Case study of a congenital malformation with piston quantification in 4 suspension systems for transtibial modular prostheses with a TSB socket

Abstract

Introduction – The piston effect is one of the main problems regarding the effectiveness of prosthesis. A decrease of the piston effect can lead to a more natural gait by increasing proprioceptivity. Objectives – Check if there is a difference in piston effect values among various suspension systems for transtibial prosthesis with the use of Liners, and test the application of imaging tests in the analysis of the better prosthetic solution for a particular individual. Methods – Radiography of the prosthesis, in charge, in the orthostatic position, keeping the weight of the amputee equally distributed on bothfeet. Then was held another x-ray in the saggittal plane with the knee flexed at 30° with a weight of 5kg applied at the distal end of the prosthesis during 30sec. After these two exams the measurements for each type of suspension system was taken. Results – Of the four studied systems only three have piston values since one of the systems did not create enough suspension to withstand the weight placed on the distal end of the prosthesis. Through the radiology exams performed, measurements of the three systems could find piston effect variations ranging from 47.91mm to 72.55mm. Conclusion – By performing the imaging study there were differences at the level of the piston effect in the various suspension systems, proving that this is a viable tool in the evaluation of the piston effect. Also through the analysis of the results was notorious that the suspension system Vacuum Assisted Suspention System (VASS) is what presents less piston effect.

Keywords

• efeito de êmbolo, transtibial, liners, sistemas de suspensão