Biomechanical Study Of Core And Peripheral Suture Order In Flexor Tendon Repair

Background and Subject Core and peripheral suture are the two maintechniques of tendon suture. Currently, it was recommended to combinethe two techniques to repair tendon injury. There was little report aboutthe difference between the tensile strength of the repaired tendon by usingcombination of the two sutures in different order. In the present study, invitro biomechanical experiment was employed to identify the influence ofcore and peripheral suture order on the tensile strength. It was confirmedthat which suture order could provide more tensile strength and lesstendon rupture with the same condition and suture method. This researchwill be benefit for the early function exercises after surgery reparation.Also it can provide a theoretical basis for clinical flexor tendon repair.Materials and Methods48fresh porcine forepaws were applied with theflexor digitorum profundus of second toe transected. Each sample wasrepaired by both core and peripheral suture. The modified Kessler andCruciate methods were chosen within the core suture，while Running andCross-stitch methods were chosen within the peripheral suture. Thesamples were divided into4groups by cross combination of the4suturemethods above，and each group contains2secondary groups (with core or peripheral suture first).6samples were included in each secondary group.During the experiment, the suture time of was recorded. The2mm spaceforce and maximum load of the repaired tendon were recorded bymechanical testing instrument. The stiffness was calculated according todisplacement-load curve. Then the statistical analysis was conducted.Results The parameters of2mm force space of subgroup in whichperipheral suture went first were significantly higher than that ofsubgroup in which core suture went first(P<0.05). The parameters ofmaximum load of subgroup in which peripheral suture went first weremuch higher than that of subgroup in which core suture went first whenthe peripheral suture method of Cross-stitch was applied. While there wasno difference with the parameter of maximum load when the peripheralsuture method of Running was applied no matter the core or peripheralsuture went first. The parameters of2mm force space and maximum loadof subgroup in which the core suture method of Cruciate than those ofsubgroup in which Kessler method were chosen no matter which suturemethod was applied.There were no differences with the stiffness of in all groups no matter thecore or peripheral suture method went first. The peripheral suturetechnique consumed more time (about5%~15%) than the core suture.Conclusions1. Peripheral suture was recommended to repair flexortendon injury with the same condition and suture method. It would provide more tensile strength which was benefit of early functionexercises.2. The present study showed the positive correlation betweenthe strength of tendon suture and the number of suture line. The numberof line should be more than four in core suture in the tendon repair works.