Osteochondrosis and arthrosis in pigs. II. Incidence in breeding animals

Joint and bone lesions in Norwegian breeding pigs are described on the background of an investigation involving 174 sows and 155 boars from 7 months to 4½ years old. Lesions, which consisted predominantly of arthrosis, degeneration of intervertebral discs, spondylosis and epiphyseal separations, were demonstrated frequently in both sexes. Osteochondrosis, a condition previously demonstrated frequently in slaughter pigs, had either completely healed, undergone repair or developed into an arthrosis by the time the animal reached an age of about 1½ years.Whereas a higher incidence of arthrosis of the intervertebral joints was found in boars than in sows, the reverse was true as regards degeneration of the intervertebral discs and anchylosing spondylosis. Possible reasons for this are discussed. Norwegian pigs show a higher incidence of lesions in the lumbar region of the vertebral column than has been described up to the present time in other countries.     

Osteochondrosis and arthrosis in pigs. V. A comparison of the incidence in three different lines of the Norwegian Landrace breed

Investigations were carried out on 289 slaughter pigs, 56 breeding boars, and 51 breeding sows in a selection experiment started in 1964. The animals belonged to 4th–6th generations. One line has been selected for thin backfat and rapid growth (LBL) and 1 for thick backfat and slow growth (HBL). In addition a control line (GL) not subjected to selection was established in 1967. The pigs were kept as far as possible under identical conditions of housing and feeding, so that differences between lines should be primarily of genetic nature. The skeleton, measured as the length of bones and vertebral column, was statistically significantly smaller (P < 0.01) in HBL than in CL and LBL. The difference between CL and LBL was slight. No essential proportional changes in the skeleton took place. Patho-anatomical findings in the skeleton comprised, in all 3 lines, osteochondrosis, arthrosis, degeneration of the intervertebral discs, spondylosis, and epiphyseal separation. There were a lower incidence and statistically significant (P < 0.01) lower degree of total lesions in joints and bones in HBL, both as regards the slaughter pigs, boars and sows. The fact that the lumbar region of the vertebral column consistently showed the greatest difference in degree and incidence of lesions between the lines, suggests that this becomes the weakest skeletal part in pigs with a rapidly growing skeleton.     

OSTEOCHONDROSIS LESIONS OF THE CANINE SHOULDER: CORRELATION OF POSITIVE CONTRAST ARTHROGRAPHY AND ARTHROSCOPY

In this study the correlation between positive contrast arthrography and arthroscopy was evaluated in a series of 20 shoulder joints (12 dogs) with radiographic and clinical evidence of osteochondrosis. The joints were consecutively examined by arthrography and arthroscopy. In 12 joints arthrography revealed the presence of a cartilage flap, and this finding was confirmed by arthroscopy. In 3 out of 8 joints where arthrography failed to demonstrate rupture of the cartilage, arthroscopy revealed the presence of a distinct fissure line. In 2 joints arthroscopy demonstrated a lesion comparable with chondromalacia and in 3 only a dimple in the articular cartilage was found. In 2 joints arthroscopy revealed the presence of small joint mice not detected by arthrography. Kissing lesions on the surface of the glenoid cavity opposite to cartilage flaps could be demonstrated as well. Evaluation of synovial inflammation, judged by the aspect and pattern of the synovial villi, correlated well with histologic findings. These results indicate that arthroscopy is a complementary examination in painful joints where arthrography fails to demonstrate rupture of the articular cartilage. It could be the procedure of choice if diagnostic and surgical arthroscopy can be combined. However, arthrography remains the technique of choice to demonstrate joint mice within the bicipital tendon sheath.     

A XERORADIOGRAPHIC STUDY OF OSTEOCHONDROSIS IN THE METACARPOPHALANGEAL REGION OF TWO FOALS

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.     

Effects of 25‐hydroxy‐cholecalciferol on the development of osteochondrosis in swine

The principal objective of this experiment was to evaluate the effect of 25‐hydroxy‐cholecalciferol (25‐OH‐D₃) on the development of osteochondrosis in 6‐ to 110‐kg castrated male pigs. The growth rate and serum calcium and inorganic phosphate levels neither increased nor decreased in response to supplementation of 25‐OH‐D₃. However, supplemental 25‐OH‐D₃ significantly increased serum levels of 25‐OH‐D₃ and 1α,25‐hydroxy‐cholecalciferol without any influence on bone mineral density. The 25‐OH‐D₃‐treated group had significant (P < 0.05) reduced incidence of osteochondrotic lesions compared to the control group as evidenced by macroscopically examining the articular cartilage of the distal humerus (32.4% vs. 59.3%) and distal femur (47.1% vs. 87.5%). Likewise, supplemental 25‐OH‐D₃ significantly reduced osteochondrotic lesions over the control when histologically examining humerus (20.6% vs. 43.8%) and femur (52.9% vs. 87.5%). The results of this experiment suggested that 25‐OH‐D₃ supplementation in pig diets had a tendency to promote normal endochondral ossification, inhibit osteochondrosis progression and possibly regenerate destroyed cartilage tissue.     

Sacral osteochondrosis in two German Shepherd Dogs

Two young adult male castrated German Shepherd Dogs were referred for evaluation of intermittent episodes of hindlimb pain. Physical examination suggested lumbosacral stenosis, and plain radiographs and computed tomography revealed lesions consistent with sacral osteochondrosis. One dog had osteochondral fragments removed surgically; the other was managed conservatively. The surgically treated dog had complete resolution of clinical signs whereas the dog managed conservatively had repeated episodes of mild pain and received one short course of non-steroidal anti-inflammatory medication in 18 months. Sacral osteochondrosis has not been previously reported in Australia.     

DIAGNOSTIC SENSITIVITY OF RADIOGRAPHY,ULTRASONOGRAPHY, AND MAGNETIC RESONANCE IMAGING FOR DETECTING SHOULDER OSTEOCHONDROSIS/OSTEOCHONDRITIS DISSECANS IN DOGS

Radiography, magnetic resonance imaging (MRI), and ultrasonography are commonly used for diagnosis of shoulder osteochondrosis and osteochondritis dissecans (OC/OCD) in dogs, however there is a lack of published information on the relative diagnostic sensitivities of these modalities. The purpose of this prospective study was to compare diagnostic sensitivities of these modalities for detecting shoulder OC/OCD in a group of dogs, using arthroscopy as the reference standard. Inclusion criteria were history and clinical findings consistent with osteochondrosis and/or osteochondritis dissecans involving at least one shoulder. With informed client consent, both shoulders for all included dogs were examined using standardized radiography, ultrasonography, MRI, and arthroscopy protocols. One of three veterinary surgeons recorded clinical and arthroscopic findings without knowledge of diagnostic imaging findings. One of two veterinary radiologists recorded diagnostic imaging findings without knowledge of clinical and arthroscopic findings. Eighteen client‐owned dogs (n = 36 shoulders) met inclusion criteria. Diagnostic sensitivity, specificity, and accuracy (correct classification rate) values for detecting presence or absence of shoulder osteochondrosis/osteochondritis dissecans were as follows: radiography (88.5%, 90%, 88.9%), ultrasonography (92%, 60%, 82.6%), and MRI (96%, 88.9%, 94.4%). Odds of a correct diagnosis for MRI were 3.2 times more than ultrasonography and two times more than radiography. For MRI detection of lesions, the sagittal T2 or PD‐FAT SAT sequences were considered to be most helpful. For radiographic detection of lesions, the additional supinated‐mediolateral and pronated‐mediolateral projections were considered to be most helpful. Findings from the current study support more evidence‐based diagnostic imaging recommendations for dogs with clinically suspected shoulder osteochondrosis or osteochondritis dissecans.     

Prevalence of various radiographic manifestations of osteochondrosis and their correlations between and within joints in Dutch Warmblood horses

Reasons for performing study: Osteochondrosis (OC) is the most important orthopaedic developmental disorder in horses and may manifest in several different forms. No detailed study on the prevalence and/or interrelation of these forms is available, even though these data are a prerequisite for conclusive genetic studies. Objectives: To assess the prevalence of the various manifestations of OC as detected radiographically and to evaluate possible relationships between their occurrence within the same joint and between different joints. Methods: The FP (femoropatellar), TC (tarsocrural) and MCP/MTP (metacarpophalangeal/metatarsophalangeal) joints of 811 yearlings selected randomly, descending from 32 representative stallions, were radiographed and scored for the presence and grade of osteochondrotic lesions. Results were compared at the sire, animal, joint and predilection site levels. Results: In the FP joint, the percentage of animals showing normal joint contours in all sites was 60.7%. For the TC joint and the combined MCP/MTP joints, these figures were 68.6 and 64.6%, respectively. For all joints combined, the percentage dropped to 30.5%. Sedation improved detection of OC lesions in the FP joint. There was a high correlation between the right and left joints. The correlation between flattened bone contours and fragments was considerably less. Conclusions: Scoring on a detailed scale is necessary to achieve good insight into the prevalence of OC. Observations on the right and left joints can be combined in further analyses, whereas flattened bone contours and fragments should be evaluated as statistically different disorders. Potential relevance: This study provides insight into the prevalences of various manifestations of OC and their relationships, within and between joints. These results form the basis for detailed quantitative and/or molecular genetic studies that should lead to the establishment of breeding indices and/or genetic marker sets for OC.