Small Animals Fracture Repair

The Spine

Atlanto-Axial subluxation

This condition is seen as a congenital defect in dogs of certain young and small breeds.

Figure 1: Atlanto-axial subluxation.

Intervertebral disc fenestration

Disc protrusion into the cervical area often causes severe pain by compression of the nerve roots, knuckling over of the forelimbs and hind limbs is common.

Figure 2: Cervical disc fenestration. Radiography often demonstrates several discs with various degressa of disc calcification and narrowing of the disc spaces.

Figure 3: Ventral cervical disc decompression. Although the affected disc can be located by a plain radiography, The definitive diagnosis is by myelography, as is shown here.

Figure 4: Radiograph showing cord compression from an intervertebral disc protrusion.

Figure 5: Radiograph of a spinal fracture.

Figure 6: Myelogram of a spinal fracture.

Figure 7: Fracture of the first lumbar vertebrae. There is evidence of abrubt angulation of the spine of at the point of the fracture; this is an important diagnostic sign.

Figure 8: Epiphyseal fracture showing only increased space at the epiphyseal line (arrow).

Figures 9, 10: A lateral projection of the cranial cervical and skull regions showing an increase in space between the dorsal process of the axis and the dorsal arch of the atlas. The odontoid process appears diminutive. This injury was the result of an acute cervical traumatic event. B, Postoperative film showing reconstruction of the atlantoaxial ligament by use of a surgical wire. Note that the space between the dorsal process of the axis and the dorsal arch of the atlas is now within normal limits. The dog made an uncomplicated recovery.

Figure 11: Osteogenic sarcoma of the vertebral body of the third cervical vertebra.

Figure 12: Metastasis of a mammary adenocarcinoma to the body of the sixth lumbar vertebrae. The metastatic lesion appears as a radiolucent area in the bone (arrow). There has been some new bone proliferation associated with the lesion. Metastases to bone in animals are in contrast to the relatively frequent occurrence in man.

Figure 13 Spondylosis deformans. The ventral new bone proliferation at the end of the vertebral bodies is typical of this condition. Narrowed intervertebral disc spaces are unrelated to spondylosis deformans. Complete bridging of the osteophytes has not occurred in this patient.

Figures 14, 15: Anomalies of the vertebrae. A, Block vertebrae. The last three vertebral bodies are fused. B, Transitional vertebra. The seventh lumbar vertebra is suuming the shape of the first segment of the sacrum on the left and the shape of the last lumbar vertebrae on the right.

Figure 16: Solitary myeloma of the spine in a dog. The neoplasm has destroyed the spinous process and part of the neural arch of the affected vertebra.

Figure 17: Severe degenerative joint disease of the spine. Subchondral sclerosis and periarticular osteophyte formation are evident. Back pain is frequently associated with this condition.

Figure 18: Moderate degenerative joint disease of the spine. Subchondral sclerosis is the major radiographic change seen, although some mild periarticular osteophyte formation is evident. This condition must not be confused with spondylosis deformans which is also present in this patient.

Figure 19: Lateral projection of the cervical spine, showing complete calcification of the nucleus pulposus with partial herniation into the spinal cord at C-6, C-7 and very minimal calcification of the nucleus pulposus at C-4, C-5.

Figures 20, 21: Intervertebral disc protrusion. Typical diagnosis radiographic signs. A, Norrowed intervertebral space (arrow). B, Calcified protruded disc material above narrowed disc space (arrow).

Figure 22: Cervical intervertebral disc protrusion C-2 and C-3. Calcified disc material can be observed in the spinal canal. An important sign is the narrowed inervertebral disc space.

Figure 23: Cervical disc protrusion at C-2 and C-3. Calcified disc material is evident in the spinal canal above the protrusion. There is no associated narrowing of the intervertevral disc space.

Figures 24, 25: A, Lateral survey film of the cervical spine showing a narrowed intervertebral disc space at C-6, C-7. B, Lateral projection of a cervical myelogram demonstrating an extradural mass dorsal to the C-6, C-7 intervertebral space. This represents the extradural location of the herniated disc. In cases such as this it is impossible to differentiate between severe protrusion and complete herniation with local containment.

Figure 26: Linear streaks within the spinal canal from L-3 to L-7 represent ossification of the ventral aspect of the dura. This should not be confused with calcification of the dorsal longitudinal ligament because the dorsal longitudinal ligament lies more closely in apposition with the floor of the spinal canal.