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.
Yovich JV, Hilbert BJ, McGill CA.Nineteen cases of fracture of the distal phalanx in horses are reviewed. This represented 1.1% of the total number of horses seen at Murdoch University Veterinary Hospital (MUVH) over a 32-month period. All horses were managed conservatively. Eight horses made a complete recovery. Three are being trained again and are not lame. Four horses made a limited recovery. Two horses are still resting and one horse was killed humanely when it still showed lameness after 2 years. One horse was killed humanely after the fracture was first diagnosed.
Trotter GW, McIlwraith CW, Norrdin RW, Turner AS.Degenerative joint disease of the proximal interphalangeal joint was diagnosed in 9 joint of 6 horses. All of the horses were 3 years old or younger and the affected joints were in the hindlimbs. Radiographic evidence of osteochondrosis involving the distal end of the proximal phalanx was apparent in 5 joints. Lameness and local soft tissue swelling were prominent in all cases. In 1 horse euthanatized tissues because of lameness, histologic examination of joint tissues revealed osteochondrosis as well as severe osteoarthritis. Surgical arthrodesis of the affected joint was performed on 2 horse...
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.
Hickman J.Sir Frederick Hobday's service as a Veterinary Officer in the Army Veterinary Corps during the Great War 1914-1918 is recorded. This is followed by a description of the fractures of the distal forelimb which can be treated satisfactorily by surgery, and includes fractures of the carpal, the small metacarpal, the proximal sesamoid bones, the first phalanx and the extensor process of the third phalanx.
Hopper SA, Schneider RK, Ratzlaff MH, White KK, Johnson CH.To determine the ability of a full-limb transfixation pin cast to protect the distal portion of the equine forelimb from weight-bearing forces by measuring bone strain in vitro on cadaver limbs loaded in a mechanical testing machine. Methods: 6 forelimbs from 6 horses. Methods: Each limb was instrumented with 3 unidirectional metal foil electrical resistant strain gauges. Gauges were placed on the dorsal aspect of the distal portion of the radius and the mid-dorsal portion of the cortex of the third metacarpal bone and the first phalanx. Each limb was tested 3 times, once supported with a tran...
MacLellan KN, MacDonald DG, Crawford WH.A 4-month-old colt with stage I flexural deformity of the distal interphalangeal joint was diagnosed as having a type IV nondisplaced fracture of the extensor process of the 3rd phalanx. An inferior check ligament desmotomy and internal fixation of the fracture were performed. Favorable long-term results for internal fixation of extensor process fractures are presented.
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 ...
Caudron I, Grulke S, Farnir F, Aupaix R, Serteyn D.This study is part of a work to develop a radiographic method that defines objectively the individual conformation of an equine digit and its appropriate trimming. The authors used isolated distal limbs fastened on a rotation support with variable inclinations to study the influence of induced asymmetric bearings on various angles measured from specific radiographs. The digit responded to asymmetric bearings by 1. deformation of the hoof; 2. rotation of the phalanges; and 3. joint asymmetry or local articular space narrowing. The two last situations occurred mainly in the distal interphalangea...
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...
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)...
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...
Stutsel M, Jordan L, Smith C, Lee WY, Symonds N, Bell R, Young A.Foot-related lameness is common in Standardbred and Thoroughbred racehorses. Magnetic resonance imaging (MRI) provides information on both the soft tissue and osseous structures of the distal extremity. The aim of this study was to determine whether abnormalities identified on distal limb MRI differed between these two racehorse populations. Methods: The records of Standardbred and Thoroughbred racehorse distal extremity MRI examinations conducted at Camden Equine Centre and Ballarat Veterinary Practice between 2013 and 2023 were retrieved. Horses were included if pain causing lameness had bee...
Colla S, Johnson JW, McGilvray KC, Zanotto GM, Seabaugh KA.Therapeutic shoeing for horses is used to affect the palmar angle (PA) of the distal phalanx. These changes may influence the strain on the distal interphalangeal joint collateral ligaments (DIJCLs). This cadaveric study aimed to assess DIJCL strain under varying loads and PA adjustments. Using 26 cadaver forelimbs, eight optical markers were placed on one DIJCL for strain measurement under five different loads (1000-5000 newtons) at a neutral PA, followed by PA increases of 2°, 4°, and 6° and decreases of -2° and -4°. The results indicate that increases in PA corresponded to significantl...
Ennsmann LH, Licka TF.Most horses are used with horseshoes additionally supported by either dorsoabaxial or dorsal clips. The effects of such clips on bone density and shape of the distal phalanx are currently unclear. The aim of this study was to identify correlations between density and shape of the distal phalanx, comparing front hooves unshod or shod with standard shoes either with two dorsoabaxial clips or with a single dorsal clip. Researchers analyzed Oxspring radiographs of either the left or right front hoof from warmblood horses ( = 137) and ponies ( = 43) aged 3-28 years. The evaluation focused...
Giessen EJM, Stas EKL, Grinwis GCM, Veraa S.A 3-month-old Friesian colt presented with severe, progressive distal limb lameness in two limbs. Radiographic and postmortem full-body CT imaging revealed severe articular deforming osteolysis and osteoproliferation at the dorsodistal navicular bone margin and the adjacent distal phalanx proximo-palmar/proximo-plantar margin in two limbs, with the remainder of the distal interphalangeal joint being unaffected. Multiple other joints showed small osteolytic subchondral defects. Postmortem histopathological examination confirmed focal joint disease of both distal interphalangeal joints, without ...
El Brini Z, Mhar I, Bouktaib FE, Piro M, Daniel C, Alyakine H.Working equids are at high risk of musculoskeletal disorders due to strenuous labor, repetitive tasks, and harsh environmental conditions. This retrospective study describes the distribution of radiographically detected musculoskeletal findings in working equids presented to four Society for the Protection of Animals Abroad (SPANA) centers in Morocco, based on 498 animals and 1125 radiographs collected between 2015 and 2022. The study population was mainly composed of horses (78.1%), followed by donkeys (15.3%) and mules (6.6%). Most were males (65.7%), and the majority were between 5 and 15 y...
