Tear of the anterior cruciate ligament (ACL) is the most common ligamentous injury of the knee. Re- constructing this ligament is often required to restore functional stability of the knee.1,2 Despite the popularity of the procedure, the preferred graft remains controversial. Ideally, the graft should have similar characteristics as the native ACL. Regardless of graft type, the biologic and mechan- ical properties of the graft material should provide a favorable setting for early biologic incorporation, be amenable to secure fixation, and limit potential morbidity related to donor site.
Many graft options are available for ACL recon- struction, including different autograft and allograft tissues. Autografts include bone-patellar tendon- bone composites (PT), combined semitendinosus and gracilis hamstring tendons (HT), and quadri- ceps tendon. Allograft options include the same types of tendons harvested from donors, in addition to Achilles and tibialis tendons. Tissue- engineered anterior cruciate grafts are not yet available for clinical use, but may become a feasible alternative in the future.
For the past few decades, PT autograft has been the gold standard for ACL reconstruction. Reasons for this include the strength of the tissue, relative ease of harvest, and bone-to-bone healing with secure fixation. More recently, HT autografts have joined PT in surgeons’ popularity.3 The recent trend toward increased use of HT resulted from concerns with use of PT relating to a potential negative effect on the knee extensor mechanism and donor site morbidity, including anterior knee pain and risk for patella fracture.4 Nevertheless, despite their increasing popularity, HT grafts also have potential limitations, including slower soft- tissue graft-tunnel healing compared with bone- to-bone healing with PT grafts, potential for tunnel