PETS (Percutaneous Epiphysiodesis Using Transphyseal Screws) in the Proximal Tibia: Deep Peroneal Nerve Proximity

Area of Science:

• Orthopedic Surgery
• Pediatric Orthopedics
• Surgical Anatomy

Background:

• Percutaneous epiphysiodesis with transphyseal screws (PETS) is a common pediatric orthopedic procedure for limb-length discrepancy and angular knee deformities.
• Instrumentation during PETS poses a risk of deep peroneal nerve (DPN) injury due to proximity.

Purpose of the Study:

• To determine the location of the DPN relative to an ideally placed PETS screw in pediatric patients undergoing medial proximal tibia hemiepiphysiodesis.
• To define the optimal PETS screw trajectory to minimize DPN injury risk.

Main Methods:

• Retrospective analysis of lower-extremity MRIs in pediatric patients.
• Simulation of an ideal medial proximal tibia PETS trajectory (55° angle).
• Measurement of distances between the DPN and the simulated screw trajectory at critical points.

Main Results:

• The DPN was consistently located anterior to the ideal screw trajectory.
• Mean distance from the DPN to the lateral cortical entry site was 1.4 cm.
• The closest mean distance between the screw and DPN was 1.0 cm.

Conclusions:

• Understanding the neurovascular anatomy is critical for safe PETS screw placement.
• An anterior screw trajectory helps maintain a safe distance from the DPN.
• Minimizing DPN proximity is essential to prevent nerve injury during pediatric epiphysiodesis.