Partially Lacerated Digital Flexor Tendons: A Cadaveric Study Determining the Intact Cross-sectional Area and...

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Musculoskeletal Research

Background:

• Partial tendon lacerations are conventionally assessed by percentage of injury.
• This subjective method lacks objectivity for surgical repair decisions.
• A more precise method is needed to evaluate remnant tendon integrity.

Purpose of the Study:

• To introduce and validate a novel method for estimating the cross-sectional area of intact tendon remnants.
• To assess if remaining tendon fibers can withstand early active mobilization forces.
• To establish objective criteria for surgical repair of partially lacerated tendons.

Main Methods:

• Twenty cadaveric tendons underwent 25%, 50%, or 75% lacerations.
• Derived cross-sectional area (D-CSA) was calculated from remnant circumference measurements.
• D-CSA was validated against computer-measured cross-sectional area (C-CSA).
• Ultimate tensile strength (UTS) was analyzed to identify repair thresholds.

Main Results:

• D-CSA showed moderate correlation with C-CSA (Pearson's r = 0.622).
• Tendons with circumferences >8 mm exhibited UTS consistently >150 N.
• A potential threshold for surgical intervention was identified.

Conclusions:

• Measuring tendon circumference to determine D-CSA is a practical and accurate approach.
• This method can reliably benchmark residual tendon strength.
• It offers an objective tool for managing partially lacerated tendons.