Diagnostics of Sacroiliac Joint Differentials to Axial Spondyloarthritis Changes by Magnetic Resonance Imaging

The diagnosis of axial spondyloarthritis (axSpA) is usually based on a pattern of imaging and clinical findings due to the lack of diagnostic criteria. The increasing use of magnetic resonance imaging (MRI) of the sacroiliac joints (SIJ) to establish the diagnosis early in the pre-radiographic phase has resulted in a shift in the paradigm with an increasing frequency of axSpA diagnoses and a changed sex distribution. Non-radiographic axSpA affects males and females nearly equally, whereas ankylosing spondylitis predominantly occurs in males. The MRI-based increasing frequency of axSpA in women is mainly due to the presence of subchondral bone marrow edema (BME) on fluid-sensitive MR sequences, which may be a non-specific finding in both women and men. Due to the somewhat different pelvic tilt and SIJ anatomy, women are more prone than men to develop strain-related MRI changes and may have pregnancy-related changes. Awareness of non-specific subchondral BME at the SIJ is important as it can imply a risk for an incorrect SpA diagnosis, especially as the clinical manifestations of axSpA may also be non-specific. Knowledge of relevant MRI and clinical features of differential diagnoses is needed in the diagnostic workout of patients with suspected axSpA considering that non-SpA-related SIJ conditions are more common in patients with low back or buttock pain than axSpA sacroiliitis. The purpose of this review was to present current knowledge of the most frequent differential diagnoses to axSpA sacroiliitis by MRI taking the clinical characteristics into account

Anatomy of the sacroiliac joints in children and adolescents by computed tomography

Abstract Background Diagnosing sacroiliitis by magnetic resonance imaging (MRI) in children/adolescents can be difficult due to the growth-related changes. This study analyzed the normal osseous anatomy of the sacroiliac joints (SIJ) in a juvenile population using computed tomography (CT). Methods The anatomy of the SIJ was retrospectively analyzed in 124 trauma patients aged 9 months – 3 mm occurred in 21 children/adolescents (17%) located to both the iliac and sacral joint facets. Conclusions Normal osseous SIJ structures in children and adolescents vary considerably. Attention to these normal anatomical structures during growth may help to avoid false positive findings by MRI

Risk factors for joint replacement in knee osteoarthritis; a 15-year follow-up study

Abstract Background To evaluate whether clinical, radiographic or MRI findings are associated with long term risk for total knee arthroplasty (TKA) in persons with knee osteoarthritis. Methods We performed a follow-up analysis of 100 persons with knee osteoarthritis who participated in a clinical trial between 2000 and 2002. Clinical data as well as radiography and MRI of the inclusion knee were obtained in all participants. Data on TKA procedures were extracted from The Danish National Patient Register. Clinical, radiographic and MRI findings were analyzed for associations with subsequent TKA. Results During a mean follow-up period of 15 years, 66% received a TKA in the included knee (target knee); 37% also received a TKA in the other knee. The degree of joint space narrowing was highly associated with subsequent TKA (adjusted odds ratio (OR) 5.0 (95% confidence interval (95% CI) 2.6 – 9.9)) as was a radiological sum score comprising joint space narrowing, osteophytes, subchondral sclerosis and cysts (adjusted OR 1.7 (95% CI 1.3 – 2.1)). MRI detected bone marrow lesions, synovitis and effusion were similarly associated with subsequent TKA with an adjusted OR of 2.3 (95% CI 1.3 – 4.0), 2.8 (95% CI 1.5 – 5.2) and 1.9 (95% CI 1.2 – 3.1), respectively. Increased body mass index (BMI) was not associated with subsequent TKA in the target knee but was associated with TKA in the other knee (OR 2.3 (95% CI 1.2 – 4.3). Conclusions Radiographic findings including joint space narrowing and MRI detected bone marrow lesions, synovitis and effusion were all significantly associated with the long term risk of TKA in persons with knee osteoarthritis