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Limited By:	Author = O'REILLY, PETER;

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Defining the impaction frequency and threshold force required for femoral impaction grafting in revision hip arthroplasty. A human cadaveric mechanical study. (2011)

O'REILLY, PETER; KELLY, DANIEL

Defining the impaction frequency and threshold force required for femoral impaction grafting in revision hip arthroplasty. A human cadaveric mechanical study. (2011)

O'REILLY, PETER; KELLY, DANIEL

Abstract:

BACKGROUND AND PURPOSE: The two most common complications of femoral impaction bone grafting are femoral fracture and massive implant subsidence. We investigated fracture forces and implant subsidence rates in embalmed human femurs undergoing impaction grafting. The study consisted of two arms, the first examining the force at which femoral fracture occurs in the embalmed human femur, and the second examining whether significant graft implant/subsidence occurs following impaction at a set force at two different impaction frequencies. METHODS: Using a standardized impaction grafting technique with modifications, an initial group of 17 femurs underwent complete destructive impaction testing, allowing sequentially increased, controlled impaction forces to be applied until femoral fracture occurred. A second group of 8 femurs underwent impaction bone grafting at constant force, at an impaction frequency of 1 Hz or 10 Hz. An Exeter stem was cemented into the neomedullary canals. These co...

http://hdl.handle.net/2262/60181

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The fracture toughness of soft tissues (2012)

TAYLOR, DAVID; SIMMS, CIARAN; O'REILLY, PETER

The fracture toughness of soft tissues (2012)

TAYLOR, DAVID; SIMMS, CIARAN; O'REILLY, PETER

Abstract:

Fracture toughness is important for any material, but to date there have been few investigations of this mechanical property in soft mammalian tissues. This paper presents new data on porcine muscle tissue and a detailed analysis of all previous work. The conclusion is that, in most cases, fracture toughness has not in fact been measured for these tissues. Reanalysis of the previous work shows that failure of the test specimens generally occurred at the material?s ultimate strength, implying that no information about toughness can be obtained from the results. This finding applied to work on cartilage, artificial neocartilage, muscle and the TMJ disc. Our own data, which was also found to be invalid, gave measured fracture toughness values which were highly variable and showed a strong dependence on the crack growth increment. The net-section failure stress and failure energy were relatively constant in large specimens, independent of crack length, whilst for smaller specimens they ...

http://hdl.handle.net/2262/61669

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The mechanical effect of the existing cement mantle on the in-cement femoral revision. (2012)

Keeling, Parnell; Lennon, Alexander B; Kenny, Patrick J; O'Reilly, Peter; Prenderg...

The mechanical effect of the existing cement mantle on the in-cement femoral revision. (2012)

Keeling, Parnell; Lennon, Alexander B; Kenny, Patrick J; O'Reilly, Peter; Prendergast, Patrick J

Abstract:

Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

http://hdl.handle.net/10147/323664

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The threshold force required for femoral impaction grafting in revision hip surgery. (2010)

Flannery, Olivia M; Britton, John R; O'Reilly, Peter; Mahony, Nicholas; Prendergas...

The threshold force required for femoral impaction grafting in revision hip surgery. (2010)

Flannery, Olivia M; Britton, John R; O'Reilly, Peter; Mahony, Nicholas; Prendergast, Patrick J; Kenny, Paddy J

Abstract:

BACKGROUND AND PURPOSE: Femoral impaction grafting requires vigorous impaction to obtain adequate stability without risk of fracture, but the force of impaction has not been determined. We determined this threshold force in a preliminary study using animal femurs. METHODS: Adult sow femurs were used because of their morphological similarity to human femurs in revision hip arthroplasty. 35 sow femurs were impacted with morselized bone chips and an increasing force was applied until the femur fractured. This allowed a threshold force to be established. 5 other femurs were impacted to this force and an Exeter stem was cemented into the neomedullary canal. A 28-mm Exeter head was attached and loaded by direct contact with a hydraulic testing machine. Axial cyclic loading was performed and the position sensor of the hydraulic testing machine measured the prosthetic head subsidence. RESULTS: 29 tests were completed successfully. The threshold force was found to be 4 kN. There was no stati...

http://hdl.handle.net/10147/108223

Displaying Results 1 - 4 of 4 on page 1 of 1