Comparison of drop jump landing biomechanics and asymmetry among adolescents with hamstring, patellar and quadriceps tendon autografts for anterior cruciate ligament reconstruction.

BACKGROUND: Adolescent anterior cruciate ligament reconstruction (ACLR) commonly utilizes hamstring (HT), patellar (PT) or quadriceps (QT) tendon autografts, but consensus is lacking regarding optimal graft choice. This study compared landing biomechanics and asymmetries among ACLR patients with HT, PT and QT grafts and uninjured controls.

METHODS: This retrospective study included 61 adolescents with unilateral ACLR (27 HT, 20 PT, 14 QT; four to 12 months post-surgery, mean 6.4; age 15.4, SD 1.4 years) and 27 controls (14.6, SD 0.9 years) who were evaluated during drop jump landings. Lower extremity 3D biomechanics and asymmetries were compared.

RESULTS: Compared to controls, all operative limbs exhibited 1) greater hip flexion and lower dorsiflexion angles; 2) higher hip and lower knee and ankle flexion moments; 3) higher energy absorption at the hip (HT and QT only) and lower at the knee and ankle; and 4) higher knee abduction moments. Asymmetries observed in all ACLR groups included 1) lower knee and ankle flexion angles; 2) lower knee and ankle flexion moments; 3) lower energy absorption at the knee and ankle; and 4) higher hip and knee abduction moments on the operative side. The PT and QT groups demonstrated greater asymmetry in hip and knee flexion moments compared to HT.

CONCLUSIONS: While adolescent ACLR limbs offloaded the knee and ankle, patients with PT or QT grafts demonstrated greater deficiencies during rehabilitation than those reconstructed with HT. Graft choice in ACLR should remain patient-specific and aim to optimize biomechanics with the ultimate goal of minimizing graft re-tear and donor site morbidity.