The distal phalanx, also known as the coffin bone, is the innermost bone located within the hoof of a horse. It is a critical component of the equine skeletal system, providing structural support and playing a significant role in weight-bearing and locomotion. The distal phalanx is encased within the hoof capsule and interacts with various soft tissue structures, including the laminae, which connect the hoof wall to the bone. Conditions affecting the distal phalanx, such as fractures, infections, or laminitis, can have significant implications for a horse's mobility and overall health. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, biomechanics, pathology, and treatment options related to the distal phalanx in horses.
Steiner J, Richter H, Kaufmann R, Ohlerth S.Single-source dual energy (SSDECT) and detector-based spectral computed tomography (DBSCT) are emerging technologies allowing the interrogation of materials that have different attenuation properties at different energies. Both technologies enable the calculation of effective atomic number (EAN), an index to determine tissue composition, and electron density (ED), which is assumed to be associated with cellularity in tissues. In the present prospective observational study, EAN and ED values were determined for 16 zones in normal subchondral and trabecular bone of 37 equine cadaver limbs. Using...
Khaledi KA, Mirshahi A, Sardari K, Azizzadeh M, Ghasemi S.The Turkmen horse is one of the oldest breeds in the world with unique characteristics in agility, endurance and jump, being publicly acclaimed. Laminitis affects the limbs and decreases athletic performance. Radiographic evaluation is essential to confirm the sinking diagnosis in every breed of a horse suffering from laminitis. Since no information about distal phalanx radiographic measurements in this breed has been reported, the current study was designed and conducted. In the present study, 24 clinically sound registered Turkmen horses of both sexes (15 mares and nine stallions) were selec...
Germonpré J, Vandekerckhove LMJ, Raes E, Chiers K, Jans L, Vanderperren K.In this proof-of-concept study, the post-mortem feasibility of dual-energy computed tomography (DECT) in the detection of bone edema-like lesions in the equine foot is described in agreement with the gold standard imaging technique, which is magnetic resonance imaging (MRI). Unassigned: A total of five equine cadaver feet were studied, of which two were pathological and three were within normal limits and served as references. A low-field MRI of each foot was performed, followed by a DECT acquisition. Multiplanar reformations of DECT virtual non-calcium images were compared with MRI for the de...
Westman S, Cullen TE, Bergstrom TC, Edwards LA, Garcia TC, Stover SM.To evaluate the effect of the application of a novel fiberglass-glue cast (FGC) on the fracture gap width in experimentally created type III distal phalanx fractures in cadaveric specimens under simulated physiologic loads. Methods: Ex vivo biomechanical laboratory study. Methods: Nine unilateral adult equine cadaver forelimbs. Methods: Type III distal phalanx fractures were created in forelimb specimens, which maintained distal components of the passive stay apparatus. The fracture gap was measured at 5%, 20%, 25%, 50%, 75%, and 95% of fracture length (palmar articular border to solar margin)...
Reiser V, Reiser A, Licka TF.To identify and measure radiolucencies at the solear margin of the distal phalanx in radiographs of healthy and laminitic hooves. Methods: Clinical records and dorsoproximal-palmarodistal radiographs of equine forelimbs with radiological diagnoses of either laminitis (n = 40, L) or navicular syndrome (n = 40, NS). Methods: Outlines of the radiolucent structures at the solar margin were drawn in ImageJ, and a customized novel plugin "Arteries Analyzer/ImageJ" was used for measurements. The diverging radiolucencies outside the terminal arc of the distal phalanx were differentiated as arterial ch...
Larsen CD, Wilkinson TE, Roberts GD, Guess SC, Mattoon JS, Sanz MG.To evaluate the radiographic thickness of the dorsal hoof wall in normal draft horse feet. Methods: 33 adult draft horses with no history of laminitis, no clinically obvious lameness, and visibly unremarkable front feet were included. Methods: This was a prospective, descriptive study of clinically normal draft horses' front feet. Lateromedial radiographs were acquired of the front feet. A ratio of the dorsal hoof wall thickness to the length of the distal phalanx (DHWP3 ratio) was calculated. Results: The dorsal hoof wall thickness to length of the distal phalanx was calculated as 0.33 ± 0.0...
Nocera I, Sorvillo B, Sgorbini M, Aliboni B, Citi S.Few studies have established the normal radiographic anatomical development of the donkey foal and, to date, no data are available for mules. Our aim was thus to evaluate the radiographic development of the fore digit and carpal joint in the mule foal from 0 to 3 months of age. Ten forelimbs of five healthy full-term mule foals were included. Radiographs of the fore digit lateromedial and dorsopalmar and the carpus dorsopalmar were performed weekly for the first month of age, and bi-monthly during the following two months. Fore digit growth plate closure times, morphological, angular, and line...
Smith S, Yohe LR, Solounias N.It has been recognized as early as the Victorian era that the apex of the distal phalanx has a distinct embryological development from the main shaft of the distal phalanx. Recent studies in regenerative medicine have placed an emphasis on the role of the apex of the distal phalanx in bone regrowth. Despite knowledge about the unique aspects of the distal phalanx, all phalanges are often treated as equivalent. Our morphological study reiterates and highlights the special anatomical and embryological properties of the apex of the distal phalanx, and names the apex "the bony cap" to distinguish ...
Hollenbach E, Robert MP, le Roux C, Smit Y.If the number of events alone is considered, endurance riding is the fastest growing and the second-most popular Fédération Equestre Internationale (FEI) discipline. Lameness is the most common cause of elimination from endurance races worldwide. To the authors' knowledge, no studies have been published investigating the prevalence of radiographic changes in the forelimb digits and metacarpophalangeal joints (MCP) of endurance racehorses in South Africa. Unassigned: Investigate the prevalence of radiographic changes in the forelimb digits and MCP joints of South African endurance racehorses....
Ammann L, Ohlerth S, Fürst AE, Jackson MA.To determine morphological characteristics of subchondral cystic lesions (SCLs) in the proximal phalanx (PP) of adult horses. Methods: Radiographs and/or CT scans of PP from 46 horses. Methods: There were horses with a SCL in PP, which was diagnosed by radiography and/or computed tomography, included. Additional data (signalment, history, orthopedic examination) were collected retrospectively for each case. Results: Forty-six horses met the required inclusion criteria, with a total of 62 SCLs. Forty-three SCLs (70.5%) were located in the proximal PP (group A). Forty-four percent of these were ...
Lean NE, Zedler ST, Van Eps AW, Engiles JB, Ford M, Stefanovski D, Walsh DM, Pollitt CC.Surgical stabilisation of the distal phalanx (DP) is a potential therapeutic strategy for severe acute laminitis. Objective: To evaluate the effects of locking compression plate (LCP) fixation of the DP to the dorsal hoof wall. Methods: Ex vivo and in vivo experiments. Methods: A T-shaped LCP was applied to one limb per pair in six pairs of cadaver forelimbs subjected to a combination of thermally induced lamellar failure and vertical load to simulate severe acute laminitis. Standard radiographic measurements were used to compare DP displacement. The LCP was then applied to one forefoot in 12 ...
Fairburn AJ, Sherlock CE, Mair TS.Radiography is a standard diagnostic test for horses with suspected fractures of the palmar/plantar processes (PP) of the distal phalanx, however published studies evaluating the diagnostic utility for radiography are currently lacking. The objectives of this retrospective, diagnostic case-control study were to determine the sensitivity of radiographs for the detection of PP fractures, and determine the diagnostic utility of the palmar/plantar oblique projections of the PP for the identification of PP fractures compared to standard radiographic series. The medical records of horses undergoing...
Sannajust K, Spriet M, Anishchenko S, Beylin D.Maximal standardized uptake values (SUV ) are commonly used for the interpretation of PET studies. Limited information regarding the SUV of F-NaF PET in horses is currently available in the literature. The goals of this retrospective secondary analysis study were to provide reference values for F-NaF SUV in the equine distal extremity and assess the effect of attenuation correction. Nonattenuation corrected (NAC) and CT-based attenuation corrected (CTAC) SUV were obtained from 19 feet and 19 fetlocks. Twenty regions of interest (ROIs) were defined for the foot and 22 for the fetlock. Areas p...
Nagel H, Lang H, Sole Guitart A, Lean N, Allavena R, Sprohnle-Barrera C, Young A.This case series presents a 20-year-old Quarter horse gelding and a 10-year-old Thoroughbred gelding with a histologic diagnosis of aggressive submural neoplasia, including an anaplastic sarcoma and a squamous cell carcinoma respectively. The current case series describes these neoplasias with radiography, computed tomography, magnetic resonance imaging and histopathology with immunohistochemistry. The purpose of this case series is to identify the clinical pattern of chronic reoccurring lameness in these cases and highlight the appearance of expansile osteolytic pathology of the distal phalan...
Grenager NS.Endocrinopathic laminitis (EL) primarily occurs because of insulin dysregulation (ID) mediated through downstream effects of insulin on IGF-1R in lamellar tissues. There is likely contributing vascular and metabolic dysfunction within the lamellae, but EL is relatively non-inflammatory. EL is associated with lamellar stretching, proliferation, and failure, ultimately causing failure of the suspensory apparatus of the distal phalanx. Proper education regarding mitigating risk factors makes this a largely preventable cause of laminitis. Annual hoof evaluation plus screening geriatric horses for ...
Sato F, Otsuka N, Kuwano A.The shape of the white line of the hoof is closely related to the shape of the notch on the dorsal distal bearing border of the distal phalanx (P3). In this study, a radiographic survey of the P3 of both forelimbs of 163 Thoroughbred yearling horses was conducted. The correlation of the depth and width of the notch were analyzed with the toe white line separation grades (0 to 3). As a result, the toe white line separation grade increased, the depth and the width of the notch also increased significantly. Radiographic examination of the P3 of the forelimbs might be useful for deciding whether t...
Pauwels F, Hartmann A, Alawneh J, Wightman P, Saunders J.The poor soft tissue conspicuity of CT can be improved by using intra-arterial CT Angiography (CTA), and intra-articular and intra-bursal contrast enhanced CT (CTAR). This retrospective study describes a combination protocol of CT and CTA of the horse's foot, and CTAR of the distal interphalangeal joint and navicular bursa. It is hypothesized this would provide a comprehensive overview of the range and severity of distal limb pathology. Radiology reports of all horses admitted for distal limb CT over a 5 year period were reviewed. All horses with a complete four stage CT examination and radiol...
Smanik LE, Stefanovski D, Reilly PT, Richardson DW.Type II distal phalanx (P3) fractures are a well-described cause of lameness in horses. Reports on outcome following internal fixation of type II P3 fractures are lacking, and with little emphasis on complications. Objective: To describe a technique for internal fixation of type II P3 fractures, and evaluate whether specific variables influenced post-operative complications or a horse's ability to return to work. Methods: Retrospective case series. Methods: Medical records of 51 horses with CT-guided internal fixation of type II P3 fractures were reviewed. Outcome data were acquired from race ...
Cardona GA, Uribe A, Ortved K.The economic relevance, populational importance and expansion of the Colombian Paso Horse to other latitudes calls for a growth in studies based on this type of horse. Lack of written reports about the relationship of the distal phalanx (DP) within the hoof in this gaited horse makes it important to establish a baseline to determine hoof health and possible alterations. The purpose of this study was to report, for the first time, the positional parameters of the distal phalanx, and its relationship within the hoof in sound Colombian Paso Horses. A latero-medial radiographic image of each dig...
Izing S, Béni D, Molnár S, Bakos Z, Bodó G.The objectives of this in vivo experimental study were to evaluate the feasibility of cortical screw insertion into the intact distal phalanx in standing sedated horses and to document potential postoperative complications. One cortical screw was randomly inserted in lag fashion into each distal phalanx in 9 horses. The second surgery on the contralateral limbs was performed 2-3 weeks after the first operation, when a 4.5-mm cortical screw was inserted in lag fashion into the distal phalanx of sedated horses following perineural analgesia. Following surgery, the drill hole was filled with an a...
Salinas P, Lira-Velásquez D, Bongiorno A, Sandoval C.The aim of this study was to quantify the distribution of aligned and non-aligned collagen in cross-sections of the superficial digital flexor tendon (SDFT) and deep digital flexor tendon (DDFT) in different levels of the distal forelimb of equines diagnosed with NS (Navicular Syndrome). Sixty equine forelimbs were collected. Was compared two groups (NA, Not affected vs. NS-group) by t-Student. Diagnosis of NS was based on clinical and lameness examination, diagnostic analgesia and radiological findings. The proportion of aligned and non-aligned collagens at 2 levels for the SDFT and 3 levels ...
Mageed M, Elfadl A.An 18-year-old Quarter Horse mare was evaluated because of moderate left forelimb lameness of 4 weeks' duration. The clinical evaluation and diagnostic perineural analgesia localized the lameness to the distal portion of the left forelimb. There was swelling on the dorsal and lateral aspect of the coronary band. Radiography, ultrasound, magnetic resonance imaging, and computed tomography of the foot revealed circumscribed well-capsulated soft tissue mass causing a focal deformation of the dorsolateral border of the middle phalanx. The treatment aimed to remove the mass surgically and stabiliz...
Norvall A, Spriet M, Espinosa P, Ariño-Estrada G, Murphy BG, Katzman SA, Galuppo LD.Increased 18 F-Sodium Fluoride (18 F-NaF) uptake at the chondrosesamoidean ligament (ChSL) attachment on the distal phalanx was identified in an exploratory positron emission tomography (PET) study. The prevalence and significance of this lesion has not been previously investigated. Objective: The goal of this study was to assess the prevalence of this lesion, its association with other imaging findings and with clinical signs. Methods: Retrospective cross-sectional analytical study. Methods: All horses with 18 F-NaF PET and computed tomography (CT) imaging of the feet performed between Octobe...
Leonardi F, Angelone M, Biacca C, Battaglia B, Pecorari L, Conti V, Costa GL, Ramoni R, Grolli S.Keratoma is a nonmalignant horse tumor that grows in the space between the horn of the hoof and the distal phalanx. Keratoma causes lameness in the horse, and surgical excision is the treatment of choice. Four horses underwent removal of a keratoma by complete hoof wall resection. The remaining wound was treated with platelet-rich plasma (PRP) combined with a sterile three-dimensional polylactic acid scaffold. The PRP was applied at 3, 6, 9, 12, 15, and 18 days postoperatively. The surgical site was cleaned with gauzes and swabs soaked in Ringer's lactate solution before applying PRP and the ...
Stewart HL, Werpy NM, McIlwraith CW, Kawcak CE.To describe the effects of distal limb immobilization and remobilization in the equine metacarpophalangeal joint. Methods: Randomized, prospective experimental study. Methods: Eight healthy, skeletally mature horses. Methods: One forelimb of each horse was immobilized in a fiberglass cast for 8 weeks; this was followed by 12 weeks of a treadmill-based training program after the cast had been removed. Clinical examinations, radiography, computed tomography (CT), nuclear scintigraphy, MRI, and histomorphometry were used to examine the third metacarpal (MC3), proximal phalanx, proximal sesamo...
Seghrouchni M, Elkasraoui H, Piro M, Alyakine H, Bouayad H, Chakir J, Tligui N, Elallali K, Azrib R.Tbourida is a traditional Moroccan equestrian sport in which 15 horses gallop 200 m in a line while riders fire into the sky with muskets. The stop is the finale and representative demands of this equestrian event. Such particular sudden stop after a fast gallop requires a hyperextension of the metacarpophalangeal joint. Indeed, it is well known that Tbourida show predisposes horses to different injuries of the hard and soft tissues of the distal forelimbs. Yet, there is a paucity of research that examined such lesions. The aim of the present study was to investigate for the first time the typ...
Balducci JJ, Barrett MF, Moorman VJ.Subchondral or osseous cyst-like lesions within the distal aspect of the middle phalanx are not commonly reported in equids. These osseous lesions, which can communicate with the distal interphalangeal joint, can result in significant lameness and may not respond well to medical management. This report describes the clinical, diagnostic imaging, and surgical management of a 4-year-old mixed breed gelding where medical management of a chronic subchondral osseous cyst-like lesion of the middle phalanx, which communicated with the distal interphalangeal joint, was unsuccessful. A successful outco...
Mizobe F, Nomura M, Kanai K, Ishikawa Y, Yamada K.Six Thoroughbred racehorses with palmar process fractures of the distal phalanx were evaluated with standing magnetic resonance imaging (sMRI). In all the cases, the fractures were detectable on T1-weighted images and fat-suppressed images. Furthermore, multi-planar reconstruction images were useful for assessing the articular involvement of the fractures. Follow-up sMRI was obtainable in 3 cases, which revealed that the area of high signal intensity on fat-suppressed images decreased over time as symptoms improved. Our findings support the use of sMRI for the detailed evaluation of distal pha...
Walmsley EA, Jackson M, Wells-Smith L, Whitton RC.Subchondral bone injury at the palmar/plantar aspect of the condyles of the third metacarpal/metatarsal bone (MC/MT3) commonly causes lameness and poor performance in racehorses. Injury occurs due to repetitive loading, the magnitude of which may be influenced by the position of the distal phalanx relative to the ground surface, i.e. the solar angle. The association of solar angle and injury at the palmar/plantar condyles of distal MC/MT3 therefore warrants investigation. Objective: Investigate the relationship between solar angle and radiopharmaceutical uptake at the palmar/plantar aspect of ...
Rowan C, Puggioni A, Hoey SE, O'Leary JM, Kearney C, Connolly SE, Skelly C.The requirement to pack the sulcus of the equine foot as an aid to diagnostic interpretation before acquisition of dorsoproximal-palmarodistal oblique projections is debatable. The purpose of this study was to investigate the benefit of packing the sulcus in the assessment of normal anatomy. 23 cadaver limbs were radiographed in a podoblock (https://www.podoblock.com/products-page/podoblock/podoblock/) A non-packed image (NP) and a packed image (P) of the same foot were acquired. The image quality of P was graded against the reference NP by five observers, where -1=P was superior, 0=no differe...
Bosch G, de Mos M, van Binsbergen R, van Schie HT, van de Lest CH, van Weeren PR.Extracorporeal shock wave therapy (ESWT) is frequently used in equine practice, but little is known about its biological action. Objective: To study the effects of ESWT on matrix structure and gene expression levels in normal, physiologically loaded tendinous structures in ponies. Methods: Six Shetland ponies, free of lameness and with ultrasonographically normal flexor and extensor tendons and suspensory ligaments (SL), were used. ESWT was applied at the origin of the suspensory ligament and the mid-metacarpal region of the superficial digital flexor tendon (SDFT) 6 weeks prior to sample taki...
Kummer M, Geyer H, Imboden I, Auer J, Lischer C.The understanding of the normal position of the third phalanx (P3) and the distal sesamoid bone in relation to the size and shape of the hoof capsule in sound horses is helpful in the diagnosis of equine foot lameness. Some measurements on radiographs used to define the position of the pedal bone within the hoof capsule are significantly influenced by hoof trimming and the height of the withers. In this study, the front hooves of 40 Warmblood horses were radiographed twice, eight weeks apart, both before and after their hooves were trimmed by an experienced farrier. Using the software programm...
Pollitt CC.The equine hoof capsule protects the softer, more sensitive, structures within. Failure of the connection between hoof and bone (suspensory apparatus of the distal phalanx or SADP) results in the crippling lameness of laminitis. Active basal cell proliferation occurs principally in tubular hoof and proximal and distal lamellae. The remaining lamellae are virtually non-proliferative and the hoof wall moves past the stationary distal phalanx, by controlled activation and inhibition of constituent proteases. The lamellar corium derives most of its blood supply from the branches of the terminal ar...
Eliashar E, McGuigan MP, Wilson AM.Collapsed heels conformation has been implicated as causing radical biomechanical alterations, predisposing horses to navicular disease. However, the correlation between hoof conformation and the forces exerted on the navicular bone has not been documented. Objective: The angle of the distal phalanx in relation to the ground is correlated to the degree of heel collapse and foot conformation is correlated to the compressive force exerted by the deep digital flexor tendon on the navicular bone. Methods: Thirty-one shod Irish Draught-cross type horses in routine work and farriery care were trotte...
Brown NA, Pandy MG, Kawcak CE, McIlwraith CW.A detailed musculoskeletal model of the distal equine forelimb was developed to study the influence of musculoskeletal geometry (i.e. muscle paths) and muscle physiology (i.e. force-length properties) on the force- and moment-generating capacities of muscles crossing the carpal and metacarpophalangeal joints. The distal forelimb skeleton was represented as a five degree-of-freedom kinematic linkage comprised of eight bones (humerus, radius and ulna combined, proximal carpus, distal carpus, metacarpus, proximal phalanx, intermediate phalanx and distal phalanx) and seven joints (elbow, radiocarp...
Dyson S, Murray R, Schramme M, Branch M.Foot pain is a common cause of equine lameness and there have been significant limitations of the methods available for the diagnosis of the causes of foot pain (radiography, nuclear scintigraphy and ultrasonography). Until recently, magnetic resonance imaging (MRI) in the horse has been limited to examination of cadaver limbs. Objective: Our purpose was to 1) describe MRI of the foot in live horses, 2) describe MRI findings in horses with foot pain in which a definitive diagnosis could not be established by alternative means and 3) correlate MRI findings with other methods of clinical investi...
Pollitt CC, Visser MB.In acute laminitis, the suspensory apparatus of the distal phalanx fails at the lamellar dermal/epidermal interface. A grading system for the histopathology of laminitis is based on the consistent pattern of histologic changes to the secondary epidermal lamellae, basal cells, and basement membrane that occur as carbohydrate-induced laminitis develops. The actual trigger factors of carbohydrate-induced laminitis remain unidentified.
Engiles JB, Galantino-Homer HL, Boston R, McDonald D, Dishowitz M, Hankenson KD.Although the equine distal phalanx and hoof lamellae are biomechanically and physiologically integrated, bony changes in the distal phalanx are poorly described in laminitis. The aims of this study were (1) to establish a laminitis grading scheme that can be applied to the wide spectrum of lesions seen in naturally occurring cases and (2) to measure and describe changes in the distal phalanx associated with laminitis using micro-computed tomography (micro-CT) and histology. Thirty-six laminitic and normal feet from 15 performance and nonperformance horses were evaluated. A laminitis grading sc...
Linford RL, O'Brien TR, Trout DR.Lameness examinations and radiography of the distal phalanx and associated soft-tissue structures of the front feet of 103 Thoroughbred racehorses, 4 to 9 years old, were performed to determine normal radiographic appearance and morphometry. Of 103 horses examined, 41 were used in the study that were without clinical signs of foot problems or lameness, had raced at least twice prior to radiography, and had raced at least twice more in the 6 months after radiography. Lateromedial and dorsoproximal-palmarodistal radiographic views of each front distal phalanx were used to measure 28 bone and sof...
Fretz PB, Cymbaluk NF, Pharr JW.Long-bone growth at the distal ends of the radial bones, the distal ends of the 3rd metacarpal bones, the distal ends of the 3rd metatarsal bones, and the proximal ends of the proximal phalangeal bones (of thoracic and pelvic limbs) was quantitatively analyzed in 9 Thoroughbred-Quarter Horse foals from birth to 2 years of age. Metal growth markers were surgically implanted in the bones of the animals at 2 to 4 days of age. Radiographs of the bones were made on the day of surgical manipulation, the next day, and then once a week for 8 months, and once a month thereafter for an additional 18 mon...
Kroekenstoel AM, van Heel MC, van Weeren PR, Back W.Distal limb conformation is generally accepted to be an important item with respect to performance and soundness in mature horses, but little is known about the developmental aspects. Objective: To gain insight into the development of distal limb conformation and to assess the possible consequences of uneven feet in foals. Methods: Conformation of the distal front limbs of 23 Warmblood foals was scored visually and measured using radiographs, at ages 27 and 55 weeks. At the same ages, pressure measurements were made under both front feet. Results: At both ages the hoof-pastern axis was broken-...
Parks A.The list of possible diagnoses derived from matching anatomic structures or tissues to pathologic processes is inevitably broad in nature. Understanding and observation of distal limb function, conformation, and balance is the basis of identifying where the greatest abnormal stresses within the distal limb are likely to occur. This is key to focusing the diagnostic process and, in some instances, to treating the horse when a definitive diagnosis cannot be achieved.
Ammann L, Ohlerth S, Fürst AE, Jackson MA.To determine morphological characteristics of subchondral cystic lesions (SCLs) in the proximal phalanx (PP) of adult horses. Methods: Radiographs and/or CT scans of PP from 46 horses. Methods: There were horses with a SCL in PP, which was diagnosed by radiography and/or computed tomography, included. Additional data (signalment, history, orthopedic examination) were collected retrospectively for each case. Results: Forty-six horses met the required inclusion criteria, with a total of 62 SCLs. Forty-three SCLs (70.5%) were located in the proximal PP (group A). Forty-four percent of these were ...
van Hoogmoed LM, Snyder JR, Thomas HL, Harmon FA.Prepurchase examinations of horses are used increasingly as a means of evaluating future soundness. Data is lacking in the literature of the radiographic findings and results of the lameness examination of comprehensive prepurchase examinations. Objective: To summarise the clinical and radiographic findings of prepurchase examinations and determine if radiographic findings correlated with the lameness examination and sale outcome. Methods: Records of 510 cases were reviewed, radiographs evaluated and grades assigned the navicular bone, distal phalanx, and tarsus. Follow-up information on the h...
O'Grady SE.Laminitis is considered chronic once the distal phalanx has displaced within the hoof capsule. Chronic laminitis generally occurs as a direct sequel to acute laminitis. Clinical evaluation of chronic laminitis is best performed with a thorough clinical examination and radiography. The mainstay of hoof care is therapeutic farriery. In this article, the goals and principles of hoof care, the appropriate trim and various shoes that form the bulk of farriery for chronic laminitis, and surgical treatments are discussed.
Hunt RJ, Wharton RE.Chronic laminitis involves laminar morphologic changes resulting in digital collapse and can vary greatly in its clinical manifestation depending on duration, severity of lameness, and stability of the distal phalanx/hoof wall interface. Accurate assessment of the whole patient is mandatory and consideration must be given to signalment, occupation, and owner expectations, as well as history and etiology, which often predict the broad course of the disease. Diagnosis is made via physical examination with adjunctive serial radiographic evaluation and possibly venography. Eventual functionality o...
Vallance SA, Bell RJ, Spriet M, Kass PH, Puchalski SM.To date, few reports exist comparing magnetic resonance imaging (MRI) and computed tomography (CT) for imaging of the equine distal limb, yet clinicians are required to decide which modality to use regularly. Objective: To report and compare anatomic visualisation scores obtained for CT, contrast enhanced CT (CECT) and standing low-field MRI (LFMRI) in the equine foot. Objective: Anatomic visualisation score discrepancies would exist between CT, CECT and LFMRI. Methods: Images of 22 lame horses (31 limbs) undergoing both CT and LFMRI of the foot were reviewed. When available, CECT images were ...
Pauwels F, Hartmann A, Alawneh J, Wightman P, Saunders J.The poor soft tissue conspicuity of CT can be improved by using intra-arterial CT Angiography (CTA), and intra-articular and intra-bursal contrast enhanced CT (CTAR). This retrospective study describes a combination protocol of CT and CTA of the horse's foot, and CTAR of the distal interphalangeal joint and navicular bursa. It is hypothesized this would provide a comprehensive overview of the range and severity of distal limb pathology. Radiology reports of all horses admitted for distal limb CT over a 5 year period were reviewed. All horses with a complete four stage CT examination and radiol...
Dyson SJ, Tranquille CA, Collins SN, Parkin TD, Murray RC.There is little scientific evidence to support the premise that poor foot conformation predisposes to foot pain and lameness. Objective: To determine relationships between external characteristics of the hoof capsule and angles of the distal phalanx; to determine variability in shape of the distal phalanx; and to investigate association between distal phalanx angles and the injury causing lameness. Methods: Feet were documented photographically and radiographically. Linear and angle measurements were obtained for the hoof capsule and distal phalanx and compared statistically. Horses were categ...
Chateau H, Degueurce C, Denoix JM.Sharp turns are suspected to increase expression of several distal forelimb lamenesses even at the walk but the biomechanical consequences of such a movement remain unknown. Objective: To quantify the effects of a sharp turn at the walk on the 3-dimensional movements of the distal segments of the forelimb. Methods: Kinematics of the distal segments were measured in 4 healthy horses invasively with an ultrasonic system. Three-dimensional rotations of the digital joints were calculated by use of a joint coordinate system. Data obtained for a turn at the walk were compared to those obtained in a ...
Norvall A, Spriet M, Espinosa P, Ariño-Estrada G, Murphy BG, Katzman SA, Galuppo LD.Increased 18 F-Sodium Fluoride (18 F-NaF) uptake at the chondrosesamoidean ligament (ChSL) attachment on the distal phalanx was identified in an exploratory positron emission tomography (PET) study. The prevalence and significance of this lesion has not been previously investigated. Objective: The goal of this study was to assess the prevalence of this lesion, its association with other imaging findings and with clinical signs. Methods: Retrospective cross-sectional analytical study. Methods: All horses with 18 F-NaF PET and computed tomography (CT) imaging of the feet performed between Octobe...
Baxter GM.Clinical data from 12 cases of equine laminitis characterized by distal displacement of the distal phalanx (P3) were reviewed. Clinical features of horses that survived the syndrome were compared with the nonsurvivors to obtain prognostic indicators. Animals affected included 8 Quarter Horses, 2 Welsh ponies, 1 Thoroughbred, and 1 Arabian. Eight of the animals were females (67%), 2 were stallions, and 2 were geldings. The mean age of affected animals was 8.6 years (2 to 14 years), and the mean body weight was 442 kg. The survivors weighed less than the nonsurvivors (384 kg vs 473 kg, respectiv...
Bowker RM, Atkinson PJ, Atkinson TS, Haut RC.To examine articular cartilage of the distal interphalangeal (DIP) joint and distal sesamoidean impar ligament (DSIL) as well as the deep digital flexor tendon (DDFT) for adaptive responses to contact stress. Methods: Specimens from 21 horses. Methods: Pressure-sensitive film was inserted between articular surfaces of the DIP joint. The digit was subjected to a load. Finite element models (FEM) were developed from the data. The navicular bone, distal phalanx, and distal attachments of the DSIL and DDFT were examined histologically. Results: Analysis of pressure-sensitive film revealed signific...
Murray RC, Dyson SJ, Schramme MC, Branch M, Woods S.Chronic laminitis is a severe disease affecting the equine digit. It was hypothesized that magnetic resonance (MR) imaging would improve visualization of structures within the foot and pathology associated with chronic laminitis. This study aimed to describe the MR imaging findings in chronic laminitis, compare different pulse sequences for visualization of pathology, and to compare MR imaging with standard radiography. Twenty (10 forelimb, 10 hindlimb) cadaver limbs from 10 horses clinically diagnosed with chronic laminitis (group L) and 10 limbs without laminitis (group N) were used. Laterom...
Dyson S, Pool R, Blunden T, Murray R.There is limited knowledge about the interpretation of alterations in the distal sesamoidean impar ligament (DSIL) detected using magnetic resonance imaging (MRI) and their correlation with histopathology. Objective: There would be: 1) a correlation between histopathology and MRI findings; and 2) a relationship between MR abnormalities at the origin and the insertion of the DSIL, between insertion and body; and origin and body. Methods: Fifty limbs from 28 horses were examined using high-field MRI and histopathology. MR abnormalities of the DSIL, its origin on the navicular bone and its insert...
Leonardi F, Angelone M, Biacca C, Battaglia B, Pecorari L, Conti V, Costa GL, Ramoni R, Grolli S.Keratoma is a nonmalignant horse tumor that grows in the space between the horn of the hoof and the distal phalanx. Keratoma causes lameness in the horse, and surgical excision is the treatment of choice. Four horses underwent removal of a keratoma by complete hoof wall resection. The remaining wound was treated with platelet-rich plasma (PRP) combined with a sterile three-dimensional polylactic acid scaffold. The PRP was applied at 3, 6, 9, 12, 15, and 18 days postoperatively. The surgical site was cleaned with gauzes and swabs soaked in Ringer's lactate solution before applying PRP and the ...
Bowker RM, Van Wulfen KK, Springer SE, Linder KE.To examine macro- and microscopic characteristics of cartilage of the distal phalanx (ungual cartilage [UC]) and digital cushion in the equine foot and to relate them to the foot's function of energy dissipation. Methods: 85 horses and 5 foals of various breeds and ages. Methods: Feet, obtained at necropsy, were perfused with India ink (n = 30), latex (5), or polymer plastic (10). Select feet were examined histologically for tissue architecture and to identify elastic fibers. Immunochemistry to identify substance P peptides in nerves (feet from foals) and gold chloride impregnation of axons (n...
Pollitt CC, Collins SN.The suspensory apparatus of the distal phalanx (SADP) is functionally and clinically important. Objective: To investigate SADP form and function and the microanatomy of its insertion zone. Methods: Descriptive gross and microanatomy. Methods: The feet of 6 normal Standardbred horses were sectioned into blocks along the traditional perpendicular transverse axis and along functional axes of the SADP, decalcified and processed for staining with haematoxylin and eosin, Jones' periodic acid silver methenamine or Masson's trichrome stains. Results: In traditional midline toe transverse plane section...
Pauwels FE, Rogers CW, Wharton H, Flemming H, Wightman PF, Green RW.Hoof balance radiographs are commonly used as the basis for corrective farriery decision-making in horses, however there are limited published data quantifying effects of the stance of the horse or the horizontal radiographic beam angle. In this analytical study, the influence of variation of the horse's stance in the craniocaudal and lateromodial plane on hoof balance measurements as well as the influence of variation of the horizontal radiographic beam angle on dorsopalmar hoof balance measurements was examined. Distal left thoracic limb lateromedial radiographs were acquired using a standar...
