Passive Eversion Assessment for Progressive Collapsing Foot Deformity After Lateral Column Lengthening: A Cadaveric...

Area of Science:

• Orthopedic surgery
• Biomechanics
• Foot and ankle anatomy

Background:

• Progressive collapsing foot deformity (PCFD) can lead to reduced hindfoot eversion.
• Lateral column lengthening (LCL) is a surgical procedure used to correct PCFD.
• The relationship between passive hindfoot eversion and plantar pressure after LCL requires further objective investigation.

Purpose of the Study:

• To quantify the correlation between maximum passive hindfoot eversion after LCL and plantar pressure during stance.
• To determine the impact of different LCL wedge sizes on hindfoot eversion and plantar pressure distribution.

Main Methods:

• Ten cadaveric lower limb specimens were tested using a robotic system to simulate walking stance.
• Five conditions were evaluated: intact, simulated PCFD, and LCL with 4, 6, and 8 mm wedges.
• Measurements included the lateral-to-medial forefoot plantar pressure (LM) ratio and maximum passive hindfoot eversion.

Main Results:

• A significant negative correlation was observed between passive subtalar eversion and the LM ratio.
• Increasing LCL wedge size strongly correlated with decreased subtalar and talonavicular eversion.
• Larger wedge sizes led to a significant increase in the LM ratio, indicating a shift towards lateral foot pressure.

Conclusions:

• Decreased hindfoot eversion following LCL is associated with increased lateral plantar pressure.
• The size of the wedge used in LCL directly influences hindfoot eversion and lateral pressure distribution.
• Intraoperative assessment of hindfoot eversion, alongside radiographic evaluation, is crucial for successful LCL outcomes.