Background: Previous studies of knee kinematics after anterior cruciate ligament (ACL) reconstruction have generally employed low-effort tasks and typically not assessed changes in kinematics over time.
Hypotheses: (1) During single-legged hop landing, ACL-reconstructed limbs will have altered kinematics compared with contralateral (ACL-intact) limbs 5 months after surgery. (2) Kinematic differences between limbs will decrease over time because of changes in both ACL-reconstructed and ACL-intact limbs.
Study Design: Controlled laboratory study.
Methods: In vivo kinematics of ACL-reconstructed and contralateral ACL-intact knees were evaluated for 14 subjects during single-legged forward-hop landings at 5 and 12 months after surgery on the basis of dynamic stereo x-ray imaging. Differences between limbs and changes over time were assessed via repeated-measures analysis of variance.
Results: Five months after surgery, ACL-reconstructed knees landed significantly less flexed compared with contralateral ACL-intact knees (20.9° vs 28.4°, respectively; P < .05). The ACL-reconstructed knees were significantly more externally rotated (12.2° vs 6.5°; P < .05) and medially translated (3.8 vs 2.3 mm; P < .009) compared with ACL-intact knees. Anterior-posterior translation was similar between limbs. From 5 to 12 months, knee flexion at landing increased in ACL-reconstructed knees (mean change, +3.4°; P < .05) and decreased in contralateral knees (mean change, -3.3°; P < .05). External tibial rotation also significantly decreased in ACL-reconstructed knees (-2.2°; P < .05) and increased in contralateral knees (+1.1°; P = .117) over time. Medial tibial translation decreased slightly over time only in ACL-reconstructed knees (-0.3 mm).
Conclusion: Five months after ACL reconstruction, landing kinematics differed between ACL-reconstructed and contralateral ACL-intact knees during a dynamic high-loading activity. These differences decreased over time, owing to changes in both the ACL-reconstructed and contralateral ACL-intact limbs.
Clinical Relevance: This study identified kinematic changes over time in both the ACL-injured and contralateral ACL-intact knees after ACL reconstruction. These kinematic adaptations could have important implications for postoperative care, including evaluating the optimal timing of return to sports and the development of bilateral neuromuscular rehabilitation programs that may improve patient outcomes and reduce reinjuries in both the short and long terms.
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http://dx.doi.org/10.1177/0363546514549444 | DOI Listing |
Knee Surg Sports Traumatol Arthrosc
May 2024
Department of Orthopaedic Surgery, Myongji Hospital, Goyang, Republic of Korea.
Purpose: In this study, ultrasonography was used to measure medial meniscus (MM) extrusion under weight-bearing and nonweight-bearing conditions in both anterior cruciate ligament (ACL)-deficient and ACL-intact knee groups. This study aimed to determine the possible differences between these groups with an eventual impact on meniscal tears in ACL-deficient knees.
Methods: A total of 107 patients who underwent ACL reconstructive surgery between June 2022 and April 2023 were enroled.
J Orthop Res
April 2023
Department of Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Smaller anterior cruciate ligament (ACL) size in females has been hypothesized to be a key contributor to a higher incidence of ACL tears in that population, as a lower cross-sectional area (CSA) directly corresponds to a larger stress on the ligament for a given load. Prior studies have used a mid-length CSA measurement to quantify ACL size. In this study, we used magnetic resonance imaging to quantify the CSA along the entire length of the intact ACL.
View Article and Find Full Text PDFJ Biomech
February 2021
Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, United States; Department of Biomedical Engineering, Duke University, Durham, NC, United States; Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, United States. Electronic address:
Anterior cruciate ligament (ACL) rupture alters knee kinematics and contributes to premature development of osteoarthritis. However, there is limited data regarding the in vivo biomechanical response of tibiofemoral cartilage to activities of daily living (ADLs) in ACL-deficient knees. In this study, eight otherwise healthy participants with chronic unilateral ACL deficiency completed a stress test to assess the effect of 20 min of level treadmill walking at a speed of 2.
View Article and Find Full Text PDFOrthop J Sports Med
August 2017
Department of Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Background: Abnormal joint motion has been linked to joint arthrosis after anterior cruciate ligament (ACL) reconstruction. However, the relationships between the graft properties (ie, structural and anatomic) and extent of posttraumatic osteoarthritis are not well defined.
Hypotheses: (1) The structural (tensile) and anatomic (area and alignment) properties of the reconstructed graft or repaired ACL correlate with the total cartilage lesion area 1 year after ACL surgery, and (2) side-to-side differences in anterior-posterior (AP) knee laxity correlate with the total cartilage lesion area 1 year postoperatively.
J Biomech
October 2016
Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA; School of Engineering, Brown University, Providence, RI, USA. Electronic address:
Trabecular bone volume fraction assessments are likely sensitive to the analysis method and selection of the region of interest. Currently, there are several methods for selecting the region of interest to analyze trabecular bone in animal models of post-traumatic osteoarthritis. The objective of this study was to compare three published methods for determining the trabecular bone volume fraction of the medial tibial epiphyses in ACL transected and contralateral ACL intact knees.
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