Biomechanical Comparison Of PDS Strengthened Suture And Modified Kessler Method In Repairing Flexor Tendon In Vitro

Research Background:With the rapid development of society and accelerated process of industrialization,tendon injuries become more common in the hand clinical surgery and receive more and more attentions. According to the literatures, the hand tendon injuries account for about30% of hand injuries. Tendon injury had a relative high probability and also a relative high morbidity and the study of tendon injury has been an important topic of hand surgery.Tendon repair and function exercise were essential for the reconstruction and recovery of patient basic hand function. Over the years, Chinese and foreign scholars conducted a large amount of clinical observation and experimental research from anatomy, physiology,pathology and other aspects of the tendons, explored a variety of tendon suture method,and strived to restore the strength of the tendon injury, so that patients are ensured to conduct functional exercises in an early period to recover the strength in the tendon injury and prevent tendon adhesion. However, the hand basic function recovery is still not satisfactory after surgery.Objective:Kessler + PDS strengthened suture method and modified Kessler suture method were compared to provide biomechanical experimental basis for the clinical application of Kessler + PDS strengthened suture method to suture the tendon.Methods:Each flexor tendon in vitro(a total of 24) was sharply cut with a surgery knife from a middle point. Then the cut flexor tendon was completely randomly divided into two groups:group A: Kessler + PDS strengthened suture group; group B: Modified Kessler suture group with 12 tendons in each group. The tendons in each group were all conducted tendon suture and group identification and placed in a fixture of material mechanics analyzer(Instron 5544 type, America). Then the analyzer was used to record 2 mm gap formation load and maximum breaking load. All the recorded data will be entered into the computer.SPSS 18.0 software package was used for statistical analysis of the experimental results. A P < 0.05 was considered significant different in two groups.Results:1. Observation of operation timeTendon suture in the two groups was completed by one person. The operation time was 30 min in the group A and 42 min in the group B.2. Biomechanics observation2.1 2-mm gap formation load of sutured tendonThe sutured tendon was placed in a material mechanics analyzer and the load testing was conducted at a speed of 25 mm/min. In the gradual stretching process of the tendon by the analyzer, the 2-mm gap formation load was defined as the tensile load recorded and the counts read by the Instron tester when the broken ends of fractured tendons appeared a2-mm gap. The statistical analysis results showed that the 2-mm gap formation load was larger in group A than group B with a significant difference(P < 0.05).2.2 Maximum breaking load of sutured tendonThe sutured tendon was placed in a material mechanics analyzer and the load testing was conducted at a speed of 25 mm/min. When the traction force of the tested tendon was gradually enhanced, the tension count change trend was calculated by a synchronous tracing curve(synchronous testing tendon real-time tensile resistance load). The maximum breaking load was defined as the load peak at the tracing sharp fall on a slide curve. The statistical analysis results showed that the maximum breaking load was larger in group A than the group B with a significant difference(P < 0.05).Conclusion:1. The biomechanical indicators of flexor tendon sutured using Kessler + PDS strengthened suture method were better than modified Kessler suture method.2. Kessler + PDS strengthened suture can provide greater tensile strength, can effectively resist the gap formed by tendon broken end suture, can provide a more powerful biomechanical support for patient to conduct active and passive functional exercise in the early stage postoperatively, so as to effectively reduce the incidence of tendon adhesion.