Three-Dimensional Mechanics, Kinematics, and Morphology of the Knee Viewed in Virtual Reality

Eckhoff, Donald G.; Bach, Joel M.; Spitzer, Victor M.; Reinig, Karl D.; Bagur, Michelle M.; Baldini, Todd; Flannery, N.

doi:10.2106/jbjs.e.00440

Cited by 167 publications

(128 citation statements)

References 15 publications

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“…The algorithm evolved from the protocol of manually fitting cylinders or circles to the condyle contours. 6,21 The premise can be best illustrated using a model of a series of parallel crosssectional ''cuts'' of a cylindrical object (Fig. 4).…”

Section: An Optimization Algorithm For Establishing a Unified Sagittamentioning

confidence: 99%

“…The interest in such knowledge has recently intensified with the advances in imaging and visualization techniques allowing more effective and accurate studies of the joint surface geometry. Eckhoff and coworkers [6][7][8] conducted a series of studies of the distal femur morphology, using computed tomography (CT); they clarified the difference between the transepicondylar axis and cylindrical axis-two common choices of knee flexion axis. The sensitivity of knee kinematic descriptions to the choice of flexion axis was demonstrated by Most et al 21 who used a digitizer to measure the femoral surface contour.…”

Section: Introductionmentioning

confidence: 99%

“…For example, the protocol employed in many previous studies all involved visually identifying cylinders [6][7][8] or circles 21,26 that best fitted the medial and lateral condyle contours.…”

Section: Introductionmentioning

confidence: 99%

“…Further, the lack of a unified and repeatable methodology can enlarge the uncertainties or artifacts to complicate the continued disputes on a variety of issues related to the distal femur geometry. These issues include, for instance, whether and how much the geometric center axis and transepicondylar axis differ 6,21 and which one better represents the tibiofemoral flexion axis, 2,7 whether the medial condyle is larger than the lateral condyle, and what the most accurate geometric characterization of condyle shapes should be. 23 In this article, we propose a new computational framework that enables automated analyses of the distal femur articular geometry based on 3D surface data.…”

Section: Introductionmentioning

confidence: 99%

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Automating Analyses of the Distal Femur Articular Geometry Based on Three-Dimensional Surface Data

Tashman

et al. 2010

Ann Biomed Eng

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Quantitative knowledge of the distal femur morphology is critical to understanding the relation between the anatomy and function of the knee joint. Prior knowledge was contaminated by manual procedures and subjective visual inspections in extracting geometric information from image data. This article proposes a new computational framework to enable automated analysis of the distal femur articular geometry based on 3D surface data. The framework consists of a pattern recognition algorithm for sectioning the sagittal-view condyle profiles, a least-squares algorithm for fitting and analyzing the profiles, and an optimization algorithm for establishing a unified sagittal plane. An application of the proposed framework to 12 knee surface models demonstrated that it can analyze the condyle contour profiles and extract geometric measures automatically and accurately. The proposed framework also facilitated a simulation-based analysis of the uncertainty associated with conventional manual approaches, elucidating how subjective determination of the sagittal plane and flexion facet can hinder accurate understanding of the distal femur morphology and related kinematics.

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Section: An Optimization Algorithm For Establishing a Unified Sagittamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Automating Analyses of the Distal Femur Articular Geometry Based on Three-Dimensional Surface Data

Tashman

et al. 2010

Ann Biomed Eng

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“…The KA concept is based on the work of authors like Eckhoff, Hollister and Coughlin [6][7][8][9][10].…”

mentioning

confidence: 99%

Alignment for total knee replacement: a comparison of kinematic axis versus mechanical axis techniques. A cadaver study

Nogler

Hozack

Collopy

et al. 2012

International Orthopaedics (SICOT)

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Purpose Standard instrumentation tries to reproduce mechanical axes based on mechanical alignment (MA) guides. A kinematic alignment (KA) technique derives its plan from pre-operative MRI-measurements. This matched-pair cadaveric study compared the resulting postoperative alignments. Methods A prospective series of 12 torsos were acquired for a total of 24 limb specimens including intact pelvises, femoral heads, knees, and ankles.The cadavers received MRI scans to manufacture the kinematic alignment cutting guides. Two investigating surgeons performed total knee arthroplasties on randomly chosen sides using MA instruments. On the contralateral sides, KA cutting guides were used. A navigation system was used to measure final alignment. Results The overall alignment showed no significant differences between the systems. In the MA group the differences between the planned and the final implantation regarding overall limb alignment ranged between 0.2°and 6.2°. In the KA group the differences between the planned and final implantation regarding overall limb alignment ranged between 0.3°and 9.1°. The differences of the deviation from plan for overall limb alignment showed no significant differences between the methods. Conclusions The different alignment strategies resulted in variations of the combinations of the three-dimensional component position on the femur and the tibia. However, the legs were aligned within comparable range for both chosen techniques.

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Quantifying lateral femoral condyle ellipticalness in chimpanzees, gorillas, and humans

Sylvester

Pfisterer

2012

American J Phys Anthropol

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Articular surfaces of limb bones provide information for understanding animal locomotion because their size and shape are a reflection of habitual postures and movements. Here we present a novel method for quantifying the ellipticalness (i.e., departure from perfectly circular) of the lateral femoral condyle (LFC), applying this technique to hominid femora. Three-dimensional surface models were created for 49 Homo sapiens, 34 Pan troglodytes and 25 Gorilla gorilla femora. Software was developed that fit separate cylinders to each of the femoral condyles. These cylinders were constrained to have a single axis, but could have different radii. The cylinder fit to the LFC was allowed to assume an elliptical cross-section, while the cylinder fit to the medial condyle was constrained to remain circular. The shape of the elliptical cylinder (ratio of the major and minor axes of the ellipse) was recorded, and the orientation of the elliptical cylinder quantified as angles between the major axis of the ellipse and the anatomical and mechanical axes of the femur. Species were compared using analysis of variance and post hoc multiple comparisons tests. Confirming qualitative descriptions, human LFCs are more elliptical than those of chimpanzees and gorillas. Human femora exhibit a narrow range for the angle between the major axis of the elliptical cylinder and femoral axes. Conversely, the chimpanzee sample is bimodal for these angles, exhibiting two ellipse orientations, while Gorilla shows no preferred angle. Our results suggest that like modern human femora, chimpanzee femoral condyles have preferentially used regions.

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Three-Dimensional Mechanics, Kinematics, and Morphology of the Knee Viewed in Virtual Reality

Cited by 167 publications

References 15 publications

Automating Analyses of the Distal Femur Articular Geometry Based on Three-Dimensional Surface Data

Automating Analyses of the Distal Femur Articular Geometry Based on Three-Dimensional Surface Data

Alignment for total knee replacement: a comparison of kinematic axis versus mechanical axis techniques. A cadaver study

Quantifying lateral femoral condyle ellipticalness in chimpanzees, gorillas, and humans

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