Compositional evaluation of lesion and parent bone in patients with juvenile osteochondritis dissecans of the knee using T2 * mapping.

Juvenile osteochondritis dissecans (JOCD) lesions contain cartilaginous, fibrous and osseous tissues which are difficult to distinguish with clinical, morphological magnetic resonance imaging (MRI). Quantitative T2 * mapping has earlier been used to evaluate microstructure and composition of all aforementioned tissues as well as bone mineral density. However, the ability of T2 * mapping to detect changes in tissue composition between different JOCD lesion regions, different disease stages, and between stable and unstable lesions has not been demonstrated. This study analyzed morphological and T2 * MRI data from 25 patients (median age, 12.1 years) with 34 JOCD-affected and 13 healthy knees. Each lesion was assigned a stage reflecting the natural history of JOCD, with stages I and IV representing early and healed lesion, respectively. T2 * values were evaluated within the progeny lesion, interface and parent bone of each lesion and in the control bone region. T2 * was negatively correlated with JOCD stage in progeny lesion (ρ = -0.871; p < 0.001) and interface regions (ρ = -0.649; p < 0.001). Stage IV progeny showed significantly lower T2 * than control bone (p = 0.028). T2 * was significantly lower in parent bone than in control bone of patients with stable lesions (p = 0.009), but not in patients with unstable lesions (p = 0.14). Clinical significance: T2 * mapping enables differentiation between different stages of JOCD and quantitative measurement of the ossification degree in progeny lesion and interface. The observed T2 * decrease in healed and stable lesions may indicate increased bone density as a result of the active repair process. T2 * mapping provides quantitative information about JOCD lesion composition.

State variation in Medicaid and Medicare reimbursements in musculoskeletal radiology.

BACKGROUND: Medicaid reimbursements for physician services are determined by each state. However, how these reimbursements vary between states, and how these reimbursements vary in comparison to Medicare reimbursements is unknown for musculoskeletal radiology studies. OBJECTIVE: To evaluate the variability in Medicaid and Medicare physician reimbursements for musculoskeletal imaging studies between states. METHODS: We evaluated the Medicare and Medicaid physician reimbursements for the most commonly performed musculoskeletal radiology studies (15 radiographs and 10 MRIs) based on Medicare's 2017 National Summary Data File. Medicare and Medicaid reimbursements for these studies were compared by dollar difference (difference in reimbursement in dollars between Medicare and Medicaid). State-wide variability in these reimbursements was quantified by the coefficient of variation (COV) and by the dollar difference in reimbursement amounts. Medicaid and Medicare reimbursement rates were compared using a paired t-test, since the data was paired by state. RESULTS: The mean Medicaid reimbursement rates were lower for musculoskeletal radiographs (p < 0.05) but higher for musculoskeletal MRI studies than the Medicare rates (p < 0.05). As hypothesized, there was variation in both Medicare and Medicaid imaging reimbursements between states, however, the variation was substantially higher for Medicaid reimbursements. We found the Medicare reimbursement COV between states was 0.07 for all imaging studies, whereas the Medicaid reimbursement COV between states varied from 0.23 to 0.55 for radiographs and from 0.31 to 0.45 for MRIs. DISCUSSION: The data show that there is mild, but constant variation across imaging studies in Medicare reimbursement for musculoskeletal imaging studies between states. However, there is more variation in the Medicaid reimbursements across imaging studies and between states. More appropriate reimbursement may increase access to care for Medicaid patients.