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.
Bolen G, Busoni V, Jacqmot O, Snaps F.Although ultrasonography is widely used in equine orthopedics, its use in the distal portion of the digit is still limited. The purpose of this descriptive study was to document the normal ultrasonographic appearance of the palmarodistal aspect of the digital area imaged between the bulbs of the heels. Ultrasonographic images were obtained with a 7.5 MHz microconvex transducer in 10 fresh equine cadaver forelimbs and five soundhorses. Sagittal, parasagittal, and transverse images were obtained from the proximal aspect of the middle phalanx to the distal sesamoid bone. Anatomic sections were ob...
Lawson SE, Chateau H, Pourcelot P, Denoix JM, Crevier-Denoix N.As equine musculoskeletal models become common, it is important to determine their sensitivity to the simplifications used. A subject-specific distal forelimb model was created using bones extracted from CT scans to examine movement from in-vivo invasive-marker motion capture. The movements of the sesamoid bones were simulated using the constraints of maintaining an isometric virtual ligament and maintaining contact between the appropriate articular surfaces, creating a variable moment arm for the tendons. The simulation of the proximal sesamoid bones was compared to movement recorded in-vitro...
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-...
Hobbs SJ, Richards J, Matuszewski B, Brigden C.To develop and evaluate a marker cluster set for measuring sagittal and extrasagittal movement of joints in the distal portion of the forelimb in ponies. Methods: 4 ponies. Methods: 5 infrared cameras were positioned on a concrete walkway in a frontal-sagittal arc and calibrated. Four segments were defined: hoof, middle phalanx, proximal phalanx, and metacarpus. Rigid clusters with 4 retroreflective markers were placed on each segment. A static trial was recorded with additional anatomic markers on the medial and lateral joint lines. Those anatomic markers were removed, and kinematic data were...
Lejeune JP, Schneider N, Caudron I, Duvivier DH, Serteyn D.Ossification of collateral cartilages is a common radiographic finding in draught horses and indication of a high frequency of interphalangeal osteo-arthropathy have been found in Ardenner horses. This study first aimed at following the evolution of the digits of the forelimbs on radiographic images in a group of 32 Ardenner horses from weaning to 852 +/- 19 days and, secondly, at evaluating the clinical significance of the observed radiographic changes. At 250 +/- 21 days, only 23% of the horses presented a small separate ossification centre of collateral cartilages above the level of the dis...
Butcher MT, Bertram JE, Benzuidenhout AJ.The distal forelimb of the horse has a complex array of ligaments that play a critical role in determining function of the digit and are often associated with the initiation of foot pathologies. The collateral ligaments of the distal sesamoid bone (CLDS) play an important role in digit stabilization near the end of foot contact and there is also limited evidence to suggest that the CLDS stabilize the proximal interphalangeal joint (PIPJ) during weight bearing. By virtue of their anatomical attachments where the ligaments pass dorsal to the axis of rotation of the PIPJ, it is reasonable to assu...
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...
Busschers E, Richardson DW.A 16-year-old Thoroughbred gelding was examined because of chronic right forelimb lameness. Results: On radiographs of the right front foot, the distal interphalangeal (DIP) joint space was narrow, and osteophytes and periarticular bony proliferation indicative of severe osteoarthritis were seen. Arthrodesis of the right DIP joint was recommended to improve the horse's comfort on the limb. Results: The horse was anesthetized, and palmar and dorsal arthroscopic approaches were used to remove as much of the articular cartilage as was accessible. Holes were then drilled through the dorsal aspect ...
Taylor DD, Hood DM, Potter GD, Hogan HA, Honnas CM.To evaluate patterns of digital cushion (DC) displacement that occur in response to vertical loading of the distal portion of the forelimb in horses. Sample Population-Forelimbs from 10 horses with normal feet. Methods: Patterns of DC displacement induced by in vitro vertical limb loading were determined. Load-induced displacement of the DC was defined as the magnitude and direction of displacement of 6 radio-dense, percutaneously implanted markers in specific regions of the DC. The effects of solar support and nonsupport on displacement of the DC were compared. Results: Regional displacement ...
Andritzky J, Rossol M, Lischer C, Auer JA.To compare the precision obtained with computer-assisted screw insertion for treatment of mid-sagittal articular fractures of the distal phalanx (P3) with results achieved with a conventional technique. Methods: In vitro experimental study. Methods: Thirty-two cadaveric equine limbs. Methods: Four groups of 8 limbs were studied. Either 1 or 2 screws were inserted perpendicular to an imaginary axial fracture of P3 using computer-assisted surgery (CAS) or conventional technique. Screw insertion time, predetermined screw length, inserted screw length, fit of the screw, and errors in placement wer...
McGuigan MP, Walsh TC, Pardoe CH, Day PS, Wilson AM.Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6-13 degrees of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at t...
Zubrod CJ, Farnsworth KD, Tucker RL, Ragle CA.We describe the clinical, imaging, and necropsy findings of two horses with severe injury of the collateral ligaments of the distal interphalangeal (DIP) joint diagnosed using magnetic resonance (MR) imaging. In MR images it was possible to examine the collateral ligaments of the DIP joint from the origin at the middle phalanx to the insertion on the distal phalanx. Both horses in this report had abnormal high signal intensity within the collateral ligaments of the DIP joint, and one horse had abnormal high signal intensity within the bone of the distal phalanx on short tau inversion recovery ...
Benninger MI, Deiss E, Ueltschi G.We describe the clinical findings and radiographic abnormalities of a horse with a bipartite distal phalanx and a bipartite navicular bone of the right forelimb. Associated findings including suspected keratoma and degenerative joint disease of the distal interphalangeal joint are described and possible etiologies are discussed.
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 ...
Olivier-Carstens A.Ultrasonographic examinations were performed on the solar aspect of the distal phalanx of 10 feet of five normal live horses (Group 1), 22 feet of seven normal cadavers (Group 2), and nine feet of five horses with pathology of the dorsal solar aspect of the distal phalanx (Group 3). Lateromedial radiographs of the distal phalanx were made in all groups, and in Group 2, digits were sagitally sectioned after imaging. The ultrasonographic and radiographic appearance of the sagittal solar aspect of the distal phalanx was described. Measurements of the distance between the sole and the distal tip o...
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...
Story MR, Bramlage LR.Historically, there has been a consensus that conservative management of subchondral cystic lesions of the distal phalanx carries a poor prognosis. Surgical management has been advocated; however, there are no reports documenting its routine use and successful surgical treatment. Objective: To describe arthroscopically-guided curettage of distal phalangeal subchondral cystic lesions (SCLs) and report the qualitative and quantitative results in 11 affected horses age 16-33 months. Methods: Medical records of horses with previously treated lameness resulting from SCLs of the third phalanx were r...
Chateau H, Degueurce C, Denoix JM.To develop a method that allows quantification of the 3 anatomic rotations in the digital joints of moving horses and measure these rotations when horses are walking in a straight line on a hard track. Methods: 4 healthy French Trotter horses. Methods: Triads of ultrasonic kinematic markers were surgically linked to the 4 distal segments of the digits of the left forelimb of each horse. Three-dimensional (3-D) coordinates of these markers were recorded in horses walking in a straight line. The three angles of rotation of each digital joint were calculated by use of a joint coordinate system as...
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...
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.
Johnson KA, Smith FW.Lag screw fixation using single 4.5 mm cortical bone screws is a recommended technique for repair of mid-sagittal plane fractures of the distal phalanx in adult horses. However, implant infection and technical difficulties in obtaining adequate interfragmentary compression have made this surgical procedure somewhat controversial. We hypothesized that use of larger diameter screws would result in increased axial compression and improved stability of this fracture. Paired distal phalanges from the forelimbs of 10 adult horses were collected at necropsy and divided in half in the midsagittal plan...
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...
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...
Oke RA.A 5-year-old quarter horse mare presented with unilateral, severe, chronic forelimb lameness. Radiographs revealed extensive hoof wall separation and capsular rotation of the distal phalanx. Treatment included dorsal hoof wall resection, phenylbutazone, a bar shoe, and stall rest. Whether white line disease or laminitis was the primary lesion remains unclear.
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...
Oosterlaan-Mayer B, Back W, Sloet van Oldruitenborgh-Oosterbaan MM.All horses and ponies with laminitis treated at the Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, between 1995 and 1998 were analysed retrospectively (n = 152). Based on the results of this study and on the world-wide knowledge on laminitis a standardised treatment protocol was adopted in 1999. Fifty-eight patients have been treated for laminitis between 1999 and 2001 following the treatment protocol. Compared to our hospital-population (orthopaedic patients), mares and ponies are at higher risk developing laminitis, but the prognosis does not differ betwee...
Melo e Silva SR, Vulcano LC.Collateral cartilage ossification of the distal phalanx in the Brazilian Jumper horse is a common finding. The objective of this study was to evaluate the prevalence and the degree of ossification of the collateral cartilages of the distal phalanx in Brazilian Jumper horses. In an analysis of 652 collateral cartilages from the front feet of 163 horses, 93% of these cartilages had collateral cartilage ossification (P < 0.005), and 7% of these cartilages did not have any type of ossification. In ossified cartilages, 86.4% had ossification beginning from the base, and 6.6% had a separate cente...
Dyson SJ.It was hypothesised that in solar bone images of the front feet of clinically normal horses, or horses with lameness unrelated to the front feet, there would be less than a 10% difference in the ratio of uptake of radiopharmaceutical in either the region of the navicular bone, or the region of insertion of the deep digital flexor tendon (DDFT), compared to the peripheral regions of the distal phalanx. Nuclear scintigraphic examination of the front feet of 15 Grand Prix show jumping horses, all of which were free from detectable lameness, was performed using dorsal, lateral and solar images. Th...
Riccaboni P, Di Giancamillo M, Leonardi L, Di Giancamillo A, Cammarata G.This paper describes a rare malformation of the distal portion of the left foredigit of a 15-month-old half-bred colt which was severely lame. Radiological, pathological and tomographic studies revealed hypoplasia of the metacarpophalangeal skeleton, absence of the distal sesamoid and deformation of the distal phalanx. Morphological analysis of the lesion and computerised measurement of the width of the articular surface of the distal phalanx suggested an early fusion between the distal sesamoid and distal phalanx.
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...
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...
Morrison S.Maggot debridement therapy is a nontraumatic, minimally invasive method to treat infections in a foot compromised by chronic laminitis. A mechanical strategy must first be in place to address the instability of the distal phalanx and hoof capsule. Adverse reactions to maggot debridement therapy are uncommon and the only side effect observed has been irritation or hypersensitivity at the site. Chronic laminitic cases of sepsis/necrosis within the hoof benefit from this procedure due to the noninvasive, continuous debridement and healing properties provided by the larvae.
Rucker A.In the chronic-laminitic foot, severe soft-tissue compression and compromised circulation can result in osteitis and sepsis at the margin of the distal phalanx. Resultant inflammation and sepsis may cause the coronary corium to swell, drain, or separate from the hoof capsule, usually within 8 weeks of laminitis onset. Slow-onset cases of soft-tissue impingement can develop secondary to distal phalanx displacement due to lack of wall attachment. With either presentation, partial upper wall resection is required to reverse compression and vascular impingement by the hoof capsule. If the patholog...
Riccaboni P, Di Giancamillo M, Leonardi L, Di Giancamillo A, Cammarata G.This paper describes a rare malformation of the distal portion of the left foredigit of a 15-month-old half-bred colt which was severely lame. Radiological, pathological and tomographic studies revealed hypoplasia of the metacarpophalangeal skeleton, absence of the distal sesamoid and deformation of the distal phalanx. Morphological analysis of the lesion and computerised measurement of the width of the articular surface of the distal phalanx suggested an early fusion between the distal sesamoid and distal phalanx.
Scott EA, Snyder SP, Schmotzer WB, Pool R.Probable cause of fracture in a Paint gelding was a congenital bone defect involving the extensor process area of the right and left forelimb distal phalanges. Radiographically and histologically, subchondral bone cysts at the fracture lines were suspected. These cysts were thought to have developed in association with abnormal ossification centers at the extensor process areas of the third phalanx. Partial avulsion of weak extensor processes would then occur from natural forces exerted on these weakened bony prominences via the common digital extensor tendon. Support for osteochondrosis as a ...
Kaneps AJ, O'Brien TR, Redden RF, Stover SM, Pool RR.The distal phalanx and metacarpal physis of both forelimbs of 32 Thoroughbred foals 3-32 weeks of age were radiographed to identify those limbs with osseous bodies at a palmar process (PP) of the distal phalanx. Osseous bodies (ossicles) were identified radiographically in 19% of the foals. Sixteen of the 32 foals were selected for microradiographic and histological evaluation: 6 foals with radiographic evidence of ossicles and 10 foals without. Fourteen ossicles of the PP were observed radiographically. Ossicles were either a triangular bone fragment at the palmar aspect of the distal angle o...
Gaughan EM, Rendano VT, Ducharme NG.Over an 8-year period, 9 horses with septic pedal osteitis were admitted to the New York State College of Veterinary Medicine. Septic pedal osteitis was defined by the presence of purulent exudate combined with radiographic evidence of lysis of the distal phalanx. The condition described involved only the distal phalanx, the laminae and hoofwall, and the soft tissues of the sole. Treatment included curettage and removal of the affected portion of the distal phalanx through a ventral approach to the foot, combined with systemic administration of antibodies. Of the 9 horses, 7 returned to soundn...
Yovich JV.Fractures of the distal phalanx are an important cause of lameness referrable to the foot. Depending on the fracture configuration and articular involvement, conservative or surgical treatment may be required. Fractures of the distal phalanx have been divided into six categories based on fracture configuration. Discussion of clinical features, management, and prognosis for horses with distal phalangeal fractures is presented for each fracture type.
Martens P, Ihler CF, Rennesund J.A horse with a suspected injury of the distal phalanx was examined using radiography at day two and 19 after the onset of the lameness, with no definite diagnosis. Using computed tomography an incomplete fracture of the lateral wing of the distal phalanx was diagnosed at day 25. Based on computed tomography it was determined that the fracture probably did not enter the joint or involve the palmar cortex throughout its length which were of prognostic importance. The day following the CT examination a new oblique radiographic projection was made. In this radiography which was based on, and never...
Vandeweerd JM, Perrin R, Launois T, Brogniez L, Clegg PD, Desbrosse FG.To compare the precision of radiography and computed tomography (CT) preoperatively in the standing position for identification of guidelines for screw insertion in the distal phalanx, and to identify whether standing CT might improve operative time compared with preoperative radiographic planning. Methods: Experimental ex vivo study. Methods: Cadaveric equine thoracic limb pairs (n=10). Methods: Insertion of a 4.5 mm cortex screw in lag fashion into an intact distal phalanx was evaluated in 2 groups (n=10) of cadaveric equine thoracic limbs. In 1 group, the site, direction, and length of the ...
Goetz TE.The structural and vascular anatomy of the healthy equine foot is compared with the pathologic changes in the foot of horses with acute and chronic laminitis. The structural and vascular abnormalities present in the foot of horses with laminitis are demonstrated in order to explain the abnormal manner in which their feet grow. The medical, surgical, dietary, and endocrine management of acute and chronic laminitis is discussed. Various forms of hoof trimming beneficial to the reestablishment of normal digital perfusion, normal hoof growth, and normal spatial orientation among the distal phalanx...
Underwood C, Collins SN, van Eps AW, Mills PC, Allavena RE, Bailey SR, Medina Torres CE, Meizler A, Pollitt CC.No validated laminitis drug therapy exists, yet pharmaceutical agents with potential for laminitis prevention have been identified. Many of these are impractical for systemic administration but may be effective if administered locally. This study compared intraosseous infusion of the distal phalanx (IOIDP) with systemic intravenous constant rate infusion (CRI) to determine which was more effective for lamellar marimastat delivery. Ultrafiltration probes were placed in both forefeet of five horses to collect lamellar interstitial fluid as lamellar ultrafiltrate (LUF). Marimastat solution (3.5â€...
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...
Schiavo S, Cillán-GarcÃa E, Elce Y, Liuti T, Taylor SE.Solar foot penetration is one of the causes of deep digital flexor tendon injuries in horses, however, limited information is available on the prognosis for return to soundness in the absence of synovial sepsis. Objectives of this retrospective observational study were to describe low-field magnetic resonance imaging (MRI) findings and long-term outcome for a group of horses with this combination of clinical problems. Horses were included if low-field standing MRI of the foot was performed following puncture wounds, injury of the deep digital flexor tendon was diagnosed, and sepsis was confirm...
Redding WR, O'Grady SE.Hoof abscesses are probably the most common cause of acute severe lameness in horses encountered by veterinarians and farriers. Most affected horses show sudden, severe (acute) lameness; the degree of lameness varies from being subtle in the early stages to non-weight bearing. There is still debate between the veterinary and farrier professions as to who should treat a hoof abscess and the best method to resolve the abscess. Puncture wounds to the sole of the foot can introduce bacteria and debris to the solar surface of the distal phalanx and produce a fracture or a septic pedal osteitis.
Scott EA, Thrall DE, Sandler GA.Vascular supply of the equine forelimb was partially disrupted by ligation of the medial palmar and medial palmar digital arteries. Vascular architecture was evaluated before and after ligation by angiography. It was apparent from the present study that existing collaterals or newly formed collaterals, or both, were sufficient to maintain limb viability.
Zubrod CJ, Farnsworth KD, Tucker RL, Ragle CA.We describe the clinical, imaging, and necropsy findings of two horses with severe injury of the collateral ligaments of the distal interphalangeal (DIP) joint diagnosed using magnetic resonance (MR) imaging. In MR images it was possible to examine the collateral ligaments of the DIP joint from the origin at the middle phalanx to the insertion on the distal phalanx. Both horses in this report had abnormal high signal intensity within the collateral ligaments of the DIP joint, and one horse had abnormal high signal intensity within the bone of the distal phalanx on short tau inversion recovery ...
Oke RA.A 5-year-old quarter horse mare presented with unilateral, severe, chronic forelimb lameness. Radiographs revealed extensive hoof wall separation and capsular rotation of the distal phalanx. Treatment included dorsal hoof wall resection, phenylbutazone, a bar shoe, and stall rest. Whether white line disease or laminitis was the primary lesion remains unclear.
Morrison S.Laminitis is a disease of the suspensory apparatus of the distal phalanx, which can advance to the chronic stage with varying degrees of structural failure. Because the disease may ultimately lead to mechanical failure of the digit, a foot management plan is required to effectively and mechanically treat these cases. Many laminitis cases can be successfully rehabilitated back to athletic soundness, light use, breeding, or pasture soundness, whereas others suffer from permanent instability and never enjoy an acceptable level of comfort. To understand how to minimize damage in the acute laminiti...
Grosenbaugh DA, Morgan SJ, Hood DM.This review indicates that the patient-to-patient uniqueness commonly seen in chronic laminitis represents the variable presence of the digital pathologies. Although some degree of mechanical failure is always present, the secondary metabolic and growth dysplasias, vascular pathologies, and sepsis may or may not be evident. The presence and severity of these pathologies appear to have a more significant impact on the prognosis of individual cases than does the displacement of the distal phalanx. It should be reiterated that it is often the combined presence of these individual pathologies that...
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 ...
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...
Lejeune JP, Schneider N, Caudron I, Duvivier DH, Serteyn D.Ossification of collateral cartilages is a common radiographic finding in draught horses and indication of a high frequency of interphalangeal osteo-arthropathy have been found in Ardenner horses. This study first aimed at following the evolution of the digits of the forelimbs on radiographic images in a group of 32 Ardenner horses from weaning to 852 +/- 19 days and, secondly, at evaluating the clinical significance of the observed radiographic changes. At 250 +/- 21 days, only 23% of the horses presented a small separate ossification centre of collateral cartilages above the level of the dis...
Anderson BH, Turner TA, Kobluk CN.Successful treatment of a comminuted frontal plane fracture of the distal phalanx in a horse is described. The bone fractured through the solar canal, close to the insertion of the deep digital flexor tendon. A hoof case was used to reduce bending and tensile stresses on the solar surface by limiting expansion of the hoof wall during weightbearing. In addition, the heel was elevated, using 3 degrees wedge pads incorporated within the hoof cast, to reduce distraction at the fracture site caused by the pull of the deep digital flexor tendon. Two casts were used over a 4-month period. Complete ra...
Koblik PD, O'Brien TR, Coyne CP.The effect of dorsopalmar projection obliquity on calculation of distal phalangeal rotation (DPR) angle was determined in 8 feet obtained from 5 horses that had been euthanatized because of laminitis. A true lateromedial view of each foot served as a reference, with additional views taken at 5, 10, 15, and 20 degrees of x-ray tube head rotation in both a dorsal and in a palmar direction. Projection obliquity resulted in consistent underestimation of DPR angle. Where projection obliquity exceeded 10 degrees, there were significant (P less than 0.05) differences in DPR angle. The magnitude of un...
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...
de Zani D, Polidori C, di Giancamillo M, Zani DD.There are few studies on the correlations between radiographic measurements of the foot and abnormalities of specific structures found with magnetic resonance imaging (MRI). Objective: To document the relationship between radiographic measurements of the equine foot and the presence of lesions in the foot on MRI. We hypothesised that different radiographic measurements would be associated with specific lesions detected by MRI. Methods: Retrospective analysis of radiographs and MRI studies. Methods: Seventy-four feet from 52 lame horses were included. Twenty parameters were measured on radiogra...
Yovich JV, Stashak TS, DeBowes RM, Ducharme NG.Fractures of the distal phalanx of the forelimb were diagnosed in 5 colts and 3 fillies ranging in age from 2 weeks to 5 1/2 months at the time of fracture. Three fractures entered the distal interphalangeal joint and 6 fractures (one foal had bilateral fractures) were nonarticular. All foals with articular fractures became sound with conservative treatment. Four of 5 foals with nonarticular fractures became sound with conservative treatment and 1 foal developed separation of the hoof at the coronary band after application of acrylic around the hoof. On the basis of our observations in these f...
