Review Question - QID 1345

Quadrupled strand hamstring grafts actually have a higher tensile strength (approximately 4,000 N) than the native ACL (approximately 2,200 N).

Hamner et al. showed that four combined strands (2 gracilis and 2 semitendinosus) that were equally tensioned with weights and clamped were stronger and stiffer than all 10mm patellar ligament grafts and stronger than all double grafts. Graft tensioning by placing weights is equivalent to manual tensioning by hand and it is critical that each strand is equally tensioned. They also demonstrated that a single semitendinosis strand has a higher tensile strength than a single gracilis strand.

Chen et al report level 5 evidence that ACL reconstruction using a quadrupled hamstring autograft has little morbidity, a low reoperation rate, and excellent clinical results.

Incorrect Answers:
Answer 1: Two equally tensioned semitendinosus strands have an average of 220 percent of the strength of one semitendinosus strand - this is a true statement.
Answer 2: Single semitendinosis strand has a higher tensile strength than a single gracilis strand - this is a true statement.
Answer 3: All strands of a hamstring graft must be equally tensioned to achieve optimum biomechanical properties - this is a true statement.
Answer 4: Quadrupled grafts have tensile properties that are higher than 10mm patellar-ligament grafts - this is a true statement.