Background: Anterior cruciate ligament reconstruction (ACLR) using a quadriceps tendon with bone (QTB) autograft has been associated with reduced quadriceps strength at 6 months postoperatively compared to other autograft options. However, limited studies have assessed strength recovery after return to sports after ACLR, particularly involving QTB autografts. Purpose: To examine factors influencing quadriceps strength recovery at 6 and 12 months after ACLR using QTB, bone–patellar tendon–bone (BPTB), and hamstring tendon (HT) autografts. Study Design: Cohort study; Level of evidence, 3. Methods: Individuals who underwent primary ACLR using QTB, BPTB, or HT autografts, had a preinjury Tegner activity scale (TAS) score >5, and completed at least 12 months of follow-up were included. Participants were classified into recovery (>90%) and nonrecovery (≤90%) groups based on the limb symmetry index of quadriceps strength compared to the contralateral leg at 6 and 12 months post-ACLR. Variables associated with quadriceps strength recovery at these time points were analyzed. Results: A total of 154 participants were included. Multivariable logistic regression showed that use of QTB (OR, 0.11; P < .001) or BPTB (OR, 0.12; P < .001) autografts, meniscal repair (OR, 0.34; P = .013), and lower preinjury TAS score (OR, 1.68; P = .011) were associated with a significantly increased risk of quadriceps strength deficit at 6 months after ACLR. At 12 months after ACLR, lower preinjury TAS score (OR, 1.48; P = .046) and lower Knee injury and Osteoarthritis Outcome Score (KOOS) pain at 3 months (OR, 1.09; P = .002) were associated with a significantly increased risk of quadriceps strength deficit. The receiver operating characteristic curve showed that a KOOS pain value at 3 months after ACLR of 83.1 points was the cutoff for indicating a strength deficit at 12 months (sensitivity, 78.4%; specificity, 59.1%). Conclusion: Use of QTB or BPTB autografts, meniscal repair, and lower preinjury TAS score were factors associated with quadriceps strength deficit at 6 months after ACLR. At 12 months, lower preinjury TAS score and lower KOOS pain at 3 months were factors associated with persistent strength deficit.
Aibara et al. (Wed,) studied this question.