Optimal needle placement for extensor hallucis longus muscle using ultrasound verification

Area of Science:

• Musculoskeletal ultrasonography
• Anatomy and biomechanics

Background:

• The extensor hallucis longus (EHL) muscle is crucial for diagnosing neurologic lesions and serves as a treatment target.
• Accurate needle placement is vital for safe and effective EHL interventions.

Purpose of the Study:

• To investigate the extensor hallucis longus (EHL) muscle using ultrasonography.
• To determine optimal needle placement for enhanced safety and accuracy in EHL procedures.

Main Methods:

• Ultrasonography was performed on 96 legs from 48 healthy volunteers.
• Four established electromyographic (EMG) methods were evaluated for EHL identification.
• The midpoint of the EHL (MD) was located using anatomical landmarks.

Main Results:

• Mean distances from anatomical landmarks (bimalleolar line and tibial crest) to the EHL midpoint (MD) were measured.
• The average depth of the EHL midpoint was determined.
• EMG methods showed variable probabilities for needle penetration of the EHL (13%-79%) and neurovascular bundle (50%-89%).

Conclusions:

• Ultrasonography enables precise determination of optimal needle placement within the extensor hallucis longus muscle.
• This technique enhances the safety and accuracy of procedures targeting the EHL.