Biomechanical Alterations in Athletes With Anterior Cruciate Ligament Reconstruction and the Implications for Osteoarthritis: A Subject Specific Finite Element Analysis Study

Links

URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1546185726941703

Abstract

Anterior cruciate ligament (ACL) rupture is one of the most common orthopedic injuries and is estimated to occur 250,000 times annually in the United States. An ACL injury is a traumatic event that comes with a large financial cost and can lead to loss of entire seasons of sports participation, loss of possible scholarship funding, lowered academic performance, long term disability, and greater risk of radiographically diagnosed osteoarthritis (OA). The ACL is responsible for passive stabilization to anterior tibial translation, and rotational loads in the frontal and transverse planes. While ACL reconstruction (ACLR) can restore anterior laxity to acceptable levels, dynamic instability can persist. Analysis of gait and other sport specific tasks show persistent changes in lower limb mechanics that not only affect second injury risk, but may be a primary factor in early onset OA. A definitive mechanistic link has yet to be established between ACL injury, ACLR and OA, but current evidence strongly indicates that OA development is related to the changes in tibiofemoral kinematics that are present after injury and ACLR.

Therefore, the aims of this dissertation were to: 1) Determine the effects of ACL injury and ACLR on lower limb biomechanics during sport specific tasks, and 2) Determine the effects of ACL injury and ACLR on subject specific model predicted ACL strain and cartilage contact patterns. The hypothesis tested was that lower limb biomechanics in those with ACLR would be significantly altered compared to their uninvolved limb and to uninjured controls. In addition, it was hypothesized that the models of ACLR subjects would predict larger ligament strains compared to the uninjured controls, and demonstrate altered cartilage contact patterns.

To test these hypotheses, patients with ACLR were recruited for these studies. First, lower limb biomechanics during a single leg hop were examined to determine correlations with patient reported function at the return to sport (RTS) time point. In addition, patients with ACLR were also examined at longer follow-up times to determine how their peak kinetics and kinematics differed from their uninvolved limbs and uninjured controls during gait and a drop vertical jump (DVJ). The latter cohort of subjects underwent identical protocols to generate subject specific finite element (FE) models. These models were based on their magnetic resonance imaging (MRI) scans and utilized their own biomechanical variables as inputs. The outputs of these FE models were compared to those from an in vitro pneumatic impactor study.

The results of the studies indicate that lower limb biomechanics after ACLR are significantly altered at short- and long-term follow-ups. Patients with ACLR at the return to sport time point had lower limb biomechanics that were significantly correlated with patient reported outcome scores. In addition, those who were identified as symptomatic demonstrated greater flexion moments and angles compared to the non-symptomatic group. Patients who had successfully returned to sport displayed “better” biomechanics compared to the uninjured control group during DVJ. The uninjured control displayed frontal plane mechanics that have been shown to increase risk for an ACL tear. The injured group also displayed altered biomechanics in the frontal and sagittal plane during gait. In addition, the injured group demonstrated significant side-to-side differences during DVJ and gait, which was evidence of preferentially off-loading the injured knee. The FE models of the injured group produced lower ACL strains compared to the uninjured group, but did not show any significant differences in cartilage contact. In comparison to the cadaveric tests, the ACL strain from the FE models did not differ significantly from the cadaveric specimens.

Cited Works (10)

Year	Entry
1984	Noyes FR, Butler DL, Grood ES, Zernicke RF, Hefzy MS. Biomechanical analysis of human ligament grafts used in knee-ligament repairs and reconstructions. J Bone Joint Surg. March 1984;66A(3):344-352.
2005	Hewett TE, Myer GD, Ford KR, Heidt RS Jr, Colosimo AJ, McLean SG, van den Bogert AJ, Paterno MV, Succop P. Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: a prospective study. Am J Sports Med. April 2005;33(4):492-501.
2007	Lohmander LS, Englund PM, Dahl LL, Roos EM. The long-term consequence of anterior cruciate ligament and meniscus injuries: osteoarthritis. Am J Sports Med. October 2007;35(10):1756-1769.
1998	Carter DR, Beaupré GS, Giori NJ, Helms JA. Mechanobiology of skeletal regeneration. Clin Orthop Relat Res. October 1998;355(suppl):S41-S55.
2004	Lohmander LS, Östenberg A, Englund M, Roos H. High prevalence of knee osteoarthritis, pain, and functional limitations in female soccer players twelve years after anterior cruciate ligament injury. Arthritis Rheum. October 2004;50(10):3145-3152.
2006	Hewett TE, Myer GD, Ford KR. Anterior cruciate ligament injuries in female athletes, I: mechanisms and risk factors. Am J Sports Med. February 2006;34(2):299-311.
2004	Andriacchi TP, Mündermann A, Smith RL, Alexander EJ, Dyrby CO, Koo S. A framework for the in vivo pathomechanics of osteoarthritis at the knee. Ann Biomed Eng. March 2004;32(3):447-457.
1995	Roos H, Adalberth T, Dahlberg L, Lohmander LS. Osteoarthritis of the knee after injury to the anterior cruciate ligament or meniscus: the influence of time and age. Osteoarthritis Cartilage. December 1995;3(3):261-267.
2000	Boden BP, Dean GS, Feagin JA Jr, Garrett WE Jr. Mechanisms of anterior cruciate ligament injury. Orthopedics. June 2000;23(6):573-578.
2005	Ford K, Myer G, Toms H, Hewett T. Gender differences in the kinematics of unanticipated cutting in young athletes. Med Sci Sports Exer. 2005;37(1):124-129.