The Evolution of Darwin's Care
Darwin, a one-year-old male neutered Newfoundland, recently proved to be a challenging case for the surgeons at Chesapeake Veterinary Surgical Specialists. He had taken a tumble while going up some stairs, and when his 138-pound body landed, his right femoral head was fractured. His owner took him to see Dr. Rich Burgess, a board-certified surgeon with CVSS, to decide how to be treated. Dr. Burgess repaired Darwin’s fracture, and also performed procedures to correct a ruptured cranial cruciate ligament and a luxating patella in Darwin’s knee joint of the same leg.
Darwin went home after surgery and had been recovering well for about 10 days when he became acutely painful in his right leg and stopped using it. His owner brought him back to CVSS to be evaluated. A swab of Darwin’s knee joint was submitted for bacterial culture and antibiotics and pain medications were started. Darwin showed some response and started to improve over the course of the next few days, but then his condition deteriorated suddenly. He was very painful and began having neurologic abnormalities in both his hind limbs. Dr. Burgess suspected that Darwin had developed meningitis after his surgical procedures.
Radiographs of his spine did not show any striking abnormalities, so Dr. Burgess recommended a MRI as the next diagnostic step to find the cause of Darwin’s clinical signs.
Darwin’s MRI showed a lesion in his lower spine impinging on the nerves as they leave the spinal column. The lesion was consistent with active inflammation, most probably discospondylitis, an infection of the endplates of several of his vertebrae. The swelling associated with this inflammation was compromising the spinal nerves and causing Darwin’s neurologic abnormalities. A spinal tap was performed and the spinal fluid was submitted for analysis to confirm the diagnosis.
Here is a brief interpretation of the disease process on the images provided.
Mid-sagittal T2 imaging of the lumbar spine shows irregular endplates of the L7 and S1 vertebra, which have been marked on the image. Also present is an abnormal diffuse hyperintensity within the disk space between L7 and S1, when compared to the normal disk marked at the L6-L7 junction. These findings are indicative of an inflammatory infectious process such as discospondylitis.
Mid-sagittal proton density imaging of the spine reveals a more detailed understanding of the endplate destruction on the L7 and S1 vertebra, as well as rules out the possibility of this merely being an extensive disk herniation.
The sagittal MRI myelogram provided reveals a marked interruption of the CSF signal due to the inflammatory process at the area of interest.
On the T2 axial image shown, you can see where we have marked the region of the extruded and inflamed disk material. There is a notable impression of the extruded disk material on the dorsal nerve roots, and compromise of the left and right vertebral foramen.
The post contrast T1 sagittal imaging shows areas of enhancement at the affected endplates of the L7 and S1 vertebra, as well as enhancement within the extruded disk material at this location on T1 axial and coronal images.
This was a great example of a case where finding the diagnosis was much easier with MRI imaging. Darwin’s antibiotic regimen was changed and he began to improve over the rest of the week.