Peri-implant bone strains and micro-motion following in vivo service: a postmortem retrieval study of 22 tibial components from total knee replacements.

ABSTRACT: Biological adaptation following placement of a total knee replacements (TKRs) affects peri-implant bone mineral density (BMD) and implant fixation. We quantified the proximal tibial bone strain and implant-bone micro-motion for functioning postmortem retrieved TKRs and assessed the strain/micro-motion relationships with chronological (donor age and time in service) and patient (body weight and BMD) factors. Twenty-two tibial constructs were functionally loaded to one body weight (60% medial/40% lateral), and the bone strains and tray/bone micro-motions were measured using a digital image correlation system. Donors with more time in service had higher bone strains (p?=?0.044), but there was not a significant (p?=?0.333) contribution from donor age. Donors with lower peri-implant BMD (p?=?0.0039) and higher body weight (p?=?0.0286) had higher bone strains. Long term implants (>11 years) had proximal bone strains 900?µ? that were almost twice as high as short term (<5 years) implants 570?µ?. Micro-motion was greater for younger donors (p?=?0.0161) and longer time in service (p?=?0.0008). Increased bone strain with long term in vivo service could contribute to loosening of TKRs by failure of the tibial peri-implant bone.

SUBMITTER: Mann KA 

PROVIDER: S-EPMC4100998 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature