Large Animals Fracture Repair

Other traumatic Conditions

Other traumatic Conditions that cause lameness are illustrated in the following figures:

Figure 38: Abnormal new bone proliferation involving the accessory carpal bone.

Figure 39a, b: Extensively thickened cortex of the great metacarpal bone due to previous periosteal and bone injury. The condition is inactive as indicated by the smoothness of the cortex.

Figure 40: Wire twisted around a leg causing abnormal new bone grwth in a four-year-old shorthorn cow.

Figure 41: Foreign body (glass) in the soft tissues of the foot of a horse (arrow). Glass is radiopaque and can be seen on a radiograph.

Figure 42a, b: Abnormal bone growth of the first phalanges due to the use of obstetrical chains at birth. This was bilateral.

Figure 43: Calcification of a bursa surrounding the fetlock joint of a horse. The radiopaque density is not attached to the bone at any point. it appears to be circumscribed as if confined within a sack. This was proven surgically. Most densities surrounding joints of horses are of bone and not a dystrophic calcification.

Infections causing Lameness

Infection causing lameness are rather common in horses.

1. Infectious Arthritis

The infectious arthritis may be haemotogenous in origin as in foals with navel ill or may be the result of a puncture wound into a joint space. The important  radiographic signs are: 1. Marked soft tissue swelling, 2. Distension of the joint capsule, 3. increase the width of the joint space due to destruction of the cartilage and lyses of the adjacent bone (Osteomyelitis) by the septic process.4. variable degrees of secondary new bone proliferation surrounding the joint in long standing cases.

Figure 44: Infectious arthritis. Typical subchondral osteolytic patches (arrows) in the tibial condyles of a cow, signifying secondary osteomyelitis. The increase in width of the joint space on a weight-bearing study indicates joint effusion.

Figure 45: Septic arthritis of the proximal intertarsal joint on the lateral side. The infectious process resulted from a penetrating wound. Localized areas of increased joint space with bone lysis and severe soft tissue swelling are characteristic of this disease process.

Osteomyelitis

Figure 46: Focal area of osteomyelitis (bone abscess) due to a puncture wound.

Figure 47a,b: Secondary joint disease. A, Large subchondral cysts (arrow) in the distal metacarpal bone in a one-year-old filly, with apparent extension into the joint space. B, Six months later there was marked healing of the cystic lesion. However, narrowing of the joint space and subchondral sclerosis are indicative of resulting secondary joint disease.

Figure 48: Ankylosis as a result of hypertrophic degenerative arthritis of the proximal interphalangeal joint developing secondarily to trauma. There is extensive new bone proliferation surrounding the entire pastern joint, and there is new bone proliferation arising from the extensor process of the third phalanx. This condition would fit into the broad category of :ringbone:.

Ossification of the Lateral Cartilages

(Sidebones)

Ossification of the lateral cartilage occurs mostly in the forefeet of the horse. It is more commonly found in horses with poor conformation than in others. Its incidence is greatest in draft horses and quarter horses; is occurs rarely in Thoroughbreds.

 Ossification of the lateral cartilages can originate either from the lip of the cartilage and proceed toward the attachment of the cartilages the third phalanx or from the base at the attachment of the cartilage to the third phalanx and proceed toward the lip (Fig. 14-59). When the ossification proceeds from the tip, a radiolucent area is seen between the calcified portion of the cartilage and the wing of the third phalanx. In some subjects, this radiolucence  may appear as a fracture line. The first radiologic signs of ossification of the lateral cartilages are seen best on an anieroposterior view. However, dirt on the bulbs of the heels may cast shadows that may be mistaken for ossification of the lateral cartilage.

A lateral view should be taken to diagnose the condition accurately. Ossification of the lateral cartilages, as seen on the lateral radiograph, will appear as rounded bony protrusions extending in a proximal and caudal direction, extending from the wings of the third phalanx. As the condition progrosses, ossification will be observed quite easily on both antcroposterior and lateral, views, Radiography is necessary to determine the extent of the ossification.

Figure 49: Sidbones. On the left, note the large sidebone. On the right, note the separate ossification center in the sidebone. This should not be confused with fracture of a sidebone, which is somtimes surgically removed. This type of ossification does not require surgical removal.

Figure 50: Pedal osteitis as shown by marked roughness of the border of the third phalanx. This was an eight-year-old quarter horse gelding that had been lame for a prolonged time.

Navicular Disease Syndrome (Podotrochleosis, Podotrochlitis)

Figure 51: Radiographic changes associated with the navicular disease syndrome. A, Fenestration of the distal border of the navicular bone. B, Radiolucent area in the center of the navicular bone. C, New bone production on the navicular bone (1) and incidentally ossification of the lateral cartilages (2)