A retrospective clinical study of osteochondrosis dissecans in 21 horses

Osteochondrosis dissecans was diagnosed clinically and radiographically in 31 joints of 21 horses. The horses ranged in age from 8 months to 5 years at the time of presentation. The usual age of onset of clinical signs was 18 to 24 months. Presenting complaints included joint effusion and lameness of either gradual or sudden onset. In Thoroughbred horses, the stifle joint was the most common site of lesions and in Standardbred horses lesions occurred more commonly in the hock. In 16 of the 21 horses, the contralateral joint was radiographed and 9 of these horses had bilateral lesions. Thoroughbred horses were affected most commonly, followed by Standardbred horses. The prevalence was higher in males than females, the male: female ratio being 2.5:1.

Do gilts and barrows react similarly with respect to leg weakness and osteochondrosis?

Clinical and pathological data concerning the degree of leg weakness and severity of osteochondral lesions in gilts and barrows have been compared. It became clear that the pathological condition of the distal part of the ulna and the medial femoral condyle of gilts was less severe than that of barrows. The clinical symptoms of leg weakness in gilts also tended to be less severe than those in barrows.

Effects of Ca and P levels in the feed on serum calcium, phosphorus, alkaline phosphatase, hydroxyproline and 25-hydroxycholecalciferol levels, and on the ash content of the third metacarpal bone in pigs

The material in the present study considered of 42 pigs. The pigs received different amounts of Ca and P in the feed. Observations were made on the blood serum Ca, P, AP, HP, and 25-OH-D3 levels, the ash content of the Mc III, and on the clinical behaviour of the pigs. The pigs were divided into 6 groups (3 X 6 Finnish Landrace and 3 X 8 Large White). The piglets used in each case were from the same sow, sired by the same boar, ensuring similar genetic backgrounds. The duration of the experiment was 85 to 100 days. The Ca and P contents of the feed were 1.24/ 1%, 0.41/0.49%, 0.48/0.76%, 1.3/0.7%, 0.41/0.74%, 0.44/1.83%. The declared content of D3 in the feed mixture was 2 000 IU/kg. At the end of the experiment, SCa levels were normal, but SP levels had risen in the groups fed 0.41/0.74% and 0.44/1.83%. SAP and SHP levels were normal. The 25-OH-D3 levels were within the same range for all groups investigated. The groups receiving low levels of Ca developed an osteodystrophia fibrosa, which, together with osteochondrosis, resulted in a leg weakness syndrome. The ash contents of the Mc III were lowest in the groups receiving a feed poor in Ca.

Morphologic and biochemical changes in cartilage of foals treated with dexamethasone

Epiphyseal and articular cartilages were examined in pony foals treated with intramuscular injections of either 0.5 mg dexamethasone per 100 kg bodyweight daily for 3, 8 or 11 months, or 5.0 mg per 100 kg for 11 months, and in horse foals treated with 5.0 mg per 100 kg for 20 weeks. The proximal femoral growth plates exhibited increased spatial separation between chondrocyte columns, narrowed zones of disorganized columnar and hypertrophic cartilage, abnormal penetration of hypertrophic cartilage by metaphyseal capillaries, retained cartilage in the spongiosa, distal terminal plate formation, transverse trabeculation, chondronecrosis and metaphyseal osteochondrosis dissecans. Destructive articular lesions were observed after 3 months of treatment with 0.5 mg per 100 kg bodyweight. Joint damage originated either at the joint surface or deep within the cartilage. Signs of surface deterioration included edema, fibrillation, enlargement of lacunae, pitting, shredding and erosions of cartilage. Inactivity of articular cartilage growth centers was common, with failure of epiphyseal capillaries to penetrate the lacunae in the calcified cartilage. Chondronecrosis adjacent to the calcification front was accompanied by cartilage ulceration and fracture. Intracartilaginous cysts and subchondral chondroid cysts were also observed. Healing responses included reparative chondrogenesis (focal cartilage hyperplasia), formation of fibrous or fibrocartilaginous "scars," subchondral osteopetrosis and epiphyseal marrow petrosis. Lactate dehydrogenase specific activities per chondrocyte, 35S uptake per cell and glycosaminoglycan contents of articular cartilages were all reduced 55% by 3 months of treatment. This inhibition of articular chondrocyte metabolism initiated cartilage degeneration. Surface destruction and osteochondrosis dissecans followed continued mechanical stress of compromised cartilage.

Joint mice in the fetlock joint--osteochondritis dissecans

Joint mice in the horse is a wellknown condition, but during the last years diagnosed with increasing frequency. Ethiology and prognosis thus become of major interest. 53 cases of mice in the fetlock are examined and divided in 3 groups on the basis of localization and appearance. On one group characterised by a localization in the plantar aspect of the joint and clearly separated from the tuberosites of the first phalanx histological investigations were carried out resulting in the statement that the mice can be the result of osteochondrosis. Surgical intervention in cases with clinical symptoms offers a fairly good prognosis, but it is underlined that the osteochondrotic defect can be restored by filling fibrocartilage.

Molecular size of chondroitin sulfate from normal and osteochondrotic joint cartilage of adolescent boars

Normal and osteochondrotic femurs and humeri were obtained from five normal and 15 lame adolescent boars to study the molecular size of joint cartilage chondroitin sulfate. Histological examination of cartilage showed a locally reduced intensity of safranin-O staining in fractured areas. Sephadex G-200 chromatography of cartilage glycosaminoglycans revealed a reduction (P less than 0.01) in the average hydrodynamic size of chondroitin sulfate in only the separated cartilage from severely damaged medial humeral condyles. Chromatography also suggested an accumulation of fragmented chondroitin sulfate chains in this cartilage. There were no other appreciable differences in the hydrodynamic size of chondroitin sulfate from normal and osteochondrotic joint cartilage.

Osteochondrosis, degenerative joint disease, and vertebral osteophytosis in middle-aged bulls

Twenty-five middle-age (65 +/- 18 months) dairy bulls sent to slaughter for nonmedical reasons were evaluated for joint disease in the stifle and the lumbar vertebrae. Fourteen bulls had degenerative joint disease and 3 had osteochondrosis (osteochondritis dissecans) of the distal end of the femur. These lesions predominantly involved the lateral trochlear ridge. Twenty-one bulls had vertebral osteophytosis. Degenerative joint disease and vertebral osteophytosis were common in these middle-aged bulls and, even when severe, were rarely associated with lameness.

Focal failures of endochondral ossification in the broiler

Two types of cartilaginous lesions were observed in a flock of 400 broilers separated into four groups and fed diets containing different energy and NH4Cl contents. The lesions appeared morphologically, histologically, and etiologically different. One lesion found in the vertebrae of 10 birds consisted of focal thickenings and necrosis of growth cartilages. Affected birds were predominantly faster-growing broilers fed diets without supplemental NH4Cl. The vertebral lesions were similar to osteochondrosis as described in mammals. A second lesion consisting of cones of retained cartilage was present in various long bones of 27.5% of all birds examined. The peak incidence of these dyschondroplastic lesions occurred in the slowest-growing group of 4-week-old birds fed diets containing 3% NH4Cl: 70% of these birds had dyschondroplasia. No positive correlation was found between the incidence of the vertebral lesions of osteochondrosis and the appendicular lesions of dyschondroplasia.

Communicating cartilage canals of the physis of the distal part of the ulna of growing swine and their potential role in healing of metaphyseal dysplasia of osteochondrosis

The distal parts of ulnae of 22 pigs ranging in age from 1 day to 6 months were studied histologically. Communicating cartilage canals passing from the epiphyseal vasculature through the physis and anastomosing with the metaphyseal vasculature were identified in neonatal pigs. In older pigs, the communicating cartilage canals had become smaller, as evidence by the presence of only capillaries. Eosinophilic matrical strekas and patches containing scattered elongated nuclei and centrally located accumulations of erythrocytes within the physis became more numerous in groups of old pigs. These streaks were considered to be compressed, nonpathologic extensions of the communicating physeal cartilage canals. In abnormally thick physeal cartilage of dysplastic 3-month-old-pigs, ossification was observed around hypertrophied communicating cartilage canals in the central portion of the lesion. Presumably, with reestablishment of endochondral ossification, the physis could return to its normal thickness and laminar pattern.

Degenerative joint disease with osteochondrosis of the proximal interphalangeal joint in young horses

Degenerative joint disease of the proximal interphalangeal joint was diagnosed in 9 joint of 6 horses. All of the horses were 3 years old or younger and the affected joints were in the hindlimbs. Radiographic evidence of osteochondrosis involving the distal end of the proximal phalanx was apparent in 5 joints. Lameness and local soft tissue swelling were prominent in all cases. In 1 horse euthanatized tissues because of lameness, histologic examination of joint tissues revealed osteochondrosis as well as severe osteoarthritis. Surgical arthrodesis of the affected joint was performed on 2 horses, one of which became sound.

Arthrosis in the elbow joint of young rapidly growing dogs. VI. Interrelation between clinical, radiographical and pathoanatomical findings

In 106 dogs in which one, two or more of the lesions A: Fragmentation of the coronoid process, B: Fissure of the coronoid process, C: Osteochondritis dissecans of the humeral condyle, or D: Ununited anconeal process, were found at autopsy, comparisons were made between clinical, radiographical and pathoanatomical findings. The 38 dogs which were put to death because of persistent lameness, represented young dogs of larger breeds only, while dogs of which no prehistory regarding foreleg lameness was given, or which had never revealed foreleg lameness, were older and represented dogs of smaller breeds as well. The lesion A was the most predominant finding, and the incidence of lesions A and A + C was slightly higher among lame legs than among legs free from lameness. Routine radiography was a reliable tool in interpreting osteochondritis dissecans, ununited anconeal process and degree of osteophyte formation when compared to the pathoanatomical examination, while lesions of the coronoid process was infrequently diagnosed by routine radiography. When comparing the various observations made clinically, radiographically and patho-anatomically, statistically significant correlations were found between all the parameters exept decreased flexibility/supination, decreased flexibility/pain and pain/arthrosis. The degree of arthrosis was higher in joints descending from lame legs than in joints descending from legs free from lameness, but was relatively high even in the latter group. The reasons why some dogs get lame in contrast to others suffering from the same lesions, are discussed.

Arthrosis in the elbow joint of young rapidly growing dogs. VII. Occurrence in the Rottweiler breed

The author has previously shown that lesions of the coronoid process are the most common reason for elbow lameness and osteophyte formation of the elbow joint in the Rottweiler and other larger breeds. To get more information regarding the elbow status of the Rottweiler breed, 207 dogs were radiographically investigated. Of these, 66 dogs were admitted because of elbow lameness, while 141 dogs more than 12 months of age, had never revealed foreleg lameness. Osteophyte formation was found in one or both elbow joints in 89.4% of the lame dogs and in 68.1% of the dogs free from lameness. When trying to elucidate the probability of inheritance, the dogs were grouped according to the elbow status of the parents. The results indicate that the percentage of lame offspring and offspring affected by osteophyte formation increases according to increase in affected elbow joints of the parents. Inherited disposition for lesions of the coronoid process is therefore suggested. Prophylactical criteria are discussed.

Lateral approach to the canine elbow by proximal ulnar diaphyseal osteotomy

A lateral approach to the elbow by proximal ulnar diaphyseal osteotomy was developed as an alternative to a number of currently used surgical approaches to that joint. The technique was easily performed, and it provided better visualization of the multiple joint compartments of the elbow than does any other technique. Repair of the osteotomy required a minimum of specialized equipment, and closure afforded excellent stabilization of the elbow and early return to function. In 3 cases, the versatility of the approach was demonstrated.

Environmental zinc and cadmium pollution associated with generalized osteochondrosis, osteoporosis, and nephrocalcinosis in horses

Several suspect causes of chronic zinc/cadmium toxicosis in horses near a zinc smelter were investigated following observations of lameness, swollen joints, and unthriftiness, particularly in foals. Two foals born and raised near the smelter were lame and had joint swellings that were attributable to severe generalized osteochondrosis. Zinc and cadmium concentrations were markedly increased in the pancreas, liver, and kidney. The serum of 1 foal, zinc and potassium concentrations were high, whereas calcium and magnesium concentrations were low. Marked nephrocalcinosis and osteoporosis were observed in this foal. Nephrocalcinosis also was observed in his dam, who died of a punctured lung following rib fractures, though there was no history of trauma. The joint cartilage lesions were similar to those induced experimentally in animals fed high-zinc diets and may have been the result of zin-induced abnormality of copper metabolism. The osteoporosis and nephrocalcinosis were consistent with chronic cadmium toxicosis.

Osteochondritis dissecans and fragmentation of the coronoid process in the elbow joint of the dog

Of 26 dogs with elbow osteochondrosis, 11 had osteochondritis dissecans of the medial humeral condyle, seven had fragmentation of the coronoid process of the ulna and eight had both these lesions. Sixteen cases had bilateral involvement. The labrador and retriever breeds were most often affected and the male sex predominated. The clinical features included a foreleg lameness in a young immature dog with pain localised to the elbow joint. The most consistent radiological feature was the presence of osteophyte development especially on the dorsal aspect of the anconeal process, caused by secondary osteoarthritis. The authors are not certain that surgical treatment of elbow osteochondrosis is justified; more extended long-term studies are necessary before surgical and conservative therapeutic regimens can be fully evaluated.

[Effect of megadose vitamin C on osteochondrosis in pigs (author's transl)]

Two experiments with daily supplementation of from 1 g vitamin C pr. pig at 10-12 kg live weight, gradually increased to about 8 g at 100 kg live weight, are described. Experiment I consisted of 9 pigs supplemented with vitamin C on the food once a day, and 9 pigs used as control group. Experiment II consisted of 2 litters, each of 10 pigs. Five pigs from each litter were given vitamin C supplement intramuscularly once a week until 6 weeks of age, thereafter on the food once a day, and the other 5 were used as control group. Incidence and degree of lesions in the elbow joint, in the distal epiphyseal plate of ulna and in the medial condyle of femur were examined after slaughtering. There was no statistically significant difference in incidence or degree of lesions between the comparable groups. However, in experiment I there was a tendency toward less severity of lesions among pigs getting vitamin C (Table I). groups were slaughtered at the same age. The mean slaughter weight was 5.2 kg higher for the pigs which had gotten vitamin C. The difference was not statistically significant.