Alteration in Microcirculation With Osteonecrosis of the Femoral Head: A Study of Dynamic Contrast-Enhanced MRI

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is commonly used in clinical practice to detect tumor blood supply, and it has recently been applied to assess skeletal vasculature. In this study, we retrospectively analyzed DCE-MRI data from 37 patients with osteonecrosis of the femoral head to evaluate alterations in microvascular circulation of the femoral head. Time-intensity curves (TICs) in the region of interest were classified into different lesion stages. In the greater trochanter area, extracellular space volume per unit volume of tissue was significantly higher in Association Research Circulation Osseous (ARCO) stage III than in ARCO stage II (P<.05 and power ≥ 0.8), while other parameters showed no statistical difference (P>.05 and/or power < 0.8). In the necrotic area, contrast enhancement ratio and maximum slope of increase were significantly lower in ARCO stage III than in ARCO stage II (P<.05 and power ≥ 0.8), while other parameters showed no statistical difference (P>.05 and/or power < 0.8). In the repair reaction area, all parameters were significantly higher in ARCO stage III than in ARCO stage II (P<.05 and power ≥ 0.8). TIC classification showed that the greater trochanter area mainly exhibited type C (plateau type), the necrotic area mainly exhibited type B (out-flow type), and the repair reaction area mainly exhibited type A (inflow type). We believe that the exchange capacity of the vessels has a much greater impact on femoral head necrosis than the number of vessels, while the generation of the repair area greatly affects the prognosis of femoral head necrosis. These findings suggest that DCE-MRI can provide a good assessment of osteonecrosis of the femoral head perfusion and can serve as a new reference for clinical treatment decisions. [Orthopedics. 2024;47(2):e73-e78.].