| [Objective]Given the peculiarity of local anatomy and mechanical features of Achilles tendon, the treatment of fresh wounds is both difficult and with poor curative effects. There are quite a few traditional methods of treating early stage Achilles tendon rupture but they carry a relatively high risk of postoperative complications which develop into chronic injuries, rendering treatment even more challenging. The alternative treatment with long term cast plantar flexion causes deformity and rigidness in ankles. The author has applied the technique of internal fixation of limiting rings to repairing Achilles tendon rupture since1996and achieved satisfactory clinical effects. To further validate the research, all kinds of operational procedures are performed on animal tendons (pig feet) for simulation and tests in radiology and biomechanics are carried out to obtain experiment data in support of the operational procedure of the study also with hopes of achieving breakthroughs in new aspects to further improve the operation procedure of "internal fixation of limiting rings". [Method](1) Group dividing:divide a total of86tendons from43pigs’ feet into two major categories according to the type of the tendon. The bulky deep digital flexor tendon is named as A Tendon, while the slightly slender superficial digital flexor tendon is named as B Tendon. They are further divided into nine groups:the blank group of8A tendons and the blank group of16B tendons; the absorbable suture group of ten tendons (8B tendons,2A tendons); the silk thread suture group of6tendons (B tendons); the group of6A tendons of internal fixation with the ring of single-strand steel wire and no reinforcement; the group of6A tendons of internal fixation with the ring of double-strand steel wire and no reinforcement; the group of12A tendons of internal fixation with the ring of single-strand steel wire and reinforcement (among them,7tendons sutured with absorbable threads,5with silk threads); the group of12B tendons of internal fixation with the ring of single-strand steel wire and reinforcement (among them,7tendons sutured with absorbable threads,5with silk threads); the group of6A tendons of internal fixation with titanium cables and reinforcement. In addition, apply the technique of internal fixation with the ring of double-strand wheel wire and reinforcement on2A tendons and the technique of internal fixation with titanium cables and no reinforcement on2A tendons on a trial basis.(2) Radiological test:the pig tendons will be sent to the department of radiology for taking DR X-rays to further observe the bony structure of the pig feet and the status of the internal fixation limiting ring. On the one hand, it is to determine the pig feet away from the fault plane so as to avoid excessive damage on bony structures that leads to mechanical instability and affects mechanical testing on the tendons. On the other hand, it is to monitor the location of bone tunnels of pig feet in all experiment groups and make sure the steel wire, titanium cable, lead wire and other threads go through the corresponding bone tunnels. After completion of the mechanical tests, take DR X-rays again to observe:destruction of the bony structures of pig feet, changes in internal fixation material location, the presence of internal fixation materials fracture, the position of material failures and etc.(3) The biomechanical test:carry out biomechanics tensile tests on each specimen of tendons. The computer connected to INSTRON-the biomechanical testing machine will automatically analyze and record the changes of all indicators. Focus on recording and comparing the maximum load that each specimen can bear. In the mean time, during the test process closely observe:the change in anastomotic ends on the tendon fracture, bending and fracture of all kinds of internal fixation materials and sutures, and clamp loosening in both upper and lower ends of specimens.(4) Statistical analysis:determine if factors such as operating procedure, internal fixation materials, the absence or presence of reinforcement treatment cause statistically significant differences in bearing load of all the specimens of the tendons on anastomotic rupture ends after the mock surgeries[Results]After carrying out statistical regression analysis on all the data, it is concluded that all experiment data accord with normal distribution thus are quite credible. And:the strength=1365.185-268.915tendon type-466.013thread type+328.628steel wire type. This can explain the phenomena observed in the experiment.In addition, pairwise comparisons are conducted:(1) Among A tendons of the pig feet:comparison between the group of internal fixation with the ring of single-strand steel wire and no reinforcement and the group of internal fixation with the ring of double-strand steel wire and no reinforcement, P=0.89>0.05, therefore there is no significant difference.(2) Among A tendons receiving the procedure of internal fixation with the ring of single-stand steel wire:compare the group with reinforcement with the group without. P=0.005<0.05, representing a highly significant difference between with and without reinforcement, implying that reinforce treatment is quite necessary when conducting limiting ring internal fixation procedure.(3) Among the groups of A tendons receiving internal fixation with the ring of single-strand steel wire and reinforcement:further compare the difference between absorbable sutures with silk threads. The result P=0.028<0.05, therefore there is significant difference, suggesting the choice of suture is also important.(4) Compare the group of A tendons of internal fixation with titanium cables and reinforcement with the group of A tendons of internal fixation with the ring of single-strand steel wire and reinforcement. P=0.009<0.05, representing a highly significant difference between with and without reinforcement, implying that internal fixation with titanium cables is more effective than that with single-strand steel wire.[Conclusion]In clinical practice, patients with Achilles tendon rupture should be actively treated with surgical procedures to achieve satisfactory healing effect. The use of the procedure of "internal fixation of limiting rings" in the study in particular, namely internal fixation with limiting rings of titanium cables or steel wire has significant mechanical advantages.This operation procedure can not only effectively suture Achilles tendon rupture ends and promote the endogenous growth and recovery of Achilles tendon but more importantly provide enough tension immediately after surgery to enable patients to start ankle function exercise on their own, thus accelerating the Achilles tendon healing, improving ankle function and preventing disability for patients with Achilles tendon injury.Certainly, with the development of technologies such as genetic strengthening tissue engineering, gene activation materials can be applied to local areas on which "limiting ring internal fixation procedure" are performed at the same time to give full play to the positive role of vascular endothelial growth factor and other cytokines, further perfect the growth and repair of cells and collagen fiber in the rupture end of Achilles tendon so as to accelerate the recovery of patients. |
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