ACL reconstruction with hamstrings: how different technique and fixation devices influence bone tunnel enlargement.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering

Background:

• Bone tunnel enlargement is a known complication following anterior cruciate ligament (ACL) reconstruction.
• The exact causes remain multifactorial, involving both mechanical and biological influences.

Purpose of the Study:

• To prospectively evaluate the impact of different surgical techniques on bone tunnel enlargement.
• To assess the influence of these techniques on clinical outcomes after ACL reconstruction.

Main Methods:

• Forty-five patients undergoing ACL reconstruction with semitendinosus and gracilis tendons were randomized into two groups.
• Group A used the In-Out technique with cortical fixation and an interference screw.
• Group B utilized the Out-In technique with metal cortical fixation.

Main Results:

• Significant femoral and tibial tunnel enlargement occurred in both groups.
• Group A (In-Out technique) exhibited significantly greater tunnel widening compared to Group B (Out-In technique) (p < 0.05).
• No significant clinical differences or correlations between radiological and clinical outcomes were observed between the groups.

Conclusions:

• Different mechanical fixation devices can influence bone tunnel widening after ACL reconstruction.
• Lower stiffness of fixation devices likely contributes to tunnel widening via micromotion within the femoral and tibial tunnels.