Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jul 6, 2022; 10(19): 6406-6416
Published online Jul 6, 2022. doi: 10.12998/wjcc.v10.i19.6406
Total knee arthroplasty in Ranawat II valgus deformity with enlarged femoral valgus cut angle: A new technique to achieve balanced gap
Shuai-Jie Lv, Xiao-Jian Wang, Jie-Feng Huang, Qiang Mao, Bang-Jian He, Pei-Jian Tong
Shuai-Jie Lv, Jie-Feng Huang, Qiang Mao, Bang-Jian He, Pei-Jian Tong, Department of Orthopedics and Traumatology, The First Affiliated Hospital and First Clinical College of Zhejiang Chinese Medical University, Hangzhou 310006, Zhejiang Province, China
Xiao-Jian Wang, The First Clinical Medical School, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang Province, China
Author contributions: Tong PJ and Lv SJ conceived and coordinated the study, designed, performed, and analyzed the experiments, and wrote the paper; He BJ and Lv SJ carried out the data collection and analysis, and revised the paper; all authors reviewed the results and approved the final version of the manuscript.
Supported by the Project of Excellent Young Talents of Traditional Chinese Medicine of Zhejiang Province, No. 2019ZQ016; and the Zhejiang Medical and Health Science and Technology Young Talents Program, No. 2019RC059.
Institutional review board statement: This study was approved by the hospital ethics and review committee of the First Affiliated Hospital of Zhejiang Chinese Medical University (No. 2019-K-207-01).
Informed consent statement: All patients provided informed consent for this study.
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Pei-Jian Tong, MD, Chief Doctor, Department of Orthopedics and Traumatology, The First Affiliated Hospital and First Clinical College of Zhejiang Chinese Medical University, No. 54 Youdian Road, Shangcheng District, Hangzhou 310006, Zhejiang Province, China. 351653161@qq.com
Received: July 23, 2021
Peer-review started: July 23, 2021
First decision: September 2, 2021
Revised: September 10, 2021
Accepted: April 21, 2022
Article in press: April 21, 2022
Published online: July 6, 2022
Processing time: 335 Days and 23.9 Hours
Abstract
BACKGROUND

Nearly 10% of patients undergoing primary total knee arthroplasty (TKA) have valgus deformity (VD) of the knee. For severe VD of the knee, a more lateral structural release is needed to achieve balance between medial and lateral space and neutral femorotibial mechanical axis (FTMA), which is challenging and technical.

AIM

To introduce a new surgical technique of resection, soft tissue release, and FTMA for Ranawat type-II VD with a 5-year follow-up.

METHODS

A retrospective study was conducted on patients who underwent TKA from December 2011 to December 2014. Hip-knee-ankle (HKA), range of motion (ROM), Oxford knee score (OKS), and knee society score (KSS) were used to assess the joint activity of patients in the new theory TKA group (NT-TKA) and were compared with those of the conventional TKA group (C-TKA).

RESULTS

A total of 103 people (103 knees) were included in this study, including 42 patients with an average follow-up period of 83 mo in the C-TKA group and 61 patients with an average follow-up period of 76 mo in the NT-TKA group. Six patients had constrained prosthesis, one had common peroneal nerve injury, and two had joint instability in the C-TKA group, but none of these occurred in the NT-TKA group. There were significant statistical differences in constrained prosthesis usage and complications between the groups (P = 0.002 and P = 0.034, respectively). The KSS at 1 mo post-operation for the C-TKA and NT-TKA groups were 11.2 ± 3.8 and 13.3 ± 2.9, respectively, with a significant difference (P = 0.007). However, the data of HKA, ROM, OKS KSS, and prosthesis survival rate were insignificant (P > 0.05) in both the preoperative and follow-up periods.

CONCLUSION

Adopting 5°-7° valgus cut angle for VD and sacrificing 2° neutral FTMA for severe VD which cannot be completely corrected during TKA can reduce the need for soft tissue release, maintain early joint stability, reduce the use of constrained prostheses, and minimize postoperative complications.

Keywords: Valgus, knee; Arthroplasty; Osteotomy; Mechanical axis; Bone and soft-tissue balance

Core Tip: This study aimed to provide a new theory of surgical resection, soft tissue release, and femorotibial mechanical axis (FTMA) for Ranawat type-II valgus deformity (VD) of the knee using bone and soft tissue co-balance theory to reduce the complexity of the surgery and to improve postoperative outcomes. Bone and soft tissue balance is equally important in a total knee arthroplasty procedure. Adopting 5°-7° valgus cut angle for VD and sacrificing 2° neutral FTMA for severe VD during surgery can reduce the need for soft tissue release, maintain joint stability, and abrogate the use of constrained prostheses while minimizing postoperative complications.