Influence of Flexing Load Position on the Loading of Cruciate Ligaments at the Knee—A Graphics-Based Analysis
01 Jan 2015-pp 123-130
TL;DR: Mechanics of the knee were analyzed for the influence of external flexing load positions on loading of the cruciate ligaments in the sagittal plane during 0° to 120° flexion to suggest rehabilitation exercises requiring protection of the ligaments need to pay attention to the position of externalflexing load on the tibia as well as flexion angle at which the exercise is performed.
Abstract: Injuries of the cruciate ligaments of the knee, particularly the anterior cruciate ligament (ACL), is a common problem in young athletes. Therefore, identification of high-risk factors that lead to injury of the knee ligaments is required to avoid loading or protecting the ligaments from injury or during rehabilitation. In the present study, mechanics of the knee was analyzed for the influence of external flexing load positions on loading of the cruciate ligaments in the sagittal plane during 0° to 120° flexion. Experimental data was taken from literature. Mechanical equilibrium of the tibia was considered due to four types of forces, namely, a force in the patellar tendon, a ligament force, a tibio-femoral joint contact force, and an external flexing load applied distally on the tibia. The analysis suggests that during the muscle exercise at the knee, loading of the cruciate ligaments depends on flexion angle as well as on the position of external load on the tibia. Far distal placements of flexing loads on the tibia can stretch the ACL significantly at low flexion angles. The PCL is stretched during mid-to-high flexion range for all positions of the external flexing loads on the tibia. However, during the mid-flexion range, the effects of placement are modest. Therefore, rehabilitation exercises requiring protection of the ligaments need to pay attention to the position of external flexing load on the tibia as well as flexion angle at which the exercise is performed.
Citations
More filters
10 Jul 2018
TL;DR: A planar mathematical model of the human knee is used for analyzing the mechanics of the joint after replacement with artificial implants using computer programming, motion and force data is generated for a large number of joint positions, which is used to simulate the knee mechanics during flexion/extension.
Abstract: A computer graphics based approach is being developed as an aid for orthopedic surgeons to learn engineering mechanic. As an application of this approach, a planar mathematical model of the human knee is used for analyzing the mechanics of the joint after replacement with artificial implants. Graphic representation is used for the bones, prosthetic components, fibers of ligaments and the lines of various forces. Using computer programming, motion and force data is generated for a large number of joint positions, which is then utilized to simulate the knee mechanics during flexion/extension. The simulations show very clearly during motion the bones relocating in relation to each other, different fibers of the ligaments becoming straight or slack and the muscle and ligament forces changing their direction and position. The simulations can also be used for analyzing the effects on joint mechanics of changing the implant design or of surgical errors.
6 citations
01 Jan 2021
TL;DR: In this paper, a model of the knee is used to simulate a knee laxity test used to judge ligament integrity and the analysis suggests that knee ligaments may be predisposed to injury during specific situations like playing football.
Abstract: Human joints are complex in structure and function that allow us a variety of activities with safe mobility and stability. However, the joints are prone to injuries that can affect life severely. Computer-based methods can be useful tools to understand the behaviour of the joints. Computational complexities in modelling and simulation can be overcome, to some extent, using input from related experimental work. Computational approach of modelling and simulation is useful in many areas including analysis of various activities, mechanisms of injuries during specific sports, designing of safe exercises, understanding effects of surgical procedures, etc. In the present study, a model of the knee is used to simulate a knee laxity test used to judge ligament integrity. Results of simulation are comparable to that of similar experiments on cadaver knees. For example, lower bone of the model knee moved 3.4, 6.1 and 5.3 mm anterior to the upper bone, respectively, at 0°, 45° and 90° flexion of the joint resulting from an external 150 N force on the lower bone. These movements were similar to those from experiment. Further, the model calculations suggest that effectiveness of the external force in translating the bone diminished with increasing force magnitude. The analysis suggests that knee ligaments may be predisposed to injury during specific situations like playing football. The results have clinical relevance.
2 citations
09 Sep 2022
TL;DR: In this article , a mathematical model is used to simulate such laxity tests and estimate cruciate ligament forces when the lower leg at the knee is translated anterior to thigh, thus, stretching the anterior cruciato ligament.
Abstract: Cruciate ligaments are main stabilizers of the joint in the sagittal plane. Anterior cruciate ligament is one of the most injured ligaments, particularly during strenuous activities. Integrity of these ligaments is examined clinically by estimating appropriate relative movements of the connected bones. Experiments on cadaver knees provide laxity measurements. However, determination of corresponding ligament forces is either difficult or not possible due to several challenges. In the present study, a mathematical model is used to simulate such laxity tests and estimate cruciate ligament forces when the lower leg at the knee is translated anterior to thigh, thus, stretching the anterior cruciate ligament. The simulation is repeated at several joint positions and with different forces that cause translation. The model calculations showed general agreement with experimental measurements in the literature. For example, the lower leg translated 6, 6.1, and 5.9 mm, respectively, at 30, 45, and 60° flexion with 150 N anterior translating load on the tibia. This is similar to the patterns reported in the literature from in vitro studies. The model helped in gaining further insight in the joint behavior with estimation of corresponding forces developed in the ligament for each simulation. The analysis suggests that 30–60° flexion may be appropriate range for clinical estimation of the ligament integrity as at these joint positions, the laxity is higher, while the ligament forces are not highest in comparison to other flexion angles.KeywordsAnterior drawer testCruciate ligamentsAnterior tibial translation (ATT)Knee laxityModeling and simulation of human knee
01 Jan 2021
TL;DR: In this article, the authors used mathematical modeling to simulate the knee function in the sagittal plane when the ligaments are intact, which could be used to investigate effects of different tunnel positions during the ligament reconstruction.
Abstract: Anterior Cruciate Ligament of the knee is injured quite often while performing strenuous activities like in sports. Due to poor healing characteristics, surgical reconstruction of the ligament is used to restore the joint function. However, many significant percentage of the patients are unable to return to their pre-injury levels of activity. In addition, more complications of the joint can result in repeated surgeries. Several clinical and experimental reports suggest the need for further investigations in order to gain insight in the behavior of the reconstructed ligament and related outcome. The present study used mathematical modelling to simulate the knee function in the sagittal plane when the ligaments are intact. The ligaments were separated into fiber bundles similar to those reported in the literature. Such simulations could be used to investigate effects of different tunnel positions during the ligament reconstruction. Knee motion during 0°–120° flexion and an anterior laxity test at different joint positions were simulated. The outcome of the model simulations suggest that anterior fibers of the ligament contribute significantly throughout the knee flexion in resisting anterior forces on the tibia. In comparison, the posterior fibers contribute in near extremes of motion only. The results of model simulations corroborated with experimental observations from literature and have clinical relevance.
References
More filters
TL;DR: A high prevalence of radiographic knee osteoarthritis was seen in male soccer players 14 years after an ACL disruption, and the patient relevant outcome was affected and did not differ between subjects with and without radiographic changes.
Abstract: Objective: To identify the consequences of an anterior cruciate ligament (ACL) tear in a cohort of male soccer players 14 years after the initial injury with respect to radiographic knee osteoarthritis and patient relevant outcomes.
Methods: Of 219 male soccer players with an ACL injury in 1986, 205 (94%) were available for follow up after 14 years; 75% of the cohort (154/205) answered mailed questionnaires (KOOS, SF-36, and Lysholm knee scoring scale) and 122 of these consented to weight bearing radiographs.
Results: Radiographic changes were found in 95 (78%) of the injured knees, while more advanced changes, comparable with Kellgren-Lawrence grade 2 or higher, were seen in 50 (41%). In the uninjured knees more advanced changes, comparable with Kellgren-Lawrence grade 2 or higher, were seen in five knees (4%). No differences were seen between surgically and conservatively treated players. The patient relevant outcome was affected and did not differ between subjects with and without radiographic changes. Eighty per cent reported reduced activity level.
Conclusions: A high prevalence of radiographic knee osteoarthritis was seen in male soccer players 14 years after an ACL disruption. The injury and the osteoarthritis, irrespective of the treatment provided to these patients, often result in knee related symptoms that severely affect the knee related quality of life by middle age.
788 citations
Journal Article•
TL;DR: In this paper, the consequences of ACL tear in a cohort of male soccer players 14 years after the initial injury with respect to radiographic knee osteoarthritis and patient relevant outcomes were identified.
Abstract: Objective: To identify the consequences of an anterior cruciate ligament (ACL) tear in a cohort of male soccer players 14 years after the initial injury with respect to radiographic knee osteoarthritis and patient relevant outcomes.
Methods: Of 219 male soccer players with an …
734 citations
TL;DR: Some principles which might guide the design of knee prostheses are deduced and it is shown that current designs transgress some of these principles.
Abstract: The mechanisms controlling and limiting movement and serving to transmit load between the femur and the tibia are discussed. Having accounted for the transmission of all components of force and couple across the joint and noted the load-bearing role of the menisci, some principles which might guide the design of knee prostheses are deduced. It is shown that current designs transgress some of these principles. An experimental prosthesis is then described, which incorporates analogues of the natural menisci. The possible practical application of this novel principle has been studied in cadaveric human joints and in living patients.
479 citations
TL;DR: Ten to 20 years after ACL injury, gonarthrosis often presents as a slight joint space reduction or, occasionally, joint space obliteration, but is usually not associated with major clinical symptoms, according to the few longitudinal studies.
Abstract: Knee ligament injuries are common in sport. A rupture of the anterior cruciate ligament (ACL) is the most serious of these injuries because it may cause long term disability. In this literature review, the frequency of post-traumatic gonarthrosis is examined. There are few long term prospective studies but a number of retrospective studies with follow-up times between 5 and 20 years have been published. These studies show that radiographic gonarthrosis is significantly increased after all knee injuries compared with the uninjured joint of the same patient. Isolated meniscus rupture and subsequent repair, or partial or total ruptures of the ACL without major concomitant injuries, seem to increase the risk 10-fold (15 to 20% incidence of gonarthrosis) compared with an age-matched, uninjured population (1 to 2%). Meniscectomy in a joint with intact ligaments further doubles the risk of gonarthrosis (30 to 40%), and 50 to 70% of patients with complete ACL rupture and associated injuries have radiographic changes after 15 to 20 years. Thus, an ACL rupture combined with meniscus rupture or other knee ligament injuries results in gonarthrosis in most patients. Ten to 20 years after ACL injury, gonarthrosis often presents as a slight joint space reduction or, occasionally, joint space obliteration (Ahlback grades I to II), but is usually not associated with major clinical symptoms. According to the few longitudinal studies, the progress of gonarthrosis is slow, and in some cases the condition seems to remain stable. Time is an important determinant for the degree of gonarthrosis and problems demanding treatment may be encountered only at > 30 years after the initial accident.
408 citations
Journal Article•
TL;DR: All lines of action and moment arms of the structures of interest were determined as a function of knee joint angles and were expressed using polynomial regression equations to allow easy application of the findings to musculoskeletal models of the human knee joint.
Abstract: The purpose of this study was to obtain lines of action and moment arms in the sagittal plane of the major force-carrying structures crossing the knee joint. The muscles and ligaments studied were the quadriceps, biceps femoris, semimembranosus, and semitendinosus muscles and the anterior and posterior cruciate and medial and lateral collateral ligaments. All lines of action and moment arms of the structures of interest were determined as a function of knee joint angles and were expressed using polynomial regression equations. This representation of the results allows for easy application of the findings to musculoskeletal models of the human knee joint.
370 citations