Tendon Inversion Improves Tendon-to-Bone Healing in a Rat Bicep Tenodesis Model

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Regenerative medicine

Background:

• Tendon-to-bone repair is challenging, with current methods failing to replicate native enthesis biomechanics.
• Bone tunnel fixation is common, but healing at the interface requires improvement.

Purpose of the Study:

• To investigate the effect of inside-out longitudinal tendon inversion on bone tunnel healing.
• To test the hypothesis that tendon inversion removes the gliding epitenon to enhance interface healing.

Main Methods:

• Forty male Sprague-Dawley rats underwent native tendon tenodesis (control) or tendon inversion tenodesis (experimental).
• Evaluated biomechanical tensile strength, failure modes, tissue architecture via histology, and epitendinous lubricin disruption via immunohistochemistry at 8 weeks post-surgery.

Main Results:

• Tendon inversion significantly increased maximum tensile strength compared to controls.
• Reduced epitendinous lubricin and improved healing scores and collagen fibril alignment were observed in the experimental group.

Conclusions:

• Longitudinal tendon inversion enhances tendon-to-bone healing in a rat model.
• Disruption of the epitendinous surface is a key factor in improved healing, offering insights for surgical technique refinement.