Gemstone Team LEGSGrafts used for anterior cruciate ligament (ACL) reconstructions fall short of
restoring native mechanics. This study investigated a morphological cause for
tension loss by comparing native ACL and two common grafts, bone-patellar tendonbone
(BPTB) and semitendinosus/gracilis hamstring tendon (ST/G), in a cadaveric
system. Tension loss during continuous passive motion was quantified via force
transducer. Microstructural changes were assessed by measuring collagen crimp
angles. No significant differences were found for rates of percent tension loss relative to total tension loss among grafts. However, all groups displayed exponential decay, implying rapid tension loss. The crimp angles for the unstressed grafts were
significantly different from each other, suggesting innate differences. The percent
change experienced by stressed grafts, normalized to their unstressed baselines,
showed that ST’s crimp behavior was significantly different from that of ACL and
BPTB, implying the BPTB graft is superior for ACL reconstruction because it better
mimics the ACL’s morphological behavior