Knee flexor strength after ACL reconstruction: comparison between hamstring autograft, tibialis anterior allograft, and non-injured controls

Abstract

Hamstring muscle group dysfunction following anterior cruciate ligament reconstruction (ACL) using a semitendinosus-gracilis autograft is a growing concern. This study compared the mean peak isometric knee flexor torque of the following three groups: subjects 2 years following ACL reconstruction using semitendinosus-gracilis autografts (Group 1), subjects 2 years following ACL reconstruction using tibialis anterior allografts (Group 2), and a non-injured, activity-level-matched control group (Group 3). We hypothesized that Group 1 would have greater mean involved lower extremity peak isometric knee flexor torque deficits than the other groups. Handheld dynamometry with subjects in prone and the test knee at 90 degrees flexion was used to determine bilateral peak isometric knee flexor torque. Group 1 (86.4 +/- 11) and Group 2 (80.5 +/- 13) had similar 2000 IKDC Subjective Knee Evaluation Form scores (P = NS). Group 1 had a mean involved lower extremity peak isometric knee flexor torque deficit of -17.0 +/- 14 Nm. Group 2 had a mean involved lower extremity peak isometric knee flexor torque deficit of -0.8 +/- 9 Nm. Group 3 (control) had a mean left and right lower extremity peak isometric knee flexor torque difference of -0.7 +/- 14 Nm. Group 1 had decreased involved lower extremity peak isometric knee flexor torque compared to Groups 2 and 3 (two-way ANOVA; group x side interaction P < 0.05, Tukey HSD = 0.008). Long-term knee flexor strength deficits exist following hamstring autograft use for ACL reconstruction that does not occur when a tibialis anterior allograft is used. Early identification of impaired knee flexor strength among this group and modified rehabilitation may reduce these deficits. Adding quantitative biomechanical testing of sprinting and sudden directional change movements to the standard physical therapy evaluation will better elucidate the clinical and functional significance of the observed knee flexor strength impairments and aid in determining sport specific activity training readiness.

Return to play following ACL reconstruction: a systematic review about strength deficits

“…Nineteen of these studies compared patients with a patellar tendon autograft to patients with a hamstring tendon autograft [2,3,11,12,14,15,20,27,33,35,41,44,50,51,53,75,79]. Seven of these studies showed that after 12-24 months after ACL reconstruction patients with BPTB graft showed a greater deficit in extensor muscle strength and lower deficit in flexor muscle strength compared with patients with HST and vice versa.…”

“…Two studies showed that patients had less flexor strength deficit after allograft ACL reconstruction versus autologous hamstring graft reconstruction [59,50].…”

Comparative study between bone patellar tendon bone and quadrupled hamstring autografts in arthroscopic anterior cruciate ligament reconstruction with aperture fixation

“…However, in ACL reconstructed knees, a flexion strength deficit occurs but has no effect on IKDC scores. 18 The purpose of this study was to compare bone-patellar tendon-bone and 4-strand hamstring tendon autografts for arthroscopic ACL reconstruction with the same type of fixation for both grafts. Other authors have compared these grafts in clinical outcome studies but have used different fixation devices for the hamstring tendons and the patellar tendon grafts.…”

Allograft versus autograft for anterior cruciate ligament reconstruction: an up-to-date meta-analysis of prospective studies

“…One study was excluded because insufficient data reported in orthopaedic conference abstracts [24]. Seven studies were excluded because of not a prospective comparative study [25][26][27][28][29][30][31]. One study was excluded because data from the same patients were reported in another study with a longer duration of follow-up [32].…”