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.
Lapjit C, Charoenchanikran P, Petchkaew P, Sukpipattanamongkol S, Yodsheewan R, Theerapan W, Chanda M.The fetlock joint is a high mobility structure that accommodates enormous loading during locomotion. An injury of the superficial constituent such as subtendinous bursitis may occur due to repeated trauma. An 8-year old school riding horse was presented with dorsomedial distension in the left hindlimb fetlock region. The lesion was noted following routine exercise. The horse demonstrated no lameness and a negative response to the fetlock flexion test. Radiographic findings revealed a smooth surface cortical thickening on the medial aspect of the distal third metatarsal bone. Furthermore, the u...
Johnston GCA, Ahern BJ, Woldeyohannes SM, Young AC.Equine advanced imaging research involving racehorse fetlock pathology commonly uses cadaver limbs and a freeze-thaw process. The presence of short tau inversion recovery (STIR) signal intensity in the distal third metacarpal/metatarsal bone is of particular interest and may be clinically relevant in the diagnosis of horses at risk of fracture. However, little is known about the effect of the freeze-thaw process on the MRI appearance of STIR hyperintensity in these bones. This study compares the low-field MRI appearance of the distal third metacarpal/metatarsal bone from cadaver limbs of Thoro...
James FM, Smith MRW, Wright IM.Fractures of the proximal phalanx are one of the most common long bone fractures of Thoroughbred racehorses. Although the degree of disruption and damage to the articular surface is generally considered a major prognostic determinant, associated arthroscopic findings have not previously been reported. Objective: To describe the metacarpo/metatarsophalangeal (MCP/MTP) joint lesions associated with parasagittal fractures of the proximal phalanx arthroscopically identified at the time of fracture repair and compare radiographic and arthroscopic appearance of complete fractures. Methods: Retrospec...
Murray RC, Tranquille CA, Walker VA, Milmine RC, Bak L, Tacey JB, Bolas NM.Standing magnetic resonance (MR) images of proximal metacarpal/metatarsal regions are increasingly being acquired. This study aimed at describing ranges of abnormalities detected in sport/racehorses, using retrospective evaluation of magnetic resonance imaging (MRI) reports from horses with lameness isolated to proximal metacarpal/metatarsal regions with images acquired standing. It was hypothesized that MRI features are different between metacarpal and metatarsal regions and between horses doing different sports. Reports from 359 forelimbs and 64 hindlimbs were included. Palmar/plantar metaca...
Donati B, Fürst AE, Del Chicca F, Jackson MA. The aim of this study was to determine the indications for, and complications of, plate removal surgery in horses that underwent internal fixation of limb fractures. Methods: Medical records of horses presented to our hospital between 1990 and 2015 for the removal of plates after treatment of limb fractures were reviewed. Data collected at the time of initial presentation, including signalment, history, fracture features and treatment and information about the indications, timing and complications of implant removal were reviewed. Results: The most common bones involved were the ulna ...
Bertoni L, Jacquet-Guibon S, Branly T, Legendre F, Desancé M, Mespoulhes C, Melin M, Hartmann DJ, Schmutz A, Denoix JM, Galéra P, Demoor M....Osteoarthritis is a common cause of pain and economic loss in both humans and horses. The horse is recognized as a suitable model for human osteoarthritis, because the thickness, structure, and mechanical properties of equine articular cartilage are highly comparable to those of humans. Although a number of equine experimental osteoarthritis models have been described in the literature, these cases generally involve the induction of osteoarthritis in just one joint of each animal. This approach necessitates the involvement of large numbers of horses to obtain reliable data and thus limits the ...
Farfan M, Genton M, Rossignol F.To describe reliable minimally invasive procedures for (1) removing cartilage by joint distraction and articular drilling for equine metacarpophalangeal (MCP)/metatarsophalangeal (MTP) arthrodesis; (2) applying a palmar/plantar tension band without MCP/MTP joint luxation. Methods: Experimental study. Methods: Cadaveric equine limbs (n = 12). Methods: All limbs were used to evaluate the drilling technique. First the MCP/MTP joint was distracted with a 5.5-mm cortical screw. Then, through four stab incisions, articular cartilage was removed with a 4.5-mm drill. Six randomly chosen limbs were the...
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...
El-Gendy SAA, Alsafy MAM, Rutland CS, El-Khamary AN, Abu-Ahmed HM, El-Kammar MH.The donkey is of socio-economic value yet imaging techniques in both healthy and abnormal limbs are a limiting factor in research and medicine. The objective was to determine anatomical features of both healthy and clinically abnormal donkey metacarpophalangeal and metatarsophalangeal joints (n = 13) using anatomical dissection, casting, X-ray and computed tomography. The joint capsule contained two palmar/plantar and two dorsal recesses. The proximal-palmar or plantar recess was larger than the distodorsal recess and potential sites of approaches to the recesses were determined. Soft tissue ...
Labens R, Schramme MC, Murray RC, Bolas N.High-field MRI of the proximal metacarpal/metatarsal region has been associated with great diagnostic potential and clinical reports of standing low-field MRI of the forelimb suggest the same. To better understand diagnostic outcomes with standing low-field MRI of the proximal suspensory region, a prospective survey study was conducted and users of a widely available system questioned on their experience, operating procedures, and interpretation of standing low-field MRI findings. Response data included scores on a modified Likert scale from which weighted ratings were calculated for statistic...
De Angelis E, Cacchioli A, Ravanetti F, Bileti R, Cavalli V, Martelli P, Borghetti P.Chondrocyte dedifferentiation is a key limitation in therapies based on autologous chondrocyte implantation for cartilage repair. Articular chondrocytes, obtained from (metacarpophalangeal and metatarsophalangeal) joints of different aged horses, were cultured in monolayer for several passages (P0 to P8). Cumulative Populations Doublings Levels (PDL) and gene expression of relevant chondrocyte phenotypic markers were analysed during culturing. Overall data confirmed that, during proliferation in vitro, horse chondrocytes undergo marked morphological and phenotypic alterations of their differen...
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...
James OA, Elce Y, Cillán-Garcia E, Reardon RJM. The aim of this study was to determine whether a clamped drill guide can be used effectively to drill across equine distal third metacarpals and metatarsals and to compare accuracy and speed of a drilling with a hand-held drill guide. Methods: Eighty equine cadaver limbs were divided between four surgeons with varying experience. The limbs were randomly allocated to clamped or hand-held drill guides and placed in a stand in an upright/standing position on a metal table. Drilling times from cis- to trans cortices were measured. Post-drilling computed tomography images were used to assess ...
Barrett E, Arkins S.Few studies are available concerning prevalences of abnormalities in the Thoroughbred horse population. Objective: Determine the prevalence of commonly observed abnormalities in a National Hunt Thoroughbred population using results of pre-purchase examinations conducted at Thoroughbred sales venues. Methods: Retrospective cross-sectional study. Methods: Veterinary pre-purchase examination certificates for 13,603 3- and 4-year-old Thoroughbred National Hunt horses from Tattersalls Ireland, Goffs Ireland and Doncaster Bloodstock Sales Ltd. (DBS) Sales were analysed. All conditions noted by the v...
Steel CM, Collins VL, Hance SR, Adkins AR, Hitchens PL.Veterinarians are required to interpret the significance of radiographic findings for sale, soundness and future racing performance of weanling and yearling Thoroughbreds. We investigated the prevalence and radiographic appearance of slab fractures of the third (T3) and central tarsal (Tc) bones. Methods: Weanling and yearling horses with complete or incomplete T3 or Tc fracture were identified by searching a database of radiographs. The prevalence and radiographic appearance at initial diagnosis and after continued pasture turnout, as well as prognosis for racing, of fractures of T3 and Tc we...
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 ...
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...
Rannamäe E, Andrianov V, Järv E, Semjonov A, Haak A, Kreem J.The remains of a horse's hind foot - a third metatarsal bone and three phalanges - were found in a presumed waste pit of a prosperous medieval household in Viljandi, Estonia, dated from the second half of the 13th to the beginning of the 15th century. The metatarsal bone had been broken during the horse's lifetime and showed evidence of partial healing. Using archaeological, zooarchaeological, morphological, microscopic, densitometric and radiographic analyses, we investigated the bones and the healing process in order to understand animal treatment in a medieval urban context. Our results sho...
Barrett MF, Selberg KT, Johnson SA, Hersman J, Frisbie DD.Injury of the distal tarsus and proximal metatarsus commonly causes lameness. Magnetic resonance imaging (MRI) allows concurrent assessment of both the distal tarsal joints and suspensory ligament origin, and aids identification of lesions that may otherwise go undetected by other modalities. In this retrospective observational study, the medical records of a veterinary imaging center were searched for MRI exams of the distal tarsus and proximal metatarsus for the years 2012 through 2014. Studies for 125 limbs of 103 horses were identified and retrospectively evaluated by two board-certified v...
Niemelä TM, Tulamo RM, Aaltonen K, Sankari SM, Hielm-Björkman AK.Inflammatory and degenerative activity inside the joint can be studied in vivo via analysis of synovial fluid (SF) biomarkers, which are molecular markers of inflammatory processes and tissue turnover. The aim of this study was to investigate the response of selected biomarkers in the SF after an intra-articular (IA) high-molecular-weight non-animal stabilized hyaluronic acid (NASHA) treatment. Our hypothesis was that prostaglandin E (PGE), substance P, aggrecan chondroitin sulfate 846 epitope (CS846), and carboxypeptide of type II collagen (CPII) concentrations in SF would decrease more in th...
Mageed M, Steinberg T, Drumm N, Stubbs N, Wegert J, Koene M.Fractures involving the proximal one-third of the splint bone are relatively rare and are challenging to treat. A variety of management techniques have been reported in the literature. The aim of this retrospective case series was to describe the clinical presentation and evaluate the efficacy of bioabsorbable polylactic acid screws in internal fixation of proximal fractures of the 2nd and 4th metacarpal and metatarsal bones in horses. Methods: The medical records, diagnostic images and outcome of all horses diagnosed with a proximal fracture of the splint bones and treated with partial resect...
Moulin N, François I, Coté N, Alford C, Cleary O, Desjardins MR.Despite the recommendation of plate fixation for propagating condylar fractures of the third metacarpal (McIII) or third metatarsal bone (MtIII), lag screw fixation can be a viable surgical option. Objective: To evaluate short-term outcome and long-term racing performance of horses that underwent lag screw fixation of long condylar fractures of the McIII/MtIII. Methods: Retrospective case series. Methods: Medical records, post-surgical racing performance and outcome of 26 horses with propagating fractures of the medial and/or lateral condyle of McIII/MtIII were reviewed. Medical information in...
May-Davis S, Brown WY, Shorter K, Vermeulen Z, Butler R, Koekkoek M.The Dutch Konik is valued from a genetic conservation perspective and also for its role in preservation of natural landscapes. The primary management objective for the captive breeding of this primitive horse is to maintain its genetic purity, whilst also maintaining the nature reserves on which they graze. Breeding selection has traditionally been based on phenotypic characteristics consistent with the breed description, and the selection of animals for removal from the breeding program is problematic at times due to high uniformity within the breed, particularly in height at the wither, colo...
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...
Bani Hassan E, Mirams M, Mackie EJ, Whitton RC.To investigate the prevalence of microscopic subchondral bone injury in the distal metacarpi/tarsi of Thoroughbred racehorses and associations with recent and cumulative training history. Methods: Metacarpi/metatarsi were obtained from postmortem examination of Thoroughbred racehorses. The severity of palmar/plantar osteochondral disease (POD) was graded in forelimbs from 38 horses and in hindlimbs from a separate cohort of 45 horses. Forelimb samples were embedded in methyl methacrylate and examined using backscattered scanning electron microscopy. Microfracture density in the condylar subcho...
Wright IM, Minshall GJ.Chip fractures of the dorsoproximal articular margin of the proximal phalanx are common injuries in racehorses. Large fractures can extend distal to the joint capsule insertion and have been described as dorsal frontal fractures. Objective: To report the location and morphology of short frontal plane fractures involving the dorsoproximal articular surface of the proximal phalanx and describe a technique for repair under arthroscopic and radiographic guidance. Methods: Single centre retrospective case study. Methods: Case records of horses with frontal plane fractures restricted to the dorsopro...
Dyson S, Blunden A, Murray R.Injuries of the plantar soft tissues of the tarsus and proximal metatarsus can be a source of lameness in horses, however published information is lacking on high field MRI characteristics of these tissues. Objectives of the current anatomic study were to (1) describe high-field MRI features of the plantar tarsal and proximal metatarsal soft tissues; and (2) compare MRI findings with gross and histological appearances of selected structures for a sample of cadaver limbs from non-lame horses. Single hindlimbs for 42 horses, and right and left hindlimbs for eight horses were scanned using high-f...
Brokken MT, Schneider RK, Roberts GD, Holmes SP, Gavin PR, Sampson SN, Farnsworth KD, Dahlgren LA.To evaluate the effects of a new microfracture and ligament splitting procedure on ligament healing and to examine the usefulness of magnetic resonance (MR) imaging for monitoring ligament healing over time using a collagenase model of hind limb proximal suspensory desmitis. Methods: Experimental in vivo study. Methods: Healthy adult horses (n=6). Methods: Horses were free of lameness with normal hind limb proximal suspensory ligaments (PSL). The origin of both hind limb PSL was injected with collagenase and underwent MR imaging 2 weeks later, followed by the microfracture and ligament splitti...
Klopfenstein Bregger MD, Fürst AE, Kircher PR, Kluge K, Kummer M.To describe minimally-invasive lag screw osteosynthesis combined with external coaptation for the treatment of Salter-Harris type II third metacarpal and third metatarsal bone fractures. Methods: Three foals aged two weeks to four months with a Salter-Harris type II third metacarpal or third metatarsal fracture. Surgery was carried out under general anaesthesia in lateral recumbency. After fracture reduction, the metaphyseal fragment was stabilized with two cortical screws placed in lag fashion under fluoroscopic control. A cast was applied for at least two weeks. Results: All foals had a good...
Barker WH, Wright IM.A technique for minimally invasive repair of slab fractures of the third tarsal bone has not previously been reported. Results of third tarsal bone slab fracture repair in Thoroughbred racehorses are lacking. Objective: To report the outcomes of repair of uniplanar frontal slab factures of the third tarsal bone using a single 3.5 mm cortex screw in lag fashion. Methods: Retrospective case series. Methods: Case records of horses that had undergone this procedure were reviewed. Results: Seventeen horses underwent surgery. Eighteen percent of cases had wedge shaped third tarsal bones. A point mid...
James FM, Richardson DW.Complications of osteosynthesis including superficial and deep infections continue to affect adversely outcome in equine surgery of the lower limb. Objective: To describe a technique for minimally invasive plate fixation in horses and evaluate clinical results of the technique. Objective: Lower complication rates would occur in horses treated with a minimally invasive approach compared with conventional techniques. Methods: Cases of minimally invasive plate fixation from January 1999 to December 2003 were evaluated. Case records, radiographs and race records for horses that sustained distal th...
Brokken MT, Schneider RK, Sampson SN, Tucker RL, Gavin PR, Ho CP.Magnetic resonance (MR) imaging abnormalities in horses with lameness localized to the proximal metacarpal or metatarsal region have not been described. To accomplish that, the medical records of 45 horses evaluated with MR imaging that had lameness localized to either the proximal metacarpal or metatarsal region were reviewed. Abnormalities observed in the proximal suspensory ligament or the accessory ligament of the deep digital flexor tendon included abnormal high signal, enlargement, or alteration in shape. Twenty-three horses had proximal suspensory ligament desmitis (13 hindlimb, 10 fore...
Riggs CM.Fractures are the cause of considerable morbidity and mortality among Thoroughbred racehorses. A significant proportion of these injuries occur in the absence of any particular traumatic incident. Evidence of prefracture pathology interpreted as fatigue damage has been identified in some such cases, but the aetiology of many of these so-called 'spontaneous' fractures remains obscure. Parasagittal fractures of the third metacarpal (McIII) and third metatarsal (MtIII) bones are one of the more common fractures to affect Thoroughbred racehorses. The configuration of each of these fracture types i...
Reed SR, Jackson BF, Wood JL, Price JS, Verheyen KL.The aim of this study was to identify exercise-related risk factors for carpal and metacarpo- and metatarso-phalangeal (MCP/MTP) joint injury occurrence in young Thoroughbreds in flat race training. In a 2-year prospective cohort study, daily exercise and joint injury data were collected from horses in 13 training yards in England. Four injury categories were defined: (1) localised to a carpal or MCP/MTP joint based on clinical examination and/or use of diagnostic analgesia with no diagnostic imaging performed; (2) localised to a carpal or MCP/MTP joint with no abnormalities detected on diagno...
Sherlock CE, Mair TS, Ter Braake F.We report the use of low-field standing magnetic resonance imaging in the standing horse for the diagnosis of osseous lesions in the metacarpophalangeal (MCP) or metatarsophalangeal (MTP) joint that were not apparent using standard radiography. Thirteen horses were studied and all had thickening of the subchondral bone plate and abnormal signal intensity in the adjacent spongiosa in either the condyles of metacarpal/metatarsal III or the proximal phalanx or both. Abnormalities were characterized by diffuse decreased signal intensity on T1-weighting adjacent to the subchondral bone and within t...
Ringer SK, Lischer CJ, Ueltschi G.To monitor the effect of focused extra-corporeal shock wave therapy (ESWT) on bone and bone-tendon junction of horses without lameness by use of nuclear scintigraphy and thermography. Methods: 6 warmblood horses without lameness. Methods: The origin of the suspensory ligament at the metacarpus (OSL-MC) and the fourth metatarsal bone were treated at 2 time points (days 0 and 16) with 2,000 shocks applied by a focused ESWT device at an energy flux density of 0.15 mJ/mm2. One forelimb and 1 hind limb were treated, and the contralateral limbs served as controls. To document the effect of focused E...
Benton HP, MacDonald MH, Tesch AM.To determine whether adenosine influences the in vitro release of nitric oxide (NO) from differentiated primary equine articular chondrocytes. Methods: Articular cartilage harvested from the metacarpophalangeal and metatarsophalangeal joints of 11 horses (3 to 11 years old) without history or clinical signs of joint disease. Methods: Chondrocytes were isolated, plated at a high density (10(5) cells/well), and treated with adenosine, the adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA), bradykinin, or other agents that modify secondary messenger pathways alone or in combination ...
Hirvinen LJ, Litsky AS, Samii VF, Weisbrode SE, Bertone AL.To compare biomechanical strength, interface quality, and effects of bone healing in bone-implant interfaces that were untreated or treated with calcium phosphate cement (Ca-cement), magnesium phosphate cement (Mg-cement), or polymethylmethacrylate (PMMA) in horses. Methods: 6 adult horses. Methods: 4 screw holes were created (day 0) in each third metacarpal and third metatarsal bone of 6 horses. In each bone, a unicortical screw was placed in each hole following application of Ca-cement, Mg-cement, PMMA, or no treatment (24 screw holes/treatment). Screws were inserted to 2.82 N m torque. Hors...
Contino EK, King MR, Valdés-Martínez A, McIlwraith CW.Hindlimb proximal suspensory desmopathy is a common injury of sport horses but diagnosis can be difficult because diagnostic analgesia of the region lacks specificity. Perineural analgesia of the deep branch of the lateral plantar nerve (DBLPN) has been proposed as a more specific method of isolating pain of the proximal aspect of the suspensory ligament but the technique has not been evaluated in vivo. Objective: To determine the extent of diffusion of contrast medium and mepivacaine following DBLPN analgesia using a single-needle injection technique and to determine if there is inadvertent i...
Benson BM, Byron CR, Pondenis H, Stewart AA.To investigate, in vitro, the effects of radial shock waves on the release of nitric oxide (NO) and synthesis of prostaglandin E2 (PGE2) and glycosaminoglycan (GAG), and liberation of GAG, from equine articular cartilage explants. Methods: Equine cartilage from normal metacarpophalangeal and metatarsophalangeal joints was exposed to radial shock waves at various impulse doses and then maintained as explants in culture for 48 h. Shock waves were delivered at 1,876 Torr pressure and a frequency of 10 Hz. Treatment groups consisted of a negative control group, or application of 500, 2,000, or 4,0...
Byron CR, Benson BM, Stewart AA, Pondenis HC.To evaluate the effects of methylprednisolone acetate (MPA) on proteoglycan production by equine chondrocytes and to investigate whether glucosamine hydrochloride modulates these effects at clinically relevant concentrations. Methods: Articular cartilage with normal gross appearance from metacarpophalangeal and metatarsophalangeal joints of 8 horses (1 to 10 years of age). Methods: In vitro chondrocyte pellets were pretreated with glucosamine (0, 1, 10, and 100 microg/mL) for 48 hours and exposed to MPA (0, 0.05, and 0.5 mg/mL) for 24 hours. Pellets and media were assayed for proteoglycan prod...
Barr ED, Clegg PD, Mark Senior J, Singer ER.To describe focal destructive lesions of the proximal sesamoid bones (PSBs) as a complication of dorsal metatarsal artery catheterization performed for direct blood pressure monitoring during equine general anesthesia. Methods: Retrospective study. Methods: Three client-owned horses. Methods: A dorsal metatarsal artery was catheterized in each of 3 horses for direct blood pressure monitoring during anesthesia. Radiography, ultrasonography, synoviocentesis, and arthroscopy were used to diagnose postoperative lameness that occurred in the limb used for blood pressure monitoring. Results: Horses ...
Jacklin BD, Wright IM.Although fractures of the metacarpal and metatarsal condyles are the most common long-bone fractures of Thoroughbred horses in training, limited data on variations in morphology and incidence have been published. Additionally, grouped analyses of previous studies from the UK and USA would permit comparison between study groups and the creation of a substantial pool of international data. Methods: Retrospective analysis of case records of horses with fractures of the distal condyles of third metacarpal/metatarsal bones seen over the last 10 years at Newmarket Equine Hospital. The current series...
Dykgraaf S, Firth EC, Rogers CW, Kawcak CE.The objective was to determine the effects of early exercise on the articular cartilage and subchondral bone at specific sites of the distal third metacarpal and metatarsal bones of 12 young Thoroughbred horses allowed free choice exercise at pasture. Six of the horses had additional controlled exercise 5 days per week from mean age of 21+/-20 days of age (range: 3-83 days) until 17.1 months of age. Confocal laser scanning microscopy was used to quantify viable and non-viable chondrocytes. Proteoglycan scoring and modified Mankin scoring was performed and subchondral bone mineral density measu...
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...
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...
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...
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...
Bogers SH, Rogers CW, Bolwell CF, Roe WD, Gee EK, McIlwraith CW.The aim of the study was to use spatial and multiple correspondence analysis (MCA) to describe and compare the regional proportion and spatial pattern of volumetric bone mineral density (BMDv) values within loaded regions of the plantar metatarsal epiphysis of young horses in race training. A single 2 mm transverse peripheral quantitative computed tomography 'slice', 10 mm proximal from the distal limit of the sagittal ridge of the distal metatarsal epiphysis was obtained from 14 2-year-old Thoroughbred fillies (7 exercised and 7 controls). Six regions of interest were generated and examin...
Dyson SJ, Arthur RM, Palmer SE, Richardson D.The gross and functional anatomy of the suspensory ligament (SL) and its ultrasonographic variability are described. Injuries of the suspensory apparatus are divided into lesions confined to the proximal one third of the metacarpus or metatarsus (proximal suspensory desmitis and avulsion fractures), lesions of the body, and branch lesions. Complete breakdown injuries are also discussed. In view of the close association of the SL, the second, third, and fourth metacarpal or metatarsal bones, and the proximal sesamoid bones, associated bony lesions are also considered.
Ramzan PH, Palmer L, Powell SE.Fracture of the metacarpal/tarsal condyle is usually preceded by prodromal pathology. Early recognition of injury is desirable to minimise the risk of serious breakdown; however, the clinical and diagnostic characteristics of unicortical condylar fractures have been poorly documented to date. Objective: To describe the clinical, imaging and outcome features of racehorses in first opinion practice diagnosed with short unicortical fracture of the metacarpal/tarsal condyle. Methods: Retrospective case series. Methods: All flat racehorses sustaining a unicortical condylar fracture while under the ...
van den Belt AJ, Dik KJ, Barneveld A.Over a 2 year-period, the ultrasonographic localization and distribution of flexor tendinous and ligamentous injuries, the long-term follow-up, and the outcome were studied in 101 Dutch Warmblood horses (DW) with a mean age of 8.7 years and in 71 Standardbred racehorses (ST) with a mean age of 5.2 years. The ratio between forelimb and hind limb flexor tendonitis/desmitis in the DW-group was 4:1 and in the ST-group group 4:3. In the DW-group, tendonitis/desmitis of the suspensory ligament (32%), the superficial digital flexor tendon (29%), the distal carpal check ligament (17%) of the forelimb ...
Mair TS, Dyson SJ, Fraser JA, Edwards GB, Hillyer MH, Love S.The case records of 23 horses and one donkey affected by hypertrophic osteopathy (HO) (Marie's disease) were reviewed. All affected animals presented with limb swellings, which were bilaterally symmetrical and usually involved both fore- and hindlimbs. Associated signs included stiffness/lameness and weight loss. Radiological features included periosteal new bone formation over the diaphyses and metaphyses of affected bones. The metacarpal and metatarsal bones were most frequently affected. Articular surfaces remained free of disease. Seventeen animals were destroyed on humane grounds, 3 horse...
Tull TM, Bramlage LR.To evaluate the diagnostic features, results of free-choice exercise treatment, prognosis, and postinjury racing performance of Thoroughbred racehorses with cumulative stress-induced bone injury (CSBI) of the distal portion of the third metacarpal and third metatarsal bones (MC3/MT3). Methods: Retrospective case series. Methods: 55 Thoroughbred racehorses with CSBI of the distal portion of MC3/MT3. Methods: Data on signalment, history, and radiographic, scintigraphic, and lameness examination findings were reviewed. Horses with lameness localized to the distal portion of MC3/MT3, and that did ...
Carstens A, Kirberger RM, Velleman M, Dahlberg LE, Fletcher L, Lammentausta E.Osteoarthritis of the metacarpo/metatarsophalangeal joints is one of the major causes of poor performance in horses. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) may be a useful technique for noninvasively quantifying articular cartilage damage in horses. The purpose of this study was to describe dGEMRIC characteristics of the distal metacarpus3/metatarsus3 (Mc3/Mt3) articular cartilage in 20 cadaver specimens collected from normal Thoroughbred horses. For each specimen, T1 relaxation time was measured from scans acquired precontrast and at 30, 60, 120, and 180...
Imboden I, Waldern NM, Wiestner T, Lischer CJ, Ueltschi G, Weishaupt MA.Extracorporeal shock wave therapy (ESWT) is an accepted form of treatment for chronic cases of proximal suspensory desmitis (PSD). Subjective evaluation of horses shortly after being treated with ESWT has led clinicians to comment on an immediate reduction in lameness. This study aimed to evaluate the analgesic effect of ESWT on 16 horses with PSD or PSD-like pain in a fore- or hindlimb. To objectively assess lameness, gait analysis was performed on an instrumented treadmill before and 6, 24, 48 and 72h after ESWT of the origin of the suspensory ligament and the results compared to the effects...
Trope GD, Anderson GA, Whitton RC.The effect of palmar osteochondral disease lesions on performance of Thoroughbred (TB) racehorses is unclear. There is a need to describe patterns of radiopharmaceutical uptake (IRU) in fetlock joints of TB racehorses and to evaluate post scintigraphy performance. Objective: IRU in the metacarpal (MC) and metatarsal (MT) condyles is more common than IRU in the parasagittal grooves and is associated with poorer post diagnosis performance than controls. Methods: Location of IRU within the fetlock region was identified and graded subjectively in TB racehorses. Performance variables were determine...
Bani Hassan E, Mirams M, Mackie EJ, Whitton RC.To investigate the prevalence of microscopic subchondral bone injury in the distal metacarpi/tarsi of Thoroughbred racehorses and associations with recent and cumulative training history. Methods: Metacarpi/metatarsi were obtained from postmortem examination of Thoroughbred racehorses. The severity of palmar/plantar osteochondral disease (POD) was graded in forelimbs from 38 horses and in hindlimbs from a separate cohort of 45 horses. Forelimb samples were embedded in methyl methacrylate and examined using backscattered scanning electron microscopy. Microfracture density in the condylar subcho...
