2023 ISAKOS Biennial Congress ePoster
The Impact of Preoperative Coronal Alignment on the Outcomes of Bicruciate-Retaining Total Knee Arthroplasty
Maroun Rizkallah, MD, MSc CANADA
Paul-Andre Synnott, MD, Montreal, QC CANADA
Dominic cadoret, Medical student, Montreal, Quebec CANADA
Fidaa Al-Shakfa, MSc, MBA, Montréal, Québec CANADA
Frédéric Lavoie, MD, MSc, FRCSC, Montreal, Québec CANADA
Centre Hospitalier de l'Universite de Montreal, Montreal, Quebec, CANADA
FDA Status Cleared
Summary
Pre-operative severe varus coronal malalignment does not impact the outcomes of a bicruciate retaining total knee arthroplasty; whereas pre-operative valgus malalignment reduces the prosthesis’ 5 years survivorship.
ePosters will be available shortly before Congress
Abstract
Introduction
Bicruciate-retaining (BCR) total knee arthroplasty (TKA) has the potential to more naturally mimic healthy knee biomechanics and improve patient-reported outcome measures. However, inconsistent findings related to BCR TKA survivorship and associated radiological outcomes limited its popularity. Therefore, little is known about the influence of pre-operative coronal alignment on the outcomes related to BCR TKA.
Methods
This is a retrospective monocentric study performed on prospectively collected data. One hundred and seventy-two knees in 163 patients with functional impairment and radiologically demonstrated osteoarthritis who underwent BCR TKA between 2009 and 2017 with a minimum two years of follow-up were included. Knees were divided into four groups according to their preoperative coronal alignment: severe varus n=31 (Hip-Knee-Ankle (HKA) angle = 170°), moderate varus n=76 (170° < HKA = 175°), mild varus n=43 (175° < HKA = 180°), and valgus n=22 (HKA > 180°). Periodic clinical and radiological follow-ups were performed. The primary outcome was BCR TKA survivorship at 5 years of follow-up whereas clinical (range of motion) and functional findings (Knee injury and Osteoarthritis Outcome Score (KOSS) and the Knee Society score (KSS)) were evaluated as secondary outcomes. The four groups were compared for these outcomes.
Results
At 5 years of follow-up, BCR TKA survivorship was 100% in the severe varus group, 94.7% (95% CI: 89.6%-99.8%) in the moderate varus group, 83.1% (95% CI: 70.4%-95.8%) in the mild varus group, and 70.0% (95% CI: 49.4%-90.6%) in the valgus group; (p = 0.016). At the latest follow-up, maximum knee flexion angle ranged between 116° and 123° and was comparable between the 4 groups (p=0.257), as well as the rate of knees with a flexion contracture (from 3.9% to 7%, p=0.634) and the rate of those with hyperextension (from 2.3% to 3.2%, p=0.822). The KSS scores ranged between 79.9 and 86.8 (p=0.904) at the latest follow-up and were comparable between the 4 groups, as well as all KOOS components [(pain ranged between 67.1 and 70.8 (p=0.955), symptoms ranged between 66.4 and 76.8 (p=0.544), daily activities ranged between 62.4 and 75.7 (p=0.535), sporting activities ranged between 34.4 and 50.0 (p=0.725), quality of life ranged between 54.4 and 63.9 (p=0.825)].
Discussion
Despite significantly reduced BCR TKA survivorship in the valgus group, good range of motion and functional outcomes were reached in all 4 groups in this study. Severe varus pre-operative coronal alignment did not impact the post-operative outcomes and should not be considered as a contra-indication for BCR TKA. Poor survival outcomes observed in the valgus group are likely to be multifactorial (use of the lateral parapatellar approach, implant alignment); therefore, BCR TKA in valgus knees should be approached with caution.