title: Loss of tibial bone density in patients with rotating- or fixed-platform TKA.
abstract: Little is known about tibial bone remodeling with TKA and its clinical relevance. We performed a randomized clinical trial to compare tibial bone density changes in cemented components with different bearing designs. Bone density changes were assessed using quantitative computed tomography (qCT)-assisted osteodensitometry. Twenty-eight rotating-platform and 26 fixed-platform cemented TKAs were included. The nonoperated contralateral side was used as a control. CT scans were performed postoperatively and 1 year and 2 years after the index operation. Cancellous bone density loss (up to 12.6% at 2 years) was observed in all proximal tibial regions in both cohorts. In contrast, we found lower cortical bone density loss (up to 3.6% at 2 years). We found no differences in bone loss between fixed- and rotating-platform implants. The decrease of cancellous bone density after TKA suggests stress transfer to the cortical bone.
authors.affiliation: Auckland Bioengineering Institute, University of Auckland, Level 6, 70 Symonds Street, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand. jacob.munro@auckland.ac.nz
authors.forename: Jacob T
authors.initials: JT
authors.lastname: Munro
authors.forename: Salil
authors.initials: S
authors.lastname: Pandit
authors.forename: Cameron G
authors.initials: CG
authors.lastname: Walker
authors.forename: Mark
authors.initials: M
authors.lastname: Clatworthy
authors.forename: Rocco P
authors.initials: RP
authors.lastname: Pitto