Prosthetic radial head stem pull-out as a mode of failure

A biomechanical study

Dave Shukla, James Fitzsimmons, Kai Nan An, Shawn O'Driscoll

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Purpose: Press-fit cementless radial head implant longevity relies on adequate bone ingrowth. Failed implant osseointegration remains a clinical concern and has been shown to lead to prosthetic failure. The purpose of this study was to test the hypothesis that implants with sufficient initial press-fit stability would be less likely to fail due to implant pull-out, as demonstrated by an increasing amount of energy required to remove the prosthesis from the canal. Methods: Ten cadaveric radii were implanted with five sizes (6-10 mm in 1-mm increments) of grit-blasted, cementless radial head stems. A customised slap hammer was used to measure the energy required to remove each stem. Stem-bone micromotion was also measured. Results: The suboptimally sized stem (Max - 1) (i.e. 1 mm undersized) required less energy (0.5 ± 0 J) to pull out than the optimally sized stem (Max) (1.7 ± 0.3 J) (p = 0.008). The optimally sized stem demonstrated greater initial stability (45 ± 7 μm) than the suboptimally sized stem (79 ± 12 μm) (p = 0.004). Conclusions: This investigation demonstrates the importance of obtaining adequate press-fit stability for the prevention of radial head stem pull-out failure. These data add to the relatively scant knowledge in the literature regarding radial head biomechanics. The energy required to remove a prosthetic radial head ingrowth stem decreases in conjunction with diameter. The use of an inadequately sized stem increases the stem's micromotion as well as the risk of prosthetic loosening due to pull-out.

Original languageEnglish (US)
Pages (from-to)89-93
Number of pages5
JournalInternational Orthopaedics
Volume38
Issue number1
DOIs
StatePublished - Jan 2014

Fingerprint

Osseointegration
Bone and Bones
Biomechanical Phenomena
Prostheses and Implants

Keywords

  • Cementless stem failure
  • Radial head arthroplasty
  • Radial head implant

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

Cite this

Prosthetic radial head stem pull-out as a mode of failure : A biomechanical study. / Shukla, Dave; Fitzsimmons, James; An, Kai Nan; O'Driscoll, Shawn.

In: International Orthopaedics, Vol. 38, No. 1, 01.2014, p. 89-93.

Research output: Contribution to journalArticle

Shukla, Dave ; Fitzsimmons, James ; An, Kai Nan ; O'Driscoll, Shawn. / Prosthetic radial head stem pull-out as a mode of failure : A biomechanical study. In: International Orthopaedics. 2014 ; Vol. 38, No. 1. pp. 89-93.
@article{83d3466aef2847a7b955aa82331c6857,
title = "Prosthetic radial head stem pull-out as a mode of failure: A biomechanical study",
abstract = "Purpose: Press-fit cementless radial head implant longevity relies on adequate bone ingrowth. Failed implant osseointegration remains a clinical concern and has been shown to lead to prosthetic failure. The purpose of this study was to test the hypothesis that implants with sufficient initial press-fit stability would be less likely to fail due to implant pull-out, as demonstrated by an increasing amount of energy required to remove the prosthesis from the canal. Methods: Ten cadaveric radii were implanted with five sizes (6-10 mm in 1-mm increments) of grit-blasted, cementless radial head stems. A customised slap hammer was used to measure the energy required to remove each stem. Stem-bone micromotion was also measured. Results: The suboptimally sized stem (Max - 1) (i.e. 1 mm undersized) required less energy (0.5 ± 0 J) to pull out than the optimally sized stem (Max) (1.7 ± 0.3 J) (p = 0.008). The optimally sized stem demonstrated greater initial stability (45 ± 7 μm) than the suboptimally sized stem (79 ± 12 μm) (p = 0.004). Conclusions: This investigation demonstrates the importance of obtaining adequate press-fit stability for the prevention of radial head stem pull-out failure. These data add to the relatively scant knowledge in the literature regarding radial head biomechanics. The energy required to remove a prosthetic radial head ingrowth stem decreases in conjunction with diameter. The use of an inadequately sized stem increases the stem's micromotion as well as the risk of prosthetic loosening due to pull-out.",
keywords = "Cementless stem failure, Radial head arthroplasty, Radial head implant",
author = "Dave Shukla and James Fitzsimmons and An, {Kai Nan} and Shawn O'Driscoll",
year = "2014",
month = "1",
doi = "10.1007/s00264-013-2074-3",
language = "English (US)",
volume = "38",
pages = "89--93",
journal = "International Orthopaedics",
issn = "0341-2695",
publisher = "Springer Verlag",
number = "1",

}

TY - JOUR

T1 - Prosthetic radial head stem pull-out as a mode of failure

T2 - A biomechanical study

AU - Shukla, Dave

AU - Fitzsimmons, James

AU - An, Kai Nan

AU - O'Driscoll, Shawn

PY - 2014/1

Y1 - 2014/1

N2 - Purpose: Press-fit cementless radial head implant longevity relies on adequate bone ingrowth. Failed implant osseointegration remains a clinical concern and has been shown to lead to prosthetic failure. The purpose of this study was to test the hypothesis that implants with sufficient initial press-fit stability would be less likely to fail due to implant pull-out, as demonstrated by an increasing amount of energy required to remove the prosthesis from the canal. Methods: Ten cadaveric radii were implanted with five sizes (6-10 mm in 1-mm increments) of grit-blasted, cementless radial head stems. A customised slap hammer was used to measure the energy required to remove each stem. Stem-bone micromotion was also measured. Results: The suboptimally sized stem (Max - 1) (i.e. 1 mm undersized) required less energy (0.5 ± 0 J) to pull out than the optimally sized stem (Max) (1.7 ± 0.3 J) (p = 0.008). The optimally sized stem demonstrated greater initial stability (45 ± 7 μm) than the suboptimally sized stem (79 ± 12 μm) (p = 0.004). Conclusions: This investigation demonstrates the importance of obtaining adequate press-fit stability for the prevention of radial head stem pull-out failure. These data add to the relatively scant knowledge in the literature regarding radial head biomechanics. The energy required to remove a prosthetic radial head ingrowth stem decreases in conjunction with diameter. The use of an inadequately sized stem increases the stem's micromotion as well as the risk of prosthetic loosening due to pull-out.

AB - Purpose: Press-fit cementless radial head implant longevity relies on adequate bone ingrowth. Failed implant osseointegration remains a clinical concern and has been shown to lead to prosthetic failure. The purpose of this study was to test the hypothesis that implants with sufficient initial press-fit stability would be less likely to fail due to implant pull-out, as demonstrated by an increasing amount of energy required to remove the prosthesis from the canal. Methods: Ten cadaveric radii were implanted with five sizes (6-10 mm in 1-mm increments) of grit-blasted, cementless radial head stems. A customised slap hammer was used to measure the energy required to remove each stem. Stem-bone micromotion was also measured. Results: The suboptimally sized stem (Max - 1) (i.e. 1 mm undersized) required less energy (0.5 ± 0 J) to pull out than the optimally sized stem (Max) (1.7 ± 0.3 J) (p = 0.008). The optimally sized stem demonstrated greater initial stability (45 ± 7 μm) than the suboptimally sized stem (79 ± 12 μm) (p = 0.004). Conclusions: This investigation demonstrates the importance of obtaining adequate press-fit stability for the prevention of radial head stem pull-out failure. These data add to the relatively scant knowledge in the literature regarding radial head biomechanics. The energy required to remove a prosthetic radial head ingrowth stem decreases in conjunction with diameter. The use of an inadequately sized stem increases the stem's micromotion as well as the risk of prosthetic loosening due to pull-out.

KW - Cementless stem failure

KW - Radial head arthroplasty

KW - Radial head implant

UR - http://www.scopus.com/inward/record.url?scp=84895056870&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84895056870&partnerID=8YFLogxK

U2 - 10.1007/s00264-013-2074-3

DO - 10.1007/s00264-013-2074-3

M3 - Article

VL - 38

SP - 89

EP - 93

JO - International Orthopaedics

JF - International Orthopaedics

SN - 0341-2695

IS - 1

ER -