Interference screw insertion angle has no effect on graft fixation strength for insertional Achilles tendon...

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Sports medicine

Background:

• Insertional Achilles tendon (IAT) reconstruction is a surgical procedure to repair damage to the Achilles tendon insertion.
• Graft fixation is a critical component of IAT reconstruction, influencing the biomechanical stability of the repair.
• Interference screws are commonly used for graft fixation, but the optimal insertion angle is not well-established.

Purpose of the Study:

• To compare the biomechanical properties of IAT reconstruction using interference screws inserted at two different angles (60° and 120°).

Main Methods:

• Nine pairs of human cadaveric Achilles tendon specimens were used.
• Specimens were randomized into two groups with interference screw insertion angles of 60° and 120°.
• The IAT reconstruction was performed, and specimens were loaded to failure to assess load at failure, stiffness, and mode of failure.

Main Results:

• No statistically significant differences were found in failure load or stiffness between the 60° and 120° groups.
• The most frequent mode of failure was graft pull-out from the bone tunnel, often associated with screw breakage.

Conclusions:

• Interference screw insertion angle does not significantly affect the biomechanical performance of IAT reconstruction.
• Surgeons can choose the interference screw insertion angle based on personal preference for IAT repair.