The metacarpal bone in horses is a key component of the equine forelimb, consisting primarily of the third metacarpal bone, commonly referred to as the cannon bone, and the smaller second and fourth metacarpal bones, known as splint bones. These bones provide structural support and play a vital role in weight-bearing and locomotion. The third metacarpal bone is the largest and most prominent, extending from the carpus (knee) to the fetlock joint. Its strength and integrity are essential for the horse's ability to perform various physical activities. The second and fourth metacarpal bones are positioned on either side of the third metacarpal and are remnants of evolutionary development. They can be involved in conditions such as splints, where inflammation occurs due to stress or trauma. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, function, and clinical aspects of metacarpal bones in horses, including their role in equine biomechanics and common pathologies.
Wood AK, Sehgal CM, Polansky M.Sonographic observations were made of the image mean gray scale (MGS) of the flexor tendons and ligaments in the left and right metacarpal regions of each of 10 clinically normal horses. In images made in the dorsal and sagittal planes, the MGS was measured at multiple sites in the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), accessory ligament (AL), and suspensory ligament (SL), and at single sites in the medial and lateral limbs of the SL, and the palmar ligament. Relative sonographic brightness of each tendon and ligament was calculated by dividing the value ...
Canè V, Botti P, Soana S.The influence of pulsed low-frequency electromagnetic fields (PEMFs) on bone formation was investigated in studies of the healing process of transcortical holes, bored at the diaphyseal region of metacarpal bones of six adult horses, exposed for 30 days to PEMFs (28 G peak amplitude, 1.3 ms rise time, and 75 Hz repetition rate). A pair of Helmholtz coils, continuously powered by a pulse generator, was applied for 30 days to the left metacarpal bone, through which two holes, of equal diameter and depth, had been bored at the diaphyseal region. Two equal holes, bored at the same level in the rig...
Glade MJ.Skeletal homeostasis during late gestation, lactation, and the post-lactational recovery period is poorly understood. In an experiment using an animal model (the horse), metacarpal breaking strengths (MBS) estimated via transmission ultrasonics were examined during the last 12 weeks of gestation and for 40 weeks after parturition. MBS increased during the last 6-10 weeks of gestation in mares fed amounts of calcium (Ca) recommended by the National Research Council; maximum MBS coincided with the week of parturition. In contrast, MBS in mares fed 20% less Ca remained relatively constant during ...
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...
Grøndahl AM, Dolvik NI.Radiography of the tibiotarsal and metacarpo- and metatarsophalangeal joints was performed on 753 Standardbred trotters (6 to 21 months old) born in 1988. The surveyed population was drawn at random from all parts of Norway and represented about 60% of Standardbred trotters born the same year. Osteochondrosis in the tibiotarsal joint was diagnosed in 108 (14.3%) horses, and the prevalence of disease in progeny groups > 10 ranged from 0 to 69%. Bony fragments in the palmar/plantar portion of the metacarpo- and metatarsophalangeal joints were diagnosed in 89 (11.8%) horses, and the prevalence of...
Nicoll RG, Wood AK, Martin IC.Observations were made in dorsal and sagittal planes of the ultrasonographic mean gray scale of the flexor tendons and ligaments of the metacarpal regions of 5 Thoroughbred geldings, during weight bearing and nonweight bearing. In images made when the horses were nonweight bearing, the mean gray scale of the superficial and deep digital flexor tendons and accessory ligament was significantly reduced, but that of the interosseous medius muscle (suspensory ligament) was not. When relaxed, collagen fiber bundles in the tendons and ligaments acted as diffuse, rather than specular, reflectors of ul...
Richardson DW, Clark CC.Hexosamine concentration (an index of proteoglycan content), DNA content (an index of cellularity), and [35S]sulfate incorporation (an index of proteoglycan synthesis) of articular cartilage were measured in biopsy specimens from medial proximal sesamoid bone, medial condyle of the third metacarpal bone, and proximal dorsal rim of the proximal phalanx in both metacarpophalangeal joints of 6 adult horses. One limb was then placed in a fiberglass cast that extended down from the proximal portion of the metacarpus and enclosed the hoof; the other limb was not casted. After 30 days of stall confin...
Davies HM, McCarthy RN, Jeffcott LB.Stacked rectangular rosette strain gages were used to measure surface bone strain on the dorsomedial cortex of the third metacarpal bones in 6 adult Thoroughbred horses during treadmill exercise. The peak principal compressive and tensile strains, angle of the peak strains and strain rate during loading were calculated and compared with speed and gait. At speeds from 4 to 14 m/s loading on the metacarpus resulted in compression of the dorsomedial cortex. Tension only occurred consistently in 1 forelimb of 1 horse at the walk (2 m/s). The angle of peak compression was within 10 degrees of the l...
Pleasant RS, Baker GJ, Muhlbauer MC, Foreman JH, Boero MJ.The case records, radiographs, and nuclear bone scans of 58 horses with stress reactions or stress fractures of the proximal palmar aspect of the third metacarpal bone (MC3) were reviewed. There were 47 Standardbreds, 4 Quarter Horses, 3 Thoroughbreds, 2 Arabians, 1 Oldenburg, and 1 Pony of America. Fifty-six of the horses were racehorses or performance horses. The mean and median ages of affected horses were 4 and 3 years, respectively. Lameness ranged from mild to severe. Physical findings were usually subtle and included signs of pain on deep palpation of the proximal palmar aspect of MC3 a...
Stover SM, Pool RR, Martin RB, Morgan JP.The dorsal cortex of the equine third metacarpal mid-diaphyseal bone was characterised during growth by the histological and microradiographic examination of specimens from 30 horses ranging in age from 2 months to 8 y. Bone from horses aged less than 6 months was characterised by rapid periosteal apposition of circumferential trabeculae of woven bone that were next connected by radial trabeculae to the parent cortex. Deposition of lamellar bone on the inner trabecular surfaces resulted in rows of primary osteons. Replacement of primary bone occurred only after 4 months of age and preferential...
Gillis JP, Zardiackas LD, Gilbert JA, St John KR.Paired equine third metacarpal bones were drilled and tapped for 4.5 mm and 5.5 mm cortical screws. Tapping was done by hand or with an air-driven reversible orthopedic drill. Screws were inserted and subjected to extraction forces to failure of the osseous threads or the screws. There was no difference in holding power of either screw size between hand-tapped and power-tapped holes.
Hanie EA, Sullins KE, Powers BE, Nelson PR.In 6 horses, bilateral metacarpal vertical series of three 4.0-mm unicortical drill holes were made. At random, one of each series of 3 holes was filled using a sternal 4.0-mm cancellous bone cylinder or a slurry of cancellous bone injected into the hole or left as an empty control. All horses had lateral metacarpal xeroradiographs at monthly intervals. Three horses (6 metacarpi) were examined post mortem after 4 months and 3 others after 6 months. Immediate through 4-month post-operative xeroradiographs demonstrated increased density in the holes with cancellous cylinders and no difference co...
Gross TS, McLeod KJ, Rubin CT.Three triple-element rosette strain gages were attached to the equine third metacarpal midshaft to record site-specific strains engendered by locomotion. The distribution of strains acting upon the midshaft cross section were characterized using a combined beam theory and finite element model analysis that did not presume the manner by which the bone was inertially loaded. A medium-speed trot (3.6 ms-1) was chosen as a representative speed and gait, with normal and shear strains, and strain energy density (SED) distributions determined throughout the stance and subsequent swing phase. Importan...
Ross MW, Martin BB.Seven Standardbred horses, all pacers, with a mean age of 2.9 years (range, 2 to 4 years), had dorsomedial articular fracture of the proximal aspect of the third metacarpal bone. Fracture caused acute, unilateral, severe lameness after training or racing. Lameness was abolished by midcarpal joint anesthesia in 4 horses. Six horses had a palpable bony swelling, which caused signs of pain. Radiography revealed a nondisplaced, articular, oblique fracture extending distad toward the dorsomedial cortex for a mean distance of 28 mm (range, 15 to 40 mm). In all horses, chronic periosteal proliferativ...
Cervantes C, Madison JB, Ackerman N, Reed WO.Between January 1985 and May 1989, 53 Thoroughbred horses (mean age 3.2 years) were surgically treated for dorsal cortical fractures of the third metacarpal bone (MC III). All horses were treated with cortical drilling through the fracture line (osteostixis). Diagnosis of the fractures was confirmed by xeroradiography. Lifetime racing records were obtained for all horses. Forty-seven horses returned to racing after surgery (89%). The mean time between surgery and the first race was 6.8 months. Horses had a mean of 10.9 starts before surgery and 16.1 starts after surgery. The mean earnings per ...
Buckingham SH, McCarthy RN, Anderson GA, McCartney RN, Jeffcott LB.Transmission ultrasound speed was determined in the third metacarpal bone of 347 Thoroughbred racehorses in training. In addition to direct measurement of apparent ultrasound speed and lateral bone diameter, several derived parameters were estimated (cortical ultrasound speed, corticomedullary ratio and cortical cross-sectional area). Multiple regression equations were developed for each ultrasound measurement using the explanatory variables: sex, age, duration and intensity of training, preparation number and previous shin soreness. The horses (114 females, 82 entire males and 151 geldings ra...
Hanie EA, Sullins KE, White NA.The results of 31 intracortical dorsal metacarpal stress fractures in 28 horses following unicortical osteostixis were reviewed. The incidence was predominately in the middle third of the lateral aspect of the left metacarpus, and males were affected more commonly. Approximately half of the surgical procedures were performed with the horse in the standing position. The mean times to return to training and racing were 4.25 and 6.9 months respectively. There was no correlation between time taken to return to racing and position of surgery. Complications experienced included lack of suture remova...
McCarthy RN, Jeffcott LB.The effects of exercise and relative inactivity on cortical bone were compared in young horses. Two groups were used; one was given a 14-week programme of exercise (n = 6) and the other kept as unexercised controls (n = 6). The first nine weeks of exercise involved trotting and cantering (2 to 4 km d-1 at speeds up to 12 m s-1) on a treadmill set at an incline of 3 degrees. Over the next five weeks the horses were trained at near maximal speeds (that is, up to 14.5 m s-1) with no incline of the treadmill. At the end of the programme marked differences in cortical porosity and distribution of s...
Canè V, Botti P, Farneti D, Soana S.The effect of pulsing electromagnetic fields (PEMFs) on bone repair was studied in principal metacarpal bones of eight adult male horses: Six horses were treated with PEMFs, and two horses were untreated. In treated horses, Helmholtz coils were applied during a 60-day period to the left metacarpal bones, bored with eight holes of equal diameter and depth, from the middiaphysis toward the distal metaphysis. Eight equal holes bored in the right metacarpal, surrounded by unactivated Helmholtz coils, were taken as controls. The two untreated horses were taken as additional control. The results of ...
Moyer W, Spencer PA, Kallish M.The relative incidence of dorsal metacarpal disease was examined in two groups of Thoroughbred racehorses training on dissimilar surfaces (dirt and wood fibre). The horses and training methods appeared to be similar. The incidence of disease was significantly greater in the group training on dirt. There was no significant difference in the age distribution of incidence between the two groups and there was no association of incidence with sex or age within the training group. The number of fast miles worked by the two groups prior to the onset of dorsal metacarpal disease was lower in the group...
Langton CM, Riggs CM, Evans GP.The velocity of ultrasound waves through bone has been used widely as a non-invasive method for assessing bone quality. Accurate measurement of velocity depends on accurate assessment of the distance travelled by the sound wave. It has been argued that the sonic pathway is deflected around the marrow cavity and so does not follow a straight line through the bone; therefore, correction factors have been developed to account for the extra distance travelled. This hypothesis was examined in vitro using sections from the equine third metacarpal bone. Two 1 MHz transducers used with the transmittin...
Young DR, Richardson DW, Markel MD, Nunamaker DM.The third carpal bone (C3) was collected from both forelimbs of 27 Thoroughbreds. On the basis of age, training, and history, specimens were assigned to 1 of 5 groups: yearling, untrained horses (group 1, n = 4); 2- to 3-year-old, untrained horses (group 2, n = 7); trained 2-year-old horses (group 3, n = 6); trained 3-year-old horses (group 4, n = 6); and 3-year-old, trained horses with carpal pathologic features (group 5, n = 4). A transverse section of subchondral bone 5-mm thick was cut in a precise fashion 10 mm below the proximal articular surface of all specimens. After high-detail radio...
Nunamaker DM, Butterweck DM, Black J.In vitro local fatigue testing of the third metacarpal bone from Thoroughbred and Standardbred racehorses was performed, using fully reversed cyclic bending. Strain number of cycle data were accumulated and indicated that significant difference did not exist between the 2 breeds. It was concluded that the marked difference in the incidence of fatigue failure in the third metacarpal bone (bucked shins, dorsal metacarpal disease) seen in Thoroughbreds and Standardbreds was not related to any differences between the 2 breeds in mechanical properties of the bone.
Nunamaker DM, Richardson DW, Butterweck DM.Plate luting, a technique that uses polymethylmethacrylate (PMMA) interposed between the plate and the bone, as well as between the screw heads and the plate, to improve the stability of internal fixation was tested in vitro using 20 paired equine third metacarpal bones with mid-diaphyseal osteotomies plated with six-hole broad ASIF compression plates. One of each pair was luted and all specimens were tested in static overload or cyclic loading at 75% of the ultimate breaking strength using four-point bending. Although no differences were measured in static overload tests between luted and non...
Hunt RJ, Allen D, Baxter GM, Jackman BR, Parks AH.Deep digital flexor tendon transection at the mid-metacarpus was performed in 20 horses with severe acute or chronic laminitis that was not responsive to conventional treatment. Sixteen horses improved within 72 hours, one horse worsened, and two horses were unaffected by the surgery. Eleven horses survived less than 1 month after surgery and six horses survived longer than 6 months. Three horses surviving longer than 6 months have remained lame and no horse has returned to athletic performance. Transection of the deep digital flexor tendon at the mid-metacarpus may decrease the pain associate...
Firth EC.In chondro-osseous disease in the foal there are three main categories of lesions: (i) synovitis alone (type S), (ii) synovitis accompanied by osteomyelitis originating in the epiphysis of the juxta-articular bone (type E) and (iii) synovitis accompanied by osteomyelitis originating directly adjacent to the physis of the juxta-articular bone (type P). Observations made in studies of the immature radius and metacarpus provide an explanation for the apparent predisposition of some joints for this disease. Relevant clinical and therapeutical aspects are discussed.
Specht TE, Miller GJ, Colahan PT.The breaking strength (stress at failure) of equine third metacarpal bones, with and without clustered drill holes, was determined in vitro. Paired ossa metacarpalia II-IV of 39 horses (n = 39) between 2 and 7 years old were tested in palmarodorsal 3-point bending. Four treatments were compared. Clustered 2.7- or 3.5-mm drill holes, in a 4- or 7-hole pattern, were made in the dorsal cortex of the distal diaphysis of the left third metacarpal bone. Undrilled right third metacarpi were used as controls. Bones with clustered drill holes failed by an oblique fracture through 1 or more drill holes,...
Foreman JH, Kneller SK, Twardock AR, Chambers MD, Inoue OJ.Scintigraphy has been used in numerous clinical settings to examine horses to determine the origin of lameness problems, but it has not been used previously to monitor prospectively the skeletal responses of a group of similarly-trained racehorses. Our hypothesis was that in naïve Thoroughbred (TB) racehorses, initial treadmill training induces increased radiopharmaceutical uptake in high-motion joints and in the dorsal third metacarpal bone (MC3). Eight previously-untrained TB racehorses underwent sequential skeletal scintigraphic examinations as they exercised daily for 9 weeks on an inclin...
Ramzan PH.Fractures involving the fetlock region are encountered commonly in Thoroughbred racehorses. Condylar fractures of the distal metacarpus/metatarsus and mid-sagittal fractures of the proximal phalanx account for the majority of fetlock injuries during both racing and training and clinical features, management and outcome of these injuries have been well described. Transverse fractures of the distal diaphysis of the third metacarpus, however, are seldom observed and have received little attention in the literature. This paper describes clinical and radiological findings associated with 6 cases en...
Rose PL, Auer JA, Hulse D, Hightower D, Schenk RK.beta-Tricalcium phosphate (TCP) was evaluated as a synthetic bone grafting material in horses. Sixteen horses were randomly assigned to 4 groups of 4 horses. In each horse, an 11-mm by 10-mm circular defect with a smooth margin was created surgically in the weight-bearing surface of both third metacarpal bones (McIII) and the left third metatarsal bone. The defect in the left McIII was filled with TCP, the defect in the right McIII was filled with a mixture of 50% autogenous cancellous bone (ACB) and 50% TCP, and the defect in the left third metatarsal bone was not filled to serve as a control...
Firth EC.In chondro-osseous disease in the foal there are three main categories of lesions: (i) synovitis alone (type S), (ii) synovitis accompanied by osteomyelitis originating in the epiphysis of the juxta-articular bone (type E) and (iii) synovitis accompanied by osteomyelitis originating directly adjacent to the physis of the juxta-articular bone (type P). Observations made in studies of the immature radius and metacarpus provide an explanation for the apparent predisposition of some joints for this disease. Relevant clinical and therapeutical aspects are discussed.
Gillis JP, Zardiackas LD, Gilbert JA, St John KR.Paired equine third metacarpal bones were drilled and tapped for 4.5 mm and 5.5 mm cortical screws. Tapping was done by hand or with an air-driven reversible orthopedic drill. Screws were inserted and subjected to extraction forces to failure of the osseous threads or the screws. There was no difference in holding power of either screw size between hand-tapped and power-tapped holes.
Nicoll RG, Wood AK, Martin IC.Observations were made in dorsal and sagittal planes of the ultrasonographic mean gray scale of the flexor tendons and ligaments of the metacarpal regions of 5 Thoroughbred geldings, during weight bearing and nonweight bearing. In images made when the horses were nonweight bearing, the mean gray scale of the superficial and deep digital flexor tendons and accessory ligament was significantly reduced, but that of the interosseous medius muscle (suspensory ligament) was not. When relaxed, collagen fiber bundles in the tendons and ligaments acted as diffuse, rather than specular, reflectors of ul...
Oheida AH, Shalgum AA, Alrtib AM, Booker AO, Ben-Naser KM, Davies HMS.Carpal conformation is an important factor in relation to joint soundness. The equine carpometacarpal joint (CMCJ) was reported to have variations in its three palmaromedial articulations. Lacking one or more of these articulations has not been radiographically evaluated in Thoroughbred (TB) and Standardbred (SB) racehorses. The study aimed to identify the prevalence of the variation in the palmaromedial articulation of the carpometacarpal joint (PM-CMCJ) in TB and SB horses. Additionally, to detect the probability of having each of the three articulations within and between the breeds. Finall...
Hobbs SJ, Mather J, Rolph C, Richards J.Radial strain in normal hooves has been found to vary with strain gauge location, limb posture and sample limb but reported magnitudes were considered to be low. More accurate measurement of radial strain may enhance the understanding of hoof function. Objective: To explore in vitro radial hoof strain in relation other kinetic and kinematic variables that may be related. Methods: Five normal forelimbs were removed at the proximal articular surface of the third metacarpal bone (McIII). The limbs were loaded using a modified Instron test machine. Six calibrated infrared cameras captured movement...
Cervantes C, Madison JB, Ackerman N, Reed WO.Between January 1985 and May 1989, 53 Thoroughbred horses (mean age 3.2 years) were surgically treated for dorsal cortical fractures of the third metacarpal bone (MC III). All horses were treated with cortical drilling through the fracture line (osteostixis). Diagnosis of the fractures was confirmed by xeroradiography. Lifetime racing records were obtained for all horses. Forty-seven horses returned to racing after surgery (89%). The mean time between surgery and the first race was 6.8 months. Horses had a mean of 10.9 starts before surgery and 16.1 starts after surgery. The mean earnings per ...
MacKay AV, Panizzi L, Sparks HD, Barber SM.To report complications of arthrodesis of the carpometacarpal (CMC) joint using a drilling technique in an adult horse. Methods: Case report. Methods: Horse (n = 1). Methods: A 12-year-old Quarter Horse mare with CMC osteoarthritis (CMC-OA) had arthrodesis under general anesthesia in right lateral recumbency. Under fluoroscopic guidance, a 4.5 mm drill bit was inserted at 3 drilling sites 5-6 cm into the CMC joint and was fanned 30-45° in the plane of the joint and 5-10° in the long axis of the limb to destroy articular cartilage and expose the subchondral bone. Results: The horse pr...
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...
Lection J, Delvescovo B, Percival A, Wu T, Southard T, Diel de Amorim M, Cheong SH.In utero fracture and malunion of long bones is a rare condition in horses. Most foals with in utero fractures are aborted, and the identification of a fetal in utero fracture in a mare with dystocia has not been reported. A 7-year-old multiparous Standardbred mare presented to a referral center for correction of dystocia. Assisted vaginal delivery and controlled vaginal delivery attempts were unsuccessful mainly because of contracted tendons impeding mutation. As the foal was alive, a cesarean section was elected. The foal was delivered but ultimately euthanized because of the congenital abno...
Tabar-Rodriguez JJ, Cruz AM, Monteith G, Gordon K, Hurtig MB.OBJECTIVE-To use quantitative ultrasonography to evaluate the association between the speed of sound (SOS) at 9 sites in the third metacarpal bone (MCIII) of racing Thoroughbreds with workload accumulation and the effect that MCIII failure has on this association. ANIMALS-Sixty-two 2- and 3-year-old Thoroughbreds in racing condition. PROCEDURES-Cumulative work index (CWI) was used to calculate total workload (CWI(total)) and also 3 independent CWIs for the various gaits (ie, trot [CWI(trot)], gallop [CWI(gallop)], and race [CWI(race)]) used during training and racing. Speed of sound was monito...
Les CM, Stover SM, Willits NH.Paired metacarpi obtained at necropsy from 100 horses ranging in age from term fetus to 35 years were examined to estimate the prevalence and sites of metacarpal fusion. Metacarpal fusion was seen in 192 of 200 metacarpi, and 78% of all horses 2 years or older had 2 or more fusions. Fusion of the second metacarpal bone to the third metacarpal bone was significantly (P < 0.001) more common than was fusion of the fourth to the third metacarpal bone. Fusions appeared for the most part in pairs and were bilaterally symmetric. Rooney-Prickett type-A carpometacarpal joint configurations (in which...
Granello ME, Weatherall KM, Lutter JD, Beard WL. The aim of this study was to compare the deflection distance, deflection angle and pre-loading sub-bandage pressure of a transverse, mid-metacarpal fracture in an equine cadaver limb when loaded in bending while stabilized with either a Robert Jones Bandage (RJB) or a single-stack bandage (SS), each containing two orthogonal splints. Methods: In an ex vivo experimental study, forelimb pairs from eight horses were collected, and one forelimb from each pair was assigned to either the SS or RJB groups. A transverse osteotomy was performed at the midpoint of the metacarpus. After bandaging, ...
Nash RA, Nunamaker DM, Boston R.To evaluate stiffness and bone-pin interface stress for a transcortical tapered-sleeve pin (TSP) that incorporates bilateral tapered sleeves over a transcortical pin. Methods: 14 third metacarpal bones (MCIII) collected from adult horses of various breeds. Methods: Each MCIII was cut in half to provide 2 test specimens. Pins (conventional and TSP) of 3 diameters (6.35, 7.94, and 9.50 mm) were inserted in specimens (3 specimens for each diameter and each type of pin). The test fixture simulated a typical sidebar-span skeletal fixation device for horses. Single cycle load-deflection tests were p...
Brommer H, Back W, Schamhardt HC, Rijkenhuizen AB, Barneveld A.To improve fracture treatment, in vitro experiments were performed to study the influence of a full limb cast and a walking cast on the loading regimen of bones in the distal portion of the equine forelimb. Methods: 6 forelimbs of 6 Shetland ponies. Methods: Loading of the third metacarpal bone was considered a representative measure for distal limb loading. Electrical resistance rosette strain gauges were attached to the dorsal, palmar, medial, and lateral surfaces of the midshaft of this bone in 6 forelimbs of 6 Shetland ponies. The limbs were tested in a pneumatic loading device to a maxima...
Dzierzęcka M, Jaworski M, Purzyc H, Barszcz K.The aim of the study was to analyse selected densitometric and geometric parameters in the third metacarpal bone along the long axis in horses. The densitometric parameters included the cortical and trabecular bone mineral density, while the geometric parameters included the cortical, trabecular, and total areas, strength strain index X, strength strain index Y, and the polar strength strain index. Methods: The parameters were analysed using eight sections from 10% to 80% of the length of the bone. Peripheral quantitative computed tomography was used in the study. Statistical analysis was carr...
Lopez MJ, Wilson DG, Vanderby R, Markel MD.To compare the mechanical properties of two stabilization methods for ostectomized equine third metacarpi (MC3): (1) an interlocking nail system and (2) two dynamic compression plates. Animal or Sample Population-Ten pairs of adult equine forelimbs intact from the midradius distally. Methods: Ten pairs of equine MC3 were divided into two test groups (five pairs each): caudocranial four-point bending and torsion. Interlocking nails (6 hole, 13-mm diameter, 230-mm length) were placed in one randomly selected bone from each pair. Two dynamic compression plates one dorsally (12 hole, 4.5-mm broad)...
Mundy LN, Lescun TB, Main RP, Hall Griffin T.To compare heat generation and mechanical bone damage achieved with 2 tapered and 1 cylindrical transfixation pin taps in third metacarpal bones from equine cadavers. Methods: 18 pairs (36 specimens) of third metacarpal bones from euthanized horses with no known metacarpal disease. Methods: In each bone, an investigator drilled 3 holes for placement of a 6.3-mm cylindrical transfixation pin, a 6.3-mm tapered pin using a prototype tapered tap, and a 6.3-mm tapered pin using a revised tapered tap. One bone of each pair was tapped by hand and the other with an electric drill. Temperatures of the ...
Lloyd KC, Koblik P, Ragle C, Wheat JD, Lakritz J.In 4 adult horses, simple, nondisplaced, incomplete fracture of the proximal extremity of the third metacarpal bone (MC3) was identified radiographically only on the dorsopalmar projection. Lameness was slight to moderate. Although nerve blocks of the foot and fetlock did not alter the lameness, high palmar regional nerve block improved the gait in 1 of the 2 horses on which it was performed. Pain on palpation or swollen distal accessory (inferior check) ligament, flexor tendons, and suspensory ligament were not found in any horse. The fracture was localized to the palmar surface of the proxim...
Maia BT, Vendruscolo CDP, de Souza AF, Zoppa ALDV.The neurovascular bundle of the equine distal cannon can dynamically vary with limb position, and this can affect the performance of low 4- or 6-point block. This study aims to identify and describe the anatomical position and variations of the lateral and medial palmar/plantar nerve at the metacarpal/metatarsal distal level in horses by ultrasonography. Eight mares underwent ultrasound examination on the lateral and medial palmar/plantar sides of the metacarpus/metatarsus. Images were obtained for measurements of the cross-sectional area of the nerve, distances between the nerve and the skin ...
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 ...
Seltzer KL, Stover SM, Taylor KT, Willits NH.The torsional monotonic structural material properties of equine metacarpi with or without, either a 5/16 inch or 3/8 inch diameter bicortical lateromedial middiaphyseal hole were assessed to determine the effect of a hole on metacarpal strength. Torsional stiffness was not significantly effected by the presence of a bicortical hole, whereas yield and failure angles, torques and energies of metacarpi with a hole were 51% to 97% of those of intact bones. Significant differences were not apparent for yield and failure mechanical properties between metacarpi with a 5/16 inch diameter hole and met...
Ehrlich PJ, Dohoo IR, O'Callaghan MW.To document anatomic patterns of scintigraphic uptake and related orthopedic disease associated with racing activity in Standardbred horses. Methods: Retrospective study. Methods: 64 Standardbred horses evaluated for lameness. Methods: Medical records at the time of discharge were reviewed, and information regarding signalment; history; results of lameness examination, scintigraphy, and radiography; diagnosis; and treatment were obtained. Results: 274 areas of increased radiopharmaceutical uptake were identified. Scintigrams of 218 limbs (106 forelimbs, 112 hind limbs) were available for revie...
Moure A, Reichmann P, Gamba HR.The application of the dual photon absorptiometry (DPA) technique, using gadolinium-153 as the photon source, to evaluate the bone mineral density (BMD) of the third metacarpal bone of horses is presented. The radiation detector was implemented with a NaI(TI) scintillator coupled to a 14 stage photomultiplier. A modular mechanical system allows the position of the prototype to be adjusted in relation to the animal. A moveable carrier makes it possible to scan the third metacarpal with a velocity adjustable between 1 and 12 mm s(-1), in steps of 1 mm s(-1), for a total distance of 250 mm. The p...
Soroko M, Górniak W, Godlewska M, Howell K.The aim of this study was to evaluate the influence of training on body surface temperature over the joints in racehorses, measured by infrared thermography. The study involved monitoring of 14 Thoroughbred racehorses in 6 imaging sessions over a period of 3 months. Temperature measurements of the forelimb and hindlimb joints were made before and just after training. Joint temperature of limbs increased significantly after training. Environmental temperature had a statistically significant influence on surface temperature over the joints. The lowest surface temperatures were recorded over the ...
Sod GA, Mitchell CF, Hubert JD, Martin GS, Gill MS.To compare monotonic biomechanical properties and fatigue life of a 5.5 mm broad limited-contact dynamic compression plate (5.5-LC-DCP) fixation with a 4.5 mm broad LC-DCP (4.5-LC-DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Methods: In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Methods: Adult equine cadaveric MC3 bones (n=18 pair). Methods: MC3 were divided into 3 test groups (6 pairs each) for: (1) 4-point bending single cycle to failure testing; (2) 4-point bendi...
Schade J, de Souza AF, Vincensi LC, Müller TR, Fonteque JH.The objective of this study was to evaluate and compare the sonographic characteristics of the digital flexor tendons and ligaments of the palmar/plantar of the metacarpal and metatarsal regions in gaited horses, as well as to establish normal reference ultrasound values for Mangalarga Marchador (MM) and Campeiro breeds. Transverse sonographic images were obtained of 50 adult and healthy horses from the MM (n = 25) and Campeiro (n = 25) breeds. The images were taken in six metacarpal/metatarsal zones, and the following measurements were taken: transverse area, circumference, dorsopalmar/planta...
