Table 1.
Breed, age, sex and body weight of horses used in the study.
Fig 1.
Illustration of lateromedial and dorsopalmar foot balance measurement.
Upper images—Lateromedial balance: Frontal tridimensional high resolution T1-weighted (T1 3D HR) images from the same fore foot (left fore foot horse 3), obtained respectively during weight-bearing (on the left) and non-weight-bearing (on the right) acquisitions. Lateral is to the right. The angle α measured between the sagittal axes of the middle phalanx (green line) and of the distal phalanx (yellow line) represents the amount of varus or valgus deviation of the distal interphalangeal joint. Bottom images—Dorsopalmar balance: Sagittal tridimensional high resolution T1-weighted (T1 3D HR) images from the same fore foot (left fore foot horse 1), obtained respectively during weight-bearing (on the left) and non-weight-bearing (on the right) acquisitions. The angle β measured between tangential lines to the dorsal cortex of the middle (green line) and distal (yellow line) phalanges represents the amount of distal interphalangeal flexion.
Fig 2.
Illustration of frontal slice selection for articular cartilage measurements.
Frontal tridimensional high resolution T1-weighted (T1 3D HR) images (on the right) are selected from sagittal T1 3D HR images (on the left) from the same fore foot, obtained respectively during weight-bearing and non-weight-bearing acquisitions. Lateral is to the left. Note perpendicular orientation of the frontal slice to the palmar aspect of the glenoid cavity of the distal phalanx. The orange lines represent the dorsal and palmar extremities of the field of view. The green line represents the selected frontal slice for measurements.
Fig 3.
Illustration of articular cartilage thickness and area measurements on a frontal tridimensional high resolution T1-weighted (T1 3D HR) image of the distal interphalangeal joint of a forefoot.
a. Individual measurements of articular cartilage thickness of the middle and distal phalanges, respectively, at 5 predetermined locations (abaxial and central aspects of medial and lateral condyles, and sagittal aspect). b. Individual measurements of articular cartilage areas from the middle and distal phalanges, respectively. c. Measurements of distal interphalangeal space thickness, combining articular cartilage from middle and distal phalanges (same locations as individual measurements in a). d. Measurement of distal interphalangeal space area, combining articular cartilage from middle and distal phalanges. Lateral is to the left.
Fig 4.
Illustration of articular cartilage thickness and area measurements on a sagittal tridimensional high resolution T1-weighted (T1 3D HR) image of the distal interphalangeal joint of a forefoot.
a. Individual measurements of articular cartilage thickness of the middle and distal phalanges, respectively, at 3 predetermined locations (dorsal, central and palmar aspect). b. Individual measurements of articular cartilage areas from the middle and distal phalanges, respectively. c. Measurements of distal interphalangeal space thickness, combining cartilage from middle and distal phalanges (same locations as individual measurements in a). d. Measurement of distal interphalangeal space area, combining cartilage from middle and distal phalanges.
Fig 5.
Comparison between tridimensional high resolution T1-weighted (T1 3D HR) frontal images from the same forefoot, respectively weight-bearing and non-weight-bearing, illustrating the difference in articular cartilage thickness and delineation between both conditions.
Articular cartilage is thicker and better delineated on the non-weight-bearing compared to the weight-bearing images. Lateral is to the left.
Fig 6.
Comparison between tridimensional high resolution T1-weighted (T1 3D HR) sagittal images from the same forefoot, respectively weight-bearing and non-weight-bearing, illustrating the difference in articular cartilage thickness and delineation between both conditions.
Articular cartilage is thicker and better delineated on the non-weight-bearing compared to the weight-bearing images. CL: centrolateral; sag: sagittal; CM: centromedial.
Table 2.
Mean values and standard deviation for distal interphalangeal joint space thickness and cross-sectional area (10 feet), articular cartilage thickness and area of middle and distal phalanges (5 feet) in weight-bearing and non-weight-bearing frontal acquisitions.
P-values for Significant Effect of the Weight-Bearing Condition on the Cartilage Thickness and Area are included.
Table 3.
Mean values and standard deviation for distal interphalangeal joint space thickness and cross-sectional area, articular cartilage thickness and area of middle and distal phalanges (9 feet) in weight-bearing and non-weight-bearing sagittal acquisitions.
P-values for Significant Effect of the Weight-Bearing Condition on the Cartilage Thickness and Area are included.
Table 4.
Results obtained during identification of weight-bearing versus non-weight-bearing frontal tridimensional high resolution T1-weighted magnetic resonance images of the distal interphalangeal joint by 3 groups of blinded readers.