Anatomic and Ultrasonic Study Based on Selective Tibial Neurotomy

Area of Science:

• Anatomy and surgical procedures
• Medical imaging and diagnostics

Background:

• Selective tibial neurotomy (STN) is a recognized treatment for spastic feet and calf reduction in some regions.
• Accurate anatomical knowledge and intraoperative guidance are crucial for successful STN.
• This study addresses the need for detailed morphologic data to support STN procedures.

Purpose of the Study:

• To provide detailed morphologic measurements of the tibial nerve and surrounding calf muscles.
• To offer theoretical support for the selective tibial neurotomy procedure and its intraoperative localization.
• To investigate the utility of ultrasound in visualizing tibial nerve anatomy.

Main Methods:

• Dissection of 50 lower legs (20 cadavers, 5 fresh) to map tibial nerve branching patterns and triceps surae dimensions.
• Ultrasound measurements of calf muscle thickness in 50 volunteers.
• Acquisition of ultrasonic images to visualize muscles and tibial nerve branches.

Main Results:

• The tibial nerve exhibits 8 distinct branching patterns, including a dual-branch innervation for the soleus muscle.
• Key branches identified: medial sural cutaneous nerve, gastrocnemius motor branches, and soleus motor branch.
• Calf muscle (gastrocnemius and soleus) thickness shows a positive correlation with calf circumference.

Conclusions:

• Calf circumference is a reliable indicator of gastrocnemius and soleus muscle thickness.
• The variability in tibial nerve branching necessitates careful surgical technique to avoid iatrogenic injury.
• Preoperative ultrasound imaging is recommended for clear visualization of tibial nerve branches and their divergence points, enhancing surgical safety.