T. Muneta et al., LOAD AFFECTS REMODELING OF TRANSPLANTED, AUTOGENOUS BONE-PATELLAR TENDON-BONE SEGMENTS IN A RABBIT MODEL, Journal of orthopaedic research, 12(1), 1994, pp. 138-143
The question of whether or not load affects the remodeling of a transp
lanted autogenous free graft was addressed by removal of the patella-p
atellar tendon-tibial tubercle complex from the right knees of 15 New
Zealand White rabbits. The tubercle was split, and the tendon was divi
ded with each half trimmed to an equal width. The autograft complex wa
s transplanted into a subcutaneous tunnel on the back of the rabbit. C
ontrolled cyclic loads were applied via transcutaneous sutures to half
of the graft, while the other half remained unloaded. The mechanical
stiffness and strength and the cell density of loaded and unloaded hal
ves of the autograft were measured in nine animals at 3 weeks and in s
ix animals at 6 weeks. Five autografts from four additional rabbits se
rved as unimplanted controls. An analysis of variance showed that the
loaded portions of the autografts had a significantly higher failure s
trength (mean of 90%) and were significantly stiffer (mean of 62%) tha
n the unloaded halves at 3 and 6 weeks. Failure strength was significa
ntly greater (mean of 90%) at 3 weeks than at 6 weeks. The autografts
were less stiff and had a lower failure strength than the unimplanted
controls, with the greatest difference occurring in the unloaded segme
nts at 6 weeks. Histology revealed that both loaded and unloaded segme
nts demonstrated an increase in cellularity at 6 weeks compared with 3
weeks. This report introduces a model for the study of the effect of
load on soft-tissue grafts and demonstrates that loading affects the r
emodeling process of a transferred autograft.