Functional and Symptomatic Improvements Based on the Femoral Tunnel Drilling Technique in Anterior Cruciate Ligament (ACL) Reconstruction

Background: The current literature comparing femoral tunnel techniques often reports on short-term outcomes after anterior cruciate ligament reconstruction (ACLR), but only a few studies have analyzed longterm outcomes. In addition, many studies have compared transtibial to anteromedial portal techniques without differentiating whether rigid or flexible reaming is used, making it difficult to infer how the techniques truly compare to one another. Purpose: This study aimed to detect differences in patient-reported outcome scores in those treated with three different femoral tunnel drilling techniques. Study design: This study is a prospective cohort study. Methods: Of 650 patients treated for anterior cruciate ligament (ACL) injuries with ACLR, 350 were 5+ years out from surgery. Of these patients, 111 completed patient-reported outcome surveys (PROs). The KruskalWallis H test was used to detect differences between patients treated with either of the three femoral tunnel drilling techniques: transtibial (TT), anteromedial portal with rigid reaming (AMP-RR), or anteromedial portal with flexible reaming (AMP-FR). Bonferroni correction was applied to the p-values to reduce the risk of making a type 1 error. Results: No differences were found between the three groups in demographics or postoperative PROs. However, there was a significant change between pre-surgery and post-surgery PROs. TT, when compared to AMP-RR, had a greater increase in satisfaction and greater improvement in a patient's ability to go up and down the stairs from pre-surgery to post-surgery. AMP-FR, when compared to TT, had greater improvement of the patient's knee stiffness/swelling. AMP-FR, when compared to AMP-RR, had greater improvement in knee pain during stairs and the ability to go down the stairs. No differences in return to sport, additional procedures on the affected knee (meniscal surgeries or cyclops lesion excisions), or revision surgery rates were found. Conclusion: Overall, postoperative PROs did not show statistically significant differences between the three femoral tunnel drilling techniques. Differences, however, were identified in the responses to specific questions on PRO surveys, which may have otherwise been overlooked. It is important to recognize the differences between TT, AMP-RR, and AMP-FR in the improvement of stair climbing and swelling/stiffness as these likely directly affect a patient's satisfaction from pre-ACLR to post-ACLR.