BACKGROUND: Changes in knee kinematics after anterior cruciate ligament (ACL) injury may alter loading of the cartilage and thus affect its homeostasis, potentially leading to the development of posttraumatic osteoarthritis. However, there are limited in vivo data to characterize local changes in cartilage thickness and strain in response to dynamic activity among patients with ACL deficiency. PURPOSE/HYPOTHESIS: The purpose was to compare in vivo tibiofemoral cartilage thickness and cartilage strain resulting from dynamic activity between ACL-deficient and intact contralateral knees. It was hypothesized that ACL-deficient knees would show localized reductions in cartilage thickness and elevated cartilage strains. STUDY DESIGN: Controlled laboratory study. METHODS: Magnetic resonance images were obtained before and after single-legged hopping on injured and uninjured knees among 8 patients with unilateral ACL rupture. Three-dimensional models of the bones and articular surfaces were created from the pre- and postactivity scans. The pre- and postactivity models were registered to each other, and cartilage strain (defined as the normalized difference in cartilage thickness pre- and postactivity) was calculated in regions across the tibial plateau, femoral condyles, and femoral cartilage adjacent to the medial intercondylar notch. These measurements were compared between ACL-deficient and intact knees. Differences in cartilage thickness and strain between knees were tested with multiple analysis of variance models with alpha set at P < .05. RESULTS: Compressive strain in the intercondylar notch was elevated in the ACL-deficient knee relative to the uninjured knee. Furthermore, cartilage in the intercondylar notch and adjacent medial tibia was significantly thinner before activity in the ACL-deficient knee versus the intact knee. In these 2 regions, thinning was significantly influenced by time since injury, with patients with more chronic ACL deficiency (>1 year since injury) experiencing greater thinning. CONCLUSION: Among patients with ACL deficiency, the medial femoral condyle adjacent to the intercondylar notch in the ACL-deficient knee exhibited elevated cartilage strain and loss of cartilage thickness, particularly with longer time from injury. It is hypothesized that these changes may be related to posttraumatic osteoarthritis development. CLINICAL RELEVANCE: This study suggests that altered mechanical loading is related to localized cartilage thinning after ACL injury.
BACKGROUND: Changes in knee kinematics after anterior cruciate ligament (ACL) injury may alter loading of the cartilage and thus affect its homeostasis, potentially leading to the development of posttraumatic osteoarthritis. However, there are limited in vivo data to characterize local changes in cartilage thickness and strain in response to dynamic activity among patients with ACL deficiency. PURPOSE/HYPOTHESIS: The purpose was to compare in vivo tibiofemoral cartilage thickness and cartilage strain resulting from dynamic activity between ACL-deficient and intact contralateral knees. It was hypothesized that ACL-deficient knees would show localized reductions in cartilage thickness and elevated cartilage strains. STUDY DESIGN: Controlled laboratory study. METHODS: Magnetic resonance images were obtained before and after single-legged hopping on injured and uninjured knees among 8 patients with unilateral ACL rupture. Three-dimensional models of the bones and articular surfaces were created from the pre- and postactivity scans. The pre- and postactivity models were registered to each other, and cartilage strain (defined as the normalized difference in cartilage thickness pre- and postactivity) was calculated in regions across the tibial plateau, femoral condyles, and femoral cartilage adjacent to the medial intercondylar notch. These measurements were compared between ACL-deficient and intact knees. Differences in cartilage thickness and strain between knees were tested with multiple analysis of variance models with alpha set at P < .05. RESULTS: Compressive strain in the intercondylar notch was elevated in the ACL-deficient knee relative to the uninjured knee. Furthermore, cartilage in the intercondylar notch and adjacent medial tibia was significantly thinner before activity in the ACL-deficient knee versus the intact knee. In these 2 regions, thinning was significantly influenced by time since injury, with patients with more chronic ACL deficiency (>1 year since injury) experiencing greater thinning. CONCLUSION: Among patients with ACL deficiency, the medial femoral condyle adjacent to the intercondylar notch in the ACL-deficient knee exhibited elevated cartilage strain and loss of cartilage thickness, particularly with longer time from injury. It is hypothesized that these changes may be related to posttraumatic osteoarthritis development. CLINICAL RELEVANCE: This study suggests that altered mechanical loading is related to localized cartilage thinning after ACL injury.
Authors: Musa Zaid; Drew Lansdown; Favian Su; Valentina Pedoia; Lauren Tufts; Sarah Rizzo; Richard B Souza; Xiaojuan Li; C Benjamin Ma Journal: J Orthop Res Date: 2015-05-21 Impact factor: 3.494
Authors: Michal Kozánek; Ali Hosseini; Samuel K Van de Velde; Mohamed E Moussa; Jing Sheng Li; Thomas J Gill; Guoan Li Journal: Clin Biomech (Bristol, Avon) Date: 2011-06-08 Impact factor: 2.063
Authors: F Eckstein; B Lemberger; C Gratzke; M Hudelmaier; C Glaser; K-H Englmeier; M Reiser Journal: Ann Rheum Dis Date: 2005-02 Impact factor: 19.103
Authors: Bruce D Beynnon; Niccolo Fiorentino; Mack Gardner-Morse; Timothy W Tourville; James R Slauterbeck; Daniel R Sturnick; Erin C Argentieri; Carl W Imhauser Journal: J Orthop Res Date: 2019-11-19 Impact factor: 3.494
Authors: Zoë A Englander; Edward L Baldwin; Wyatt A R Smith; William E Garrett; Charles E Spritzer; Louis E DeFrate Journal: Am J Sports Med Date: 2019-10-08 Impact factor: 6.202
Authors: Bryan S Crook; Amber T Collins; Nimit K Lad; Charles E Spritzer; Jocelyn R Wittstein; Louis E DeFrate Journal: J Biomech Date: 2020-12-28 Impact factor: 2.712
Authors: Chinmay S Paranjape; Hattie C Cutcliffe; Steven C Grambow; Gangadhar M Utturkar; Amber T Collins; William E Garrett; Charles E Spritzer; Louis E DeFrate Journal: Sci Rep Date: 2019-02-19 Impact factor: 4.379
Authors: Robert J Nims; Lara Pferdehirt; Noelani B Ho; Alireza Savadipour; Jeremiah Lorentz; Sima Sohi; Jordan Kassab; Alison K Ross; Christopher J O'Conor; Wolfgang B Liedtke; Bo Zhang; Amy L McNulty; Farshid Guilak Journal: Sci Adv Date: 2021-01-27 Impact factor: 14.136