AB277. SOH26AB_0177. Ischiofemoral hip impingement and hydrodissection: a case report

Background: External (ischiofemoral) hip impingement is where there is a reduced distance between the ischial tuberosity and the lesser trochanter. The quadratus femoris is the muscle contained within the ischiofemoral space. With impingement, the contents of the ischiofemoral space can become pinched or impinged. Hydrodissection is a minimally invasive technique involving the injection of fluid to separate fascial layers and release entrapped nerves and tendons. Its use in ischiofemoral hip impingement has not been reported.

Case Description: We present the case of a 37-year-old woman who experienced chronic left gluteal pain. She had a positive flexion, adduction, internal rotation (FADIR) test and magnetic resonance imaging (MRI) scanning confirming left ischiofemoral hip impingement. She was experiencing limitations to her normal range of motion and had undergone pain interventions in the past, with mixed benefits at identified sites each time. A theatre-based procedure using ultrasound with a curvilinear 5 MHz ultrasound probe was undertaken, with markedly increased echolucency of the fascial plane at the point of maximal tenderness as reported by the patient. Following this identification, hydrodissection with 5% dextrose (15 mL) was performed to separate the fascial layers, release entrapped small nerves, and address perineural inflammation around the quadratus femoris muscle. Following this targeted hydrodissection, the patient experienced substantial improvement in both pain and range of movement, facilitating engagement with a recommended course of exercises. At 2 months of follow-up, there was continued improvement in the range of movement and a substantial reduction in her pain experienced. No complications were reported.

Conclusions: This case supports the use of targeted hydrodissection in ischiofemoral impingement. Further investigation into the potential benefit of targeted hydrodissection in ischiofemoral impingement is warranted.

Keywords: Hydrodissection; ischiofemoral impingement; ultrasound; pain medicine; case report