The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Sue J Dyson - One of the best experts on this subject based on the ideXlab platform.
-
unusual Navicular Bone fractures in hindlimbs clinical and imaging findings
Journal of Equine Veterinary Science, 2013Co-Authors: Marianna Biggi, Sue J DysonAbstract:Three horses were identified with an unusual fracture configuration of a hindlimb Navicular Bone. All horses had unilateral lameness which was worse on a circle on a firm surface and was abolished by plantar nerve blocks performed at the base of the proximal sesamoid Bones. Radiological findings included an ill-defined curvilinear radiolucent line along the distal horizontal border of the Navicular Bone in case 1; cases 2 and 3 had three fragments along the distal horizontal border, associated, in case 2, with marked abnormalities extending into the spongiosa of the Bone. Lesions in case 2 were bilateral despite unilateral lameness. Fractures parallel to the distal horizontal border of the Navicular Bone have not been described in front limbs; neither have more than two fragments been observed along the distal border. One previous report describes a lesion similar to that in case 1 in a hindlimb Navicular Bone. Fragmentation of the distal horizontal border associated with rupture of the distal sesamoidean impar ligament and proximal displacement of the Bone has been reported in hindlimbs. It is likely that biomechanical reasons are responsible for the occurrence of these lesions in hindlimbs.
-
can distal border fragments of the Navicular Bone be a primary cause of lameness
Equine Veterinary Education, 2013Co-Authors: Marianna Biggi, T Blunden, Sue J DysonAbstract:Summary A horse with unilateral forelimb lameness and pain localised to the palmar aspect of the foot was evaluated using radiography and low field magnetic resonance (MR) imaging. A distal border fragment of the Navicular Bone, an osseous cyst-like lesion (OCLL) in the distal third of the Navicular Bone and focal distal sesamoidean impar desmitis were identified as the most likely causes of pain and lameness. No other lesions likely to contribute to pain and lameness were identified on MR images or gross post mortem examination. The OCLL was characterised histologically by enlarged Bone lacunae containing proliferative fibrovascular tissue. Focal lesions of the distal aspect of the Navicular Bone are rarely found in isolation but can be causes of pain and lameness in horses.
-
comparison between magnetic resonance imaging and histological findings in the Navicular Bone of horses with foot pain
Equine Veterinary Journal, 2012Co-Authors: Sue J Dyson, T Blunden, Rachel C MurrayAbstract:Summary Reasons for performing study: There is limited knowledge about both histological features in early Navicular disease and what histological features are represented by increased signal intensity in fat-suppressed magnetic resonance (MR) images of the Navicular Bone. Objective: To characterise increased signal intensity in the spongiosa of the Navicular Bone in fat-suppressed MR images and to compare this with histopathology; and to compare objective grading of all aspects of the Navicular Bone on MR images with histological findings. Methods: One or both front feet of 22 horses with foot pain and a median lameness duration of 3 months were examined using high-field MR imaging (MRI) and histopathology. The dorsal, palmar, proximal and distal borders of the Navicular Bone and the spongiosa were assigned an MRI grade (0–3) and a histological grade and compared statistically. Results: Increased signal intensity in the spongiosa of the Navicular Bone was associated with a variety of abnormalities, including fat atrophy, with lipocytes showing loss of definition of cytoplasmic borders, a proliferation of capillaries within the altered marrow fat, perivascular or interstitial oedema, enlarged intertrabecular Bone spaces, fibroplasia and thinned trabeculae showing loss of Bone with irregularly spiculated edges of moth-eaten appearance. There were significant associations among histological lesions of the fibrocartilage, calcified cartilage and subchondral Bone. There were also significant associations between MRI grading of the spongiosa and both histological marrow fat grade and the combined maximum of the MRI grades for the fibrocartilage. Conclusions and potential relevance: Increased signal intensity in the spongiosa of the Navicular Bone in fat-suppressed MR images may occur in association with lesions of the fibrocartilage with or without subchondral Bone or may represent a separate disease entity, particularly if diffuse, reflecting a variety of alterations of trabecular Bone and marrow fat architecture.
-
distal border fragments and shape of the Navicular Bone radiological evaluation in lame horses and horses free from lameness
Equine Veterinary Journal, 2012Co-Authors: Marianna Biggi, Sue J DysonAbstract:Summary Reasons for performing study: The significance of distal border fragments of the Navicular Bone is not well understood. There are also no objective data about changes in thickness and proximal/distal extension of the palmar cortex of the Navicular Bone. Objectives: To describe the distribution of distal border fragments and their association with other radiological abnormalities of the Navicular Bone and describe the shape of the Navicular Bone in sound horses and horses with foot-related lameness, including Navicular pathology. Methods: Sound horses had radiographs acquired as part of a prepurchase examination. Lame horses had forelimb lameness abolished by palmar nerve blocks performed at the base of the proximal sesamoid Bones. Diagnosis was assigned prospectively based on results of local analgesia and all imaging findings. The thickness of the palmar cortex of the Navicular Bone and size of proximal/distal extensions were measured objectively. Other radiological abnormalities were evaluated subjectively and each Navicular Bone graded. Results: Fifty-five sound and 377 lame horses were included. All measurements were larger in lame compared with sound horses except the size of the distal extension of the palmar cortex. Fragments were observed in 3.6 and 8.7% of sound and lame horses respectively and in 24.1% of horses with a diagnosis of primary Navicular pathology. There was an association between fragments and overall Navicular Bone grade, radiolucent areas at the angles of the distal border of the Navicular Bone and number and size of the synovial invaginations. Conclusions and potential relevance: The palmar cortex of the Navicular Bone was thicker in lame compared with sound horses. Distal border fragments were most frequent in horses with Navicular pathology. Evaluation of changes in shape of the Navicular Bone may also be important for recognition of pathological abnormalities of the Bone.
-
histopathology in horses with chronic palmar foot pain and age matched controls part 1 Navicular Bone and related structures
Equine Veterinary Journal, 2010Co-Authors: A S Blunden, Sue J Dyson, R Murray, M SchrammeAbstract:Summary Reasons for performing study: Causes of palmar foot pain and the aetiopathogenesis of Navicular disease remain poorly understood, despite the high incidence of foot-related lameness. Hypotheses: Abnormalities of the collateral sesamoidean ligaments (CSLs), distal sesamoidean impar ligament (DSIL), deep digital flexor tendon (DDFT), Navicular Bone, Navicular bursa, distal interphalangeal (DIP) joint or collateral ligaments (CLs) of the DIP joint may contribute to palmar foot pain. Methods: Feet were selected from horses with a history of unilateral or bilateral forelimb lameness of at least 2 months' duration that was improved by perineural analgesia of the palmar digital nerves, immediately proximal to the cartilages of the foot (Group 1, n = 32); or from age-matched control horses (Group 2, n = 19) that were humanely destroyed for other reasons and had no history of forelimb foot pain. Eight units of tissue were collected for histology: the palmar half of the articular surface of the distal phalanx, including the insertions of the DDFT and DSIL; Navicular Bone and insertion of the CSLs; DDFT from the level of the proximal interphalangeal (PIP) joint to 5 mm proximal to its insertion; synovial membrane from the palmar pouch of the DIP joint and the Navicular bursa; CLs of the DIP joint and DSIL. The severity of histological lesions for each site were graded. Results were compared between Groups 1 and 2. Results: There was no relationship between age and grade of histological abnormality. There were significant histological differences between groups for lesions of the flexor aspect, proximal and distal borders, and medulla of the Navicular Bone; the DSIL and its insertion and the Navicular bursa; but not for lesions of the CSLs, the dorsal aspect of the Navicular Bone, distal phalanx and articular cartilage, synovium or CLs of the DIP joint. Conclusions: Pathological abnormalities in lame horses often involved not only the Navicular Bone, but also the DSIL and Navicular bursa. Abnormalities of the Navicular Bone medulla were generally only seen dorsal to lesions of the FFC. Potential relevance: Adaptive and reactive change may be occurring in the Navicular apparatus in all horses to variable degrees and determination of the pathogenesis of lesions that lead to pain and biomechanical dysfunction should assist specific preventative or treatment protocols.
R Murray - One of the best experts on this subject based on the ideXlab platform.
-
histopathology in horses with chronic palmar foot pain and age matched controls part 1 Navicular Bone and related structures
Equine Veterinary Journal, 2010Co-Authors: A S Blunden, Sue J Dyson, R Murray, M SchrammeAbstract:Summary Reasons for performing study: Causes of palmar foot pain and the aetiopathogenesis of Navicular disease remain poorly understood, despite the high incidence of foot-related lameness. Hypotheses: Abnormalities of the collateral sesamoidean ligaments (CSLs), distal sesamoidean impar ligament (DSIL), deep digital flexor tendon (DDFT), Navicular Bone, Navicular bursa, distal interphalangeal (DIP) joint or collateral ligaments (CLs) of the DIP joint may contribute to palmar foot pain. Methods: Feet were selected from horses with a history of unilateral or bilateral forelimb lameness of at least 2 months' duration that was improved by perineural analgesia of the palmar digital nerves, immediately proximal to the cartilages of the foot (Group 1, n = 32); or from age-matched control horses (Group 2, n = 19) that were humanely destroyed for other reasons and had no history of forelimb foot pain. Eight units of tissue were collected for histology: the palmar half of the articular surface of the distal phalanx, including the insertions of the DDFT and DSIL; Navicular Bone and insertion of the CSLs; DDFT from the level of the proximal interphalangeal (PIP) joint to 5 mm proximal to its insertion; synovial membrane from the palmar pouch of the DIP joint and the Navicular bursa; CLs of the DIP joint and DSIL. The severity of histological lesions for each site were graded. Results were compared between Groups 1 and 2. Results: There was no relationship between age and grade of histological abnormality. There were significant histological differences between groups for lesions of the flexor aspect, proximal and distal borders, and medulla of the Navicular Bone; the DSIL and its insertion and the Navicular bursa; but not for lesions of the CSLs, the dorsal aspect of the Navicular Bone, distal phalanx and articular cartilage, synovium or CLs of the DIP joint. Conclusions: Pathological abnormalities in lame horses often involved not only the Navicular Bone, but also the DSIL and Navicular bursa. Abnormalities of the Navicular Bone medulla were generally only seen dorsal to lesions of the FFC. Potential relevance: Adaptive and reactive change may be occurring in the Navicular apparatus in all horses to variable degrees and determination of the pathogenesis of lesions that lead to pain and biomechanical dysfunction should assist specific preventative or treatment protocols.
-
magnetic resonance imaging evaluation of 264 horses with foot pain the podotrochlear apparatus deep digital flexor tendon and collateral ligaments of the distal interphalangeal joint
Equine Veterinary Journal, 2007Co-Authors: Sue J Dyson, R MurrayAbstract:Summary Reasons for performing study: To improve understanding of the interrelationships between injuries of the podotrochlear apparatus and deep digital flexor tendon (DDFT). Hypotheses: There is a difference in frequency of different types of lesions at different anatomical sites of the DDFT. Lesions of the collateral sesamoidean ligament (CSL), distal sesamoidean impar ligament (DSIL), distal interphalangeal (DIP) joint and Navicular bursa are seen in association with lesions of the Navicular Bone. Methods: The magnetic resonance (MR) images of 264 horses with unilateral or bilateral foot pain were analysed and graded. Descriptive statistics were performed to establish the frequency of occurrence of DDFT lesion types at different anatomical levels, and lesions of the CSL, DSIL, Navicular bursa, DIP joint and collateral ligaments (CLs) of the DIP joint. A Chi-square test was used to test for a difference in the proportion of Navicular Bone grades between limbs with and without DDFT lesions at each level, and to compare Navicular Bone grades for limbs with and without each of DSIL, CSL, Navicular bursa or DIP joint lesions. Results: Lesions of the DDFT occurred in 82.6% of limbs, occurring most commonly at the level of the CSL (59.4%) and the Navicular Bone (59.0%). Core lesions predominated at the level of the proximal phalanx (90.3%), whereas at the level of the CSL and Navicular Bone core lesions, sagittal splits and dorsal abrasions were most common. There was a positive association between DDFT lesions and Navicular Bone pathology involving all aspects of the Bone. Lesions of the DSIL (38.2% limbs) were more common than those of the CSL (10.5%), but the presence of either was associated with abnormalities of the Navicular Bone, especially involving the proximal or distal borders and the medulla. Conclusions and clinical relevance: There are close interactions between injuries of the components of the podotrochlear apparatus, the DDFT, the Navicular bursa and the DIP joint. Further knowledge about the biomechanical risk factors for injury may have importance for both disease prevention and management.
P J Fuller - One of the best experts on this subject based on the ideXlab platform.
-
stress fractures of the tarsal Navicular Bone ct findings in 55 cases
American Journal of Roentgenology, 1993Co-Authors: Z S Kiss, K M Khan, P J FullerAbstract:The purpose of this article is to present the CT findings in 55 cases of tarsal Navicular stress fracture before and after treatment and to describe the CT protocol used.Fifty-five Navicular stress fractures in 54 patients whose initial and follow-up CT scans were available for study were retrospectively reviewed. In most cases, contiguous 1.5-mm axial and 3-mm coronal scans of the Navicular Bone had been obtained. Both feet were scanned for comparison. Follow-up scans were obtained between 4 weeks and 6 years.On review, fractures were evident in all cases, but six small fractures (11%) were missed at the initial interpretation. All fractures involved the central third of the proximal dorsal margin of the Navicular Bone. Fifty-three fractures (96%) were partial. Forty-three partial fractures were linear, five were linear with Bone fragments, and five were rim defects with ossicles. In 13 cases (24%) the fracture was small, 10% or less of Bone height. The earliest sign of healing, slight dorsal cortical br...
-
stress fractures of the tarsal Navicular Bone ct findings in 55 cases
American Journal of Roentgenology, 1993Co-Authors: Z S Kiss, K M Khan, P J FullerAbstract:OBJECTIVE: The purpose of this article is to present the CT findings in 55 cases of tarsal Navicular stress fracture before and after treatment and to describe the CT protocol used. MATERIALS AND METHODS: Fifty-five Navicular stress fractures in 54 patients whose initial and follow-up CT scans were available for study were retrospectively reviewed. In most cases, contiguous 1.5-mm axial and 3-mm coronal scans of the Navicular Bone had been obtained. Both feet were scanned for comparison. Follow-up scans were obtained between 4 weeks and 6 years. RESULTS: On review, fractures were evident in all cases, but six small fractures (11%) were missed at the initial interpretation. All fractures involved the central third of the proximal dorsal margin of the Navicular Bone. Fifty-three fractures (96%) were partial. Forty-three partial fractures were linear, five were linear with Bone fragments, and five were rim defects with ossicles. In 13 cases (24%) the fracture was small, 10% or less of Bone height. The earliest sign of healing, slight dorsal cortical bridging, was seen in three of eight cases in which follow-up was done at 6 weeks. Firm cortical union was noted in 10 (32%) of 31 by 4 months. Nonunion occurred in 12 and was indicated by the persistence of the fracture gap and lack of cortical healing. Medullary cysts (five) and cortical notching (two) were noted to persist after complete healing. CONCLUSION: CT scanning is a suitable method for detecting Navicular stress fracture and for performing follow-up examinations. Small fractures may be overlooked owing to lack of familiarity with their appearance.
L H Gandolfo - One of the best experts on this subject based on the ideXlab platform.
-
the symptomatic accessory tarsal Navicular Bone assessment with mr imaging
Radiology, 1995Co-Authors: Theodore T Miller, Ronald B Staron, Frieda Feldman, M Parisien, W J Glucksman, L H GandolfoAbstract:PURPOSE: To determine if a symptomatic accessory Navicular Bone, a normal variant, displays a pattern of altered signal intensity on magnetic resonance (MR) images indicative of an abnormality that could account for the patient's foot pain. MATERIALS AND METHODS: Both feet were imaged in seven patients with an accessory Navicular Bone on radiographs and unilateral foot pain. Five patients had focal medial foot pain, and two had vague, diffuse pain. T1-weighted spin-echo and T2-weighted fat-suppressed sequences were used. RESULTS: A Bone marrow edema pattern (BMEP) was noted in the accessory Navicular Bones of the five patients with focal pain and in the adjacent Navicular tuberosities of three of them. The two patients with vague pain showed no osseous or soft-tissue abnormalities. Two patients with positive MR images underwent surgical excision of the accessory Navicular Bone, and histologic examination revealed osteonecrosis in one patient. CONCLUSION: The BMEP in a symptomatic accessory Navicular Bone ...
Z S Kiss - One of the best experts on this subject based on the ideXlab platform.
-
the bipartite tarsal Navicular Bone radiographic and computed tomography findings
Journal of Medical Imaging and Radiation Oncology, 1995Co-Authors: A Shawdon, Z S Kiss, P FullerAbstract:SUMMARY Two cases of bipartite tarsal Navicular Bone are presented. The radiographic and computed tomography (CT) findings of this anatomical variant are described. Correct recognition of this entity is important, both because it may be the cause of symptoms perse, and because it may be misdiagnosed as a fracture. When plain films are not diagnostic, CT scanning is helpful in distinguishing between a fracture and this variant.
-
stress fractures of the tarsal Navicular Bone ct findings in 55 cases
American Journal of Roentgenology, 1993Co-Authors: Z S Kiss, K M Khan, P J FullerAbstract:The purpose of this article is to present the CT findings in 55 cases of tarsal Navicular stress fracture before and after treatment and to describe the CT protocol used.Fifty-five Navicular stress fractures in 54 patients whose initial and follow-up CT scans were available for study were retrospectively reviewed. In most cases, contiguous 1.5-mm axial and 3-mm coronal scans of the Navicular Bone had been obtained. Both feet were scanned for comparison. Follow-up scans were obtained between 4 weeks and 6 years.On review, fractures were evident in all cases, but six small fractures (11%) were missed at the initial interpretation. All fractures involved the central third of the proximal dorsal margin of the Navicular Bone. Fifty-three fractures (96%) were partial. Forty-three partial fractures were linear, five were linear with Bone fragments, and five were rim defects with ossicles. In 13 cases (24%) the fracture was small, 10% or less of Bone height. The earliest sign of healing, slight dorsal cortical br...
-
stress fractures of the tarsal Navicular Bone ct findings in 55 cases
American Journal of Roentgenology, 1993Co-Authors: Z S Kiss, K M Khan, P J FullerAbstract:OBJECTIVE: The purpose of this article is to present the CT findings in 55 cases of tarsal Navicular stress fracture before and after treatment and to describe the CT protocol used. MATERIALS AND METHODS: Fifty-five Navicular stress fractures in 54 patients whose initial and follow-up CT scans were available for study were retrospectively reviewed. In most cases, contiguous 1.5-mm axial and 3-mm coronal scans of the Navicular Bone had been obtained. Both feet were scanned for comparison. Follow-up scans were obtained between 4 weeks and 6 years. RESULTS: On review, fractures were evident in all cases, but six small fractures (11%) were missed at the initial interpretation. All fractures involved the central third of the proximal dorsal margin of the Navicular Bone. Fifty-three fractures (96%) were partial. Forty-three partial fractures were linear, five were linear with Bone fragments, and five were rim defects with ossicles. In 13 cases (24%) the fracture was small, 10% or less of Bone height. The earliest sign of healing, slight dorsal cortical bridging, was seen in three of eight cases in which follow-up was done at 6 weeks. Firm cortical union was noted in 10 (32%) of 31 by 4 months. Nonunion occurred in 12 and was indicated by the persistence of the fracture gap and lack of cortical healing. Medullary cysts (five) and cortical notching (two) were noted to persist after complete healing. CONCLUSION: CT scanning is a suitable method for detecting Navicular stress fracture and for performing follow-up examinations. Small fractures may be overlooked owing to lack of familiarity with their appearance.
