Alexis Maillot - Academia.edu (original) (raw)

Papers by Alexis Maillot

Fractured bony fragments (circle and star) of the distal phalanx of the left front centr... more Fractured bony fragments (circle and star) of the distal phalanx of the left front central digit are imaged ventral to the central small sesamoid (S) by means of: analog radiography (AR), digital radiography (DR), computed tomography (CT), and synchronized CT-DR (Synch CT-DR). Uppermost CT images reveal additional osteopathologies: the second phalanx - dorso-lateral fracture with a displaced fragment (curved arrow); the third phalanx - complete fracture of the medial palmar process (processus palmaris medialis, straight arrow).</p

Graphic numerical representation of the pathological bone sites (vertical axis) found in... more Graphic numerical representation of the pathological bone sites (vertical axis) found in each autopodial element (horizontal axis). For podial elements (carpal and tarsal bones), the number of osteopathologies per bone was small and therefore we included the carpal (n = 7) and, respectively, tarsal (n = 8) joint as one unit. The data was collected from all four hind legs (“Hindleg”) and from all four front legs (“Frontleg”), therefore, for example, “Ph I-DII” of “Hindleg” represents the first phalanx of the second digit in all four hind legs. Abbreviations: Mt-metatarsal, Mc-metacarpal, S-large sesamoids, Ph-phalanx, D-digit, s-small sesamoids.</p

Ceratotherium simum simum- Southern white rhinoceros, Rhinoc... more Ceratotherium simum simum- Southern white rhinoceros, Rhinoceros unicornis- Indian rhinoceros, FR - front right, FL - front left, HR - hind right, HL - hind left autopodium.</p

Dorsomedial-palmarolateral (DMPL) 20° oblique view performed at a projection angle of 20... more Dorsomedial-palmarolateral (DMPL) 20° oblique view performed at a projection angle of 20° from the dorsal mid-plane (arrow) allows a better visualization of all digits than the traditional DMPL 45° oblique view. Positioning technique is demonstrated on tri-dimensional computed tomographic (3D CT) image of Indian rhinoceros 3 right front foot (right side image) and schematically represented using a cross-sectional CT image (left side image). Semi-transparent 3D CT imaging protocol was employed to show both foot's exterior aspect and the underlying bony structures.</p

Whole foot radiographic diagnostic value per view was calculated based on: a) number of ... more Whole foot radiographic diagnostic value per view was calculated based on: a) number of bones that could be discerned at a diagnostic value (“Number”, presented as percentage from the total number of foot's bones); b) perceptible radiographic details of each bone estimated with a 5-point radiographic rating scale and summated for all foot's bones (“Detail”). The results are shown for hind feet in Southern white and Indian rhinoceroses. The abbreviations used are: dorso-palmar (plantar) [DPa(l)], palmaro (plantaro)-dorsal [Pa(l)D], medio-lateral [ML], latero-medial [LM], and four oblique projections: dorsomedial-palmaro (plantaro) lateral [DM-Pa(l)LO], dorsolateral-palmaro (plantaro) medial [DL-Pa(l)MO], palmaro (plantaro) medial-dorsolateral [Pa(l)M-DLO] and palmaro (plantaro) lateral-dorsomedial [Pa(l)L-DMO].</p

This projection (B) allows the best visualization of calcaneus (highlighted on CT image ... more This projection (B) allows the best visualization of calcaneus (highlighted on CT image A) with minimal superimposition of other bony elements. The abbreviations used are: 1-tibia, 2- fibula, 3- talus, 4- calcaneus, 5- navicular, 6-tarsal III, and 7- tarsal IV bones.</p

Chart representing the most frequent osteopathologies encountered in each rhinoceros and... more Chart representing the most frequent osteopathologies encountered in each rhinoceros and all three together.</p

Tri-dimensional computed tomographic (3D CT) images of CTB allowed comparison of multipl... more Tri-dimensional computed tomographic (3D CT) images of CTB allowed comparison of multiple bone pathologies (A) in rhinoceros 1 with normal anatomical aspect (B) in rhinoceros 2. Encountered osteopathologies are: cortical osteogenesis represented by massive, unstructured new bone production and remodelling, with a beak-like formation oriented plantaro-medially (arrow). Additionally (A), the articular surface between CTB and first tarsal bone (TI) is highly irregular, characterized by decreased joint space width and articular bone proliferation that bridges the contiguous bones (ankylosis). The second (TII) and the third (TIII) tarsal bones are within normal limits on both rhinoceroses (A, B).</p

$Research paper thumbnail of Left central tarsal bone (CTB) fractures in rhinoceros 1$

Tridimensional computed tomographic reconstruction of the left tarsal joint with oblique... more Tridimensional computed tomographic reconstruction of the left tarsal joint with oblique multiplanar reconstructions (MPR) showing minimally displaced, multiple fractures of the left CTB situated in different planes (arrows). First line of fracture (A) descends in proximo-plantar to distalo-dorsal direction (large arrows), ending at the junction between CTB, first tarsal bone (T I) and second tarsal bone (T II). The second line of fracture (B) is oriented from dorsal to plantar surfaces, in proximo-medial to distalo-plantar direction, reaching the midline of the proximal articular surface of T I with CTB (small arrows). At the level of these fractures, CTB distalo-medial aspect reveals a mixed pattern of trabecular focal bone loss (osteolysis) and cortical osteogenesis represented by massive, unstructured new bone production and remodelling, with a beak-like formation oriented plantaro-medially, hook-shaped in axial plane. Additionally, the articular surface between CTB and TI is highly irregular, characterized by decreased joint space width, articular bone proliferation that bridges the contiguous bones (ankylosis), erosion and lysis of the articular cartilage and underlying bone (asterisk).</p

Radiographic diagnostic value per view was calculated by summation of the perceptible ra... more Radiographic diagnostic value per view was calculated by summation of the perceptible radiographic detail assessed with a 5-point rating scale for each autopodial bone of front and, respectively, hind feet in Indian rhinoceroses. Standard radiographic views are schematically represented on the top row. Abbreviations: digits II, III, IV [D II, D III, D IV]; views: dorso-palmar (plantar) [DPa(l)], palmaro (plantaro)-dorsal [Pa(l)D], medio-lateral [ML], latero-medial [LM], and four oblique projections: dorsomedial-palmaro (plantaro) lateral [DM-Pa(l)LO], dorsolateral-palmaro (plantaro) medial [DL-Pa(l)MO], palmaro (plantaro) medial-dorsolateral [Pa(l)M-DLO] and palmaro (plantaro) lateral-dorsomedial [Pa(l)L-DMO].</p

Computed tomographic tridimensional images of the distal autopodium, dorsal aspect (A) a... more Computed tomographic tridimensional images of the distal autopodium, dorsal aspect (A) and the correspondent digital radiographic images, palmaro-dorsal view (B). The third or middle digit (D III) presents fractures on all three phalanges: the first phalanx (Ph I) - chip fracture with a small fragment (4.7 mm diameter) on the dorso-lateral aspect (A, B- small arrows); the second phalanx (Ph II) - dorso-lateral fracture with a displaced fragment (18,3×14,4×12,1 mm, A, B-circles); the third phalanx (Ph III) - chip fracture of the medial palmar process (processus palmaris medialis, A, B- large arrows).</p

WR 1- white rhinoceros 1, WR 2- white rhinoceros 2; IR- Indian rhinoceros, FR-front righ... more WR 1- white rhinoceros 1, WR 2- white rhinoceros 2; IR- Indian rhinoceros, FR-front right, FL-front left, HR-hind right, HL-hind left autopodium, R-radial carpal bone, I-intermediate carpal bone, U-ulnar carpal bone, Ta-talus, Ca-Calcaneus, CTB-central tarsal bone, T I-first tarsal bone, Mc-metacarpal bone, Mt-metatarsal bone, D-digit, Ph-phalanx, S-large or proximal sesamoids. The lesions visible on digital radiographs are underlined.</p

PLoS ONE, 2013

Chronic foot disease poses a threat to the general health, represents a tremendous clinical chall... more Chronic foot disease poses a threat to the general health, represents a tremendous clinical challenge, and often is a reason for euthanasia in captive megaherbivores, among them the elephant and rhinoceros. Nevertheless, apart from the elephant, foot pathology is handled as being confined only to soft tissues whereas bone pathology is often overlooked. As a case in point, the authors selected the second largest mammal on land, the rhinoceros. We performed a computed tomographic (CT) study using the highest resolution available in veterinary world, followed by digital radiography of eight distal limbs from two white and one Indian rhinoceroses. Our study demonstrated that bone pathology in rhinoceroses' foot is present and in large numbers, yet none of these were diagnosed ante mortem. Even when the animals were euthanized due to foot problems, the decision was based on soft tissue pathology rather than orthopedic reasons. Even more worrying is the fact that the largest number of osteopathologies was present in one of the white rhinoceroses that showed no discernable related clinical signs. This study describes for the first time the existence of bone pathology in white rhinoceros foot, in addition to the two previously described rhinoceros species-Indian and black rhinoceroses. Furthermore, the chronic foot disease reported for the Indian rhinoceros in our study was not restricted to soft tissue structures as was presumed ante mortem but included severe bone pathology. New evidence suggesting that osteopathology in rhinoceroses' distal limb is more widespread than it was thought before could force us to rethink of radiographic diagnosis in captive megaherbivores as routine examination incorporated into their health management. The anticipated improvements in radiologic examinations in megaherbivores will increase the effectiveness of their management and husbandry and open the way for improved animal welfare and better wildlife conservation.

PLoS ONE, 2014

Currently, radiography is the only imaging technique used to diagnose bone pathology in wild anim... more Currently, radiography is the only imaging technique used to diagnose bone pathology in wild animals situated under ''field conditions''. Nevertheless, while chronic foot disease in captive mega-herbivores is widely reported, foot radiographic imaging is confronted with scarcity of studies. Numerous hindrances lead to such limited numbers and it became very clear that the traditional perspective on bone imaging in domestic animals based on extensive studies and elaborated statistical evaluations cannot be extrapolated to their non-domestic relatives. For these reasons, the authors initiated a multi-modality imaging study and established a pioneering approach of synchronized computed tomography (CT) and digital radiography (DR), based on X-ray projections derived from three-dimensional CT reconstructed images. Whereas this approach can be applied in any clinical field, as a case of outstanding importance and great concern for zoological institutions, we selected foot bone pathologies in captive rhinoceroses to demonstrate the manifold applications of the method. Several advances were achieved, endowing the wildlife clinician with all-important tools: prototype DR exposure protocols and a modus operandi for foot positioning, advancing both traditional projections and, for the first-time, species-related radiographic views; assessment of radiographic diagnostic value for the whole foot and, in premiere, for each autopodial bone; together with additional insights into radiographic appearance of bone anatomy and pathology with a unique, simultaneous CT-DR correlation. Based on its main advantages in availing a wide range of keystone data in wildlife imaging from a limited number of examined subjects and combining advantages of CT as the golden standard method for bone diseases' diagnostic with DR's clinical feasibility under field conditions, synchronized CT-DR presents a new perspective on wildlife's health management. With this we hope to provide veterinary clinicians with concrete imaging techniques and substantial diagnostic tools, which facilitate straightforward attainment and interpretation of field radiography images taken worldwide.

PLoS ONE, 2013

Chronic foot disease poses a threat to the general health, represents a tremendous clinical chall... more Chronic foot disease poses a threat to the general health, represents a tremendous clinical challenge, and often is a reason for euthanasia in captive megaherbivores, among them the elephant and rhinoceros. Nevertheless, apart from the elephant, foot pathology is handled as being confined only to soft tissues whereas bone pathology is often overlooked. As a case in point, the authors selected the second largest mammal on land, the rhinoceros. We performed a computed tomographic (CT) study using the highest resolution available in veterinary world, followed by digital radiography of eight distal limbs from two white and one Indian rhinoceroses. Our study demonstrated that bone pathology in rhinoceroses' foot is present and in large numbers, yet none of these were diagnosed ante mortem. Even when the animals were euthanized due to foot problems, the decision was based on soft tissue pathology rather than orthopedic reasons. Even more worrying is the fact that the largest number of osteopathologies was present in one of the white rhinoceroses that showed no discernable related clinical signs. This study describes for the first time the existence of bone pathology in white rhinoceros foot, in addition to the two previously described rhinoceros species -Indian and black rhinoceroses. Furthermore, the chronic foot disease reported for the Indian rhinoceros in our study was not restricted to soft tissue structures as was presumed ante mortem but included severe bone pathology. New evidence suggesting that osteopathology in rhinoceroses' distal limb is more widespread than it was thought before could force us to rethink of radiographic diagnosis in captive megaherbivores as routine examination incorporated into their health management. The anticipated improvements in radiologic examinations in megaherbivores will increase the effectiveness of their management and husbandry and open the way for improved animal welfare and better wildlife conservation.

$Research paper thumbnail of Left central tarsal bone (CTB) fractures in rhinoceros 1$

PLoS ONE, 2013

PLoS ONE, 2014

PLoS ONE, 2013

Chronic foot disease poses a threat to the general health, represents a tremendous clinical chall... more Chronic foot disease poses a threat to the general health, represents a tremendous clinical challenge, and often is a reason for euthanasia in captive megaherbivores, among them the elephant and rhinoceros. Nevertheless, apart from the elephant, foot pathology is handled as being confined only to soft tissues whereas bone pathology is often overlooked. As a case in point, the authors selected the second largest mammal on land, the rhinoceros. We performed a computed tomographic (CT) study using the highest resolution available in veterinary world, followed by digital radiography of eight distal limbs from two white and one Indian rhinoceroses. Our study demonstrated that bone pathology in rhinoceroses' foot is present and in large numbers, yet none of these were diagnosed ante mortem. Even when the animals were euthanized due to foot problems, the decision was based on soft tissue pathology rather than orthopedic reasons. Even more worrying is the fact that the largest number of osteopathologies was present in one of the white rhinoceroses that showed no discernable related clinical signs. This study describes for the first time the existence of bone pathology in white rhinoceros foot, in addition to the two previously described rhinoceros species -Indian and black rhinoceroses. Furthermore, the chronic foot disease reported for the Indian rhinoceros in our study was not restricted to soft tissue structures as was presumed ante mortem but included severe bone pathology. New evidence suggesting that osteopathology in rhinoceroses' distal limb is more widespread than it was thought before could force us to rethink of radiographic diagnosis in captive megaherbivores as routine examination incorporated into their health management. The anticipated improvements in radiologic examinations in megaherbivores will increase the effectiveness of their management and husbandry and open the way for improved animal welfare and better wildlife conservation.