Biomechanical and histologic comparison of Achilles tendon ruptures reinforced with intratendinous and peritendinous plantaris tendon grafts in rabbits: an experimental study.
BACKGROUND
We hypothesized that the closer the reinforcing graft was to the repair zone, the more strength the healed tendon would achieved. Therefore, we compared the ruptured rabbit Achilles tendons reinforced with intratendinous and peritendinous plantaris grafts.


METHODS
The experimental study was performed on Achilles tendons of 20 rabbits. First, they were divided into two groups: group I (n=10) underwent intratendinous graft and end-to-end tenorraphy, and group P (n=10) were repaired end-to-end and then reinforced with a peritendinous plantaris graft. An above-knee cast was applied during 6 weeks postoperatively. The two groups were compared to each other biomechanically and histologically. Seven randomly selected rabbits from each group were used for biomechanical evaluation. The remaining six rabbits (three from each group) were used for histologic comparison. Non-operated sides (n=20) served as the control group.


RESULTS
The mean maximum load at rupture of the repaired and control groups was 159.9+/-31 N, 83+/-7.5 N, and 207.5+/-35 N for group I, group P, and the control group, respectively. Values between groups were significantly different considering maximum load and absorbed energy to rupture. There was no significant difference between groups I and P in respect to strain. Control group tendons (groups I-C and P-C) had significantly more lengthening capability than operated tendons. Macroscopically, group I tendons were thicker and stiffer than group P tendons. Histologically, differences between the group I and group P specimens revealed that the healing process was faster in tendons augmented intratendinously.


CONCLUSIONS
In reinforcing Achilles tendon repair, the site of the tendon graft affected the result. When the graft was used intratendinously, the healed tendon was more similar biomechanically to normal tendon and had more graft-tendon orientation histologically than the tendon augmented peritendinously.
Ilhami
Kuru
K
Middle East Technical University, Turkey. ikuru@isnet.net.tr
Gokhan
Maralcan
M
Ulukan
Inan
I
Eray
Bozan M
BM
Levent
Altinel
A
Ciğdem
Tokyol
T
D000125:Achilles Tendon / Q000293:injuries*; D000818:Animals; D001696:Biomechanical Phenomena; D008297:Male; D011817:Rabbits; D012421:Rupture; D013710:Tendons / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology*