Mechanism of Anterior Impingement Damage in Total Knee Arthroplasty by Scott A. Banks, Melinda K....

Mechanism of Anterior Impingement Damage in Total Knee Arthroplasty

by Scott A. Banks, Melinda K. Harman, and W. Andrew Hodge

J Bone Joint Surg AmVolume 84(suppl 2):S37-S42

November 1, 2002

©2002 by The Journal of Bone and Joint Surgery, Inc.

Damage on the anterior part of the post of a retrieved PCL-substituting polyethylene tibial insert.

Scott A. Banks et al. J Bone Joint Surg Am 2002;84:S37-S42


Both PCL-retaining (Fig. 2-A and 2-B) and PCL-substituting (Fig. 2-C and 2-D) designs from many different implant manufacturers show symmetrical deformation (arrows) on the tibial spine or

anterior part of the post at retrieval.



Femoral component impingement can cause delamination, forming a shallow groove on the anterior part of the tibial post.



Fig. 4-A With knee flexion, there is no contact between the femoral component and the anterior part of the tibial eminence.



Implant flexion angle exceeded 0° (hyperextension) during the gait cycle in some patients, independent of the prosthesis design implanted.



Fig. 6-A Fluorscopic image, made at heel-strike, of a knee with a mobile-bearing translating and rotating cruciate-retaining prosthesis.



Fig. 7-A Prostheses are not aligned perpendicular to the mechanical axis of the bones.



Fig. 8-A External goniometric measurements of the knee angle reflect the bone alignment, not the implant alignment.



An external marker-based tracking system measured bone position, and a fluoroscopy system tracked the position of the implants as the patients walked on a treadmill.



The knee flexion angle was 10° more extended throughout the entire gait cycle when measured with use of the implant position compared with the bone position.



External goniometry of the skeletal landmarks and fluoroscopic images of the implant position were used to measure knee flexion during kneeling.



Mechanism of Anterior Impingement Damage in Total Knee Arthroplasty by Scott A. Banks, Melinda K....

Documents

Transcript of Mechanism of Anterior Impingement Damage in Total Knee Arthroplasty by Scott A. Banks, Melinda K....