Impact of Quadriceps Tendon Graft Thickness on Electromechanical Delay and Neuromuscular Performance After ACL Reconstruction.

Abstract

Both partial- and full-thickness quadriceps tendon (QT) graft harvests are used for anterior cruciate ligament reconstruction (ACLR). To evaluate the impact of QT graft harvest depth (full or partial thickness) on electromechanical delay (EMD), peak torque (PT), and rate of torque development (RTD) after ACLR. Controlled laboratory study. A total of 26 patients who underwent either partial-thickness (n = 14) or full-thickness (n = 12) autograft QT ACLR were recruited between June and November 2021 (>1 year before participation). Patients performed isokinetic knee extension testing with surface electromyography of the quadriceps muscles. Mixed repeated-measures analysis of variance with least significant difference post hoc testing was used to determine significant differences (mean difference [MD] ± SE) or interactions for all variables. A significant speed×depth interaction was seen for the vastus medialis (P = .005). Pairwise analyses showed significantly longer EMD for the partial-thickness graft than the full-thickness graft (MD ± SE, 19.92 ± 6.33 ms; P = .006). In the partial-thickness graft, the EMD was significantly longer at 90 deg/s versus 180 deg/s (MD ± SE, 19.11 ± 3.95 ms; P < .001) and 300 deg/s (MD ± SE, 16.43 ± 5.30 ms; P = .006). For PT, the full-thickness graft had a significantly lower PT on the operated versus nonoperated side at all speeds (MD ± SE: 90 deg/s, -57.0 ± 10.5 N·m, P < .001; 180 deg/s, -26.0 ± 10.2 N·m, P = .020; 300 deg/s, -20.3 ± 8.9 N·m, P = .034). For RTD, the full-thickness graft showed significantly Slower RTD for the operated versus nonoperated side at all time points (MD ± SD: RTD0-25 (0-25% of the range of motion), -131.3 ± 50.9 N·m/s, P = .018; RTD25-50, -197.0 ± 72.5 N·m/s, P = .014; RTD50-75, -113.3 ± 39.8 N·m/s, P = .013; RTD75-100, -149.4 ± 35.9 N·m/s, P < .001). Compared with partial-thickness QT, full-thickness QT showed a shorter vastus medialis EMD at higher loading, and therefore greater stiffness, as well as slower RTD and lower PT across all testing speeds. The impact of full-thickness QT autograft on EMD and neuromuscular performance should be considered for ACLR.