The effect of strand configuration on the tensile properties of quadrupled tendon grafts.
OBJECTIVE
To compare selected biomechanical properties of 4 different quadrupled tendon graft preparations applicable for anterior cruciate ligament reconstruction.


METHODS
Biomechanical investigation in a cadaver model.


METHODS
Graft strands were arranged in parallel, braided, bolo-plait, and twist configurations. Elongation of the graft was monitored during loading with an infrared optical measurement system, which measured the 3-dimensional position of twelve spherical reflective markers mounted within the camera field. Permanent elongation, stiffness, and ultimate strength of each graft configuration were determined.


RESULTS
Permanent graft strain after the first incremental loading cycle was 7.2% in braid, 6.6% in twist, 6.5% in bolo-plait, and 3.3% in parallel constructs (P <.0001). Permanent graft strain after a second incremental loading cycle was 1.2% in bolo-plait, 1.1% in braid, 0.7% in twist, and 0.7% in parallel preparations (P =.0012). Braid and bolo-plait grafts were less stiff than twist or parallel grafts (P <.0001). Differences in failure load were not significant (P =.171).


CONCLUSIONS
Variation in graft configuration from the conventional, parallel strand pattern lead to increased viscoelasticity and permanent elongation of grafts with repetitive loading. This deficit is expected to cause increased laxity of the reconstructed knee.
Rittmeister
Markus
M
Baylor Sports Medicine Institute, Orthopedic Research Laboratory, Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Texas, USA. merittmeister@aol.com
Noble
Philipp C
PC
Lintner
David M
DM
Alexander
Jerry W
JW
Conditt
Michael
M
Kohl
Harold W
HW
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery; D002417:Cattle; D004548:Elasticity; D013710:Tendons / Q000033:anatomy & histology / Q000502:physiology* / Q000637:transplantation; D013718:Tensile Strength; D016378:Tissue Transplantation / Q000379:methods