Clinical Outcomes of Patients with Valgus Deformity Undergoing Minimally Invasive Total Knee Arthroplasty Through the Medial Approach
Kosuke Hamahashi1, *, Genya Mitani2, Tomonori Takagaki1, 3, Kenji Serigano1, Joji Mochida1, 3, Masato Sato1, Masahiko Watanabe1
Identifiers and Pagination:Year: 2016
First Page: 717
Last Page: 724
Publisher ID: TOORTHJ-10-717
Article History:Received Date: 06/10/2016
Revision Received Date: 18/11/2016
Acceptance Date: 23/11/2016
Electronic publication date: 21/12/2016
Collection year: 2016
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The purpose of this study was to compare the clinical outcomes between patients with a valgus or varus deformity undergoing minimally invasive total knee arthroplasty through the medial approach.
The patients were classified into 2 groups according to the preoperative femorotibial angle measured on an anteroposterior long leg roentgenogram. The valgus group comprised of 26 knees in 21 patients with a femorotibial angle <170° (163.5 ± 5.7), and the varus group comprised of 24 knees in 21 patients with a femorotibial angle >190° (195.9 ± 5.5). The following background variables were compared between the groups: age at the time of the operation, sex, causative disease, preoperative femoral mechanical–anatomical angle, and postoperative knee range of motion, Knee Society score, femorotibial angle, and implant position.
There were significant differences between the valgus and varus groups in the age (68.0 ± 6.9 vs 75.8 ± 6.2 years), percentage of males (23.8% vs 0%), percentage with rheumatoid arthritis (61.9% vs 4.8%), and preoperative femoral mechanical–anatomical angle (6.2 ± 1.0° vs 7.4 ± 2.1°). Clinical outcome variables of postoperative femorotibial angle (173.1 ± 3.9° vs 175.2 ± 1.6°) and α angle (96.6 ± 3.1° vs 95.0 ± 1.9°) also differed.
It was assumed that over-valgus resection of the femur is a contributory factor to residual valgus alignment. However, knee range of motion and Knee Society score did not differ between the groups. We suggest that minimally invasive total knee arthroplasty through the medial approach is one of the treatment options for patients with valgus deformity.