Radiography and the Purchase Examination in the Horse

Radiographic assessment of navicular bones, based on changes in the distal nutrient foramina

“…The conical shaped nutrient foramina were classified into two types, those which were located on the distal border of the navicular bone, Type A, and those which were located in the distal border of the wings of the navicular bone, Type B. The conical nutrient foramina were classified in this way because earlier work (Reid 1980;Colles 1982;MacGregor 1984) has indicated that the presence of conical nutrient foramina in the wings of the navicular bone was a significant finding in navicular disease cases. All of the types of nutrient foramina except Types G and H were found in the navicular bones of both the sound horses and those with clinical evidence of navicular disease.…”

“…It is considered by some (Wintzer 1964;Morgan 1972) that the presence of radiographs of distal nutrient foramina in a navicular bone regardless of their number and morphology is indicative of navicular disease, whereas others maintain that nutrient foramina are normally present and that a widening (Wilkinson 1952). or a change in shape from a normally conical shape, confirms its presence (Colles and Hickman 1977;Reid 1980). Colles (1982) observed that in the sound horse there were up to seven distal nutrient foramina, normally of a triangular shape.…”

“…In addition to clinical examination, radiographic examination plays an important part in the diagnosis. Affected navicular bones show a variety of specific radiographic changes which include an increase in the number and size of nutrient foramina, areas of increased density around the nutrient foramina, areas of radiolucency in the body of the bone, spur formation in the medial and lateral extremities of the proximal border, osteophyte formation along the proximal border and fractures of the navicular bone (Olsson 1954;Hickman 1964;Reid 1980;Colles 1982;Oxspring 1985).…”

Relationship between ossification of the cartilages of the foot and conformation and radiographic measurements of the front feet in Finnhorses

“…The cartilages of the foot are elastic structures and are considered to be important in the reduction of concussion and in assisting blood flow by compressing the venous plexuses of the foot at weightbearing (Butler 1985a;Kainer 1987Kainer , 1989Balch et al 1991). Ossification of the cartilages (side-bone) is a common radiographic finding in the front feet of heavy horses (Reid 1980Colles 1983Schneider and Stickle 1987;Stashak 1987;McNeel 1994), but the aetiology and clinical significance of ossification are not fully understood and may vary between breeds. Increased concussion of the heel is often suggested as a cause of side-bone formation (Rooney 1975;Schneider and Stickle 1987;Stashak 1987).…”

“…On the other hand, no relation of practical importance was proven between the size of the feet and presence of side-bone (Waxberg 1953). In horses with broad feet, even extensive ossification may not be clinically significant (Reid 1980;Moyer 1991;McNeel 1994), but in a narrow foot with little room for expansion, side-bone may cause lameness (Milne 1967).…”