Background: Asymmetric landing kinetics 6 months after anterior cruciate ligament reconstruction (ACLR) are associated with higher risk of second anterior cruciate ligament injury. Little is known about landing kinetics after ACLR with an all-soft tissue quadriceps tendon (QT) autograft despite its increasingly common use in young, active patients.
Purpose/hypothesis: The purpose of this study was to compare landing kinetics during a bilateral drop vertical jump (DVJ) 6 months after ACLR in participants who had undergone primary ACLR with a QT or bone-patellar tendon-bone (BTB) autograft. The hypothesis was that patients with a QT autograft will experience more asymmetry during a bilateral DVJ than patients with a BTB autograft 6 months after ACLR. In addition, greater impact force asymmetry will be associated with worse patient-reported outcome measures.
Study design: Controlled laboratory study.
Methods: Participants who underwent primary unilateral ACLR with a QT or BTB autograft between May 2022 and December 2023 were prospectively recruited to undergo DVJ assessment and patient-reported outcome measures 6 months after ACLR. DVJ assessment was completed using force-sensing insoles. Peak impact force, average loading rate, and impulse data were collected at 100 Hz.
Results: Forty-four participants (22 BTB, 22 QT) completed DVJ assessment and International Knee Documentation Committee (IKDC) and Anterior Cruciate Ligament-Return to Sport After Injury (ACL-RSI) surveys at 6 ± 1 months after ACLR. Graft source groups did not differ by age (P = .884), sex (P = .531), mass (P = .872), height (P = .572), months since surgery (P = .683), or lateral (P = .637) or medial (P = .416) meniscal tear treatment rate. On average, participants with a QT autograft demonstrated 26.2% greater contralateral limb peak impact force (P = .004), 18.4% lower peak impact force limb symmetry index (P = .009), 18.5% lower involved limb impulse (P < .001), and 15.1% lower impulse limb symmetry index (P < .001) when compared with participants with a BTB autograft. Graft source groups did not differ in IKDC score (P = .333) or ACL-RSI score (P = .070). Neither IKDC nor ACL-RSI score was strongly associated with any kinetic variables.
Conclusion/clinical relevance: Participants with a QT autograft exhibit greater asymmetry in landing kinetics when compared with participants with a BTB autograft 6 months after ACLR, and landing kinetics were not associated with IKDC or ACL-RSI score.
Keywords: anterior cruciate ligament; biomechanics; graft choice; jump landing; knee kinetics; wearable technology.