Prospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Sep 18, 2018; 9(9): 149-155
Published online Sep 18, 2018. doi: 10.5312/wjo.v9.i9.149
Outcomes of mobile bearing unicompartmental knee arthroplasty in medial osteoarthritis knee with and without preoperative genu recurvatum
Boonchana Pongcharoen, Krit Boontanapibul
Boonchana Pongcharoen, Orthopedics, Faculty of medicine, Thammasat University, Klongluang 12120, Thailand
Krit Boontanapibul, Orthopedics, Thammasat University, Klongluang 12120, Thailand
Author contributions: The authors contributed equally to this study, in all aspects of its design, performance, interpretation and write-up.
Institutional review board statement: The study was reviewed and approved for publication by the Institutional Reviewer of Thammasat University.
Clinical trial registration statement: The clinical trial is registered with ClinicalTrials.gov, using identifier NCT02854189. Details can be found at https://clinicaltrials.gov/ct2/show/NCT02854189?term= NCT02854189&rank=1.
Informed consent statement: All study participants or their legal guardian provided informed written consent prior to study enrolment for the collection and publication of their anonymized personal and medical data.
Conflict-of-interest statement: The authors have no conflict of interest related to the manuscript.
CONSORT 2010 statement: The authors have read the CONSORT 2010 Statement, and the manuscript was prepared and revised according to the CONSORT 2010 Statement.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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/
Correspondence to: Boonchana Pongcharoen, MD, Associate Professor, Orthopedics, Faculty of Medicine, Thammasat University, 95 Paholyothin Road, Klongluang 12120, Thailand. poboonch@tu.ac.th
Telephone: +66-89-7472423
Received: March 2, 2018
Peer-review started: March 2, 2018
First decision: March 18, 2018
Revised: July 3, 2018
Accepted: July 14, 2018
Article in press: July 15, 2018
Published online: September 18, 2018
Abstract
AIM

To compare clinical outcomes of patients with and without preoperative genu recurvatum (GR) following mobile bearing unicompartmental knee arthroplasty (UKA).

METHODS

We prospectively followed 176 patients for at least 24 mo who had been treated by unilateral, minimally invasive, Oxford UKA. Patients with medial osteoarthritis (OA) knee and preoperative GR (Group I) accounted for 18% (n = 32) and patients without preoperative GR (Group II) accounted for the remaining 82% (n = 144). Knee score, pain scores, and functional scores were assessed for each patient and compared between the two groups. The incidence of postoperative GR and the postoperative hyperextension angles also were recorded and analyzed.

RESULTS

The pain score, knee score and functional score were not significantly different between the two groups. Similarly, the incidence of postoperative GR and the measured hyperextension angles were not significantly different between the two groups. The incidence of postoperative GR was 1/32 (3.12%) in Group I and 1/144 (0.69%) in Group II (P = 0.34). The mean postoperative hyperextension angles were 2.40° ± 2.19° (range: 1°-7°) for Group I and 1.57° ± 3.51° (range: 1°-6°) for Group II (P = 0.65).

CONCLUSION

Medial OA of the knee and concomitant GR is not a contraindication for the mobile bearing UKA.

Keywords: Unicompartmental knee, Genu recurvatum, Osteoarthritis, Hyperextension knee, Knee arthroplasty, Oxford knee

Core tip: There is no previous study addressing the results of mobile bearing unicompartmental knee arthroplasty (UKA) in medial osteoarthritis (OA) knees with preexisting genu recurvatum (GR). This study determined the clinical outcomes and incidence of postoperative GR of medial OA knees with and without preexisting GR following mobile bearing UKA. Clinical outcomes, postoperative GR and hyperextension angle were evaluated at minimal 2 years of follow-up. Medial OA knees with and without GR showed no difference in clinical outcomes, incidence of postoperative GR or hyperextension angle. Therefore, medial OA knee with preoperative GR is not a contraindication for mobile bearing UKA.