In this paper, we present an in vitro and in situ protocol to repair a tendon gap of up to 1.5 cm by filling it with engineered collagen graft. This was performed by developing a modified suture technique to take the mechanical load until the graft matures into the host tissue.
So this surgical technique of suturing, a tissue engineered piece of collagen will revolutionize the way we use tissue engineered graphs to replace tendon autographs that are used currently for tendon reconstruction. The main advantage of this technique is that it uses a surgically optimized suture technique to accommodate a tissue neuro tendon in vivo. This method can help answer key questions in the attendant tissue engineering field about the using of collagen graphs for tendon reconstruction.
The main advantage of this technique is that it uses a surgically optimized graph insertion technique to accommodate a tissue engineered, tendon graph in vivo. The implications of this technique extend towards the therapy of a tendon gap. Because it is off the shelf and readily available to surgeons.
Though, this method can provide insights into the surgical repair of tendons. It can also be applied to other crafting procedures. Visual demonstration of this method is critical as the vivo application of suture can be difficult to master without the use of a large number of animals.
Begin by Alec Walton, four milliliters of rat tail collagen type one, monomeric collagen solution. Then add 500 microliters of 10 times minimal essential medium to the collagen solution and titrate against five and one molar sodium hydroxide to neutralize the solution. Next add 500 microliters of Dulbecco's Modified Eagle Medium to the solution and transfer five milliliters of the mixture into a custom built rectangular metal mold.
then place the mold at 37 degrees Celsius and 5%CO2 for 15 minutes to facilitate matrix assembly. After polymerization, transfer the collagen hydro gel from the mold into a standard plastic compression assembly in between two 50 micrometer nylon mesh sheets. Apply a static load of 120 grams to the assembly for five minutes to remove the interstitial fluid from the hydro gel, using four layers oF filter paper to absorb the discharged fluid.
After preparing three more hydrogels in the same manner, roll all four compressed gels together and cut the roll into 15 millimeter segments. Before beginning the procedure, trim the hair on both hind limbs of a 16 to 25 week old male rabbit and use a number 20 surgical blade to make a nine centimeter incision in one limb around the inferior tubular fibular area, to expose the tibialis posterior tendon. Then expose a 17 millimeter sectional tendon and wet the tissue with PBS to keep the tissue hydrated.
Next, remove a 15 millimeter segment from the tendon at the midpoint and replace the excised tissue with the engineered tissue collagen graft. Using three zero core sutures, inter-lock the graft proximally from the native tendon ends. Passing the sutures over the entire length of the graft to interlock the graft distally from the cut end.
Secure both ends of the engineered tissue to the native tendon with six zero continuous running sutures around the periphery of the graft. Then manually confirm that the tension on the sutures is appropriate and that there is no flacidity in any of this sutures. As demonstrated the excised tendon gap is filled with a 15 millimeter long engineered tissue tendon graft, and secured with three zero interlock sutures at 17 millimeters to act as load barriers and with six zero sutures to the native tissue.
The mean break strength of the repair was about 51 newtons, significantly higher than that, of the control Kessler repair of approximately 12 Newtons. Demonstrating the influence of the core suture length and the distal interlocking in preventing repair failure at higher magnitude forces. In suture resistance experiments, demonstrated a mean break strength of approximately 25 Newtons, significantly higher than the control mean break strength of about 14 Newtons.
There are two key things to remember. Number one, make sure that you neutralize a collagen solution at appropriate pH. And secondly, there should be enough suture tension and there is no flacidity within suture.
So after the development of the suture technique, it has brought new perspectives in the way researchers in the field of tissue engineering of tendons, can approach tendon repair, and tendon replacement and tendon regeneration, in human beings in the future. Remember to formulate in neutralized collagen solution, at an ideal pH. And to manually ensure that the suture tension is appropriate, so that there's no flacidity within the suture.
After its development, this technique paved the way for researchers in the field of tissue engineering, and tending regeneration to explore, tendon gap repair in humans.
