Piero Agostinone1, Stefano Di Paolo2, Alberto Grassi1, Erika Pinelli3, Marco Bontempi4, Laura Bragonzoni3, Stefano Zaffagnini1,5. 1. Clinica Ortopedica e Traumatologica II, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy. 2. Dipartimento di Scienze Biomediche e Neuromotorie DIBINEM, Università di Bologna, Via Giulio Cesare Pupilli, 1, 40136, Bologna, BO, Italy. stefano.dipaolo@ior.it. 3. Dipartimento di Scienze per la Qualità della Vita QuVi, Università di Bologna, Bologna, Italy. 4. Laboratorio di Biomeccanica ed Innovazione Tecnologica, IRCSS Istituto Ortopedico Rizzoli, Bologna, Italy. 5. Dipartimento di Scienze Biomediche e Neuromotorie DIBINEM, Università di Bologna, Via Giulio Cesare Pupilli, 1, 40136, Bologna, BO, Italy.
Abstract
PURPOSE: The role of the anterior cruciate ligament (ACL) in knee biomechanics in vivo and under weight-bearing is still unclear. The purpose of this study was to compare the tibiofemoral kinematics of ACL-deficient knees to healthy contralateral ones during the execution of weight-bearing activities. METHODS: Eight patients with isolated ACL injury and healthy contralateral knees were included in the study. Patients were asked to perform a single step forward and a single leg squat first with the injured knee and then with the contralateral one. Knee motion was determined using a validated model-based tracking process that matched subject-specific MRI bone models to dynamic biplane radiographic images, under the principles of Roentgen stereophotogrammetric analysis (RSA). Data processing was performed in a specific software developed in Matlab. RESULTS: Statistically significant differences (p < 0.05) were found for single leg squat along the frontal plane: ACL-deficient knees showed a more varus angle, especially at the highest knee flexion angles (40°-50° on average), compared to the contralateral knees. Furthermore, ACL-deficient knees showed tibial medialization along the entire task, while contralateral knees were always laterally aligned. This difference became statistically relevant (p < 0.05) for knee flexion angles included between 0° and about 30°. CONCLUSION: ACL-deficient knees showed an abnormal tibial medialization and increased varus angle during single leg squat when compared to the contralateral knees. These biomechanical anomalies could cause a different force distribution on tibial plateau, explaining the higher risk of early osteoarthritis in ACL deficiency. The clinical relevance of this study is that also safe activities used in ACL rehabilitation protocols are significantly altered in ACL deficiency. LEVEL OF EVIDENCE: III.
PURPOSE: The role of the anterior cruciate ligament (ACL) in knee biomechanics in vivo and under weight-bearing is still unclear. The purpose of this study was to compare the tibiofemoral kinematics of ACL-deficient knees to healthy contralateral ones during the execution of weight-bearing activities. METHODS: Eight patients with isolated ACL injury and healthy contralateral knees were included in the study. Patients were asked to perform a single step forward and a single leg squat first with the injured knee and then with the contralateral one. Knee motion was determined using a validated model-based tracking process that matched subject-specific MRI bone models to dynamic biplane radiographic images, under the principles of Roentgen stereophotogrammetric analysis (RSA). Data processing was performed in a specific software developed in Matlab. RESULTS: Statistically significant differences (p < 0.05) were found for single leg squat along the frontal plane: ACL-deficient knees showed a more varus angle, especially at the highest knee flexion angles (40°-50° on average), compared to the contralateral knees. Furthermore, ACL-deficient knees showed tibial medialization along the entire task, while contralateral knees were always laterally aligned. This difference became statistically relevant (p < 0.05) for knee flexion angles included between 0° and about 30°. CONCLUSION: ACL-deficient knees showed an abnormal tibial medialization and increased varus angle during single leg squat when compared to the contralateral knees. These biomechanical anomalies could cause a different force distribution on tibial plateau, explaining the higher risk of early osteoarthritis in ACL deficiency. The clinical relevance of this study is that also safe activities used in ACL rehabilitation protocols are significantly altered in ACL deficiency. LEVEL OF EVIDENCE: III.
Entities:
Keywords:
Anterior cruciate ligament; Biplane radiography; In vivo; Knee kinematics; Single leg squat
Authors: Baris B Koc; Edwin J P Jansen; Paul van Dijk; Pieter J Emans; Arno Lataster Journal: Knee Surg Sports Traumatol Arthrosc Date: 2020-08-01 Impact factor: 4.342
Authors: Bob J Evers; Martijn H J Van Den Bosch; Arjen B Blom; Peter M van der Kraan; Sander Koëter; Rogier M Thurlings Journal: Front Med (Lausanne) Date: 2022-08-22
Authors: Stefano Di Paolo; Piero Agostinone; Alberto Grassi; Gian Andrea Lucidi; Erika Pinelli; Marco Bontempi; Gregorio Marchiori; Laura Bragonzoni; Stefano Zaffagnini Journal: Orthop J Sports Med Date: 2021-07-15