Early tunnel enlargement after arthroscopic ACL reconstructions

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Sports medicine

Background:

• Anterior cruciate ligament (ACL) reconstruction is a common orthopedic procedure.
• Tunnel enlargement in the femur and tibia is a known complication following ACL reconstruction.
• The cross-pin technique with hamstring tendons is frequently used for ACL graft fixation.

Purpose of the Study:

• To evaluate the phenomenon of tunnel enlargement after ACL reconstruction using hamstring tendons and the cross-pin technique.
• To assess the clinical implications of femoral and tibial tunnel enlargement over a two-year follow-up period.
• To investigate the timing and potential causes of tunnel enlargement.

Main Methods:

• A prospective study involving 62 patients (62 knees) undergoing ACL reconstruction with hamstring tendons and cross-pin fixation.
• Clinical outcomes were assessed using the International Knee Documentation Committee (IKDC) and Lysholm knee scores.
• KT-1000 arthrometer measurements were used to quantify knee laxity.
• Computed tomography (CT) and conventional radiography were performed at multiple time points (3 days, 6 weeks, 6, 12, and 24 months) to evaluate tunnel dimensions.

Main Results:

• Tunnel enlargement was observed relatively early after surgery, potentially related to the tunnel drilling process.
• No significant impact of tunnel enlargement on clinical results (IKDC, Lysholm scores, KT-1000 measurements) was noted during the two-year follow-up.
• The study identified early tunnel enlargement as a phenomenon requiring further investigation for long-term implications.

Conclusions:

• While early tunnel enlargement after ACL reconstruction with hamstring tendons and cross-pin fixation did not appear to affect short-term clinical outcomes, its long-term consequences and potential need for revision surgery warrant careful consideration.
• A potential technique modification involves drilling tunnels 1 mm smaller than the graft diameter and using a dilator to achieve the final graft size, aiming to mitigate tunnel enlargement.
• Further research is needed to fully understand the long-term implications of tunnel enlargement and to validate proposed preventive strategies.