Quadriceps tendon size does not affect postoperative strength recovery following quadriceps tendon anterior cruciate ligament reconstruction.

Objective: The influence of quadriceps tendon (QT) size on postoperative quadriceps strength following QT anterior cruciate ligament reconstruction (ACLR) is unclear. Therefore, this study aimed to determine the relationship between QT morphology and postoperative quadriceps strength recovery following primary ACLR using a QT autograft.
Methods: Patients who underwent primary ACLR using QT autograft from 2014 to 2022 followed by a postoperative isometric strength measurement between 5 and 8 months were retrospectively reviewed. Using preoperative magnetic resonance imaging findings, the anterior-posterior (A-P) thickness, medial-lateral (M-L) width, and cross-sectional area (CSA) of the QT were measured. Postoperative residual CSA of QT was estimated based on the graft-harvest diameter. The quadriceps index (QI) was also calculated, which was determined by dividing the maximum isometric quadriceps torque on the involved side by the maximum quadriceps torque on the uninvolved side. Associations between the QI and QT morphology were assessed. Furthermore, multivariable logistic regression analysis with the addition of sex as a covariate was performed with the addition of each individual measure of QT morphology to determine the association with a QI ​≥80%.
Results: A total of 84 patients (mean age: 21.9 ​± ​7.3 years; 46 female) were included. Residual CSA showed a statistically significant positive correlation with the QI (r ​= ​0.221, p ​= ​0.043). There were no statistically significant correlations between QI and CSA, A-P thickness, or M-L width. Multivariable logistic analysis adjusting for sex demonstrated that each individual measure of QT morphology was not statistically significantly associated with a QI ​≥80%.
Conclusion: A statistically significant correlation between measures of preoperative QT size and postoperative quadriceps strength were not detected in patients undergoing primary QT autograft ACLR. A smaller residual QT CSA based on QT harvest diameter was weakly associated with decreased quadriceps strength 5-8 months postoperatively, but this association was not independent of sex. Future studies examining the impact of QT morphology on quadriceps strength at longer follow-up intervals are needed.
Level of Evidence: IV.
Competing Interests: Declaration of competing interest Volker Musahl reports a relationship with Smith & Nephew plc that includes consulting or advisory, funding grants, and speaking and lecture fees. Volker Musahl reports a relationship with Arthrex Inc that includes funding grants. Volker Musahl reports a relationship with DePuy Synthes that includes funding grants. Volker Musahl reports a relationship with International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine that includes board membership. Volker Musahl reports a relationship with Knee Surgery, Sports Traumatology, Arthroscopy that includes board membership. James J. Irrgang, reports a relationship with Journal of Orthopaedic and Sports Physical Therapy that includes board membership. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)