitfalls, key points, and approaches for treating patients with suspected inflammatory back pain.

Pyogenic sacroiliitis caused by Salmonella schwarzengrund in a young healthy woman: a case report and literature review

BACKGROUND

Salmonella species are a leading cause of diarrheal diseases worldwide. Recent epidemiological studies have shown that Salmonella schwarzengrund (S. schwarzengrund) is highly prevalent in various regions. Herein, we report that S. schwarzengrund caused sacroiliac joint (SIJ) infection with septic shock in a young woman, although she was immunocompetent.

CASE PRESENTATION

A 20-year-old woman presented with left hip pain, accompanied by vasopressor-requiring hypotension. Her imaging examinations showed fluid collection in her SIJ and a small abscess in the left iliac muscle. Later, the blood and aspiration fluid culture and genetic analysis revealed the presence of S. schwarzengrund. We diagnosed sacroiliac joint (SIJ) infection with septic shock caused by S. schwarzengrund. Her condition improved after performing several interventional radiology (IVR) procedures for SIJ abscesses and providing appropriate antibiotic treatment. Finally, she was discharged without any sequelae. Screening tests and genetic analysis about her immunodeficiency did not indicate a congenital disorder.

CONCLUSION

These clinical courses indicate that S. schwarzengrund could cause the fatal SIJ infection irrespective of the host immunocompetence. Considering the recent increase in the diagnostic rate of S. schwarzengrund, this case emphasized the need to be more cautious about Salmonella species infection.

Complex Case Management of Mycobacterium Tuberculosis Extrapulmonary Manifestation to the Right Sacroiliac Joint

While Mycobacterium tuberculosis is a common bacterial pathogen that infects the respiratory system, especially in endemic regions, it may uncommonly manifest in other organ systems, such as the nervous, gastrointestinal, or musculoskeletal systems. Sacroiliac joint infections are rare, and only 1%-5% of all infections are tuberculous in nature. Given nonspecific inflammatory signs in both laboratory and radiologic examinations, early identification of the causative agent can be difficult. In this report, we present the case of a 29-year-old Eritrean woman who presented with an uncommon extrapulmonary tuberculosis manifestation of the right sacroiliac joint. The patient reported pain for two years before a formal diagnosis with multiple computed tomography scans demonstrated fluid collections about her right hip and thigh. The patient's medical history of developmental delay, psychosis, outdated medication documentation, non-therapeutic use of numerous psychiatric medications contraindicated for traditional anti-tubercular therapy, and socioeconomic history of a lack of social support and treatment arrangements with the patient's caregiver all complicated the treatment course. Given the rise in tuberculosis cases worldwide and vulnerability factors in patients with mental illnesses such as poverty, homelessness, diabetes, and HIV infection that can predispose patients to tuberculosis infections, early diagnosis and treatment are essential to reduce long-term consequences and improve clinical outcomes. Further research in the development of new tuberculosis treatment plans is essential to addressing an equitable treatment course alongside fighting against the recent rise in drug-resistant tuberculosis.

Minimally Invasive Sacroiliac Joint Fusion for the Treatment of Brucella Pyogenic Sacroiliitis: A Case Report

A 39-year-old male presented with a two-month history of right hip pain. Computed tomography (CT) scan demonstrated right sacroiliac joint space widening with cortical destruction and erosive changes in the iliopsoas muscle. Minimally invasive right sacroiliac joint fusion was performed with biopsy and aspirate, which confirmed positive Brucella cultures. The patient was started on long-term antibiotic therapy, and his pain significantly improved. Pyogenic sacroiliitis is a rare condition that requires a high index of suspicion. In this case, minimally invasive sacroiliac joint fusion successfully treated the patient’s pain and instability as well as aided in the diagnosis of Brucella infection.

Technical variation of trans-articular sacroiliac joint (SIJ) fusion using three screws considering the effects of sacral dysplasia in patients with non-traumatic SIJ pain

Background

This study evaluated the technical adequacy of trans-articular sacroiliac joint (SIJ) fusion using three screws for non-traumatic SIJ pain, considering different grades of sacral dysplasia.

Methods

Cadaveric CT data of unilateral sacropelvic complexes for 72 individuals (53.4 ± 8.4 years) were selected. A 3D model was reformatted into the plain lateral radiograph to mark the articular surface of the SIJ. Subjects were classified into dysplastic (DYS) and non-dysplastic sacrum (NDS) groups. Proximal (PS), middle (MS), and distal screws (DS) with 10-mm diameter were virtually introduced to the iliac bone and the SIJ on the lateral image with a 5-mm safety margin. On a corresponding axial image, each screw was advanced vertically to the sagittal plane with the same safety margin. The entry points for each screw to the endplate of S1 (S2) and to the corresponding anterior sacral margin on the lateral image were measured, along with the maximal screw lengths on the axial image. Whether each screw passed through the SIJ was determined. Different types of sacral dysplasia and screws were compared statistically.

Results

Thirty-eight (26.4%) cases were DYS, and 106 (73.6%) were NDS. The entry points of all screws were significantly more distal in DYS than in NDS groups. The PS and MS screw lengths differed significantly between the 2 groups. Incidences of short sacral fixation (< 10 mm) were significantly higher for the DS in both NDS (38.7%) and DYS (39.5%) groups. Incidences of screw pass were lowest for the MS in both NDS (43.4%) and DYS (47.4%) groups.

Conclusions

Sacral dysplasia locates the SIJ more distally and therefore affects the entry point locations and screw lengths for all screws in trans-articular SIJ fusion, compared with a non-dysplastic sacrum. Moreover, three-screw fixation risks the development of unstable DS fixation and a high extra-articular fixation rate in MS.

Pyogenic sacroiliitis: A rare complication of inflammatory bowel disease

Although sacroiliitis is not uncommon in patients with inflammatory bowel diseases (IBD), bacterial infection of the sacroiliac joint is rare. The diagnosis is often delayed because of low clinical suspicion, a vague clinical picture and poorly defined localization of symptoms. We report a case of pyogenic sacroiliitis in a patient with Crohn's disease caused by Clostridia spp. and discuss key clinical components and protocol for the successful evaluation, diagnosis, and treatment of this uncommon illness.

Klebsiella pneumoniae sacroiliac septic arthritis: First case report

Infective sacroiliitis is a rare disease with misleading clinical signs that often delay diagnosis. We report a case of pyogenic sacroiliac joint septic arthritis caused by Klebsiella pneumoniae that has not been reported in the literature highlighting its importance especially among diabetics.

Tuberculous sacroiliitis in a patient with systemic lupus erythematosus: a case report and literature review

Systemic lupus erythematosus (SLE) patients are at higher risk of developing opportunistic infections such as tuberculosis (TB), especially extrapulmonary forms like osteoarticular TB, compared to the general population. However, tuberculous sacroiliitis has been scarcely reported in these patients. We present a 34-year-old woman with SLE who developed articular tuberculosis simultaneously affecting the right sacroiliac joint and the left knee. The patient was successfully treated with antituberculosis therapy for nine months. In this case, in addition to the immunological abnormalities of lupus, the long-term glucocorticoid therapy at high dosages was the main risk factor for the development of osteoarticular tuberculosis.

Septic arthritis of the sacroiliac joint

Septic arthritis is an inflammation of a joint caused directly by various microorganisms. It is often characterized by many unspecific symptoms. Bacteria is the most often etiological factor.

We present a case report of a 76-years old woman with a unilateral septic arthritis of the sacroiliac joint. Bacterial sacroiliitis should be taken into account in patients with sacroiliitis and fever onset.

Proper diagnosis can be very often difficult and delayed but fast implementation of antibiotic therapy is extremely important in the treatment process. Diagnostic imaging is crucial to the diagnosis and monitoring of septic arthritis. Magnetic resonance imaging is the most relevant tool for the detection of sacroiliitis, allowing the institution of therapeutic strategies to impede the progression of the disease.