Correlation between fixation systems elasticity and bone tunnel widening after ACL reconstruction

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Radiology

Background:

• Tunnel widening (TW) post-ACL reconstruction is increasingly discussed.
• Underlying biological and mechanical factors contribute to TW.

Purpose of the Study:

• To assess the relationship between bone tunnel enlargement and two distinct ACL fixation systems.
• Compare stiff fixation versus elastic fixation in ACL reconstruction.

Main Methods:

• 40 patients underwent ACL reconstruction with hamstring grafts.
• Randomized into two groups: Group A (stiff fixation) and Group B (elastic fixation).
• Knee MRI evaluated tunnel diameters at 40 days, 3 months, and 6 months postoperatively.

Main Results:

• No significant difference in tunnel widening at 40 days.
• At 3 and 6 months, the elastic fixation group (Group B) showed significantly greater femoral and tibial tunnel widening compared to the stiff fixation group (Group A).
• Tunnel widening increased over time in both groups, but more pronouncedly in Group B.

Conclusions:

• Elastic fixation systems are associated with increased bone tunnel enlargement after ACL reconstruction with hamstring.
• This bone tunnel enlargement did not correlate with worse clinical performance.
• Further research may explore optimal fixation methods to mitigate tunnel widening.