Anatomic single-bundle anterior cruciate ligament reconstruction improves walking economy: hamstrings tendon versus patellar tendon grafts

Anterior cruciate ligament (ACL) injury is associated with a pathologic gait pattern and increased energy cost during locomotion. ACL reconstruction could improve the gait pattern. Hamstrings tendon (HAM) and bone–patellar tendon–bone (BPTB) grafts are usually used for reconstruction. The aim of this study was to compare the efficacy of anatomic ACL reconstruction with HAM and BPTB grafts on improving and normalizing the energy cost and physiologic reserves during flat, uphill, and downhill walking. Twenty male subjects with unilateral ACL injuries were randomly assigned to ACL reconstruction with a HAM (n = 10) or BPTB (n = 10) graft. Ten matched controls were also enrolled. All participants performed three 8-min walking tasks at 0, +10, and −10 % gradients before and 9 months after surgery. Energy cost (oxygen consumption, VO2), heart rate (HR), and ventilation (VE) were measured. Lysholm/IKDC scores were recorded. Pre-operatively, VO2, HR, and VE were higher in the HAM and BPTB groups than in controls during walking at 0, +10, and −10 % gradients (p