Weight-bearing CT Technology in Musculoskeletal Pathologies of the Lower Limbs: Techniques, Initial Applications, and Preliminary Combinations with Gait-Analysis Measurements at the Istituto Ortopedico Rizzoli

2019 ◽  
Vol 23 (06) ◽  
pp. 643-656 ◽  
Author(s):  
Alberto Leardini ◽  
Stefano Durante ◽  
Claudio Belvedere ◽  
Paolo Caravaggi ◽  
Claudio Carrara ◽  
...  
Keyword(s):  
Weight Bearing ◽  
Three Dimensional ◽  
3D Models ◽  
Two Dimensions ◽  
Lower Limbs ◽  
Flat Foot ◽  
Musculoskeletal Radiology ◽  
Foot Bones ◽  
Patellofemoral Alignment ◽  
3D Scans

AbstractMusculoskeletal radiology has been mostly limited by the option between imaging under load but in two dimensions (i.e., radiographs) and three-dimensional (3D) scans but in unloaded conditions (i.e., computed tomography [CT] and magnetic resonance imaging in a supine position). Cone-beam technology is now also a way to image the extremities with 3D and weight-bearing CT. This article discusses the initial experience over a few studies in progress at an orthopaedic center. The custom design of total ankle replacements, the patellofemoral alignment after medial ligament reconstruction, the overall architecture of the foot bones in the diabetic foot, and the radiographic assessment of the rearfoot after subtalar fusion for correction of severe flat foot have all taken advantage of the 3D and weight-bearing feature of relevant CT scans. To further support these novel assessments, techniques have been developed to obtain 3D models of the bones from the scans and to merge these with state-of-the-art gait analyses.

scholarly journals Three Dimensional Weightbearing CT Assessment of Metatarsal Osteotomies for Hallux Valgus Correction

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0015
Author(s):  
Jarrett D. Cain ◽  
Jordan T. Stolle ◽  
Sorin Siegler
Keyword(s):  
Hallux Valgus ◽  
Weight Bearing ◽  
Three Dimensional ◽  
3D Models ◽  
Two Dimensions ◽  
Axial Plane ◽  
Ct Scans ◽  
First Metatarsal ◽  
3D Measurements ◽  
2D And 3D

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Hallux valgus (HV) is a tri-plane deformity of the foot corresponding to a medial deviation of the first metatarsal and a lateral deviation of the hallux. Understanding key angles between bones, as well as how these deformity changes in each plane, is critical to generating pre-operative insights into the most effective surgical correction of the deformity. While two- dimenional (2D) imaging can provide some information; utilizing three-dimensional (3D) imaging can include more precise and accurate measures of hallux valgus. The purpose of this study is to evaluate the metatarsal osteotomies for correction of hallux valgus deformity in axial, coronal and sagittal plane with 2D and 3D measurements with the hypothesis that 3D measurements will provide greater accuracy of pre and post surgical changes Methods: Ten cadaveric specimens were selected and weight-bearing CT scans were taken pre operatively with an applied an axial load of 80 pounds. Midshaft osteotomies were then performed on the cadaveric specimens followed by weight-bearing CT scans taken post-operatively.3D models of the pre-operative and post-operative specimens were created and differences in pre and post operative changes were analyzed using conventional 2D and 3D models of the first metatarsal (M1), second metatarsal (M2), fifth metatarsal (M5), and proximal phalanx of the hallux (PP1) using a paired student t-test. Quantitative examination of foot and ankle offset (FAO) alignment along with congruity of first metatarsal phalangeal and first tarsometatarsal joints Results: 3D measurements of the Inter-Metatarsal (IM) Angle, was 12.3 degrees pre-opeative and 10.4 degrees post-operative with no significant differences in all three planes while the M1M5 Angle, measured between the principle axes of the first metatarsal and fifth metatarsal was 25.3 degrees pre-operative and 22.0 degrees post-operative were statistically significant with the greatest change in the axial plane. 2D measurements of the hallux valgus angle, measured the longitudineal axes of the first metatarsal and proximal phalange of the hallux was 22.6 degrees pre opereative and 21.7 degrees post opereative with no statistical difference while the metatarsal parabola, measured in two dimensions projected onto the axial plane was 157.1 degrees before and 141.5 degrees after surgery was statistical significant. Conclusion: When comparing 2D and 3D pre and post surgical hallux valgus values, the only significant differences were identified in the absolute M1M5 values in the axial plane and a significant change was also observed in the metatarsal parabola angle. While the metatarsal parabola angle are sensitive measures, these results suggest that the M1 M5 angle allows for precise, efficient measurements in axial, coronal and sagittal planes that is previously unknown through two-dimensional radiographic measurements for quantifying the effect of metatarsal osteotomies on hallux valgus

Increase in Tibial Internal Rotation Due to Weight-bearing is a Key Feature to Diagnose Early-stage Knee Osteoarthritis: A Study with Upright Computed Tomography

2021 ◽  
Author(s):  
Kazuya Kaneda ◽  
Kengo Harato ◽  
Satoshi Oki ◽  
Yoshitake Yamada ◽  
Masaya Nakamura ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Internal Rotation ◽  
Early Stage ◽  
Weight Bearing ◽  
Three Dimensional ◽  
Surface Registration ◽  
Lower Limbs ◽  
Clinical Issue ◽  
Osteoarthritic Change ◽  
Tibial Internal Rotation

Abstract Background The classification of knee osteoarthritis is an essential clinical issue, particularly in terms of diagnosing early knee osteoarthritis. However, the evaluation of three-dimensional limb alignment on two-dimensional radiographs is limited. This study evaluated the three-dimensional changes induced by weight-bearing in the alignments of lower limbs at various stages of knee osteoarthritis.Methods 45 knees of 25 patients (69.9 ± 8.9 years) with knee OA were examined in the study. CT images of the entire leg were obtained in the supine and standing positions using conventional CT and 320 low-detector upright CT, respectively. Next, the differences in the three-dimensional alignment of the entire leg in the supine and standing positions were obtained using 3D-3D surface registration technique, and those were compared for each Kellgren–Lawrence grade. Results Increased flexion, adduction, and tibial internal rotation were observed in the standing position, as opposed to the supine position. Kellgren–Lawrence grades 1 and 4 showed significant differences in flexion, adduction, and tibial internal rotation between two postures. Grades 2 and 4 showed significant differences in adduction, while grades 1 and 2, and 1 and 3 showed significant differences in tibial internal rotation between standing and supine positions.Conclusions Weight-bearing increased the three-dimensional deformities in knees with osteoarthritis. Particularly, increased tibial internal rotation was observed in patients with grades 2 and 3 compared to those with grade 1. The increase in tibial internal rotation due to weight-bearing is a key pathologic feature to detect early osteoarthritic change in knees undergoing osteoarthritis.

scholarly journals Three-Dimensional Displacement after a Medializing Calcaneal Osteotomy in Relation to the Hindfoot Alignment and Osteotomy Angle

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0006
Author(s):  
Matthias Peiffer ◽  
C. Belvedere ◽  
S. Clockaerts ◽  
T. Leenders ◽  
Alexej Barg ◽  
...  
Keyword(s):  
Weight Bearing ◽  
Three Dimensional ◽  
Valgus Deformity ◽  
Flat Foot ◽  
Hindfoot Alignment ◽  
Calcaneal Osteotomy ◽  
Bony Landmarks ◽  
Operative Planning ◽  
Osteotomy Plane ◽  
Computer Based

Category: Hindfoot Introduction/Purpose: An adult-acquired flatfoot deformity is a three-dimensional (3D) condition characterized by a loss of the medial longitudinal arch, valgus alignment of the hindfoot, and abduction of the midfoot. When conservative measures are not sufficient, a medializing calcaneal osteotomy (MCO) is frequently performed to correct the deformity, but there is lack of data on the associated three-dimensional variables defining the final correction. A possible reason for this shortcoming could be the current image-based analyses, mainly performed on bi-dimensional radiographs. These are hampered by errors in 3D rotations and superimposition of bony structures. The aim of this study was therefore to assess the correlation between the preoperative hindfoot valgus deformity and calcaneal osteotomy angle and the postoperative calcaneal displacement by use of weightbearing CT (WBCT). Methods: Weight-bearing CT scans obtained pre- and post-operatively were analyzed for sixteen patients with a mean age of 49.4 years (range: 18-66 years). Indication for surgery was adult-acquired flat foot deformity stage II. Based on the WBCT images, pre- and post-operative 3D bone morphological models of the tibia, talus, calcaneus, and the second metatarsal were created, on which anatomical bony landmarks were computationally identified to define a Foot Anatomical reference Frame (FAF). This FAF was used to measure valgus deformity pre- and post-operatively, inclination of the osteotomy plane, and displacement of the calcaneus (Fig. 1). Linear regression was conducted to assess the relationship between these measurements. Results: On average, the hindfoot valgus changed from 13.1° (±4.6) preoperatively to 5.7° (±4.3) postoperatively. A mean inferior displacement of 3.2 mm (±1.3) was observed along the osteotomy with a mean inclination angle of 54.6° (±5.6), 80.5° (±10.7), - 13.7° (±15.7) in the axial, sagittal and coronal planes, respectively. A statistically significant positive relationship (P < .05, R2 = 0.6) was found between the preoperative valgus, the axial osteotomy inclination, and the inferior displacement. Conclusion: This study shows that the degree of preoperative valgus of the hindfoot and the axial osteotomy angle are predictive factors for the amount of postoperative plantar displacement of the calcaneus. These findings contrast the general recommendation of performing a 90° calcaneal osteotomy angle, i.e. perpendicular to the lateral calcaneal wall in every patient. The obtained factors should be taken into account when performing a MCO and could be integrated in a computer-based pre- operative planning.

The Relationship of Transepicondylar Width with the Distal and Posterior Femoral Condyles and Its Clinical Implications: A Three-Dimensional Study

2020 ◽  
Author(s):  
Merrill Lee ◽  
Jade Pei Yuik Ho ◽  
Jerry Yongqiang Chen ◽  
Chung Kia Ng ◽  
Seng Jin Yeo ◽  
...  
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Ct Images ◽  
Revision Total Knee Arthroplasty ◽  
Joint Line ◽  
Lower Limbs ◽  
Anatomical Landmarks ◽  
Medial Condyle ◽  
Lateral Epicondyle ◽  
Femoral Condyles

Abstract Background Restoration of the anatomical joint line, while important for clinical outcomes, is difficult to achieve in revision total knee arthroplasty (rTKA) due to distal femoral bone loss. The objective of this study was to determine a reliable method of restoring the anatomical joint line and posterior condylar offset in the setting of rTKA based on three-dimensional (3D) reconstruction of computed tomography (CT) images of the distal femur. Methods CT scans of 50 lower limbs were analyzed. Key anatomical landmarks such as the medial epicondyle (ME), lateral epicondyle, and transepicondylar width (TEW) were determined on 3D models constructed from the CT images. Best-fit planes placed on the most distal and posterior loci of points on the femoral condyles were used to define the distal and posterior joint lines, respectively. Statistical analysis was performed to determine the relationships between the anatomical landmarks and the distal and posterior joint lines. Results There was a strong correlation between the distance from the ME to the distal joint line of the medial condyle (MEDC) and the distance from the ME to the posterior joint line of the medial condyle (MEPC) (p < 0.001; r = 0.865). The mean ratio of MEPC to MEDC was 1.06 (standard deviation [SD]: 0.07; range: 0.88–1.27) and that of MEPC to TEW was 0.33 (SD: 0.03; range: 0.25–0.38). Conclusions Our findings suggest that the fixed ratios of MEPC to TEW (0.33) and that of MEPC to MEDC (1.06) provide a reliable means for the surgeon to determine the anatomical joint line when used in combination.

scholarly journals Effects of Unweighting on Gait Kinematics During Walking on a Lower-Body Positive Pressure Treadmill in Patients with Hip Osteoarthritis

2020 ◽  
Author(s):  
Yoshiaki Kataoka ◽  
Tomohiro Shimizu ◽  
Ryo Takeda ◽  
Shigeru Tadano ◽  
Yuki Saito ◽  
...  
Keyword(s):  
Rating Scale ◽  
Weight Bearing ◽  
Three Dimensional ◽  
Hip Osteoarthritis ◽  
Lower Limbs ◽  
Positive Pressure ◽  
Lower Body ◽  
Lower Body Positive Pressure ◽  
Gait Kinematics ◽  
Body Positive

Abstract Background: Hip osteoarthritis (OA) is a musculoskeletal condition that makes walking difficult due to pain induced by weight-bearing activity. Treadmills that support body weight reduce the load on the lower limbs, and those equipped with a lower-body positive pressure (LBPP) device, developed as a new method for unweighting, significantly reduce pain in patients with knee OA. However, the effects of unweighting on gait kinematics remain unclear in patients with hip OA. Therefore, we investigated the effects of unweighting on kinematics in patients with hip OA during walking on a treadmill equipped with an LBPP device.Methods: Fifteen women with hip OA and fifteen age-matched female controls wore a three-dimensional motion analysis system and walked at a self-selected speed on the LBPP treadmill. Data regarding hip pain using a numeric rating scale under three different unweighting conditions (100%, 75%, and 50% bodyweight) were collected. Three-dimensional peak joint angles during gait under each condition were calculated and compared.Results: In the hip OA group, numerical rating scores at the unweighted conditions were significantly decreased compared to the 100% bodyweight condition, and peak hip extension angle decreased compared to the healthy controls. In both groups, unweighting significantly decreased the peak hip and knee flexion angle and increased the peak ankle plantarflexion angle during walking.Conclusions: Although unweighting by LBPP decreased pain in the hip OA group, gait kinematics did not alter despite less load on the hip joint. Therefore, clinicians should consider the benefits of pain reduction, rather than the alternation of gait kinematics, when considering LBPP treadmill for patients with hip OA.

scholarly journals Three-dimensional imaging mass cytometry for highly multiplexed molecular and cellular mapping of tissues and the tumor microenvironment

Nature Cancer ◽  
2021 ◽  
Author(s):  
Laura Kuett ◽  
Raúl Catena ◽  
Alaz Özcan ◽  
Alex Plüss ◽  
H. R. Ali ◽  
...  
Keyword(s):  
Simultaneous Detection ◽  
Three Dimensional ◽  
3D Models ◽  
Two Dimensions ◽  
Mass Cytometry ◽  
3D Space ◽  
Tissue Organization ◽  
Holistic Understanding ◽  
Cellular Microenvironments ◽  
And Function

AbstractA holistic understanding of tissue and organ structure and function requires the detection of molecular constituents in their original three-dimensional (3D) context. Imaging mass cytometry (IMC) enables simultaneous detection of up to 40 antigens and transcripts using metal-tagged antibodies but has so far been restricted to two-dimensional imaging. Here we report the development of 3D IMC for multiplexed 3D tissue analysis at single-cell resolution and demonstrate the utility of the technology by analysis of human breast cancer samples. The resulting 3D models reveal cellular and microenvironmental heterogeneity and cell-level tissue organization not detectable in two dimensions. 3D IMC will prove powerful in the study of phenomena occurring in 3D space such as tumor cell invasion and is expected to provide invaluable insights into cellular microenvironments and tissue architecture.

scholarly journals Comparative radiographic analysis of three-dimensional innate mobility of the foot bones under axial loading of humans and African great apes

2021 ◽  
Vol 8 (11) ◽  
Author(s):  
Takuo Negishi ◽  
Kohta Ito ◽  
Koh Hosoda ◽  
Takeo Nagura ◽  
Tomohiko Ota ◽  
...  
Keyword(s):  
Weight Bearing ◽  
Three Dimensional ◽  
Axial Loading ◽  
Great Apes ◽  
Bipedal Locomotion ◽  
Human Foot ◽  
Foot Bones ◽  
Coupling Motion ◽  
African Great Apes ◽  
The Difference

The human foot is considered to be morphologically adapted for habitual bipedal locomotion. However, how the mobility and mechanical interaction of the human foot with the ground under a weight-bearing condition differ from those of African great apes is not well understood. We compared three-dimensional (3D) bone kinematics of cadaver feet under axial loading of humans and African great apes using a biplanar X-ray fluoroscopy system. The calcaneus was everted and the talus and tibia were internally rotated in the human foot, but such coupling motion was much smaller in the feet of African great apes, possibly due to the difference in morphology of the foot bones and articular surfaces. This study also found that the changes in the length of the longitudinal arch were larger in the human foot than in the feet of chimpanzees and gorillas, indicating that the human foot is more deformable, possibly to allow storage and release of the elastic energy during locomotion. The coupling motion of the calcaneus and the tibia, and the larger capacity to be flattened due to axial loading observed in the human foot are possibly morphological adaptations for habitual bipedal locomotion that has evolved in the human lineage.

scholarly journals Understanding and Creating 3D Forms Using Familiar Objects

2016 ◽  
Vol 4 (1) ◽  
pp. 1-8
Author(s):  
Mithra Zahedi
Keyword(s):  
Design Process ◽  
Three Dimensional ◽  
3D Models ◽  
Learning By Doing ◽  
Two Dimensions ◽  
Project Based Learning ◽  
Basic Knowledge ◽  
First Semester ◽  
Spatial Geometry ◽  
High Level

A fundamental for first-year design students is to express ideas by drawing and creating volumetric models. Traditionally, this education includes spatial geometry and generation of forms whereby students learn to appreciate intersections of volumes and projections to describe three-dimensional (3D) forms in two dimensions. However, given the aptitude of today’s students to operate 3D-modelling software and the general accessibility of current technology, spatial geometry as a core subject may seem less relevant. Our goal is to re-engage students in learning required basic knowledge and skills through a complex multifaceted design process. We have designed a first-semester course of four project-based learning activities that apply learning-by-doing methodology. For each of the past three years, 65 to 75 students have participated in our 3D Expression studio course, in which they develop understanding of design process, vocabulary, and skills to create 3D models with precision, refinements, and high-level visual impact. This paper reports on the successful results of activities conducted during the 14 full days of this studio course.

scholarly journals Three-dimensional innate mobility of the human foot bones under axial loading using biplane X-ray fluoroscopy

2017 ◽  
Vol 4 (10) ◽  
pp. 171086 ◽  
Author(s):  
Kohta Ito ◽  
Koh Hosoda ◽  
Masahiro Shimizu ◽  
Shuhei Ikemoto ◽  
Takeo Nagura ◽  
...  
Keyword(s):  
Weight Bearing ◽  
Three Dimensional ◽  
Axial Loading ◽  
Functional Adaptation ◽  
Bipedal Walking ◽  
X Ray ◽  
Human Foot ◽  
Foot Bones ◽  
Locking Mechanism ◽  
Morphology And Structure

The anatomical design of the human foot is considered to facilitate generation of bipedal walking. However, how the morphology and structure of the human foot actually contribute to generation of bipedal walking remains unclear. In the present study, we investigated the three-dimensional kinematics of the foot bones under a weight-bearing condition using cadaver specimens, to characterize the innate mobility of the human foot inherently prescribed in its morphology and structure. Five cadaver feet were axially loaded up to 588 N (60 kgf), and radiographic images were captured using a biplane X-ray fluoroscopy system. The present study demonstrated that the talus is medioinferiorly translated and internally rotated as the calcaneus is everted owing to axial loading, causing internal rotation of the tibia and flattening of the medial longitudinal arch in the foot. Furthermore, as the talus is internally rotated, the talar head moves medially with respect to the navicular, inducing external rotation of the navicular and metatarsals. Under axial loading, the cuboid is everted simultaneously with the calcaneus owing to the osseous locking mechanism in the calcaneocuboid joint. Such detailed descriptions about the innate mobility of the human foot will contribute to clarifying functional adaptation and pathogenic mechanisms of the human foot.

Laser Scanning Confocal Microscopy and Three-Dimesnsional Reconstruction of the Mitotic Spindles of Unequally Dividing Embryonic Cells

1990 ◽  
Vol 48 (3) ◽  
pp. 166-167
Author(s):  
J. Holy ◽  
G. Schatten
Keyword(s):  
Confocal Microscopy ◽  
Mitotic Spindle ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Two Dimensions ◽  
Embryonic Cells ◽  
Mitotic Spindles ◽  
Cleavage Division ◽  
Scanning Confocal Microscopy

One of the classic limitations of light microscopy has been the fact that three dimensional biological events could only be visualized in two dimensions. Recently, this shortcoming has been overcome by combining the technologies of laser scanning confocal microscopy (LSCM) and computer processing of microscopical data by volume rendering methods. We have employed these techniques to examine morphogenetic events characterizing early development of sea urchin embryos. Specifically, the fourth cleavage division was examined because it is at this point that the first morphological signs of cell differentiation appear, manifested in the production of macromeres and micromeres by unequally dividing vegetal blastomeres.The mitotic spindle within vegetal blastomeres undergoing unequal cleavage are highly polarized and develop specialized, flattened asters toward the micromere pole. In order to reconstruct the three-dimensional features of these spindles, both isolated spindles and intact, extracted embryos were fluorescently labeled with antibodies directed against either centrosomes or tubulin.

Sign in / Sign up

Export Citation Format

Share Document