PolyethyleneDebris particle size▪ 0.1-0.5 μm²6▪ 0.69 μm³3Wear rate▪ 0.04-0.26 mm per year³4■ Non-crossed-linked polyethylene: 39 mm³ per 106cycles (simulator) 35. Cross-linked polyethylene: 5-9 mm³ per 106 cycles(simulator)35 A total hip replacement consisting of a 28 mm diameter Co-Cr femoral head articulatingagainst a UHMWPE cup functions in a patient for 5 years before it is removed during revision arthroplasty. You perform a detailed analysis of theexplanted cup. The articular surface of the explanted UHMWPE cup shows a change in geometry such that the cup is 0.75 mm deeper (see photo).Radiograph of THR at the time of surgeryAssumptions:28 mmPatient weighs 70kg with an average load of a gate cycle of 2.5BWNeglect creep for all questionsAssume 1 million steps per yearANSWER COLUMNTHR at day 1QUESTIONS0.75 mmTHR at 5 yearsTotal angular motion per gait stride (hip flexion-extension-flexion OR heel strike to heel strike) is 80 degreesHint: Recall details of UHMWPE materials and applications in THR from Lecture 9 Notes.Q1A: Calculate the annual volume of UHMWPE wear debris.UHMWPE after 5 yearsshowing progression ofworn region (dark grey)

Given data, Diameter D= 25mm The projected area =π4×D2 epth of wear= 0.76Total time = 5 years

Answered: Polyethylene Debris particle size ▪…

Engineering

Mechanical Engineering

Polyethylene Debris particle size ▪ 0.1-0.5 μm²6 ▪ 0.69 μm33 Wear rate

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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