MRI diagnostic criteria for ischiofemoral impingement syndrome / 中国组织工程研究

ABSTRACT

BACKGROUND: Ischiofemoral impingement (IFI) syndrome has attracted more and more attention, but there is little report on IFI because of its low incidence. Moreover, its imaging characters have not yet been fully understood.OBJECTIVE: To discuss the MRI diagnostic criteria for IFI, thus understanding the imaging characters of IFI revealed on MRI.METHODS: Sixteen cases (21 hips) of suspected IFI were selected as experimental group, and 25 healthy volunteers as control group. The bilateral ischiofemoral space (IFS, the shortest distance between the ischial tuberosity and lesser trochanter of femur) and quadratus femoris space (QFS, distance between the lesser trochanter of femur and hamstring tendon insertion) were measured on MRI axial image. The signal and morphology of the quadratus femoris were observed. The differences in QFS and IFS were compared between two groups.RESULTS AND CONCLUSION: (1) Among 16 patients, there were 13 females, and 3 males, and 5 female cases of bilateral IFI. (2) In the experimental group, the IFS ((13.65±3.87) mm versus (22.17±5.75) mm) and QFS ((7.15±3.50) mm versus (12.89±3.13) mm) showed significant differences between affected and opposite sides (P 0.05). (4) Compared with the control group, there were significant differences in IFS and QFS of the affected side in the experimental group, and no significant differences in IFS and QFS of the opposite side. (5) In the experimental group, quadratus femoris appeared with deformation, edema and atrophy. (6) To conclude, the incidence of IFI in females is significantly higher than that in males, and bilateral hips are usually affected. MRI diagnostic criteria for IFI are IFS ≤ 11.46 mm, QFS ≤ 5.53 mm of the affected side, and quadratus femoris present edema and deformation, which are more sensitive on axial fat-suppressed MRI imaging.