ABSTRACT
ObjectiveTo study the histologic changes of contracture Achilles tendon under Ilizarov distraction technique.MethodsEighteen dogs were installed ilizarov external fixation frames on the right hind leg in a neutral position.Pull traction started 1 week postoperatively with speed of 1 mm/day for 3 weeks.After 15 degrees of foot drop,the fixation was still maintained for 3 weeks.Nine animals were randomly selected and put to death(Contracture group),other animals corrected for 3 weeks with the same speed and methods,then put to death(Force group),health specimens as control group.(1)Observe tendon cells arranged distribution and collagen fiber form with HE dyeing,and analysis of tendon retinal thickness with image analysis software.(2)Observe collagen Ⅰ and Ⅲ with picrosirius red dying,and analyzed both content changes with image analysis software.(3)Determination of protein contents of polysaccharide with phloroglucinol spectrophotometry.Results (1)In the contracture group,the collagenous fibre gap was not obvious,the tendon cell assumes spindle-shaped,saccate,the collagen fibrous bundle distortion,the arrangement was scattered in disorder,difficult to see the intercellular substance.Tendon retinal thickness showed obvious differences with the health side (Control group).In the force group,the tendon cells were round or oval,located in collagen bundles in a string of alignment,inflammatory cells were seen.Tendon retinal thickness showed no differences with the health side.(2)With polarized light microscopy,the collagen Ⅰ and collagen Ⅲ composition proportion in the contracture group showed obvious differences with the control group,force group had not obvious differences with health side.(3)The content of polysaccharide in the contracture group were obviously reduced,while force group returned to normal level.ConclusionThe tissue form of contracture Achilles tendon can recovered to normal with the Ilizarov technology.