Dataset Information

The Influence of Component Alignment and Ligament Properties on Tibiofemoral Contact Forces in Total Knee Replacement.

ABSTRACT: The study objective was to investigate the influence of coronal plane alignment and ligament properties on total knee replacement (TKR) contact loads during walking. We created a subject-specific knee model of an 83-year-old male who had an instrumented TKR. The knee model was incorporated into a lower extremity musculoskeletal model and included deformable contact, ligamentous structures, and six degrees-of-freedom (DOF) tibiofemoral and patellofemoral joints. A novel numerical optimization technique was used to simultaneously predict muscle forces, secondary knee kinematics, ligament forces, and joint contact pressures from standard gait analysis data collected on the subject. The nominal knee model predictions of medial, lateral, and total contact forces during gait agreed well with TKR measures, with root-mean-square (rms) errors of 0.23, 0.22, and 0.33 body weight (BW), respectively. Coronal plane component alignment did not affect total knee contact loads, but did alter the medial-lateral load distribution, with 4?deg varus and 4?deg valgus rotations in component alignment inducing +17% and -23% changes in the first peak medial tibiofemoral contact forces, respectively. A Monte Carlo analysis showed that uncertainties in ligament stiffness and reference strains induce ±0.2 BW uncertainty in tibiofemoral force estimates over the gait cycle. Ligament properties had substantial influence on the TKR load distributions, with the medial collateral ligament and iliotibial band (ITB) properties having the largest effects on medial and lateral compartment loading, respectively. The computational framework provides a viable approach for virtually designing TKR components, considering parametric uncertainty and predicting the effects of joint alignment and soft tissue balancing procedures on TKR function during movement.

SUBMITTER: Smith CR

PROVIDER: S-EPMC4844247 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The Influence of Component Alignment and Ligament Properties on Tibiofemoral Contact Forces in Total Knee Replacement.

Smith Colin R CR Vignos Michael F MF Lenhart Rachel L RL Kaiser Jarred J Thelen Darryl G DG

Journal of biomechanical engineering 20160201 2

The study objective was to investigate the influence of coronal plane alignment and ligament properties on total knee replacement (TKR) contact loads during walking. We created a subject-specific knee model of an 83-year-old male who had an instrumented TKR. The knee model was incorporated into a lower extremity musculoskeletal model and included deformable contact, ligamentous structures, and six degrees-of-freedom (DOF) tibiofemoral and patellofemoral joints. A novel numerical optimization tec ...[more]

PMID: 26769446

Similar Datasets

Project description:Introduction: Knee OA progression is related to medial knee contact forces, which can be altered by anatomical parameters of tibiofemoral alignment and contact point locations. There is limited and controversial literature on medial-lateral force distribution and the effect of anatomical parameters, especially in motor activities different from walking. We analyzed the effect of tibiofemoral alignment and contact point locations on knee contact forces, and the medial-lateral force distribution in knee OA subjects with varus malalignment during walking, stair ascending and stair descending. Methods: Fifty-one knee OA subjects with varus malalignment underwent weight-bearing radiographs and motion capture during walking, stair ascending and stair descending. We created a set of four musculoskeletal models per subject with increasing level of personalization, and calculated medial and lateral knee contact forces. To analyze the effect of the anatomical parameters, statistically-significant differences in knee contact forces among models were evaluated. Then, to analyze the force distribution, the medial-to-total contact force ratios were calculated from the fully-informed models. In addition, a multiple regression analysis was performed to evaluate correlations between forces and anatomical parameters. Results: The anatomical parameters significantly affected the knee contact forces. However, the contact points decreased medial forces and increased lateral forces and led to more marked variations compared to tibiofemoral alignment, which produced an opposite effect. The forces were less medially-distributed during stair negotiation, with medial-to-total ratios below 50% at force peaks. The anatomical parameters explained 30%-67% of the variability in the knee forces, where the medial contact points were the best predictors of medial contact forces. Discussion: Including personalized locations of contact points is crucial when analyzing knee contact forces in subjects with varus malalignment, and especially the medial contact points have a major effect on the forces rather than tibiofemoral alignment. Remarkably, the medial-lateral force distribution depends on the motor activity, where stair ascending and descending show increased lateral forces that lead to less medially-distributed loads compared to walking.

Project description:BackgroundThe mechanisms of noncontact anterior cruciate ligament injury remain undefined. The purpose of this study was to identify the tibiofemoral alignment in the lateral compartment of the knee for three variations of a one-limb landing in noncontact sports activities: the safe, provocative, and exaggerated provocative positions. These positions were chosen on the basis of a previous study that measured the average joint angles of the limb at the point of ground contact for athletes who landed without injury (safe) and those who sustained an anterior cruciate ligament injury (provocative). It was hypothesized that, in the provocative positions, altered tibiofemoral alignment predisposes the knee to possible subluxation, potentially leading to an anterior cruciate ligament injury.MethodsMagnetic resonance images were acquired for a single knee in twenty-five noninjured athletes for the three landing positions. The angle between the posterior tibial slope and the femur along with three distances (from the tibiofemoral point of contact to [1] the femoral sulcus point, [2] the posterior tibial point, and [3] the most anterior point of the circular posterior aspect of the condyle) were measured for each acquisition.ResultsThe tibial slope relative to the femur was directed significantly more inferior to superior in the provocative and exaggerated positions than in the safe landing position. Similarly, as the limb transitioned from the safe to the provocative positions, the tibiofemoral joint contact point was significantly closer to the femoral sulcus point and to the most anterior point of the circular posterior portion of the lateral femoral condyle.ConclusionsAs the limb moves toward the provocative landing position, the anatomical alignment based on slope and contact characteristics places the knee at possible risk for noncontact anterior cruciate ligament injury. An enhanced understanding of the mechanism of anterior cruciate ligament injury may lead to improved preventative strategies.

Project description:BackgroundDegeneration of the tibiofemoral articular cartilage often develops in patients with posterior cruciate ligament deficiency, yet little research has focused on the etiology of this specific type of cartilage degeneration. In this study, we hypothesized that posterior cruciate ligament deficiency changes the location and magnitude of cartilage deformation in the tibiofemoral joint.MethodsFourteen patients with a posterior cruciate ligament injury in one knee and the contralateral side intact participated in the study. First, both knees were imaged with use of a specific magnetic resonance imaging sequence to create three-dimensional knee models of the surfaces of the bone and cartilage. Next, each patient performed a single leg lunge as images were recorded with a dual fluoroscopic system at 0 degrees, 30 degrees, 60 degrees, 75 degrees, 90 degrees, 105 degrees, and 120 degrees of knee flexion. Finally, the three-dimensional knee models and fluoroscopic images were used to reproduce the in vivo knee position at each flexion angle with use of a previously described image-matching method. With use of these series of knee models, the location and magnitude of peak tibiofemoral cartilage deformation at each flexion angle were compared between the intact contralateral and posterior cruciate ligament-deficient knees.ResultsIn the medial compartment of the posterior cruciate ligament-deficient knees, the location and magnitude of peak cartilage deformation were significantly changed, compared with those in the intact contralateral knees, between 75 degrees and 120 degrees of flexion, with a more anterior and medial location of peak cartilage deformation on the tibial plateau as well as increased deformation of the cartilage. In the lateral compartment, no significant differences in the location or magnitude of peak cartilage deformation were found between the intact and posterior cruciate ligament-deficient knees.ConclusionsThe altered kinematics associated with posterior cruciate ligament deficiency resulted in a shift of the tibiofemoral contact location and an increase in cartilage deformation in the medial compartment beyond 75 degrees of knee flexion. The magnitude of the medial contact shift in the posterior cruciate ligament-deficient knee was on the same order as that of the anterior contact shift.

Project description:ObjectiveTotal knee arthroplasty (TKA) is currently the best option for management of advanced knee arthritis for patients who have exhausted conservative management. There have been significant implant design improvements and this is a continuing process to help the surgeon replicate patient anatomy and kinematics. Amongst the many variables in implantation to achieve a well-functioning TKA, getting optimal femoral component sizing is one. Every implant system has certain discreet implant sizes and the surgeon has to strive to obtain the best fit possible for the patient and attain a well aligned and stable TKA. The aim of this study was to assess the frequency of various femoral component sizes being implanted with a system which has 2.5 mm antero-posterior increment between sizes, and to assess the incidence of anterior femoral notching when using a posterior referencing system.Materials and methodsA retrospective analysis of 739 TKAs implanted in 532 patients between January 2013 and January 2016 at a single center using a single posterior stabilized implant system was done. Patient demographics and femur component size used was obtained from hospital patient records. Immediate post-operative radiographs were analyzed to look for anterior femoral notching and presence of this was classified according to Tayside classification. A telephonic follow up at minimum 2 tears post-surgery was done to interview for occurrence of supracondylar femur fracture or revision for any other causes.ResultsThere were 207 bilateral and 325 unilateral TKAs performed in 532 patients during the study period. There were 245 males and 287 females with an average age of 61.3 years (43-81 years, SD = 7.2). The most commonly used femoral component was 60 mm and an intermediate size prosthesis was used in 43.11% patients. The incidence of femoral notching ranged from 0 to 6.3%. No patient had sustained a supracondylar condylar fracture at minimum 2 years follow up.ConclusionThe availability of a larger number of femoral components in a TKA system allows the surgeon the modularity to choose and obtain the best fit possible. Restoration of posterior condylar offset, preventing anterior notching, medio-lateral overhang and patellofemoral joint stuffing are greatly dependent on correct femoral component sizing. The findings from our study underscore the need to use an implant system with as many femoral size options as possible with lesser increments in between sizes to minimize anterior femoral notching when using a posterior referencing technique.

Project description:Introduction:The aim of this work is to compare in a retrospective study, the radiological results of three series of different total knee replacements performed using Orthopilot computer-based alignment system (Group A, 31 patients), a totally intramedullary alignment system (Group B, 34 patients) and a totally extramedullary alignment system (Group C, 32 patients). Materials and methods:At a medium follow-up of 15 years, all patients underwent call interview for clinical update. Of the 115 patients initially enrolled in the study, only 97 were available for radiological assessment. Both standing long-leg antero-posterior radiographs and lateral radiographs of the knee had been taken for every patient at 1 year-follow-up and at the last follow-up. Results:At the last follow-up, the mean hip-knee-ankle angle (HKA) was 179.1° (range: 176°-184°) for group A, 178.6° (range: 173°-186°) for group B and 177.8° (range: 172°-186°) for group C with no statistically significant difference among the 3 groups. The mean frontal femoral component angle (FFC) was 90.5° (range: 87°-94°) for group A, 91.05° (range: 85°-95°) for group B and 91.19° (range: 85°-96°) for group C and there was no statistically significant difference among the three groups. The mean frontal tibial component angle (FTC) was 89.9° (range: 83°-97°) for group A, 90.6° (range: 87°-95°) for group B and 90.8° (range: 86°-95°) for group C and there was no statistically significant difference among the three groups. The mean tibial component inclination in the sagittal plane was 1° (range: 3°-0°) for group A, 3.6° (range: 7°-0°) for group B and 3.1° (range: 6°-0°) for group C. Discussion and conclusion:Our results demonstrated statistically significant differences between computer-assisted and extramedullary group, in favour of navigated group in terms of implant position and mechanical alignment. Computer-assisted group showed superior but not statistically significant differences compared to intramedullary alignment system in terms of implant position and mechanical alignment. We advocate the use of computer-assisted system routinely in total knee replacement. As an alternative, we suggest the use of intramedullary system.

Dataset Information

The Influence of Component Alignment and Ligament Properties on Tibiofemoral Contact Forces in Total Knee Replacement.

Publications

The Influence of Component Alignment and Ligament Properties on Tibiofemoral Contact Forces in Total Knee Replacement.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets