Biomechanical Study On The Pie-crusting Technique Of Multiple Needle Puncturing Versus Multiple Stab Incision In Sheep

Backgroud:Knee osteoarthritis(KOA) is a chronically non-inflammatory arthritis. It mostly strikes in elderly people. With joint pain, deformation and restricted movement as clinical characteristics, the pathological changes include the disappear of cartilage, subchondral bone changes, synovitis and gradual meniscal degeneration. The pathogenesis of KOA is unclear until now. It is associated with aging, trauma, inflammation, obesity and genetic factors. Total Knee Athroplasty(TKA) is considered to be the most effective manner of the treatment of KOA, which can lift patients’ joint pain, improve the quality of their lives. The history of TKA has been more than 30 years. There are amount of long follolw-up data, which shows encouraging. However, some patients with knee osteoarthritis, often accompanied by a knee joint deformity, this is also one of the major late complications, mainly including valgus, varus, flexion contracture and ankylosis. These deformities not only pose challenges to the surgery, but even lead to poor prognosis. When the knee joint deformity occurs, it makes the soft tissue around it too tight or loose. For example, the medial collateral ligament is contracting in varus knee while the lateral collateral ligament was gradually stretched. In this case, effective medial collateral ligament release and establishing soft tissue balance, becomes the key to the surgery. In recent years, with the continuous development of TKA, the manners of ligament release are also constantly changing. One called "Pie Crusting" presented by Insall was invented. This new technology is being more and more popular that many doctors applied it to clinical practice. Pie Crusting technique is divided into two kinds, one is Multiple Stab Incision which is a commonly used method, and the other is a new method called Multiple Needle Puncturing which was put forward in recent five years. For surgeon, however, in the art of the release, the choice of which method can obtain better result and make sure not too loose, depends entirely on surgeon’s own experience. And for the two kinds of release the biomechanics characteristic of them, at present did not see the reports. In this paper, we focus on the differences between Multiple Needle Puncturing and Multiple Stab Incision in the biomechanics. Objective:This study was conducted with fresh sheep patellar ligament as an experimental model, by using two different methods, multiple needles puncturing and multiple stab incision. Base on the biomechanics, the discussion was about the characteristic of each method and to provide theoretical basis for clinical operation. Methods:28 sheep patellar ligament was freshly taken before the experiment; equally divide each ligament into two pieces by reading microscope to become one text group. Randomly choose one ligament from the text group perform multiple needles puncturing method leave the other ligament for multiple stab incision method. Run the text with electronic universal testing machine(AG-X plus Shimadzu Kyoto), record the maximum loading capacity for each ligament and then compare with the control ligament in the group. In the meantime compare the puncturing times for each method to reach the same releasing level. Results:The maximum loading capacity of multiple needles puncturing is 127.37±46.14N; The maximum loading capacity of multiple stab incision is 86.82±28.33 N. The results of comparison of Multiple Needles Puncturing and Multiple Stab Incision are statistically significant(P < 0.05). The Puncturing times for each method to reach the same releasing level are statistically significant(P < 0.05). The median of the needle group is 25 and the stab’s is 15. Conclusion:The maximum loading capacities of Multiple Needles Puncturing and Multiple Stab Incision are different. And the former numerical value is greater than the latter. This shows that the ligaments of Multiple Needles Puncturing are tougher. This also means that using this method of ligament release, not only obtained the release, but can provide more powerful protection.The Puncturing times for each method to reach the same releasing level are statistically significant, and the times of the needle puncture group are obviously more than the other group. From this set of data, Multiple Needles Puncturing is a safer, more progressive and more controllable way of ligament release.