Metatarsal bones in horses are a group of long bones located in the hind limbs, extending from the tarsal bones to the phalanges. These bones play a role in supporting weight and facilitating locomotion. The equine metatarsus typically comprises the third metatarsal bone, also known as the cannon bone, and the second and fourth metatarsal bones, referred to as splint bones. The structure and health of these bones are significant for the overall mobility and performance of the horse. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, function, and clinical considerations of metatarsal bones in equine physiology.
White KK.Angular limb deformities in 3 foals were found to originate in the diaphyseal region of the 3rd metacarpal (2) and metatarsal (1) bones. In each case, treatment consisted of wedge ostectomy followed by compression plating. Two foals survived for useful performance; the 3rd was euthanatized because of ischemia of the operated limb. The condition appeared to resemble a similar syndrome in man involving tibial curvature.
Fretz PB, McIlwraith CW.Five young horses with fetlock varus deformities of 8 degrees or greater were treated by means of wedge osteotomy of the distal end of the 3rd metacarpal or metatarsal bone. Three patients were admitted to the Western College of Veterinary Medicine and 2 to Colorado State University. Their selection as surgical patients was based on the following criteria: (1) an angular limb deformity of 8 degrees or greater, (2) patient older than 120 days, (3) no evidence of lameness, and (4) no evidence of degenerative joint disease. The surgery was successful in all cases.
Auer JA, Martens RJ, Williams EH.Seventeen foals with angular limb deformities of the distal end of the radius (valgus: 26 limbs), distal end of the tibia (valgus: 6 limbs), and distal end of the 3rd metacarpal bone/metatarsal bone (varus: 4 limbs) were treated surgically by means of hemicircumferential division of the periosteum proximal to the involved growth plate, at the concave side of the bone. There was some correction in all cases. The best results were seen in the radius, where 22 of 25 limbs were corrected to a deviation of 4 degrees or less. Satisfactory correction was obtained in the 6 tibias, the 2 third metacarp...
Jakovljevic S, Gibbs C, Yeats JJ.The clinical features, radiographic findings, management and outcome in 13 cases of traumatic fracture of the hock joint are reported. The principal fracture sites were the distal tibial malleoli (5 cases), the fibular tarsal bone (4 cases), the tibial tarsal bone (3 cases) and the proximal end of metatarsal IV (one case). An additional small chip fracture of the central tarsal was noted in 2 cases. Three horses were destroyed immediately after diagnosis, 2 failed to recover following surgical intervention and one remained lame and was destroyed after 3 months' rest. Seven horses recovered com...
Sack WO, Orsini PG.One hundred three equine hocks, obtained from the postmortem room, were used to study the communication and injection of material into the distal intertarsal and tarsometatarsal joints. Excluding the hocks with fused central and 3rd tarsal bones, in 8.3% of hocks injected with low (clinical) pressure and in 23.8% injected with high pressure, the distal intertarsal and tarsometatarsal joints communicated by dissection of the material through 2 internal spaces: the tarsal canal and the space between the combined tarsal bones 1 and 2 tarsal bone 3. A "pop" sometimes felt when high pressure was us...
Goyal HO, MacCallum FJ, Brown MP, Delack JB.Measurements were made of growth at the extremities of all the long bones of the left limbs of 23 horses between 52 and 104 days of age. Growth rates were more rapid in the younger than in the older animals. Growth was more rapid in the hind limb than in the forelimb. Growth rates were greater for males than in females. Although this age group represents only two of the 60 or so months necessary for maturity to be reached, oxytetracycline bone-labelling produced results which are more precise than measurements obtained by other methods. This study provides a substantial amount of data for an a...
Rose RJ.The case histories of four horses with osteomyelitis involving the metacarpal and metatarsal bones are reviewed and the surgical treatments discussed. The horses recovered after curettage of all infected tissue and post operative drainage. The role of antibiotics in treatment is considered and reference is made to the acute treatment of deep wounds to avoid osteomyelitis.
Denny HR.The current trends in equine fracture treatment are reviewed. Surgical approach, method of fixation, the advantages of Association for the Study of Internal Fixation (ASIF) implants and the complications of treatment are discussed with reference to 21 fracture cases. Normal limb function was restored in four horses with fractures of the olecranon and one with a mid shaft fracture of the tibia following stabilisation of the fracture with plates. A horse with a chip fracture of the distal radius and three other animals with fractures of the lateral condyle of the third metacarpal bone were also ...
Jones RD, Fessler JF.ALTHOUGH METACARPAL TI-IV and metatarsal II-IV (MC II-IV, MT II-IV) fractures are frequent in horses and surgical intervention routine, a review of the current literature revealed little information about this subject. The authors have found only two complete accounts of this problem (1, 6). The incidence of suspensory desmitis has been previously reported (3), but we find no previous correla-tion of MC II-IV, MT II-IV fractures with suspensory, desmitis. On these bases, a re-trospective study was conducted. At Purdue University from 1967 through 1974, 50 Standardbred horses underwent sur-gery...
Meek DG, Dickinson EO.An illustrated approach to the medial aspect of the equine fetlock joint is described, whereby the collateral ligaments are transected. This approach is suggested as a possible technique for metatarsal or metacarpal bone fracture repair by retrograde pinning, arthrodesis of the fetlock joint and other joint and sesamoid bone surgery. The histological evidence of satisfactory healing is presented and the advantages and disadvantages are discussed.
Turner AS, Milne DW, Gabel AA.Long-bone fractures of 6 foals admitted consecutively to the Ohio State University Veterinary Hospital were treated successfully with ASIF dynamic compression plating. The cases included 2 foals with closed fracture of the metacarpus, and 1 foal each with open nonunion of the metatarsus, closed fracture of the radius, open fracture of the tibia, and open fracture of the ulna. Five of these foals became sound, with no deformity, so they could be trained for racing or showing. The 6th foal, a filly with nonunion, became "pasture-sound" and was scheduled for breeding. It was concluded that the dy...
Milne DW, Turner AS, Gabel AA.In the horse, surgical approaches for plating fractures of the ulna, radius, metacarpus, tibia, and metatarsus involved a single curvilinear skin incision and incision of the superficial fascia in a manner to prevent postoperative dehiscence. The tension side of the bones, as well as location of nerves, arteries, veins, and muscles, were the major determinants in developing these approaches for atraumatic surgery and short operative time.
Turner AS, Mills EJ, Gabel AA.Strain gauges were successfully bonded in vivo to the cranial, caudal, medial, and lateral aspects of the equine radium and tibia and to the dorsal, palmar, or plantar, medial, the lateral aspects of the metacarpus and metatarsus--all in the mid-diaphyseal region. Various activities were investigated, including walking, trotting or pacing, and standing up from anesthesia. The strain patterns showed that each stride produced a characteristic deformation cycle. The strains were measured and the axial loads were calculated as the horse performed certain activities. The tension band side of each b...
Morgan JW, Santschi EM, Zekas LJ, Scollay-Ward MC, Markel MD, Radtke CL, Sample SJ, Keuler NS, Muir P.To compare the orthogonal radiographic (OR) and computed tomographic (CT) appearance of paired Thoroughbred racehorse limbs with severe condylar fracture. Methods: In vitro study. Methods: Cadaveric paired limbs with severe condylar fracture (n=11 horses). Methods: Four standard radiographic and multiple transverse CT images were obtained of the fractured and contralateral limbs centering on the metacarpo/metatarsophalangeal (fetlock) joints. Radiographs and CT images were graded by 4 raters, and interobserver agreement was calculated. Imaging evaluations were supplemented by fetlock joint dis...
Furniss C, Carstens A, van den Berg SS.This study involves the evaluation of pre-purchase radiographic studies of South African Thoroughbred yearlings. Radiographic changes were recorded and compared with similar international studies. The study differs from other studies in that a lower prevalence of pedal osteitis (1.26%), dorsal osteochondral fragmentation of the metatarsophalangeal joint (1.60%), distal metacarpal sagittal ridge changes (15.7%), ulnar carpal bone lucencies (8.33%), carpal osteophytes (1.19%), distal intertarsal and tarsometatarsal joint radiographic changes (9.92%), tarsal osteochondrosis lesions (4.40%) and st...
Bischofberger AS, Ringer SK, Geyer H, Imboden I, Ueltschi G, Lischer CJ.To determine via histologic examination and scintigraphy the effect of focused extracorporeal shock wave therapy (ESWT) on normal bone and the bone-ligament interface in horses. Methods: 6 horses without lameness. Methods: Origins of the suspensory ligament at the metacarpus (35-mm probe depth) and fourth metatarsal bone (5-mm probe depth) were treated twice (days 0 and 16) with 2,000 shocks (energy flux density, 0.15 mJ/mm2). One forelimb and 1 hind limb were randomly treated, and the contralateral limbs served as nontreated controls. Bone scans were performed on days -1 (before ESWT), 3, 16,...
Miyakoshi D, Senba H, Shikichi M, Maeda M, Shibata R, Misumi K.This study aimed to evaluate whether radiographic abnormalities at yearling sales were associated with the failure to start racing at 2-3 years of age. Radiographic abnormalities in the carpal (n=852), tarsal (n=976), metacarpophalangeal (n=1,055), and metatarsophalangeal joints (n=1,031) from 1,082 horses, recorded at yearling sale, were reviewed. Eighty-two horses (7.6%) failed to start racing. Radiographic abnormalities such as wedged or collapsed tarsal bones, irregular lucency of a sagittal ridge at the distal aspect of the distal third metatarsal bone, and proximal dorsal fragmentation o...
Morgan DD, McClure S, Yaeger MJ, Schumacher J, Evans RB.To evaluate the effects of focused, extracorporeal shock wave therapy (ESWT) on the healing of wounds of the distal portion of the limbs in horses. Methods: Randomized controlled trial. Methods: 6 healthy adult horses. Methods: In each horse, a 4-cm-diameter full-thickness wound that included underlying periosteum was created on the dorsomedial aspect of each metacarpus and two 3-cm-diameter full-thickness wounds that included underlying periosteum were created on the dorsomedial aspect of each metatarsus. One randomly selected metacarpal wound and a randomly selected pair of metatarsal wounds...
Andrade DGA, Basso RM, Castiglioni MCR, Silva JP, Machado VMV, Laufer-Amorim R, Borges AS, Oliveira-Filho JP.Four causative mutations (D1, D2, D3*, and D4) of chondrodysplastic dwarfism have been described in the equine () gene. Homozygotes for one of these mutations and heterozygotes for any combination of these mutations exhibit the disproportionate dwarfism phenotype. However, no case description of homozygotes for D4 (D4/D4) has been reported in the literature, to our knowledge. We report 2 Miniature horses with the genotype D4/D4 in the gene. Clinically, the 2 dwarfs had a domed head that was large compared to the rest of the body, mandibular prognathism, and short and bowed limbs, mainly in t...
Kähn W, Palmer J, Vaala W.Various techniques for support and control of respiration in neonatal foals are described. It is crucial to evaluate respiration through frequent arterial blood gas analysis. Details for blood sampling from the metatarsal arteries and interpretation of results are provided. Typical diseases in newborn foals, which cause hypoxemia and/or hypercapnia and can be indications for respiratory support are apnea, hypopnea, pulmonary atelectasis, surfactant deficiency, meconium-, fetal fluid- and milk aspiration, maladjustment syndrome, cardiovascular abnormalities, anemia, airway obstruction, compromi...
Dyson S.Proximal suspensory desmitis of the hindlimb was diagnosed using local analgesic techniques and ultrasonography in 42 horses. Subtarsal analgesia resulted in substantial improvement in lameness in 36 of 41 horses in which local analgesic techniques were used. In the remaining five horses lameness was improved by perineural analgesia of the tibial nerve (three) or the tibial and fibular nerves. Intra-articular analgesia of the tarso-metatarsal joint produced a similar degree of improvement in two of 24 horses in which lameness had been improved by subtarsal analgesia. Ultrasonographic abnormali...
Preston SA, Zimmel DN, Chmielewski TL, Trumble TN, Brown MP, Boneau JC, Hernandez JA.To estimate prevalences of various presale radiographic findings and of presale arthroscopy in horses offered for sale at the 2006 Keeneland September yearling sale and to compare sales prices between yearlings with and without various presale radiographic findings or a history of arthroscopy. Methods: 397 Thoroughbred yearlings. Methods: Cross-sectional study. Methods: Presale radiographs and health records were examined to estimate prevalences of various radiographic findings and presale arthroscopy. Sales price records were used to compare sales prices between yearlings with and without var...
Vanderperren K, Gielen I, Van Caelenberg A, Van der Vekens E, Raes EV, Hauspie S, van Bree H, Saunders JH.This article describes the ultrasonographic (US) appearance of bony abnormalities on the dorsal aspect of the third metacarpal/metatarsal bone of the equine fetlock in cadavers with radiographic signs of osteoarthrosis. After US, computed tomography was undertaken to better characterise the lesions. Twelve fetlock joints were collected and all had more than one bone abnormality on US. Normal subchondral bone appeared on US as a well-defined and regular hyperechoic line with distal acoustic shadowing. Bone abnormalities detected on US included (1) gaps in the proximal subchondral bone filled wi...
Da Costa Gómez TM, Radtke CL, Kalscheur VL, Swain CA, Scollay MC, Edwards RB, Santschi EM, Markel MD, Muir P.To determine whether bone microcracks are altered after application of focused and radial extracorporeal shock wave therapy (ESWT) to the equine distal limb. Methods: An ex vivo experimental model. Methods: A contralateral limb specimen was obtained from 11 Thoroughbred racehorses with a unilateral catastrophic injury. Distal limb specimens were also obtained from 5 non-racing horses. Methods: Three separate skin-covered bone segments were obtained from the mid-diaphysis of the metacarpus (MC3) or metatarsus (MT3). Focused (9,000 shockwaves, 0.15 mJ/mm2, 4 Hz) and radial (9,000 shockwaves, 0.1...
Firth EC.The site of occurrence of 490 bone sequestra in horses and cattle was investigated. Most sequestra occurred in the proximal half of the third metatarsal bone and the third metacarpal bone. The most common clinical features included swelling, presence of a draining tract, impaired function and delayed wound healing. These diagnostic features, and the preferred time to confirm the diagnosis by radiological examination are discussed. The surgical treatment is relatively simple and the prognosis favourable in most cases. It is suggested that soft tissue injury and the presence of infection are of ...
Ross MW.To correlate scintigraphic and clinical findings of the metatarsophalangeal joint (MTPJ) in Standardbreds, radiographic findings in horses with confirmed MTPJ lameness, and determine if stress reaction and more advanced bone remodelling occurred in the MTPJ, medical records of 114 Standardbreds admitted between September 1993 and April 1995 in which bone scintigraphy included standing lateral and plantar views of the metatarsophalangeal joint (MTPJ) were reviewed. Images obtained using a large field of view gamma camera were evaluated visually for location, definition and intensity of increase...
Moreno KL, Scallan EM, Friedeck WO, Simon BT.Pelvic limb neuropathy is a rare post-anaesthetic complication. In the authors' experiences, the incidence of post-anaesthesia neuropathy is increased following MRI of the proximal metatarsus and tarsal regions when compared with previously reported incidences of post-anaesthetic neuropathy. Objective: This study reports the incidence, diagnosis, treatment and outcome of seven horses with post-anaesthesia neuropathy following proximal metatarsal and tarsal MRI. Methods: Retrospective case series. Methods: Case record review of horses receiving general anaesthesia for MRI between 1 January 2012...
Espinosa-Mur P, Spriet M, Manso-Diaz G, Arndt S, Perez-Nogues M, Roman JL, Garcia-Mata R, Katzman SA, Galuppo LD.To assess the value of 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) for imaging the tarsus and proximal metatarsus and compare it with CT and lameness evaluation. Methods: 25 horses with lameness localized to the tarsal and proximal metatarsal regions that underwent 18F-NaF PET/CT between 2016 and 2021. Methods: 18F-NaF PET and CT images were retrospectively independently evaluated by 3 observers. Standardized uptake values (SUV) were used to characterize 18F-NaF uptake. Correlation between PET and CT findings with subjective and objective maximum (Max-D) and minimum pelvic...
Bertoni L, Forresu D, Coudry V, Audigie F, Denoix JM.To characterize the clinical features, diagnostic procedures, treatment, and outcome for horses with an exostosis on the palmar or plantar cortex of the third metacarpal bone (MC3) or third metatarsal bone (MT3). Methods: Retrospective case series. Methods: 16 horses. Methods: Records from 2001 through 2010 were evaluated to identify horses with radiographic and ultrasonographic evidence of an exostosis on an MC3 or MT3. Signalment, history, lameness examination results, diagnostic imaging results, surgical and histopathologic findings, treatment, and outcome were evaluated. Results: 9 horses ...
Zekas LJ, Bramlage LR, Embertson RM, Hance SR.The objective of this retrospective study was to provide a detailed description of the characteristics of condylar fractures represented in a population of 135 horses who sustained 145 fractures. Records and radiographic studies were examined. Fifty-nine percent of the horses were male and the majority Thoroughbreds. The distribution of fractures was 37% incomplete-nondisplaced, 30% complete-nondisplaced and 32% complete-displaced. The right front was more likely to sustain a complete-displaced fracture, whereas the left front was more likely to sustain an incomplete-nondisplaced fracture. For...
Kraus-Hansen AE, Jann HW, Kerr DV, Fackelman GE.The intra-articular anatomy of 103 equine tarsi was studied by contrast radiography with image intensification and computerized tomography. There was communication between the tarsometatarsal and distal intertarsal joints in 21 of 55 (38%) interpretable tarsometatarsal arthrograms, and in 11 of 48 (23%) interpretable distal intertarsal arthrograms. The difference was not significant. The volume of contrast agent and the pressure of injection did not correlate with communication. Forced injection caused subcutaneous leakage of contrast medium but not communication. Communication occurred via th...
Sidhu ABS, Rosanowski SM, Davis AM, Griffith JF, Robinson P.To quantitate the iatrogenic injury associated with deep plantar metatarsal fasciotomy performed with Metzenbaum scissors compared with a Y-shaped fasciotome. Methods: Experimental ex vivo surgical study. Methods: Cadaveric hind limbs (n = 20) from 10 sound thoroughbred racehorses. Methods: A plantar metatarsal fasciotomy was performed, extending from the proximal extent of the deep metatarsal fascia, distally. Hind limbs were randomly assigned to 2 groups, undergoing fasciotomy with straight Metzenbaum scissors (n = 10) or a Y-shaped fasciotome (n = 10). Magnetic resonance imaging...
Turner AS, Milne DW, Gabel AA.Long-bone fractures of 6 foals admitted consecutively to the Ohio State University Veterinary Hospital were treated successfully with ASIF dynamic compression plating. The cases included 2 foals with closed fracture of the metacarpus, and 1 foal each with open nonunion of the metatarsus, closed fracture of the radius, open fracture of the tibia, and open fracture of the ulna. Five of these foals became sound, with no deformity, so they could be trained for racing or showing. The 6th foal, a filly with nonunion, became "pasture-sound" and was scheduled for breeding. It was concluded that the dy...
Fitch GL, Galuppo LD, Stover SM, Willits NH.To evaluate a dorsoproximal extra-articular approach for insertion of 8.25-mm, solid-titanium, intramedullary (IM) interlocking nails into ostectomized foal third metacarpal (MC3) and third metatarsal (MT3) bones; to compare the monotonic mechanical properties of IM nail constructs with paired intact bones; and to determine the effects of age, body weight, fore- or hindlimb, and left or right limb on the mechanical testing variables. Methods: Twenty bone pairs (10 MC3, 10 MT3) collected from 10 foals of various weights and ages. Methods: One bone from each pair was randomly selected to be oste...
Stolk PW, Firth EC.Eight metatarsophalangeal (fetlock) joints were studied in anaesthetized young ponies. Pressure measurements were made in the joint and at various sites in the marrow cavity of the third metatarsal bone with simultaneous measurement of systemic arterial and venous blood pressures. Fetlock joint flexion was always associated with a statistically significant initial decrease in intra-articular pressure (p < 0.05) followed by a marked increase in pressure (p < 0.05). Subsequent extension was accompanied by a similar pressure pattern, although there appeared to be a hysteretic relationship. ...
Lempe-Troillet A, Ludewig E, Brehm W, Budras KD, Winter K, Edinger J.The object of this study was to describe previously defined soft tissue structures by using spin and gradient sequences in a 0.5 Tesla magnetic resonance system in order to improve the characterisation of tendon and ligaments at the plantar region of the equine tarsus and metatarsus while considering possible age-related variations. Methods: Cadaveric hindlimbs from twenty-two Warmblood horses with an age range from one month to twenty-five years were examined in spin and gradient echoes. The proximal suspensory ligament from six limbs was dissected to assign the signal intensities histologica...
Müller EMT, Vanderperren K, Merle R, Rheinfeld S, Leelamankong P, Lischer CJ, Ehrle A.The objective of this retrospective, observational, controlled study was to evaluate bone and soft tissue window CT images of the proximoplantar metatarsus III region in twenty horses with pain localized to the proximal suspensory ligament (PSL) and 20 horses with findings nonrelated to tarsal pain. All horses underwent CT and radiographic examination. Images were reviewed by three independent observers who graded the severity and localization of findings. Bone-related categories as well as soft tissue-related categories were evaluated. For the comparison of imaging findings in horses with and...
Daniel CR, Taylor SE, McPhee S, Wolfram U, Schwarz T, Sommer S, Kershaw LE.Fatigue-related subchondral bone injuries of the third metacarpal/metatarsal (McIII/MtIII) bones are common causes of wastage, and they are welfare concerns in racehorses. A better understanding of bone health and strength would improve animal welfare and be of benefit for the racing industry. The porosity index (PI) is an indirect measure of osseous pore size and number in bones, and it is therefore an interesting indicator of bone strength. MRI of compact bone using traditional methods, even with short echo times, fail to generate enough signal to assess bone architecture as water protons ar...
Hewitt-Dedman CL, Kershaw LE, Schwarz T, Del-Pozo J, Duncan J, Daniel CR, Cillán-García E, Pressanto MC, Taylor SE.Magnetic resonance spectroscopy (MRS) has been used to investigate metabolic changes within human bone. It may be possible to use MRS to investigate bone metabolism and fracture risk in the distal third metacarpal/tarsal bone (MC/MTIII) in racehorses. Objective: To determine the feasibility of using MRS as a quantitative imaging technique in equine bone by using the H spectra for the MC/MTIII to calculate fat content (FC). Methods: Observational cross-sectional study. Methods: Limbs from Thoroughbred racehorses were collected from horses that died or were subjected to euthanasia on racecourses...
