No difference in clinical outcome between quadriceps tendon anterior cruciate ligament reconstruction with and without bone block: Results from the Danish Knee Ligament Registry.

Abstract

Purpose: The quadriceps tendon (QT) has recently gained increasing interest as an anterior cruciate ligament reconstruction (ACLR) graft due to minimally invasive harvesting techniques and low donor site morbidity. QT grafts can be used both with a patella bone block and as complete soft tissue grafts. However, it is unknown whether the QT graft type affects clinical outcomes. This study used data from the Danish Knee Ligament Reconstruction Registry (DKRR) to compare revision rates, knee stability and subjective clinical outcomes in patients who underwent ACLR with QT graft with bone block (QT-B) or soft tissue only (QT-S).

Methods: Patients who underwent primary ACL reconstruction with QT autografts documented in the DKRR were included and divided into the QT-B (n = 925) and QT-S (n = 659) groups. The clinical outcome was evaluated using objective-instrumented knee stability, pivot shift test, knee injury osteoarthritis outcome score (KOOS) and Tegner activity scores for the two cohorts performed at the 1-year follow-up. The overall revision rates were determined as well.

Results: Revision rates at 2 years were equally low in both graft groups at 2.8%. Similarly, post-operative knee laxity was equal at 1.5 (1.4) and 1.6 (1.4) mm side-to-side laxity, respectively. However, QT-B exhibited a reduced post-operative positive pivot shift of 22% compared with 31% for QT-S. Although the subjective outcomes were equal for the KOOS and Tegner activity scale scores at the 1-year follow-up, reduced improvements in KOOS were observed for QT-B compared to QT-S.

Conclusion: ACL with a QT autograft harvested either with a bone block or as a soft tissue graft exhibited comparable revision rates and sagittal knee stability. Furthermore, ACL reconstruction using a QT graft with a bone block achieved better rotational stability with less pivot shift than ACL reconstruction using complete soft tissue QT grafts.

Level of evidence: Level III.