Journal ArticleDOI
Three-dimensional mechanics, kinematics, and morphology of the knee viewed in virtual reality.
Donald G. Eckhoff,Joel M. Bach,Victor M. Spitzer,Karl D. Reinig,Michelle M. Bagur,Todd Baldini,Nicolas M P Flannery +6 more
TLDR
New studies relate the morphology of the femur (condyles and epicondyles) and the axis of the limb (mechanical axis) to the location and orientation of the flexion-extension axis ofThe knee in three-dimensional space.Abstract:
T he premise of this article, and the scientific exhibit upon which it is based, is that the morphologic shape of the distal aspect of the femur and its relation to the tibia and the patella dictates the kinematics of the knee. The morphologic and kinematic characteristics of the knee presented in earlier exhibits1,2 at the 2001 and 2003 Annual Meetings of the American Academy of Orthopaedic Surgeons demonstrated the following relationships. The location and orientation of the femoral sulcus is lateral to the midplane between the femoral condyles and is oriented between the anatomic and mechanical axes of the femur (Figs. 1-A and 1-B). The center of the femur in cross section is offset, medial and anterior, to the center of the tibia, and these offset cross sections are rotated relative to each other in the pathologic knee (Fig. 2). A single, fixed flexion-extension axis of the knee is centered in the asymmetric cylindrical femoral condyles (Fig. 3). These and other observations1-8 of distal femoral morphology and their relationship to knee kinematics form the basis for the additional studies in the present article. These new studies relate the morphology of the femur (condyles and epicondyles) and the axis of the limb (mechanical axis) to the location and orientation of the flexion-extension axis of the knee in three-dimensional space.
The clinical importance of this work is found in its application to ligament reconstruction and total knee arthroplasty. Despite improvements in design, implant alignment in total knee arthroplasty remains a crucial factor in the function and longevity of the implant9-11. It has been demonstrated that malalignment causes increased wear of the implant and premature failure of the construct11-14. Most contemporary implants are designed to be aligned to …read more
Citations
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Journal ArticleDOI
Does A Kinematically Aligned Total Knee Arthroplasty Restore Function Without Failure Regardless of Alignment Category
TL;DR: ConclusionsKinematically aligned TKA restores function without catastrophic failure regardless of the alignment category, and the concern that kinematic alignment compromises function and places the components at a high risk for catastrophic failure is unfounded.
Journal ArticleDOI
A randomised controlled trial of kinematically and mechanically aligned total knee replacements
TL;DR: In this study, the use of a kinematic alignment technique performed with patient-specific guides provided better pain relief and restored better function and range of movement than the mechanical alignment techniques performed with conventional instruments.
Patent
System and method for image segmentation in generating computer models of a joint to undergo arthroplasty
TL;DR: In this article, a method for image segmentation in generating computer models of a joint to undergo arthroplasty is described, where the method may include obtaining a plurality of volumetric image slices of the bone.
Patent
Patient Specific Knee Alignment Guide And Associated Method
Robert Metzger,Keith R. Berend,Michael E. Berend,Adolph V. Lombardi,Lance D. Perry,Ryan J. Schoenefeld +5 more
TL;DR: In this paper, a femoral alignment guide is pre-configured from medical scans of the knee joint of the patient. And the femoral joints are pre-aligned by drilling holes into an anterior portion of the femural joint surface through corresponding first and second guiding apertures of the alignment guide.
Journal ArticleDOI
Accurate alignment and high function after kinematically aligned TKA performed with generic instruments
TL;DR: The authors prefer the use of generic instruments to perform kinematically aligned TKA in place of mechanicallyaligned TKA because five of six alignments were accurate and because high function was restored regardless of whether patients had an alignment categorized as an outlier or in-range.
References
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Journal ArticleDOI
Influence of positioning of prosthesis in total knee replacement
Paul A. Lotke,Malcolm L. Ecker +1 more
TL;DR: There is a statistically significant positive correlation between a good clinical result and a well positioned prosthesis and it is believed that the long-term clinical results, wear resistance, and resistance to prosthetic failure depend on correct positioning of the devices.
Journal ArticleDOI
Wear patterns on retrieved polyethylene tibial inserts and their relationship to technical considerations during total knee arthroplasty.
TL;DR: It is indicated that unconstrained tibial component wear patterns and severity may be associated with clinical and mechanical factors under the surgeon's control, including component size and position, and knee alignment and ligament balance.
Journal ArticleDOI
The axes of rotation of the knee.
TL;DR: The authors used a mechanical device to locate the FE and the LR axes of six fresh anatomic specimen knees, and images in planes perpendicular to the FE axis showed a circular profile for the femoral condyles.
Journal ArticleDOI
The anatomy and functional axes of the femur
TL;DR: The condylar width, the length of each interepicondylar line, correlated well with depth, but the projections of the condyles from the transverse plane revealed significant variations from specimen to specimen.
Journal ArticleDOI
The transepicondylar axis approximates the optimal flexion axis of the knee
TL;DR: The traditional understanding of knee kinematics holds that no single fixed axis of rotation exists in the knee, but this hypothesis has been tested and the optimal flexion axis is fixed in the femur and can be considered the trueflexion axis of the knee.