Clinical and Histologic Evaluation of Partial Achilles Tendon Injury Repair with Amniotic Membrane in Rats.

BACKGROUND:Adhesions after tendinopathy in individuals who perform physical work and those physically active in middle age are a challenging problem for orthopedic surgeons. We evaluated the effects of human-derivated amniotic membrane on tendon healing, adhesions, angiogenesis, and the inflammatory process. METHODS:Thirty-five rats were divided evenly into five groups, and the left lower extremity was used in this study. No interventions were applied to the control group (group 5). In the other groups, Achilles tendons were partially cut to the midline. Then, primary repair (group 1), amniotic membrane treatment with no repair (group 2), primary repair and amniotic membrane treatment (group 3), or secondary healing with no repair (group 4) was performed. RESULTS:Use of amniotic membrane in tendon healing resulted in decreased adhesion formation and positive effects on collagen sequencing and anti-inflammatory effects. In addition, for the vascular endothelial growth factor evaluation there was no difference among the amniotic membrane repair groups, but there was an increase in vascular endothelial growth factor positivity compared with the control group. CONCLUSIONS:These data show that amniotic membrane treatment can alter biological behavior and induce surface-dependent angiogenesis and can have angiogenetic effects on ischemia and inflammation.