Sagittal Profile of the Femoral Condyles and Its Application to Femorotibial Contact Analysis

2000 ◽  
Vol 123 (1) ◽  
pp. 18-26 ◽  
Author(s):  
N. Nun˜o ◽  
A. M. Ahmed
Keyword(s):  
Contact Region ◽  
Contact Analysis ◽  
Sagittal Profile ◽  
Laser Range Finder ◽  
Spring Model ◽  
Arc Model ◽  
Articular Surfaces ◽  
Simple Geometry ◽  
Nonlinear Force ◽  
Femoral Condyles

Measurements of the sagittal profiles of the articular surfaces of 24 femoral condyles were performed using a laser range finder. An algebraic algorithm was developed to reconstruct the measured sagittal profiles with simple geometry. In particular, it has been shown that a two-circular-arc model provides a very accurate reconstruction of the actual profiles in the femorotibial contact region. The average sagittal profile was used for a femorotibial contact analysis of TKA implants. The contact analysis was performed by using a rigid-body-spring model extended to the case of nonlinear force-deformation behavior of the tibial polyethylene component.

Proximal Interphalangeal Joint Dimensions for the Design of a Surface Replacement Prosthesis

1996 ◽  
Vol 210 (2) ◽  
pp. 95-108 ◽  
Author(s):  
H E Ash ◽  
A Unsworth
Keyword(s):  
Sagittal Plane ◽  
Middle Finger ◽  
Proximal Interphalangeal Joint ◽  
Sagittal Profile ◽  
Radius Of Curvature ◽  
Surface Replacement ◽  
Articular Surfaces ◽  
Phalangeal Bone ◽  
Best Fit ◽  
Replacement Prosthesis

The bones from 83 proximal interphalangeal joints (PIPJs) were dissected in order to determine the shape and size of the articular surfaces. The bones were modelled in acrylic dental bone cement and the original bones and replicas were then sectioned and shadow-graphed. Dimensions were taken from these shadowgraphs to be used in the design of a surface replacement prosthesis for the PIPJ. It was found that the bi-condylar heads of the proximal and middle phalanges were circular in the sagittal plane as was the base of the middle phalanx. However, the radius of curvature of the middle phalangeal base was greater than that of the proximal phalangeal head indicating that the PIPJ is not a conforming joint. The alignment of the radial and ulnar condyles of the proximal phalangeal bones was investigated and it was found that the index and middle finger bones tended to have a more prominent ulnar condyle while the ring and little finger bones tended to have a more prominent radial condyle. This was due to a slight difference in diameters of the two condyles. The proximal phalangeal bone lengths L ranged from 29–52 mm, maximum head widths W from 8.5–15.5 mm and maximum diameters D of the best-fit circles to the sagittal profile of the bone head from 6–11 mm. The middle phalangeal bone lengths ranged from 16–35 mm, maximum head widths from 8.5–12 mm and maximum diameters from 5–7.5 mm. The relationships and ratios between these dimensions for the proximal and middle phalanges have been calculated.

scholarly journals Automatic standardized shape analysis of the sagittal profiles (J-Curves) of the femoral condyles based on three-dimensional (3D) surface data

10.29007/pc21 ◽  
2019 ◽  
Author(s):  
Malte Asseln ◽  
Maximilian C. M. Fischer ◽  
Hao Yang Chan ◽  
Patrick Meere ◽  
Peter Walker ◽  
...  
Keyword(s):  
Sagittal Plane ◽  
Quantitative Description ◽  
Extreme Points ◽  
High Mobility ◽  
Sagittal Profile ◽  
Circular Arcs ◽  
Logarithmic Spirals ◽  
Flexion Extension ◽  
Single Radius ◽  
Femoral Condyles

The sagittal geometry of the articular surfaces of the femoral condyles, also called J-Curves because of the letter J-shaped profiles, is one of the main factors affecting knee kinematics in the normal knee[1] as well as artificial knee [2]. For example, Clary et al. [2] showed that large changes in the J-curves’ radii cause abrupt changes in the center of rotation, leading to decreased anterior-posterior stability. In literature, the sagittal profile has been described mathematically by different geometric figures, such as arcs, circles, involutes of a circle, and Archimedean and logarithmic spirals [3]. The circular approximation has been often followed in the different concepts of knee implant designs, such as single- radius-, dual-radius-, or multiple-radius-designs. Single-radius-designs have a fixed flexion-extension axis. Dual-radius-designs consist of a larger distal and smaller posterior radius aiming a higher congruence during low flexion (high loading) and lower congruence at high flexion angles (high mobility). Multi-radius-designs try to mimic a physiological roll-glide ratio. However, the description of these circles is usually not standardized. A summary of different measurement methods was given by Nuno and Ahmed [4].Thereby, the radii are very sensitive regarding the length of the fitting arc [5] and position of the sagittal plane [3]. Nuno and Ahmed [3] found that medial and lateral condyles can be adequately described by two-circular arcs and proposed a quantitative description. However, the posterior limits of their arcs were not considered individually, the anterior limits were defined based on soft-tissue measurements (anterior margins of the menisci), and the sagittal plane was positioned at the posterior extreme points, which might be inadequate in arthritic knees.The goal of this study was to automatically analyse the medial and lateral sagittal profiles of the femoral condyles mathematically by two-circular arcs in a standardized and robust fashion.

Computerized Matching of Autologous Femoral Grafts for the Treatment of Medial Talar Osteochondral Defects

2005 ◽  
Vol 26 (9) ◽  
pp. 708-712 ◽  
Author(s):  
John V. Marymont ◽  
Gerald Shute ◽  
Hongseng Zhu ◽  
Kevin E. Varner ◽  
Vibor Paravic ◽  
...  
Keyword(s):  
Distal Femur ◽  
Donor Site ◽  
Computer Software ◽  
Optimal Location ◽  
Osteochondral Graft ◽  
Osteochondral Defects ◽  
Potential Donor ◽  
Articular Surfaces ◽  
Surface Contour ◽  
Femoral Condyles

Background: Cored autologous graft from the distal ipsilateral femur has been used to fill osteochondral defects in the talus. There are no studies that compare the articular morphology of potential donor sites on the distal femur with recipient sites on the talus. Methods: Using coronal MRI of the talus and distal femur of five matched cadaver, computer reconstructions of the articular surfaces were prepared. From these, six 10-mm in diameter donor sites from the nonweightbearing surfaces of the medial and lateral aspects of the femoral condyles were matched to three recipient sites on the anterior, middle, and posterior aspects of the corresponding medial talus using customized computer software that minimized differences between the articular surfaces of the graft and the talus. After matching the femoral to the talar graft, the average and maximal distances between the surfaces (surface contour) and the average and maximal distances of the offset at the outer 1 mm of the graft periphery (step-off) were determined. Results: For all graft combinations, the average step-off was 0.24 +/−0.03 mm and the maximum 0.60 mm. The average surface contour was 0.32 +/−0.04 mm and the maximum was 1.16 mm. In all cases, the best donor site was from the superolateral femur for any medial talar lesion. Conclusion: In this study of grafts from the femoral condyles, the superolateral femur was the optimal location for an osteochondral graft for any medial talar lesion.

scholarly journals The effects of captive versus wild rearing environments on long bone articular surfaces in common chimpanzees (Pan troglodytes)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3668 ◽  
Author(s):  
Kristi L. Lewton
Keyword(s):  
Distal Radius ◽  
Pan Troglodytes ◽  
Articular Surface ◽  
Long Bone ◽  
Environmental Groups ◽  
Skeletal Morphology ◽  
Surface Areas ◽  
Articular Surfaces ◽  
Physical Environments ◽  
Femoral Condyles

The physical environments of captive and wild animals frequently differ in substrate types and compliance. As a result, there is an assumption that differences in rearing environments between captive and wild individuals produce differences in skeletal morphology. Here, this hypothesis is tested using a sample of 42 captive and wild common chimpanzees (Pan troglodytes). Articular surface areas of the humerus, radius, ulna, femur, and tibia were calculated from linear breadth measurements, adjusted for size differences using Mosimann shape variables, and compared across sex and environmental groups using two-way ANOVA. Results indicate that the articular surfaces of the wrist and knee differ between captive and wild chimpanzees; captive individuals have significantly larger distal ulna and tibial plateau articular surfaces. In both captive and wild chimpanzees, males have significantly larger femoral condyles and distal radius surfaces than females. Finally, there is an interaction effect between sex and rearing in the articular surfaces of the femoral condyles and distal radius in which captive males have significantly larger surface areas than all other sex-rearing groups. These data suggest that long bone articular surfaces may be sensitive to differences experienced by captive and wild individuals, such as differences in diet, body mass, positional behaviors, and presumed loading environments. Importantly, these results only find differences due to rearing environment in some long bone articular surfaces. Thus, future work on skeletal morphology could cautiously incorporate data from captive individuals, but should first investigate potential intraspecific differences between captive and wild individuals.

Transosseous Osteosynthesis with External Fixation Devices in Intraarticular Fractures of Knee Joint Area

2009 ◽  
Vol 16 (4) ◽  
pp. 29-34
Author(s):  
Igor' Olegovich Pankov ◽  
A L Emelin ◽  
I O Pankov ◽  
A L Emelin
Keyword(s):  
Knee Joint ◽  
Treatment Outcomes ◽  
External Fixation ◽  
Treatment Results ◽  
Compression Fractures ◽  
Articular Surfaces ◽  
Intraarticular Fractures ◽  
Fixation Devices ◽  
Severity Of Injury ◽  
Femoral Condyles

Peculiarities of transosseous osteosynthesis with pin-rod external fixation devices at treatment of various intraarticular fractures in the area of the knee joint are presented. Analysis of treatment outcomes for 108 patients with 110 fractures (18 fractures of femoral condyles and 92 fractures of tibial condyles) was performed. Excellent and good results were achieved in 83 (75.4%) cases. In polysegmental and impression-compression fractures of femoral and tibial condyles the treatment results were most often only satisfactory or unsatisfactory that was accounted for the severity of injury with massive destruction of the articular surfaces.

Forelimb posture in neoceratopsian dinosaurs: implications for gait and locomotion

Paleobiology ◽  
2000 ◽  
Vol 26 (3) ◽  
pp. 450-465 ◽  
Author(s):  
Gregory S. Paul ◽  
Per Christiansen
Keyword(s):  
Alternative View ◽  
Running Speed ◽  
High Speeds ◽  
Articular Surfaces ◽  
Parasagittal Plane ◽  
Sprawling Posture ◽  
Femoral Condyles

Ceratopsid dinosaurs traditionally have been restored with sprawling forelimbs and were considered unable to run at high speeds. An alternative view restores the ceratopsids as rhinoceros-like with parasagittal forelimb kinematics and the ability to run faster than extant elephants. Several anatomical difficulties concerning the mounting of ceratopsid skeletons with nearly parasagittal forelimbs stem not from the forelimb itself, but from errors in rib and vertebral articulation. Matching a skeletal restoration to a probable ceratopsid trackway shows that the hands were placed directly beneath the glenoids, and that manual impressions were directed laterally, not medially as in sprawling reptiles. Pedal impressions in trackways are medial to the manual impressions, owing to the slightly averted elbow and to the asymmetrical distal femoral condyles, which directed the crus slightly medially. The limbs of ceratopsians of all sizes display substantial joint flexure, strongly indicating that the elephantine forelimb posture that has sometimes been suggested as the alternative to a sprawling posture is erroneous. The articular surfaces of uncrushed ceratopsian scapulocoracoids and forelimb joints confirm that the forelimb operated in a near-parasagittal plane with the elbows only slightly averted. The maximal running speed of even the largest ceratopsids is inferred to have significantly exceeded that of elephants and was probably broadly similar to that of rhinos.

Compensatory Tibial Overgrowth Following Healing of Closed Femoral Fractures in Young Dogs

1995 ◽  
Vol 08 (03) ◽  
pp. 159-162 ◽  
Author(s):  
L. Susan ◽  
R. T. O’Brien ◽  
K. A. Johnson
Keyword(s):  
Internal Fixation ◽  
Femoral Fractures ◽  
Surgical Reduction ◽  
Femoral Shortening ◽  
Hindlimb Lameness ◽  
Femoral Condyles

SummaryTwo young dogs examined for hindlimb lameness were found to have healed femoral fractures, 2-4 cm of femoral shortening, and 1 cm of compensatory ipsilateral tibial overgrowth. Neither dog had had surgery or internal fixation. Although tibial overgrowth partially corrected for limb shortening, both dogs had chronic intermittent lameness due to malformation of the femoral condyles and secondary stifle osteoarthritis.Compensatory tibial overgrowth was found in two young dogs with femoral fractures which had healed without any surgical reduction or internal fixation. Tibial overgrowth of approximately 1 cm in each case partially compensated for 2-4 cm of femoral shortening.

Dependence of the joint configuration on the dynamic immobility fulcrum

2019 ◽  
pp. 108-114
Author(s):  
A. D. Kozlov ◽  
Yu. P. Potekhina
Keyword(s):  
Kinetic Energy ◽  
Convex Surface ◽  
The Other ◽  
Concave Surface ◽  
Joint Configuration ◽  
Articular Surfaces

Although joints with synovial cavities and articular surfaces are very variable, they all have one common peculiarity. In most cases, one of the articular surfaces is concave, whereas the other one is convex. During the formation of a joint, the epiphysis, which has less kinetic energy during the movements in the joint, forms a convex surface, whereas large kinetic energy forms the epiphysis with a concave surface. Basing on this concept, the analysis of the structure of the joints, allows to determine forces involved into their formation, and to identify the general patterns of the formation of the skeleton.

Arc Model to Evaluate D.C. Interruption Performance for Molded Case Circuit Breaker

2018 ◽  
Vol 138 (6) ◽  
pp. 529-534
Author(s):  
Yoshihisa Ogawa ◽  
Tadashi Koshizuka ◽  
Koichi Asakusa ◽  
Tsuyoshi Wakasa
Keyword(s):  
Circuit Breaker ◽  
Arc Model
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