scholarly journals In vivo knee loading characteristics during activities of daily living as measured by an instrumented total knee replacement

2008 ◽  
Vol 26 (9) ◽  
pp. 1167-1172 ◽  
Author(s):  
Annegret Mündermann ◽  
Chris O. Dyrby ◽  
Darryl D. D'Lima ◽  
Clifford W. Colwell ◽  
Thomas P. Andriacchi
Author(s):  
Matthew J. Adams ◽  
Cameron J. Turner ◽  
Anne K. Silverman

Total knee replacement is a viable treatment for end-stage knee arthritis. With a greater number of younger patients opting for total knee replacement surgery, their increasingly active lifestyles will result in higher wear rates while decreasing the life expectancy of the tibial insert component of the knee replacement implant. In response to the eventuality of patients with more active lifestyles requiring knee replacement surgery, this research proposed to accurately estimate in vivo knee loading over a gait cycle using a dynamically consistent whole-body modeling and simulation method. However, medical treatment based on modeling and simulation must be validated before clinical application becomes feasible. Estimates for knee loading were compared to publicly-available in vivo knee loading measurements from a telemetric implant [1]. A whole-body musculoskeletal modeling approach was used to simulate the gait cycle of a person who had undergone total knee replacement surgery. This approach was used to calculate net knee joint contact forces. Results suggest that generic whole-body modeling and hybrid forward dynamic simulation techniques for estimating knee joint loads may become clinically feasible in the near future.


2019 ◽  
Vol 8 (2) ◽  
pp. 221
Author(s):  
Yen-Feng Lai ◽  
Pei-Chao Lin ◽  
Chung-Hwan Chen ◽  
Jyu-Lin Chen ◽  
Hsin-Tien Hsu

Knee osteoarthritis (OA) is a very common disease in the elderly, and total knee replacement (TKR) surgery is currently considered the most effective treatment. A prospective, observational, repeated measures study was performed to explore the current status and changes in pain and activities of daily living (ADL) in 58 OA elderly patients undergoing unilateral TKR. The Wong–Baker Faces Pain Rating Scale (WBS) for pain and the self-reported Barthel Index for ADL were measured on the day before surgery, 48 hours after surgery, and the day before discharge. Moderate pain was reported before surgery. Pain significantly improved after surgery and before discharge. At all three time points, pain scores were significantly higher in patients who used assistive devices compared to those who did not. Partial independence in ADL was reported before surgery. The ADL scores reported were highest before surgery, and those reported after surgery were lowest. However, ADL scores gradually increased before discharge. ADL scores were higher in the subjects who lived in a detached, single-family homes compared to those who lived in bungalows at all three time points. The results could be used to screen for knee OA elderly patients at high-risk for pain or low ADL and to provide timely intervention strategies as soon as possible.


Thrombosis ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Lars C. Borris ◽  
Morten Breindahl ◽  
Michael R. Lassen ◽  
Ákos F. Pap

Prothrombin fragment 1+2 is excreted in urine (uF1+2) as a result of in vivo thrombin generation and can be a marker of coagulation status after an operative procedure. This study compared uF1+2 levels in patients with symptomatic and non-symptomatic venous thromboembolism (VTE) after total knee replacement (TKR) and in event-free sex- and age-matched controls. Significantly higher median uF1+2 levels were seen in the VTE patients on days 1, 3, and the day of venography (mostly day 7) after TKR compared with controls. The uF1+2 levels tended to be high in some patients with symptomatic VTE; however, the discriminatory efficacy of the test could not be evaluated. In conclusion, this study showed that patients with VTE tend to have significantly higher uF1+2 levels compared with patients without events between days 1 and 7 after TKR surgery. Measurement of uF1+2 could provide a simple, non-invasive clinical test to identify patients at risk of VTE.


Author(s):  
Hannah J. Lundberg ◽  
Christopher B. Knowlton ◽  
Diego Orozco ◽  
Markus A. Wimmer

Knowledge of in vivo knee contact forces is essential for evaluating total knee replacement (TKR) designs. This is particularly true for activities other than walking, because there is still a limited understanding of its impact on wear. It has been shown that wear scars from retrieved implants have obvious differences compared with simulator tested components in both size of worn area and in damage mode. The divergence could be related to the omission of other activities than walking when testing components in the simulator. The purpose of this study was to use a parametric numerical model for predicting joint contact forces during stair ascent/descent and chair sitting/rising and compare those to measured forces from a database. We hypothesized that the contact force output of the numeric model would be similar to the measured forces.


Author(s):  
Michael D Stokes ◽  
Brendan C Greene ◽  
Luke W Pietrykowski ◽  
Taylor M Gambon ◽  
Caroline E Bales ◽  
...  

Current total knee replacement designs work to address clinically desired knee stability and range of motion through a balance of retained anatomy and added implant geometry. However, simplified implant geometries such as bearing surfaces, posts, and cams are often used to replace complex ligamentous constraints that are sacrificed during most total knee replacement procedures. This article evaluates a novel total knee replacement design that incorporates synthetic ligaments to enhance the stability of the total knee replacement system. It was hypothesized that by incorporating artificial cruciate ligaments into a total knee replacement design at specific locations and lengths, the stability of the total knee replacement could be significantly altered while maintaining active ranges of motion. The ligament attachment mechanisms used in the design were evaluated using a tensile test, and determined to have a safety factor of three with respect to expected ligamentous loading in vivo. Following initial computational modeling of possible ligament orientations, a physical prototype was constructed to verify the function of the design by performing anterior/posterior drawer tests under physiologic load. Synthetic ligament configurations were found to increase total knee replacement stability up to 94% compared to the no-ligament case, while maintaining total knee replacement flexion range of motion between 0° and 120°, indicating that a total knee replacement that incorporates synthetic ligaments with calibrated location and lengths should be able to significantly enhance and control the kinematic performance of a total knee replacement system.


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