An evaluation of the effectiveness of the patellar tendon bar in the trans-tibial patellar-tendon-bearing prosthesis socket

Abstract

The aim of this study is to determine the relationship between varying depths of the patellar tendon bar in trans-tibial prosthesis sockets and the pressures exerted by other regions within the socket, such as the tibial crest, medial and lateral tibial condyles, lateral femoral condyle and the distal tibial end.

Five (5) patients selected from a population of trans-tibial amputees in Singapore. Patellar-tendon-bearing (PTB) sockets were made for them. Polypropylene spacers 2mm thick were used to simulate the increasing depths of the patellar tendon bar. P-Scan pressure transducers were inserted into the sockets to measure the pressures exerted by the socket and the data collected were analysed statistically to see if there was a relationship between varying PTB depths and pressures exerted from selected parts of the socket.

References

Buis

Convery

. Calibration problems encountered while monitoring stump/socket pressures with force sensing resistors: techniques adopted to minimise inaccuracies. Prosthet Orthot Int 1997; 21: 179–182

Convery

Buis

. Conventional patellar-tendon-bearing (PTB) socket/stump interface dynamic pressure distributions recorded during the prosthetic stance phase of gait of a trans-tibial amputee. Prosthet Orthot Int 1998; 22: 193–198

Hulshof

. Trans-tibial socket design variations and their influence on static and dynamic pressure patterns. 1985, M Phil Thesis.—Glasgow: NCTEPO, University of Strathclyde.

Jones

Bashford

Mann

. Weight-bearing and velocity in trans-tibial and trans-femoral amputees. Prosthet Orthot Int 1997; 21: 183–186

Keppel

. Design and analysis: a researcher's handbook. Prentice Hall, Englewood Cliffs 1991

Sanders

Daly

. Interface pressures and shear stresses: sagittal plane angular alignment effects in three trans-tibial amputee case studies. Prosthet Orthot Int 1999; 23: 21–29

Sanders

Lam

Dralle

Okumara

. Interface pressures and shear stresses at thirteen socket sites on two persons with trans-tibial amputation. J Rehabil Res 1997; 34: 19–43

Silver-Thorn

Childress

. Parametric analysis using the finite element method to investigate prosthetic interface stresses for persons with transtibial amputation. J Rehabil Res 1996; 33: 227–238

Silver-Thorn

Steege

Childress

. A review of prosthetic interface stress investigations. J Rehabil Res 1996; 33: 253–266

10.

William

Porter

Roberts

Regan

. Triaxial force transducer for investigating stresses at the stump/socket interface. Med Biol Eng Comput 1992; 30: 89–96

11.

Zhang

Mak

Roberts

. Finite element modeling of a residual lower-limb in a prosthetic socket: a survey of the development in the first decade. Med Eng Phys 1998; 20: 360–373

12.

Zhang

Roberts

. Comparison of computational analysis with clinical measurement of stresses on below-knee residual limb in a prosthetic socket. Med Eng Phys 2000; 22: 607–612

13.

Zhang

Turner-Smith

Tanner

Roberts

. Clinical investigation of the pressure and shear stress on the trans-tibial stump with a prosthesis. Med Eng Phys 1998; 20: 188–198