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1.
The most prevalent causes of death in racehorses are musculoskeletal injuries, causing ~83% of deaths within the racing industry in California and elsewhere. The vast majority of these injuries have preexisting lesions that predispose to fatal injury. A 4-y-old Thoroughbred colt suffered an acute suspensory apparatus failure, including biaxial proximal sesamoid bone fractures of the right front fetlock, causing loss of support of the fetlock joint and consequent fall with fractures of the cervical and sacral spine. Cervical fracture caused spinal cord damage that resulted in sudden death. A preexisting lesion in the medial proximal sesamoid bone likely predisposed to complete fracture of this bone and fetlock breakdown. Interestingly, a comparable osteopenic lesion was present in the intact medial proximal sesamoid bone of the left forelimb, which is consistent with bilateral repetitive overuse injury in racehorses. The morphologic features of the cervical and sacral spine fractures were compatible with acute injury; no evidence of preexisting lesions was seen. Most likely, these acute vertebral fractures occurred as a result of the horse falling. This case emphasizes the importance of performing a detailed autopsy in horses that suffer an appendicular musculoskeletal injury, particularly in fatal cases when the horse dies following a leg injury.  相似文献   

2.
Using xeroradiographic techniques, both metacarpophalangeal regions of six quarter horse foals were radiographed at 1 day of age and at 2-week intervals until they were 6 weeks old, and then at 4-week intervals until they were 12 months old. Lateromedial and dorsopalmar xeroradiographs of each metacarpophalangeal region were made per examination; dorsomedial-palmarolateral projections of the left metacarpophalangeal joint of foal 6 were also made. The foals were weighed and measured at the withers immediately prior to each examination. Representative xeroradiographs were selected to demonstrate progression of the osteochondrosis (OCH) lesions in two of these foals. Radiographic evidence of osteochondrosis in the metacarpophalangeal region was first detected at 10 weeks and followed through 12 months of age. In one foal the lesions were bilaterally symmetric and involved the dorsoproximal aspect of the sagittal ridge of metacarpal 3; in the other, the left medial proximal sesamoid bone was affected. One of the sagittal ridge lesions progressed to osteochondritis dissecans by 26 weeks; the other sagittal ridge lesion and that of the sesamoid bone healed spontaneously, but residual radiographic evidence of the disease persisted throughout the study in both foals.  相似文献   

3.
Rupture of the suspensory ligament at the insertions on the proximal sesamoid bones, and of the superficial flexor tendon of the left fore limb, occurred in an adult Angus bull as a result of fighting. There was severe hyperextension of the metacarpophalangeal (MCP) joint with the dewclaws almost touching the ground. Radiographs revealed severe hyper-extension of the MCP joint with the sesamoid bones aligned directly distal to the metacarpus. Initially, a full length fiberglass cast was applied with the limb partially flexed within the cast and the heels elevated. The cast was replaced twice. The cast was removed after 136 days and the bull was bearing full weight on the limb. Prolonged immobilisation of the limb produced new bone in the area (a normal response in cattle) to cause ankylosis of the traumatized MCP joint and partial ankylosis of the carpus. The bull was being used for pasture breeding one year after the injury.  相似文献   

4.
Eighteen cases of fractures of the proximal sesamoid bones in Thoroughbred foals are described. Most of the fractures were in foals under 2 months old and all but one occurred in the forelegs. The bones commonly fractured when the foal galloped to exhaustion trying to keep up with its dam in the paddock. The types of fracture varied but a simple fracture of the medial sesamoid was most frequent and the majority were towards the base of the bone. Six foals sustained a fracture of more than one sesamoid bone and one foal fractured all 4 proximal sesamoid bones in its front legs. Treatment included box rest and the surgical removal of the separated piece of sesamoid bone. Only 3 of the foals treated have raced. One of these was treated surgically.  相似文献   

5.
OBJECTIVE: This study compared the mechanical properties of the normal intact suspensory apparatus and two methods of fixation for repair of transverse, midbody fractures of the proximal sesamoid bones of adult horses: transfixation wiring (TW) and screws placed in lag fashion (LS). STUDY DESIGN: An in vitro, paired study using equine cadaver limbs mounted in a loading apparatus was used to test the mechanical properties of TW and LS. ANIMAL OR SAMPLE POPULATION: Seventeen paired (13 repaired, 4 normal) equine cadaver limbs consisting of the suspensory apparatus third metacarpal bone, and first and second phalanges. METHOD: The two methods of repair and normal intact specimens were evaluated in single cycle-to-failure loading. Yield failure was defined to occur at the first notable discontinuity (>50 N) in the load-displacement curve, the first visible failure as evident on the videotape, or a change in the slope of the moment-fetlock angle curve. Ultimate failure was defined to occur at the highest load resisted by the specimen. Corresponding resultant force and force per kg of body weight on the suspensory apparatus, fetlock joint moment, and angle of fetlock dorsiflexion were calculated by use of specimen dimensions and applied load. These were compared along with specimen stiffness, and ram displacement. RESULTS: Load on the suspensory apparatus, load on the suspensory apparatus per kg of body weight, moment, applied load, and angle of fetlock dorsiflexion at yield failure were significantly greater for the TW-repaired than for the LS-repaired specimens. A 3 to 5 mm gap was observed before yield failure in most TW-repaired osteotomies. CONCLUSIONS: Transfixation wiring provided greater strength to yield failure than screws placed in lag fashion in single cycle load-to-failure mechanical testing of repaired transverse osteotomized specimens of the medial proximal forelimb sesamoid bone.  相似文献   

6.
REASONS FOR PERFORMING STUDY: Studies have shown that surgical removal of apical fracture fragments in Standardbred racehorses carries the best prognosis for return to racing performance, but there are no reports involving mature Thoroughbred (TB) racehorses. OBJECTIVES: To describe the incidence of apical proximal sesamoid fractures in TB racehorses and determine probability and quality of racing performance after arthroscopic removal of such fractures in TB racehorses age > or = 2 years. METHODS: Medical records and pre- and post operative race records of TB racehorses age > or = 2 years that underwent arthroscopic surgery for removal of apical proximal sesamoid fracture fragments were reviewed. RESULTS: Sixty-four percent of fractures occurred in the hindlimbs and 36% in the forelimbs. Horses with forelimb fractures had a reduced probability of return to racing (67%) compared to those with hindlimb fractures (83%), but the majority (77%) of treated horses recovered to return to race post operatively. Horses with medial forelimb fractures raced at only a 47% rate; those with suspensory desmitis at 63%. Unlike Standardbreds, there was no difference in probability of racing post operatively between horses that had, and had not, raced preoperatively. CONCLUSIONS: Data show that arthroscopic removal of apical proximal sesamoid fracture fragments is successful at restoring ability to race in skeletally mature TB horses without evidence of severe suspensory ligament damage. Prognosis for return to racing is excellent (83%) in horses with hindlimb fractures and good (67%) in those with forelimb fractures. Medial fractures of the forelimb have the worst prognosis. POTENTIAL RELEVANCE: The determination of prognosis for differing sites in TB racehorses should increase knowledge of apical proximal sesamoid bone fractures and improve communication from veterinarian to owner, and trainer, on the potential for arthroscopic restoration of the ability to race.  相似文献   

7.
Forty-eight limbs of 12 freshly euthanized horses were used to generate data on the strength of the equine suspensory apparatus. The point of failure of the suspensory apparatus of each limb was determined. Immediately before euthanasia, 6 of the 12 horses (thoroughbreds and standardbreds) had been engaged in active training or racing, and six horses in stall and/or pasture activity. In the actively training or racing horses, the point of acute failure of the suspensory apparatus was within the proximal sesamoid bones in 20 (83%) limbs (resulting in 17 apical fractures, 2 basilar fractures, and 1 midbody fracture). In the pasture exercised or stalled horses, the point of failure of the suspensory apparatus was either acutely within the suspensory ligament (10 horses, 42%) or, if no acute failure occurred, insidiously within the suspensory ligament (12 horses, 50%). Active training appeared to have a strengthening effect on the suspensory ligament, causing the weakest point in the suspensory apparatus to become the sesamoid bones rather than the suspensory ligament. An average force of 1338 kg (between 1082 and 1673 kg) was needed to fail the suspensory apparatus in this group of horses. In nontraining horses, the site of failure was most often the suspensory ligament. An average force of 1100 kg (between 918 and 1241 kg) used to fail the suspensory apparatus in this group of horses was significantly (p less than 0.5) less than in the first group.  相似文献   

8.
Fractures of the distal phalanx of the forelimb were diagnosed in 5 colts and 3 fillies ranging in age from 2 weeks to 5 1/2 months at the time of fracture. Three fractures entered the distal interphalangeal joint and 6 fractures (one foal had bilateral fractures) were nonarticular. All foals with articular fractures became sound with conservative treatment. Four of 5 foals with nonarticular fractures became sound with conservative treatment and 1 foal developed separation of the hoof at the coronary band after application of acrylic around the hoof. On the basis of our observations in these foals, sagittal articular and nonarticular distal phalangeal fractures in foals should be treated conservatively. Foals so treated would have an excellent prognosis for return to soundness.  相似文献   

9.
Twelve foals with unusual sesamoid development were found in a population of 107 Thoroughbred foals (60 males, 47 females) over a three year period. Radiographic examination was done at 14 days of age and at 42 day intervals thereafter. The routine administration was of a dorsopalmar view of the proximal sesamoid bones in the left forelimb. Changes of the proximal sesamoid bones were found in 11% of the foals between 14 and 56 days of age. The change was a radiolucent line at the junction of the middle and proximal third of the sesamoid bone. Of those which were observed with sesamoid bone changes, 8 had a normal radiographic appearance at 60 days. In most foals at least 2 or 3 sesamoid bones of the forelegs were affected. In some only 1 sesamoid bone was affected. The changes did not correlate with a clinical joint disorder. However, females seemed to be affected more than males. This condition may be similar to bipartite sesamoid bones described by others and probably a manifestation of secondary ossification centers.  相似文献   

10.
OBJECTIVE: To determine whether fracture fragment dimensions, suspensory ligament damage, and racing status at the time of injury were associated with outcome in Standardbred horses with apical fracture of the proximal sesamoid bone. DESIGN: Retrospective study. ANIMALS: 43 Standardbred racehorses. PROCEDURE: Medical records, racing records, and radiographs were reviewed, and ultrasonographic findings were scored. Measurements of the fractured portion of the proximal sesamoid bone were made. RESULTS: Seventy-four percent (32/43) of horses were pacers, and 26% (11/43) were trotters. Statistical differences between trotters and pacers regarding ability to start, number of starts, or amount of money earned after injury were not detected. Females earned significantly more money per start after injury than males. Eighty-six percent (37/43) of fractures involved hind limbs and 14% (6/43) involved forelimbs. Horses with forelimb injuries earned less money per start. Severity of suspensory ligament damage did not affect postinjury racing performance. A higher proportion of horses that had raced before injury returned to racing after surgery than horses that had not raced before injury, although a significant difference between these groups was not detected. Eighty-eight percent of horses that raced before injury raced after injury. Fifty-six percent of horses that did not race before injury raced after injury. Fracture fragment dimensions did not affect outcome. CLINICAL IMPLICATIONS: Dimensions of the apical fracture fragment of the proximal sesamoid bone in Standardbred horses and degree of suspensory ligament damage did not affect outcome. Prognosis for return to racing soundness is good in horses that had raced before injury and fair in horses that had not raced before injury.  相似文献   

11.
OBJECTIVES : To compare the biomechanical properties of a prototype intramedullary pin-plate (IMPP) implant specifically designed for equine metacarpophalangeal (MCP) arthrodesis with a dynamic compression plate (DCP) system. STUDY DESIGN : In vitro biomechanical testing of paired cadaveric equine forelimbs with a simulated traumatic disruption of the suspensory apparatus, stabilized by one of two methods for MCP arthrodesis. ANIMAL POPULATION : Twenty-one pairs of adult equine cadaveric forelimbs. METHODS : Each forelimb had the distal sesamoidean ligaments severed to create a disrupted suspensory apparatus. For each forelimb pair, the MCP joint was stabilized with the IMPP in one limb, and a DCP in the other limb. Seven matching limb pairs were tested in axial compression in a single cycle to failure, 7 matching limb pairs were tested in torsion in a single cycle to failure, and 7 matching limb pairs were fatigued tested in axial compression. Mean test variable values for each method were compared using a paired t-test within each group. Significance was set at P<.05. RESULTS : The mean yield load, yield stiffness, and failure load (axial compression, torsional loading) was significantly greater for the IMPP compared with the DCP system. Mean cycles to failure for axial compression was significantly greater for the IMPP compared with the DCP system. Significance in all tests was P<.0001. CONCLUSION : The IMPP was superior to the DCP system in resisting the biomechanical forces most likely to cause failure of MCP joint arthrodesis. CLINICAL RELEVANCE : The IMPP implant should be considered for MCP arthrodesis in horses with traumatic disruption of the suspensory apparatus. The specific design of the IMPP implant may facilitate equine MCP arthrodesis and avoid convalescent complications related to cyclic fatigue.  相似文献   

12.
A 3-month-old Quarter Horse colt sustained a penetrating injury over the coronary band on the right forelimb resulting in an articular bone sequestrum and septic arthritis of the distal interphalangeal joint. Despite aggressive treatment for septic arthritis, severe osteoarthritis and ongoing sepsis resulted in persistent lameness. Facilitated ankylosis of the distal interphalangeal joint was performed using a combination of open surgical debridement, placement of an autogenous cancellous bone graft and stabilisation within a transfixation cast. Bony ankylosis of the joint was observed radiographically 7 weeks following surgery. Evaluation of the horse 30 months following surgery revealed complete fusion of the middle and distal phalanges, and the distal sesamoid bone. The horse is pasture sound and is used as a breeding stallion. This report describes the surgical approach and case management employed to achieve facilitated ankylosis as a treatment for unresolved septic arthritis of the distal interphalangeal joint. This is the first report of successful facilitated ankylosis of the distal interphalangeal joint in a foal.  相似文献   

13.
Case records of 25 horses with transverse fractures of the proximal sesamoid bone were reviewed to evaluate the success of treatment. All fractures were repaired by use of lag screw fixation and an autogenous cancellous bone graft because the fracture fragments were considered too large for surgical removal and reconstruction of the suspensory apparatus was necessary. Radiography was performed in all cases, and the fractures were classified into 3 types: (1) proximal midbody fractures, which included all fractures in the proximal aspect of the sesamoid bone that resulted in fragments involving greater than one third but less than one half of the total mass of the sesamoid bone; (2) midbody fractures that divided the bone into 2 equal portions; and (3) distal midbody fractures, which included transverse fractures in the distal aspect of the sesamoid bone that resulted in fragments involving greater than one third but less than one half of the total mass of the sesamoid bone. Of these cases, race records were obtained for 9 Standardbreds and 5 Thoroughbreds. Postoperative performance criteria evaluated were the ability to train and start 1 race, ability to maintain preinjury class of racing, earnings per start, and the number of starts following surgery. In Thoroughbreds, fractures occurred most commonly in the right forelimb; in Standardbreds, the left hind limb was most commonly involved. The midbody fracture was the most common type in both breeds, and the distribution of fracture location within the sesamoid bone was similar for both breeds.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

14.
OBJECTIVE: To assess individual and combined associations of high-speed exercise and horseshoe characteristics with risk of forelimb proximal sesamoid bone fractures and proximal sesamoid bone midbody fractures in Thoroughbred racehorses. ANIMALS: 269 deceased Thoroughbred racehorses. PROCEDURES: A case-control study design was used to compare 121 horses with a fracture of at least 1 of 4 forelimb proximal sesamoid bones (75 horses had a midbody fracture) and 148 horses without a forelimb proximal sesamoid bone fracture. Univariable and multivariable logistic regression analyses were used to evaluate potential risk factors for association with proximal sesamoid bone fracture. RESULTS: Compared with horses that died without proximal sesamoid bone fractures, horses that died with proximal sesamoid bone fractures were more likely to be sexually intact males, spend more time in active trainingand racing, complete more events, train and race longer since their last layup, have higher exercise intensities during the 12 months prior to death, and have greater cumulative distances for their career. Horses with proximal sesamoid bone midbody fractures were more likely to be sexually intact males, train and race longer since their last layup, and have higher exercise intensities during the 12 months prior to death. CONCLUSIONS AND CLINICAL RELEVANCE: Limitingexercise intensity and the continuous time spent in activity duringa horse's career may decrease the frequency of forelimb proximal sesamoid bone fractures in Thoroughbred horses.  相似文献   

15.
A 2‐day‐old Warmblood filly was presented for examination of an angular limb deformity of the left front limb and an upright conformation of both metacarpophalangeal joints. Radiological examination revealed bilateral absence of the metacarpophalangeal joint space with fusion of the third metacarpal bone and first phalanx (synostosis). No treatment was undertaken. The filly was readmitted to the clinic 10 weeks later for bilateral front limb lameness. On radiological examination, the synostosis of the front metacarpophalangeal joints was still present. Physitis of the distal growth plate of the right third metacarpal bone and proximal growth plate of the right proximal phalanx, and an avulsion fracture of the palmaromedial and proximal aspect of the left middle phalanx, with a cystic like lesion on the medial aspect of distal first phalanx and proximal middle phalanx were diagnosed. Given the poor prognosis, the foal was subjected to euthanasia. Post mortem examination confirmed the absence of the metacarpophalangeal joint space with a trabecular bony union between the third metacarpal bone and the first phalanx. A rudimentary joint capsule was present at the level of the absent joints as well as a small zone of articular cartilage, which invaginated over a short distance into the dorsal trabecular bone on the right front limb. On the medial aspect of the left proximal interphalangeal joint, a focal defect of articular cartilage with exposure of subchondral bone was observed. This is the first case report of a foal born with congenital aplasia of both metacarpophalangeal joints. Congenital malformations should be considered as differential diagnosis in lame foals or foals born with angular or flexural limb deformities.  相似文献   

16.
The suspensory apparatus of one forelimb was surgically disrupted in six adult horses by transecting the distal sesamoidean ligaments. A double-braided prosthetic ligament made of aramid yarn was installed to support the flexor surface of the metacarpophalangeal joint. The prosthesis was routed through tunnels in the third metacarpal bone and proximal phalanx, and secured to bone with screws. Evaluation by radiography, synovial fluid analysis, cinematography, and dynamography was performed before surgery and at weeks 16 and 30. Supracondylar cortical lysis and periosteal proliferation were observed on postoperative radiographs. Synovitis and fragmentation of the prosthesis were apparent from synovial fluid evaluation. Weight bearing and metacarpophalangeal joint motion were decreased and loading was transferred in part to the opposite forelimb. Clinical lameness improved and weight bearing increased during the second half of the 30-week period. At necropsy, there was abrasion of the prosthesis and the articular surfaces in contact with the prosthesis. Diffuse granulomatous synovitis developed in response to aramid fiber fragments within the synovium.  相似文献   

17.
OBJECTIVE: To evaluate 2 methods of midbody proximal sesamoid bone repair--fixation by a screw placed in lag fashion and circumferential wire fixation--by comparing yield load and the adjacent soft-tissue strain during monotonic loading. STUDY DESIGN: Experimental study. SAMPLE POPULATION: 10 paired equine cadaver forelimbs from race-trained horses. METHODS: A transverse midbody osteotomy of the medial proximal sesamoid bone (PSB) was created. The osteotomy was repaired with a 4.5-mm cortex bone screw placed in lag fashion or a 1.25-mm circumferential wire. The limbs were instrumented with differential variable reluctance transducers placed in the suspensory apparatus and distal sesamoidean ligaments. The limbs were tested in axial compression in a single cycle until failure. RESULTS: The cortex bone screw repairs had a mean yield load of 2,908.2 N; 1 limb did not fail when tested to 5,000 N. All circumferential wire repairs failed with a mean yield load of 3,406.3 N. There was no statistical difference in mean yield load between the 2 repair methods. The maximum strain generated in the soft tissues attached to the proximal sesamoid bones was not significantly different between repair groups. CONCLUSIONS: All repaired limbs were able to withstand loads equal to those reportedly applied to the suspensory apparatus in vivo during walking. CLINICAL RELEVANCE: Each repair technique should have adequate yield strength for repair of midbody fractures of the PSB immediately after surgery.  相似文献   

18.
Bilateral angular limb deformities of the metacarpo/metatarsophalangeal regions in 2 foals are discussed. Periosteal transection was used to correct the deformity in both foals. In one foal, only the right forelimb was treated because the deformity in the left forelimb did not appear to warrant surgery. Subsequently, an angular limb deformity, which could have been prevented, developed in the left forelimb. A third foal developed a deformity in the proximal phalanx after periosteal transection of the distal third metatarsal bone.  相似文献   

19.
Objective— To report use of a locking compression plate (LCP) for fetlock arthrodesis in Thoroughbred racehorses after catastrophic disruption of the suspensory apparatus.
Study Design— Retrospective case study.
Animals— Racing Thoroughbreds (n=6) with a catastrophic breakdown injury of the suspensory apparatus.
Methods— Medical records (2004–2006) of horses that had fetlock arthrodesis using an LCP were reviewed. Preoperative recorded variables were: age, gender, affected limb, injury type and occurrence, limb support used and time to surgery. Recorded surgical variables were: implants used and cost, surgery time, and anesthetic recovery method. Postoperative recorded variables included: treatment, physical status, complications, and outcome.
Results— Of 6 Thoroughbred racehorses that had LCP arthrodesis, 4 were sound for breeding purposes the next year and 2 horses were euthanatized (1 at 16 days, 1 at 68 days) because of proximal interphalangeal joint (PIJ) luxation. No surgical complications were associated with implant application. Postoperative complications were similar to those reported for other arthrodesis techniques.
Conclusions— LCP is a viable option for fetlock arthrodesis in Thoroughbred racehorses after catastrophic suspensory apparatus disruption.
Clinical Relevance— Adequate fetlock stability can be achieved with an LCP, and although the repair is likely more stable it is ∼3 times more expensive than using a limited contact dynamic compression plate (LC-DCP) with cortical screws.  相似文献   

20.
The purpose of this study was to describe the pattern of radiopharmaceutical uptake in the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) (fetlock) joints in clinically sound horses. Scintigraphic images from 29 clinically normal horses were evaluated. All the images were assessed subjectively. The lateral views were assessed quantitatively using vertical line profiles through the center of the joint, and mean ratios of radiopharmaceutical uptake were calculated from regions of interest around the third metacarpal or metatarsal bones, and the proximal phalanx and proximal sesamoid bones. From the vertical line profiles, in the majority of forelimbs (65%) the peak activity of radiopharmaceutical distribution was at the proximal region of the proximal phalanx, with a significantly lower activity within the condyles of the third metacarpal bone. However, in 84% of hindlimbs there was a broader profile peak incorporating the condyles of the third metatarsal bone and the proximal aspect of the proximal phalanx, indicating a more generalized even uptake of radiopharmaceutical across the MTP joint. When the regions of interest were compared between front and hindlimbs, there was no significant difference between proximal phalanx and proximal sesamoid bones, but the distal condyles of the third metacarpal bone of the forelimb had significantly lower radiopharmaceutical activity than hindlimbs (P < 0.04). In lateral images, the mean forelimb ratios tended to be higher in the left MCP joint compared with the right (P = 0.069). In hindlimbs, the mean ratios tended to be higher in the right MTP joint than the left (P = 0.052). There was no significant effect of age.  相似文献   

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