{"title":"A new parameter in the era of robotic total knee arthroplasty: Coronal alignment at 90° of flexion impacts clinical outcomes.","authors":"Luca Andriollo, Christos Koutserimpas, Pietro Gregori, Elvire Servien, Cécile Batailler, Sébastien Lustig","doi":"10.1002/ksa.12648","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>Alignment strategies in total knee arthroplasty (TKA) have predominantly emphasized coronal alignment in extension, with minimal focus on dynamic alignment during flexion. This study aims to identify the predictors of the intraoperative robotic hip-knee-ankle angle at 90° of flexion (rHKA-90F) and assess its clinical significance in postoperative outcomes, proposing that rHKA-90F may be a critical factor in enhancing functional results in TKA.</p><p><strong>Methods: </strong>A retrospective analysis was conducted on 180 patients with varus deformity undergoing robotic-assisted TKA under the functional alignment principles. Clinical outcomes were assessed using the Knee Society Score (KSS), Forgotten Joint Score (FJS-12) and Kujala Anterior Knee Pain Scale (AKPS) score. Predictors for final rHKA-90F and its intraoperative changes were identified using multiple linear regression models. Initial and intraoperative robotic measurements were also analyzed.</p><p><strong>Results: </strong>Significant predictors of the final rHKA-90F included femoral rotation, tibial varus/valgus alignment, initial rHKA-90F and the final robotic axis in extensions. Patients with a final rHKA-90F ≥ 5° of varus demonstrated superior KSS function and KSS knee compared to those with a final rHKA-90F between 0° and 4° of varus. Furthermore, patients with intraoperative changes of rHKA-90F > 2.5° neutralization (varus reduction or with a valgus value) achieved better FJS and AKPS score.</p><p><strong>Conclusions: </strong>This study highlights the clinical relevance of rHKA-90F as an intraoperative tool in robotic knee arthroplasty, emphasizing the need to balance the correction of varus deformity with the maintenance of slight varus alignment in flexion. Personalized alignment strategies tailored to patient-specific anatomy and kinematics are crucial to optimizing outcomes. There is still a need for future research on the long-term effects of dynamic alignment.</p><p><strong>Level of evidence: </strong>Level III.</p>","PeriodicalId":17880,"journal":{"name":"Knee Surgery, Sports Traumatology, Arthroscopy","volume":" ","pages":""},"PeriodicalIF":3.3000,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Knee Surgery, Sports Traumatology, Arthroscopy","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1002/ksa.12648","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ORTHOPEDICS","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: Alignment strategies in total knee arthroplasty (TKA) have predominantly emphasized coronal alignment in extension, with minimal focus on dynamic alignment during flexion. This study aims to identify the predictors of the intraoperative robotic hip-knee-ankle angle at 90° of flexion (rHKA-90F) and assess its clinical significance in postoperative outcomes, proposing that rHKA-90F may be a critical factor in enhancing functional results in TKA.
Methods: A retrospective analysis was conducted on 180 patients with varus deformity undergoing robotic-assisted TKA under the functional alignment principles. Clinical outcomes were assessed using the Knee Society Score (KSS), Forgotten Joint Score (FJS-12) and Kujala Anterior Knee Pain Scale (AKPS) score. Predictors for final rHKA-90F and its intraoperative changes were identified using multiple linear regression models. Initial and intraoperative robotic measurements were also analyzed.
Results: Significant predictors of the final rHKA-90F included femoral rotation, tibial varus/valgus alignment, initial rHKA-90F and the final robotic axis in extensions. Patients with a final rHKA-90F ≥ 5° of varus demonstrated superior KSS function and KSS knee compared to those with a final rHKA-90F between 0° and 4° of varus. Furthermore, patients with intraoperative changes of rHKA-90F > 2.5° neutralization (varus reduction or with a valgus value) achieved better FJS and AKPS score.
Conclusions: This study highlights the clinical relevance of rHKA-90F as an intraoperative tool in robotic knee arthroplasty, emphasizing the need to balance the correction of varus deformity with the maintenance of slight varus alignment in flexion. Personalized alignment strategies tailored to patient-specific anatomy and kinematics are crucial to optimizing outcomes. There is still a need for future research on the long-term effects of dynamic alignment.
期刊介绍:
Few other areas of orthopedic surgery and traumatology have undergone such a dramatic evolution in the last 10 years as knee surgery, arthroscopy and sports traumatology. Ranked among the top 33% of journals in both Orthopedics and Sports Sciences, the goal of this European journal is to publish papers about innovative knee surgery, sports trauma surgery and arthroscopy. Each issue features a series of peer-reviewed articles that deal with diagnosis and management and with basic research. Each issue also contains at least one review article about an important clinical problem. Case presentations or short notes about technical innovations are also accepted for publication.
The articles cover all aspects of knee surgery and all types of sports trauma; in addition, epidemiology, diagnosis, treatment and prevention, and all types of arthroscopy (not only the knee but also the shoulder, elbow, wrist, hip, ankle, etc.) are addressed. Articles on new diagnostic techniques such as MRI and ultrasound and high-quality articles about the biomechanics of joints, muscles and tendons are included. Although this is largely a clinical journal, it is also open to basic research with clinical relevance.
Because the journal is supported by a distinguished European Editorial Board, assisted by an international Advisory Board, you can be assured that the journal maintains the highest standards.
Official Clinical Journal of the European Society of Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA).