Pathophysiology and MRI Findings of Infectious Spondylitis and the Differential Diagnosis

On MRI, abnormal signals of the intervertebral disc, destruction of the upper and lower vertebral body endplate around the disc, and bone marrow edema around the endplate are considered typical findings of infectious spondylitis. These findings can also appear in various non-infectious spinal diseases, such as degenerative changes, acute Schmorl’s node, spondyloarthropathy, synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO), chronic recurrent multifocal osteomyelitis, and calcium pyrophosphate dihydrate crystal deposition disease. The imaging findings of infectious spondylitis that can be differentiated from these non-infectious spinal diseases on MRI are high signal intensity and abscess of the disc space, an abscess in the paraspinal soft tissue, and the loss of the linear low signal intensity on T1-weighted images of the bony endplate. However, these differentiation points do not always apply since there are many similarities in the imaging findings of infectious and non-infectious diseases. Therefore, for an accurate diagnosis, it is important to know the imaging characteristics related to the pathophysiology of not only infectious spondylitis but also non-infectious spinal diseases, which requires differentiation from infection.

Functional index for hand osteoarthritis (FIHOA) is associated with pain, muscle strength, and EQ-5D in hand osteoarthritis

Abstract Background: This study identified whether Functional Index for Hand Osteoarthritis (FIHOA) is associated with pain, hand muscle strength, health-related quality of life, and radiographic severity in hand osteoarthritis (OA). Methods: We consecutively recruited 95 patients with hand OA. The FIHOA was used to assess questionnaire-based physical function in hand OA. Health-related quality of life was evaluated using EuroQol-5 dimension (EQ-5D). Radiographic changes of hand joints were measured by Kellgren-Lawrence (K-L) grade, which was determined based on total radiographic severity score and number of affected joints. Other measures included patient's visual analogue scale (VAS) score for pain and performance-based function indexes such as grip and pinch strength. Statistical analysis was performed using Mann-Whitney U test, Spearman's correlation analysis, and multivariate logistic regression analysis. Results: FIHOA score was negatively associated with grip and pinch hand strength and EQ-5D and positively correlated to VAS pain (p < 0.05 for all). There were significant differences of grip and pinch strength, VAS pain, EQ-5D index, and EQ-VAS between two FIHOA groups (≤ 4 vs. > 4) (p < 0.05 for all). Multivariate logistic regression analysis showed that higher FIHOA score (FIHOA > 4) was related with increased VAS pain and with lower EQ-5D index (p = 0.008 and p = 0.013, respectively). There was no association between FIHOA score and measures of total radiographic severity score and number of affected joints. Conclusion: This study observes that FIHOA score is associated with patient-reported VAS pain, hand muscle strength indexes, and EQ-5D but not radiographic severity in hand OA.