Kneeling tolerance when using quadriceps tendon autograft for anterior cruciate ligament reconstruction is superior to hamstring tendon autograft

Purpose: To investigate kneeling tolerance in patients undergoing hamstring (HT) versus quadriceps (QT) anterior cruciate ligament reconstruction (ACLR) and investigate correlation with patient-reported outcome measures (PROMs). Methods: After recruitment and randomisation, 112 patients (HT = 55; QT = 57) underwent ACLR. Patients were assessed at 6, 12 and 24 months using the Kneeling Tolerance Test, which evaluates patient-reported pain in a position of both 90 (KT90) and 110 (KT110) degrees of knee flexion. PROMs collected included the International Knee Documentation Committee (IKDC) questionnaire and the ACL Return to Sport after Injury (ACL-RSI) questionnaire. Results: Kneeling tolerance at KT90 and KT110 improved (p < 0.05) for both graft types across all time points. There was no difference in KT90 scores between groups at 6 or 12 months. At 24 months, kneeling tolerance was superior in the QT group (mean HT 93 ± 9 vs. QT 98 ± 5; p = 0.003). For KT110 scores, a statistically significant difference was noted at 6 (mean HT 80 ± 25 vs. QT 89 ± 12; p = 0.027), 12 (mean HT 90 ± 13 vs. QT 95 ± 10; p = 0.040) and 24 months (mean HT 92 ± 10 vs. QT 97 ± 5; p = 0.003). The ACL-RSI was significantly correlated with KT90 and KT110 at 24 months (r = 0.40, p < 0.001; r = 0.40, p < 0.001). Other PROMs demonstrated significant weak-to-moderate correlations with kneeling tolerance. Conclusion: Patients undergoing ACLR with a QT versus HT autograft report superior kneeling tolerance up to 2 years postsurgery, more prominent in deeper (110°) knee flexion. A strong correlation with ACL-RSI was demonstrated at 2 years. Registration: ACTRN12618001520224p (Australian New Zealand Clinical Trials Registry). Level of Evidence: Level 1.