The Biomechanics Analysis And Clinical Application Of Rotolation Flap

Objective: This study was mainly designed to investigate the biomechanics transformation of rotation flap (the symmetric triangular flap ,rhomboid flap, bilobate flap) by means of biomechanics test-machine and analyze the difference of biomechanical force. Assisted by clinical application, the merit of bilobate flap was testified.Methods: 1. Three deerskins (drown on 7 mm×7mm square reseaus )was pegged on the board by thumbtack. Then line scar and imperfects of rhomboid or rounded were made in the deerskins .Around the damages, the symmetric triangular flap, rhomboid flap and bilobate flap were designed in the proper position in order to simulate the courses of restoring the damages. After suture, all the skin flaps' tension distributing and the maximum tension on the flap were studied.2. Three healthy pigs were selected and butchered, then cutting the uniform part of the pigskin along spinal column. Pigskin fattiness was wiped off and putted on the board . Three skin flaps were designed and cut,then sutured .At the same time, some special points were marked at the flap edge. Then the stress and displacement of the flaps were measured with CSS-2201 biomechanics test-machine. The experiment data were exported by the computer connected with biomechanics test-machine. The force's average was counted. After the flaps' rotation, the changes of points with more tension were investigated.Results: 1.After the rotation of symmetric triangular flap, B and D points hunches, while A and C points are cupped. The length of the contracture scar extendsand the tissue around it is laxity. The reseaus around the fundus to cusp of the flap change significantly following the extending line.After rotation of rhomboid flap, the tissue around the inferior and superior imperfects hunched. The reseaus around the fundus to cusp of the flap show significant changes in the direction of the extending line. The force on the D point is obvice and B point is less than that.After suturing of the bilobate flap, the reseaus of the first valve and surrounding the imperfects aren't changed. Because the two valves rotating around one pedicel, there is much tension in the far off pedicel part, while the near part of it always turns to cat ear. The reseaus of pedicel of flap and surrounding the second valve change obviously.2. The points of more tension of the symmetric triangular flap are mostly along the assistant incision, that is to say, these points are on the two sides of the line scar. The most tension points are on the cusp of the two triangular flaps. The orientation of the tension is plumb to the line scar.The points of more tension of rhomboid flap are mostly on the flap and around the farness of the flap. The most tension points are on the short diagonal of the flap. The orientation of the one tension is horizontal, the other has 60 to 75 degree to the short diagonal.The points of more tension in bilobate flap are mostly around the frist flap, the second flap and its around. The most tension points are on the farness pedicel of the flap. The orientation of the one tension is 30 degree to the X axis.After the flaps' rotation, the tension of the imperfect about bilobate flap is least and there is almost no tension. The tension of the imperfect about the symmetric triangular flap is bigger than bilobate flap but less than rhomboid flap.Conclusion: 1.Around the imperfect of bilobate flap, there is almost no tension, so after rotation there is no following distortion. While on the imperfect of rhomboid flap, there is more tension than bilobate flap. Especially on the horizontal line of the rhomboid flap, there are two point of more tension. As the symmetric triangular flap, on cusps of the opposite scar have some tension, but the tension among the both.2. The subjective viewpoint of that simulate experiment was demonstrated by the biomechanics experiment from impersonality. After rotation of skin flaps the tension around the imperfect isn't the same. Among them bilobate flap is least. The symmetric triangular flap is greater than it but is less than rhomboid flap. The greatest tension of the symmetric triangular flap is on the cusp of the triangular flap. The greatest tension of the rhomboid flap is on the short diagonal. While the greatest tension of the bilabate flap is on the base of the flap.