Component positioning of the first 300 mobile bearing unicompartmental knee arthroplasties

Landon H Morikawa; Dylan B Combs; Samantha N Andrews; Kristin Mathews; Cass K Nakasone

doi:10.1016/j.jor.2021.08.002

Component positioning of the first 300 mobile bearing unicompartmental knee arthroplasties

J Orthop. 2021 Aug 10:27:9-12. doi: 10.1016/j.jor.2021.08.002. eCollection 2021 Sep-Oct.

Authors

Landon H Morikawa^{1

2}, Dylan B Combs¹, Samantha N Andrews^{2

3}, Kristin Mathews², Cass K Nakasone^{2

3}

Affiliations

¹ John A Burns School of Medicine, 651 Ilalo Street, Honolulu, HI, 96813, USA.
² Straub Medical Center, Bone and Joint Center, 888 South King Street, Honolulu, HI, USA.
³ University of Hawai'i, John A Burns School of Medicine, Department of Surgery, 1356 Lusitana Street, Honolulu, HI, 96813, USA.

Abstract

The Oxford® Partial Knee has excellent long-term survivorship but high surgical times indicate a learn curve. This retrospective review included a radiographic evaluation of component placement of the initial 300 procedures following conversion from fixed bearing implant use. The anteroposterior and sagittal femoral angles were considered inaccurate in 1.7% and 3.9% of cases, respectively. The anteroposterior and sagittal tibial angles were considered inaccurate in 18.7% and 6.0% of cases, respectively. Overall, a learning curve appears to be present regarding the anteroposterior tibial component angle, with the greatest percentage of inaccuracies occurring within the initial 20 cases.

Keywords: Alignment; Learning curve; Mobile bearing.