Impingement of the patellar component against the tibial post depends on the design of the post-cam mechanism: Comparison between 12 posterior stabilized total knee prostheses

Biomechanics of post-cam mechanism is essential in determining the longevity of knee implant. Computational knee simulator is an efficient method in characterizing TKA performance under various boundary conditions. The existing knee simulators, however, were actuated only by quadriceps translation and hip load to perform squatting motion. The present computational knee simulator was developed based on lower limb of Japanese female subject having body weight, W = 51 kg and height, H = 148 cm. Two different designs of PS-type knee prostheses were tested namely Superflex and NRG. The knee motion was driven by three major muscles; quadriceps, hamstrings and gastrocnemius. The biomechanical behavior of tibiofemoral articulation associated with post-cam engagement mechanics was observed. Post-cam engagement occurred at 80° and 65° of flexion angles for Superflex and NRG, respectively. Maximum von Mises stresses at tibial post were 80 MPa and 50 MPa for Superflex and NRG, respectively. The developed computational muscle driven knee simulator has successfully assessed the performance of TKA prostheses.

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Damages of the tibial post in constrained total knee prostheses in the early postoperative course – a scanning electron microscopic study of polyethylene inlays

BMC Musculoskeletal Disorders ◽

10.1186/1471-2474-9-83 ◽

2008 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Adrian Skwara ◽

Carsten O Tibesku ◽

Rudolf Reichelt ◽

Susanne Fuchs-Winkelmann

Keyword(s):

Microscopic Study ◽

Electron Microscopic Study ◽

Knee Prostheses ◽

Electron Microscopic ◽

Postoperative Course ◽

Scanning Electron Microscopic Study ◽

Scanning Electron Microscopic ◽

Total Knee ◽

Tibial Post ◽

Scanning Electron

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Comparison of micromotion in mobile bearing and posterior stabilized total knee prostheses

Acta Orthopaedica ◽

10.1080/00016470510030823 ◽

2005 ◽

Vol 76 (3) ◽

pp. 353-361 ◽

Cited By ~ 32

Author(s):

Eric H Garling ◽

Edward R Valstar ◽

Rob G H H Nelissen

Keyword(s):

Mobile Bearing ◽

Knee Prostheses ◽

Posterior Stabilized ◽

Total Knee

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POSTERIOR STABILIZED AND CRUCIATE RETAINING KNEE PROSTHESES: COMPARISON OF IN VIVO 3D KINEMATICS USING FLUOROSCOPY

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519405001539 ◽

2005 ◽

Vol 05 (02) ◽

pp. 391-395

Author(s):

SILVIA FANTOZZI ◽

ALBERTO LEARDINI ◽

ANDREA ENSINI ◽

ANGELO CAPPELLO ◽

FABIO CATANI

Keyword(s):

Total Joint Replacement ◽

Knee Prostheses ◽

Posterior Stabilized ◽

Single Plane ◽

Cruciate Retaining ◽

Cam Mechanism ◽

In Vivo Kinematics ◽

3D Geometry ◽

Plane Projection

Accurate measurement of in vivo kinematics of total joint replacement is fundamental to improve prosthesis design and clinical outcome. In fluoroscopic analysis, the 3D relative pose of joint prosthesis components is reconstructed from the knowledge of the 3D geometry of each component and from a single plane projection. This is achieved with an accuracy of a few millimetres and a few degrees. Twenty-three patients with cruciate retaining and posterior stabilized prostheses were analyzed in order to assess the in vivo performance of the spine-cam mechanism. The posterior stabilized design exhibits a more physiological pattern of the anteroposterior motion of the condyles during flexion. This result is well-suited with the larger active knee flexion exhibited by the posterior stabilized knees.

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