Defining the Structures at Risk and an Anatomical Safe Zone for Percutaneous Antegrade Subtalar Joint Fixation With a...

Area of Science:

• Orthopedic Surgery
• Anatomy
• Biomechanics

Background:

• Percutaneous antegrade fixation for subtalar joint (STJ) arthrodesis presents advantages but lacks a clearly defined, safe entry point.
• Existing literature does not detail at-risk anatomic structures for this procedure.

Purpose of the Study:

• To define an anatomically safe and reproducible entry point for percutaneous antegrade STJ arthrodesis screw fixation.
• To identify and describe anatomic structures at risk during this fixation technique.

Main Methods:

• Ten cadaver limbs were utilized for the investigation.
• A guidewire was inserted 5 mm lateral to the tibialis anterior tendon, with the talar neck midpoint as the sagittal starting point.
• A 6.5-mm cannulated screw was inserted antegrade across the STJ into the calcaneus, followed by dissection to assess proximity to structures.

Main Results:

• The study hypothesized that screws would encroach on anatomic structures, but this was incorrect.
• 0/10 screws invaded neurovascular or tendinous structures.
• The dorsalis pedis artery and deep peroneal nerve were, on average, 12.1 mm and 12.2 mm lateral to the screw, respectively.

Conclusions:

• A safe and reproducible entry point for percutaneous antegrade STJ single screw fixation has been defined.
• This technique minimizes the risk of neurovascular or tendinous injury.
• Findings provide crucial anatomical data for surgeons performing STJ arthrodesis.