Sonographically guided obturator internus injections: techniques and validation

Area of Science:

• Musculoskeletal imaging
• Interventional radiology
• Anatomy

Background:

• Gluteal and retrotrochanteric pain syndromes are common clinical challenges.
• Accurate diagnosis and targeted treatment are crucial for patient outcomes.
• The obturator internus (OI) muscle and bursa are potential pain generators in this region.

Purpose of the Study:

• To describe and validate sonographically guided injection techniques for the obturator internus (OI) muscle and bursa.
• To assess the feasibility and accuracy of these procedures in a cadaveric model.

Main Methods:

• Ten sonographically guided OI injections were performed in 5 unembalmed cadaveric pelvis specimens.
• Four techniques were utilized: OI tendon sheath, OI intramuscular, OI bursa trans-tendinous, and OI bursa short-axis.
• Latex was injected under sonographic guidance, followed by dissection to evaluate injectate placement.

Main Results:

• All 10 injections accurately placed latex into the intended target sites (OI muscle or bursa).
• Specific techniques showed high accuracy, with minimal or no extra-articular/extra-muscular spread.
• No adverse events, such as injury to nearby nerves or vessels, were observed.

Conclusions:

• Sonographically guided injections into the obturator internus (OI) muscle or bursa are technically feasible.
• These validated techniques offer a potential tool for diagnosing and managing gluteal and retrotrochanteric pain.