An overlooked cause of groin pain: Ischiofemoral impingement syndrome

Background Ischiofemoral impingement syndrome (IFI) is a condition characterized by narrowing of the space between the ischium and femur, potentially compressing the quadratus femoris muscle. Although associated with hip pain, its role in groin pain is underexplored. Objective To assess the relationship between IFI and groin pain and examine the association between quadratus femoris muscle edema and ischiofemoral space (IFS) and quadratus femoris space (QFS) measurements. Methods A retrospective study was performed on 568 hips from 284 patients who underwent pelvic MRI between January and September 2024. Patients were grouped based on groin pain. IFS and QFS were measured on T1-weighted axial MRI images, and quadratus femoris muscle edema was evaluated on T2-weighted fat-suppressed axial images. Statistical analysis included the Independent Samples t-test, Pearson Chi-square test, and ROC analysis, with significance set at p < 0.005. Results Groin pain was present in 23 of 568 hips (4%), with quadratus femoris muscle edema detected in 19 of these cases (82.6%, p < 0.001). Quadratus femoris edema was found in 116 of the 568 hips (20.4%). IFS and QFS measurements were significantly lower in patients with quadratus femoris edema. ROC analysis revealed an IFS cut-off of 16 mm (86.5% sensitivity, 80.3% specificity) and a QFS cut-off of 9.5 mm (92% sensitivity, 93.2% specificity). Conclusions IFI should be considered in the differential diagnosis of unexplained groin pain, as smaller IFS and QFS are linked to quadratus femoris muscle edema.