Ultrasound-guided first metatarsophalangeal joint injections: description of an in-plane, gel standoff technique in a cadaveric study.

Overview

OBJECTIVE: To describe a longitudinal ultrasound-guided in-plane approach for injection into the first metatarsophalangeal (MTP) joint and assess its accuracy in a cadaveric model. DESIGN: A prospective anatomical cadaver study model was used. A total of 10 first MTP joints using the described technique were injected with 0.5 mL of dye under ultrasound guidance. The joints were later dissected, and accuracy was classified as accurate, accurate with overflow, or inaccurate with no injectate in the target area. RESULTS: Of the injections, 9 were classified as accurate injections, and 1 was classified accurate with overflow. CONCLUSION: This cadaveric study suggests that ultrasound-guided injections of the first MTP joint can be accurately and reproducibly performed with a gel standoff, long-axis in-plane approach. This technique attempts to minimize the collateral damage to the surrounding tissue, specifically the articular cartilage. Clinicians should consider using this technique when performing ultrasound-guided injections to the first MTP joint. LEVEL OF EVIDENCE: Cadaveric, Level V.