Ischiofemoral impingement secondary to chronic ulcerative colitis-associated ischial enthesopathy

Ischiofemoral impingement causes hip pain and sciatica through mechanical space narrowing between the lesser trochanter and ischial tuberosity, where systemic enthesopathy can induce secondary restriction. We present a rare case of a middle-aged female with ulcerative colitis and severe right sciatica who underwent pelvic magnetic resonance (MR) imaging and high-resolution coronal short tau inversion recovery MR neurography. Imaging revealed severe right ischiofemoral narrowing secondary to chronic hamstring enthesopathy, contrasting with a normal left side. MR neurography demonstrated a massive, multi-loculated intraneural ganglion cyst tracking continuously along the sciatic nerve trunk, accompanied by quadratus femoris muscle fatty atrophy and impingement edema. This case illustrates how inflammatory enthesopathy can trigger secondary ischiofemoral narrowing and intraneural cyst propagation.