Summary

This study investigates sex-based differences in the outcomes of anterior cruciate ligament reconstruction with quadriceps tendon - patellar autograft in adolescent subjects.

Abstract

Background

Female athletes suffer anterior cruciate ligament (ACL) injuries at a 2- to 10-fold greater rate than their male counterparts. Current research demonstrates that females with a hamstring tendon autograft have lower patient reported outcome scores and increased postoperative anterior-posterior laxity compared to their male counterparts. Quadriceps tendon-patellar autograft has been established as a reliable graft choice for adolescent ACL reconstruction. The purpose of this study is to investigate sex-based differences in graft survival, patient reported outcomes, and joint laxity after ACL reconstruction with QPA among adolescent patients.

Methods

All patients who underwent ACL reconstruction with QPA between January 2014 and April 2016 who were a minimum of 2-years postoperative were identified. Demographic data, surgical information, and graft failure was collected retrospectively. International Knee Documentation Committee (IKDC) and Lysholm questionnaires were collected prospectively. KT1000 arthrometer measurements were available for a subset of patients who attended a clinic follow-up appointment greater than 2 years postoperative.

Results

The final cohort included 55 females and 45 males from ages 10 to 18 years old at time of surgery. After adjusting for age and medial meniscus procedures, the hazard of graft failure among male athletes was 2.3 times [95% CI: 0.4 to 11.8, p=0.3273] the hazard of graft failure among female athletes. At 36 months post-injury 93.3% [95% CI: 85.7-100%] of male athletes compared to 82.6% [95% CI: 73.0-93.4%] of female athletes returned to play. KT1000 measurements were 1.0 mm [interquartile range: 1.0 to 2.0 mm] in males and 1.5 mm [interquartile range: 0.5 to 2.0 mm] in females. IKDC scores were significantly worse among female subjects [females interquartile rang: 86.8–97.7, males interquartile range: 94.3-98.9, p=0.0168]. Lysholm score were also decreased among female subjects [female interquartile range: 86-100, male interquartile range: 94-100]. No significant sex-based differences were found in time to return to sport, contralateral ACL injuries, or joint laxity.

Conclusion/Significance

Overall the QPA provided favorable outcomes for both males and females. Males in this cohort were more likely to re-injure their ACL compared to females. However, previous literature suggests females are at the same or higher risk of graft failure as well as increased laxity of the reconstructed knee. Males were more likely to return to sport within 36 months and demonstrated better patient reported outcomes. We believe that these differences may be due to anatomical and neuromuscular factors.