The Design And Initial Biomechanical Study Of New Minimally Invasive Suture Method For Achilles Tendon Rupture

ObjectiveTo design and manufacture small percutaneous incision suture instrument for rupture of Achilles tendon;to establish animal model of rupture of Achilles tendon;to investigate the the initial strength of Achilles tendon rupture with different suture methods via a comparative study,so as to provide a more effective clinical treatment for Achilles tendon rupture.MethodsSmall percutaneous incision suture instrument for rupture of Achilles tendon was designed and manufactured.Fresh pork leg specimens(n = 34,separated below the knee joint)were selected at room temperature,among which 10 specimens were used for anatomical observation and measurement.Meanwhile,the experiment was carried out by replacing the Achilles tendon with the deep flexor tendon of the pig.The other 24 specimens were anatomized to expose the deep flexor tendon of toes and to stimulate rupture of Achilles tendon.For the establishment of Achilles tendon rupture model,the deep toe flexor tendon was separated transversely and sharply,the incision was in parallel with the shape of tendinous fibers,meanwhile,the broken ends were split into horsetail shape.Subsequently,the remaining 24 specimens were randomly divided into three groups(group A,group B and group C),eight tendons in each group,adopting self-made small incision suture instrument(group A),Kessler method(group B)and Krackow suture method(group C),respectively.After the suture,specimens were stored in refrigerator at-10? for further usage.Then the tendon specimens were placed in the loading tray of SHIMADZU AG-1SOKN tensile testing machine,followed by uniform stretching to suture failure,corresponding maximum loading,the failure mode of deformation and other information were recorded when the failure of the suture was occurred.All collected data were analyzed by using spss15.0 system software.Finally,the experimental results are obtained.ResultsThe mean length of the Achilles tendon was(155.2±5.3)mm,the width was(12.2 ±0,9)mm,the thickness was(6.1±0.3)mm the mean length of the deep toe flexor tendon was(128.5±10,3)mm,the thickness was(5.2± 0.5)mm,and the width was(11.8±0.8)mm,which could be used to replace human Achilles tendon for the following experiment.Furthermore,the failure load of minimally invasive suture,Kessler method and Krackow method of three groups were(193.8±36.7),(159.3±5.7)and(211±28.5)N,respectively.Pairwise comparison was performed concerning maximum load of three groups by using LSD-t test,there was no significant difference between minimally invasive suture group and Krackow group,however,statistical differences were found in the comparison of Kessler group with minimally invasive suture group and Krackow group,respectively.ConclusionThe new minimally invasive method is superior to Kessler suture method,among the three methods,Kessler method provided the minimum failure load,and there is no statistical difference between new minimally invasive method and Krakow group.Biomechanical test suggests that the new minimally invasive suture method is simpler than the traditional fixation method,which can achieve the similar suture effect of traditional fixation method.The new minimally invasive suture has the advantages of reliable,easy to use,minimally invasive,and less postoperative complications;by comparison,the advantages are more prominent,such as is simple,minimally invasive,economical and practical.