The Ossification of the Pelvic Girdle and Leg Skeleton of the Quail (Coturnix coturnix japonica)

The onset of ossification centres of the pelvic girdle and leg skeleton of the quail in embryos and juvenile birds were studied. Specimens, which were cleared and were stained with Alcian Blue and Alizarin Red S, were examined at the stereomicroscope. The ilium and the pubis began to ossify at the 8th day (E8), whereas the ischium at E9. Perichondral ossification was observed at E6 in the femur, tibia and fibula. A secondary ossification centre was detected in the proximal epiphysis of the tibiotarsus at the 15th post‐hatching day (P15). The patella began to ossify at P30. Regarding the tarsal bones tibiale, pre‐tibiale and fibulare, ossification was observed at the E15, E12 and E16, respectively. The metatarsals II, III, IV ossified at E7, whereas the metatarsal I at E11. The centres of ossification of the 1st phalanges of all digits were observed at E9. At the same day, the ossification centres of the 2nd phalanx of digits II and III as well as the 3rd phalanx of digit III appeared. At E10, ossification was observed in the 2nd phalanx of digit I, in the 3rd phalanx of digit II and in the 2nd and 3rd phalanx of digit IV. In the 4th phalanx of digit III and in the terminal phalanges of digit IV, ossification was observed at E11. The data presented here provide useful baseline information on the normal sequential pattern of ossification in the pelvic girdle and leg skeleton in this species.     

A morphological study of skeletal development in turkeys during the pre-hatching stage

Skeletal chondrofication, ossification and growth of turkey embryos were investigated and analysed to enable assessment of the developmental status and evaluation of the experimental effects on skeletal development, skeletal mutations and development of cultured embryos. Ten embryos were prepared every 24 h from 8 to 28 days of incubation. The fixed embryos were cleared and stained in toto with Alcian blue & Alizarin red for cartilage and ossified components, respectively. Observation of the skeleton was performed under a stereoscopic microscopy, with special attention to the timing of chondrofication and ossification of the bones. The first occurrence of the primary ossification centres was observed in the femur, tibiotarsus, and the dentary and supra-angular of the mandible on the 12th day, followed immediately by the other long bones. Skeletal features of the skull were determined to show the latest appearance of cartilage and ossification. Hence, all elements of the hyolingual apparatus remained cartilaginous until hatching took place except for the ceratobranchial. Even though the vertebral column chondrified earlier as compared with the ribs and sternum, they ossified later. While chondrofication was present in all the regions of the vertebral column at the same time, ossification progressed from the cervical through caudal regions. The growth rate of the femur was eminently higher than that of the humerus with increase in time, particularly after the 20th day of incubation. This seems to be obviously natural because the eggs used in the study are from the broiler turkey, which gains giant muscle mass at a very short period; precocity is probably at the expense of the bones of the leg rather than those of the wing.     

Ossification and Growth Rates of the Limb Long Bones during the Prehatching Period in the Quail (Coturnix coturnix japonica)

The timing of ossification and the growth of six long bones of the prehatching period in the quail was studied. Ninety-nine quail eggs were incubated and in total nine fetuses were selected daily from the sixth to the sixteenth day of incubation. The fetuses were stained with alizarine and alcian blue double colouration. The fetuses were studied under the stereoscopic microscope and linear measurements were obtained from the humerus, ulna, radius, femur, tibia and fibula. The first appearance of the primary ossification centres in the diaphysis of the studied bones was found to occur between the sixth and the seventh day of incubation. Different growth patterns between the bones of the leg and of the wing were observed. Humerus and tibia showed the greatest growth rate while the radius and fibula showed the lowest.     

Postnatal Osteological Development of the Hyoid Bone in the New Zealand White Rabbit

This study augments knowledge of bone growth by observing the development of the hyoid bone in the New Zealand White rabbit. Preserved hyoid bones representing five different age periods, each period including five individuals and the total number of animals being 25, were fixed in 3.5% formaldehyde solution and 95% ethanol, followed by a pure acetone bath. They were then stained with an alcian blue–alizarin red combination. The mode of bone formation was intracartilaginous type ossification. While the basihyoideum and thyrohyoideum were observed to start ossifying first at prenatal stage, indicating that they are the main skeletal structures of the hyoid apparatus, the ceratohyoideum and lingual process began to ossify in the second and third periods. The separately occurring primary ossification centres fused completely among themselves in the fifth period. Because no further ossification centers were observed and the ossified parts continued the development and growth, the research was terminated after 10 weeks of age.     

Unilateral forelimb partial aphalangia in a kitten

Congenital limb deformities are rarely reported in the cat. The macroscopic and radiographic features of aphalangia are described in a 2-month-old male kitten showing a shortened limb that ended, at the level of the carpus, in a stump without digits. A nail was present at the level of the first phalanx and on the palmar surface only two footpads were present. The radiographs showed an absence of phalanges. The first metacarpal and the proximal and distal phalanges of digit 1 were present. The deformed metacarpal bones were reduced in length; the carpal bones were incompletely ossified. This defect is a rare condition in many animal species. To the author's knowledge, the congenital fore limb deformity described here is the first documented case in a cat.     

Effect of Maternal Lead Exposure on Craniofacial Ossification in Rat Fetuses and the Role of Antioxidant Therapy

Lead exposure during intrauterine life was found to result in reduced birth weight, impaired skeletal development and post‐natal neurotoxic effects. In this study, the effect of pre‐natal exposure to different doses of lead on the development of craniofacial skeleton in rat fetuses was investigated. Vitamin E was tested as a concomitant treatment, aiming to improve the fetotoxic effects of lead. Positively pregnant female rats were randomly divided into four groups; groups I and II (L250 and L500), exposed to lead acetate in doses of 250 and 500 mg/l respectively, group III (L500 + E), exposed to lead acetate (500 mg/l) wit concomitant vitamin E and group IV (Control) which was given sodium acetate only. All the treatments started from the first day of gestation till the 20th day, where all rats were sacrificed and the fetuses were recovered. Fetuses were processed to alizarin red staining for ossified components. Twenty‐seven bones of the craniofacial skeleton were studied in each fetus where the ossification was scored as being complete, delayed or absent. In all studied fetuses from all groups, changes were found only in eight bones while the remaining craniofacial bones were normally ossified. In affected bones there was a significant decrease in the number of completely ossified bones; associated with a significant increase of both partially ossified and absent bones in L₂₅₀ and L₅₀₀ treated groups when compared to the control group. These differences were more significant in the L₅₀₀ treated group. Giving vitamin E improved the percentage of completely ossified craniofacial bones and decreased the percentage of both partially ossified and absent bones. The most affected bone was presphenoid, then to a lesser extent supraoccipital, squamosal, parietal, interparietal and frontal bone respectively. In conclusion, lead exposure to rats during pregnancy led to varying degrees of fetal growth retardation as well as delayed ossification of some craniofacial bones which were dose dependent and the concomitant supplementation with vitamin E greatly improved the deleterious effect of lead.     

A XERORADIOGRAPHIC STUDY OF THE DEVELOPING QUARTERHORSE FOREDIGIT AND METACARPOPHALANGEAL REGION FROM SIX TO TWELVE MONTHS OF AGE

The purpose of the project was to provide a reference for radiographic anatomy of the developing equine foredigit and metacarpophalangeal region. Using xeroradiographic techniques, both foredigits and metacarpophalangeal regions of six Quarter Horse foals were radiographed at 1 day of age and then at 2-week intervals until the foals were 6 weeks old. The foals were then radiographed at 4-week intervals until they were 12 months old. The period from birth to 6 months has been described in a previous report. This paper deals with the period from 6 to 12 months of age. Lateromedial and dorsopalmar xeroradiographs of each foredigit and metacarpophalangeal region and a dorsal 65° proximal-palmarodistal oblique view of the distal part of the digit were made at each examination. Foals were weighed and were measured at the withers immediately prior to each examination. Representative xeroradiographs were selected and appropriately labeled to demonstrate normal radiographic anatomy of these regions. Earliest radiographic visualization of distal epiphyseal ossification in metacarpal 2 and metacarpal 4 was extremely variable and ranged from 4 to 38 weeks. It was not possible to determine accurately the ages at which distal physes of the small metacarpal bones closed. In one foal, three of four of these physes were closed at 26 weeks, while in another foal, none had closed when last radiographed at 54 weeks. Radiographic closure of the proximal physis of the middle phalanx ranged from 18 to 30 weeks (mean = 26 weeks). Radiographic closure of the proximal physis of the proximal phalanx ranged from 22 to 38 weeks (mean = 30 weeks). Radiographic closure of the distal physis of metacarpal 3 ranged from 18 to 38 weeks (mean = 29 weeks).     

The normal development of Mongolian gerbil foetuses and, in particular, the timing and sequence of the appearance of ossification centres

To elucidate the normal development and growth of Mongolian gerbils, the timing and sequence of the appearance of ossification centres within foetuses were investigated. Average foetus body weight and tail length on the 15th day of pregnancy were found to be 0.042 g and 6.2 mm, respectively. For the 25th day of pregnancy, these measurements were 2.601 g and 29.4 mm, respectively. The body weight and tail length of foetuses increased significantly from the 20th day of pregnancy. Also, the first ossification centre of Mongolian gerbil foetuses appeared in the clavicle at the 17th day of pregnancy. The order in which ossification centres appeared in Mongolian gerbils resembles the pattern for rats and mice, except in some areas of the skull. Except for the clavicle, in which ossification centres appeared rather early, most ossification centres appeared in the last quarter of pregnancy. These results suggest that Mongolian gerbil foetal development is near completion by the last gestational stage. Also, ossification centres appear sooner in the skull and nasal bones than in other rodents.     

Congenital malformation of the front limbs in a llama (Lama glama): polydactyly in combination with arthrogryposis

A male, 10 month old llama with malformation of both front limbs was presented. Both front limbs had one more digit located medially. The distal phalanx of this additional digit at the left front limb reached the ground by the tip of the keratinzed pad and the toenail. The accessory digit at the right front limb was bent in a 90 degree angle caudolateraly. Beside the digital bones of the accessory digits the second metacarpal bone and the first carpal bone could be detected in both front limbs by radiological examination. Secondary a bilateral slight carpal valgus deformity could be seen.     

Postnatal ossification centers of the atlas and axis in miniature schnauzers

Postnatal ossification of the atlas and axis was studied in Miniature Schnauzers by examining alizarin-stained bone clearings, cleaned dry bones, radiographs, histologic sections, and arterially perfused bone clearings. Sixty-two pups (1 day to 16 weeks old) and 4 adults were examined. In 1-day-old pups, the atlas consisted of 3 separate ossification centers: a left and right neural arch center and midventrally, the intercentrum 1, which formed the body of the atlas. The axis contained 4 separate ossification centers: a left and right neural arch center; centrum 2 in the main part of the axis body; and centrum 1, which formed the caudal part of the dens and the cranial part of the axis body. By 6 weeks of age, the epiphysis on the caudal end of the axis body had begun to ossify. At this time, the intercentrum 2, which developed as a cuboidal ossification center intercalated between centrum 1 and centrum 2 in the middle of the cranial half of the axis body, also began to ossify. The centrum of the proatlas, which formed the apex of the dens, was first seen ossified in a 9-week-old pup. These 10 ossification centers were seen as constant and separate elements. In all dogs, the dens developed from 2 separate ossification centers: the centrum of the proatlas formed the cranial one-quarter, and centrum 1 formed the caudal three-quarters. Dens dysplasia is unlikely to be a result of failure of development of one of the ossification centers for the dens.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in the skeletal dimensions of the digits of the thoracic limb of Holstein cows after maturation

The 12 left digits of the thoracic limb of Holstein female cows were obtained from a slaughterhouse, and 13 linear measurements of skeletal specimens of the digits of the thoracic limb were used in this study. Bivariate plots, regressions and correlation analyses were performed to assess the relationships between osteometric data and age, and between osteometric data and body size. The geometric mean (GM) of the metacarpal size was used as a proxy of body weight. The results of the regression analysis demonstrated that the length and the width of the distal phalanx were significantly correlated with age, whereas those of other bones were not. In addition, the correlations of the distal phalanx tended to be higher with age than with the GM of the metacarpal size, and their skeletal measurements tended to be longer in older animals than in younger animals. These findings suggest that the distal phalanx is slightly elongated and enlarged in its solear aspect with increasing age in skeletally mature cows. Moreover, although the side difference in the distal phalanx between the lateral and medial digits did not increase significantly with age, the solear aspect of the distal phalanx tended to be rougher, and deformation of the flexor tubercle tended to be more pronounced in the medial digit compared with the lateral digit. Therefore, in the distal phalanx of the front feet, the skeletal deformation with age and asymmetrical bone development might be related to the pathogenesis of claw horn lesions, as in the hind feet.     

Is there an association between ossification of the cartilages of the foot and collateral desmopathy of the distal interphalangeal joint or distal phalanx injury?

Reasons for performing study: Associations between degree of ossification of the cartilages of the foot and injuries to other structures of the foot have been suggested, but have not been investigated by large scale studies. Objectives: To describe the frequency of grade >3 ossification of the cartilages of the foot (possibly significant ossification, PSO), mediolateral symmetry of ossification and left‐right symmetry between feet; and to investigate associations between PSO and injury of either the collateral ligaments (CLs) of the distal interphalangeal (DIP) joint or the distal phalanx. Hypotheses: Possibly significant ossification of the cartilages of the foot is associated with CL and distal phalanx injury. Distal phalanx injury is associated with a mediolateral difference in ossification grade of ≥2. Methods: Horses were examined for lameness localised to the foot by perineural analgesia, and underwent radiographic and magnetic resonance imaging examinations. Age, breed, occupation, duration of lameness, lame(st) limb, primary cause of lameness, and presence or absence of CL injury were recorded. Dorsopalmar (dorsoplantar) radiographs were examined and ossification of the cartilages of the foot graded using a modification of a previously published scale. Results: One foot from each of 462 horses was included for analysis. There was left‐right symmetry of ossification between feet, and significant association between grades of each foot, with lateral ≥medial cartilages. Possibly significant ossification occurred in the maximally ossified cartilage in 59 (12.8%) feet. There were significant associations between PSO of the maximally ossified cartilage of the foot and injuries of both the CLs of the DIP joint and the distal phalanx. There was no association between distal phalanx injury and marked asymmetry of the ossified cartilages of the foot. Conclusions and clinical relevance: Extensively ossified cartilages of the foot are significantly associated with CL or distal phalanx injury. Markedly asymmetric ossification did not increase the likelihood of distal phalanx injury and should be considered at a prepurchase examination.     

EVALUATION OF THE VARIABLY OSSIFIED COLLATERAL CARTILAGES OF THE DISTAL PHALANX AND ADJACENT ANATOMIC STRUCTURES IN THE FINNHORSE WITH COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING

Six Finnhorse cadaver forefeet were selected to represent radiographically different types and grades of ossification of the collateral cartilages of the distal phalanx. These cartilages and adjacent tissues were evaluated with computed tomography (CT) and high field magnetic resonance imaging (MRI). In CT the internal structure of the cartilages was consistent, but in MRI some differences were noted. The shape of the collateral cartilages and their ligamentous attachments varied. The border between ossified and non-ossified cartilage appeared distinct, with considerable variation in the extent of the ossified area in regard to the cross-sectional area of the cartilage. Ossification originating from the palmar processes and extending in the proximaVpalmaroproximal direction, without separate centers of ossification, generally appeared smooth and inactive. Palmar ossification followed the irregular shape of the cartilage. Separate centers of ossification had a medullary cavity or were sclerotic. Presence ofamedullary cavity or sclerosis were also found at the base of the cartilages. The incomplete fusion lines between separate centres of ossification and the ossified base of the cartilage varied from congruent and inactive to reactive with marked sclerosis, flared margins and parachondral changes. Incomplete fusion may be clinically significant. Local conformational adaptations of the hoof were also documented with extensive ossification of the collateral cartilage.     

Clinical significance of ossification of the cartilages of the front feet based on nuclear bone scintigraphy, radiography and lameness examinations in 21 Finnhorses

REASONS FOR PERFORMING STUDY: Research on the clinical significance of ossification of the cartilages of the foot has been limited, despite the common nature of the condition and conflicting reports in previous literature. HYPOTHESIS: Some radiographic features in the ossification of the cartilages, such as incomplete fusion lines between separate centres of ossification and the ossified base, are of clinical significance. METHODS: The relationships between radiopharmaceutical uptake in bone phase nuclear scintigraphy at the heels (palmar processes of the distal phalanx, including ossification of the cartilages of the foot), radiographic extent and type of ossification of the cartilages and clinical lameness were evaluated retrospectively in 21 Finnhorses (age > or = 4 years) in a total of 36 front feet. RESULTS: No significant relationship between height of the ossifications and radiopharmaceutical uptake at the ipsilateral heels existed. Clearly separate centres of ossification were not associated with increased uptake. Moderately increased uptake was suspected to be associated with ossification of the adjacent cartilage in only one foot. Intense uptake was present unilaterally in 4 horses, at one medial and 3 lateral heels. In 2 of these horses, a unilateral palmar digital nerve block relieved the mild lameness; 2 horses had no obvious lameness but had a history of being stiff or having locomotion problems during high speed trot. At 2 of the lateral heels, an incomplete fusion line was present between a large separate centre of ossification and the base, and the third horse had a high sidebone with bony protrusions, suggestive of chronic entheseopathy in a narrow foot. At the medial heel, an oblique radiograph revealed a faint radiolucent line at the base of the ossification. In all cartilages with intense radiopharmaceutical uptake at the heel and/or lameness, the ossified part of the cartilage was wider and more irregular compared to other ossifications of the front feet of the individual. CONCLUSIONS: Increased radiopharmaceutical uptake, associated with a different radiographic appearance from that of other ossifications of the front feet, was a conclusive sign of clinical significance. Obscure locomotion problems were more commonly associated with ossification of the cartilages than true lameness. POTENTIAL RELEVANCE: This information is useful in lameness and prepurchase examinations and is likely also to be applicable to other coldblooded breeds used for athletic purposes.     

Osteological Development of the Garfish (Belone belone) Larvae

Garfish, Belone belone (Linnaeus, 1761) is an elongate, slander fish inhabiting the Eastern Atlantic and Mediterranean Sea. These fish from the Belonidae (Actinopterygii) family have important commercial value for Croatian fisheries. Samples for research were collected from experimental hatching in the Novigrad Sea. Preparation techniques included fixation in buffered formalin, trypsin clearing and staining with alcian blue and alizarin red. As little is known of garfish osteology and bone morphology, the main goal of this study was to describe ossification process in garfish fry. At hatching, no skeletal structure is present. Newly-hatched larvae also had no osteological elements. Ossification started at 7 day post-hatching (DPH) [total length (TL) 18 mm] with head bones and vertebral neural arch. Head skeleton continued to develop mostly over the period from 7 to 10 DPH. At 21 DPH (TL 49 mm), ossification process seemed to be finished, but it was not possible to distinguish borders of all bones. The primary interest of our research was to understand the growth dynamics as well as transformation of supporting body elements from cartilage to bone. At the end, developmental characteristics and functional aspects of this formation in different fish species are discussed.     

FRACTURES OF THE DISTAL PHALANX AND ASSOCIATED SOFT TISSUE AND OSSEOUS ABNORMALITIES IN 22 HORSES WITH OSSIFIED SCLEROTIC UNGUAL CARTILAGES DIAGNOSED WITH MAGNETIC RESONANCE IMAGING

Ungual cartilage ossification in the forelimb is a common finding in horses. Subtle abnormalities associated with the ungual cartilages can be difficult to identify on radiographs. Magnetic resonance (MR) imaging findings of 22 horses (23 forelimbs) with a fracture of the distal phalanx and ossified ungual cartilage were characterized and graded. All horses had a forelimb fracture. Eleven involved a left forelimb (seven medial; four lateral), and 12 involved a right forelimb (five medial; seven lateral). All fractures were nonarticular, simple in configuration, and nondisplaced. The fractures were oriented in an axial proximal to abaxial distal and palmar to dorsal direction, and extended from the base of the ossified ungual cartilage into the distal phalanx. The fracture involved the fossa of the collateral ligament on the distal phalanx in 17 of 23 limbs. The palmar process and ossified ungual cartilage was abnormally mineralized in all horses. Ligaments and soft tissues adjacent to the ossified ungual cartilages were affected in all horses. The routine site of fracture in this study at the base of the ossified ungual cartilage extending into the distal phalanx suggests a biomechanical cause or focal stress point from cycling. The ligamentous structures associated with the ungual cartilages were often affected, showed altered signal intensity as well as enlargement and were thought to be contributing to the lameness. In conclusion, ossified ungual cartilages may lead to fracture of the palmar process of the distal phalanx and injury of the ungual cartilage ligaments.     

A system of grading ossification in limbs of foals to assist in radiologic interpretation.

Tetracycline-labeled bones of 23 foals from 52 to 104 days old were sectioned and macroscopically examined to assess the extent of ossification or fusion of ossification centers. A grading system was devised with which to record information about the ossification centers and growth plates. The objective was to define anatomic standards which could contribute toward obtaining an accurate radiologic interpretation. Labeled limb bones of 3 neonatal foals were similarly treated, but grading of these was limited to the consideration of whether each site was still cartilaginous or had commenced to ossify.     

A XERORADIOGRAPHIC STUDY OF THE DEVELOPING EQUINE FOREDIGIT AND METACARPOPHALANGEAL REGION FROM BIRTH TO SIX MONTHS OF AGE

The purpose of the project was to provide a reference for radiographic anatomy of the developing equine foredigit and metacarpophalangeal region. Using xeroradiographic techniques, both foredigits and meta-carpophalangeal regions of six Quarter Horse foals were radiographed at one day of age and at two-week intervals until the foals were six weeks old. The foals were then radiographed at four-week intervals until they were 12 months old. This report deals specifically with the first six months of postnatal development. Lateromedial and dorsopalmar xeroradiographs of each foredigit and metacarpophalangeal region and a dorsal 65° proximal-palmarodistal oblique view of the distal part of the digit were made for each examination. The foals were weighed and measured at the withers immediately prior to each examination. Representative xeroradiographs were selected and appropriately labeled to demonstrate normal radio-graphic anatomy of these regions. First radiographic appearance of distal epiphyseal ossification in metacarpal 2 and metacarpal 4 was extremely variable and ranged from four to 38 weeks. Radiographic closure of the proximal physis of the middle phalanx ranged from 18 to 30 weeks (mean = 26 weeks). Radiographic closure of the proximal physis of the proximal phalanx ranged from 22 to 38 weeks (mean = 30 weeks). Radiographic closure of the distal physis of metacarpal 3 ranged from 18 to 38 weeks (mean = 29 weeks). When xeroradiographic physeal closure times were compared with scintigraphic closure times from a companion study, results correlated very well. A crena marginis solearis was observed in ten of 12 forelimbs (83.3%); its first radiographic appearance ranged from four to 22 weeks (mean = 11–12 weeks). A consistent groove in the hoof wall, which formed near the time of birth and moved distally at about 3 mm per week, was noted. The groove's distance from the proximal hoof border may be useful in age estimation of foals less than 18–20 weeks old.     

COLLATERAL CARTILAGE OSSIFICATION OF THE DISTAL PHALANX IN THE BRAZILIAN JUMPER HORSE

Collateral cartilage ossification of the distal phalanx in the Brazilian Jumper horse is a common finding. The objective of this study was to evaluate the prevalence and the degree of ossification of the collateral cartilages of the distal phalanx in Brazilian Jumper horses. In an analysis of 652 collateral cartilages from the front feet of 163 horses, 93% of these cartilages had collateral cartilage ossification (P < 0.005), and 7% of these cartilages did not have any type of ossification. In ossified cartilages, 86.4% had ossification beginning from the base, and 6.6% had a separate center of ossification.     

ECTRODACTYLY (SPLIT-HAND DEFORMITY) IN THE DOG

Radiographs of 14 dogs with ectrodactyly of the forelimb were evaluated and the defect classified according to the site of division of the longitudinal axis of the paw. The majority of separations occurred between metacarpal bones one and two, although separations were also noted between metacarpal bones two and three, two and four, and three and four. Other lesions noted in affected limbs included digit contracture, digit aplasia, metacarpal hypoplasia and metacarpal fusions. Bilateral involvement was noted in only one of 14 cases. No breed or sex predisposition was found and there was equal involvement of the left and right limbs.