Clinical history 11 year old pinscher with thoracic kyphosis of a questionable clinical importance - no pain was evident on palpation of spine. Thoracic radiographs were made as a part of a data base in an older patient. Today’s study Today’s study enlarged Radiographic diagnosis
- Lung must be evaluated with caution because of the age of the patient, expiratory nature of the study, and obesity of the patient
- Fat is deposited in both the cranial and caudal mediastinum
- Cardiac silhouette appears enlarged because of the expiratory nature of the study
- Collapse of Th 4-8 disc spaces with suggestion of bony fusion
- Position of the caudally displaced air-filled pyloric antrum suggests hepatic enlargement
2 years earlier 2 years earlier enlargedRadiographic diagnosis Discospondylitis with
- end plate destruction at Th 4-7
- disc space collapse at Th 4-7
The diagnosis at this earlier stage of the disease is more obvious since the nature of the end plates and the narrowing of the disc spaces is more easy to see - the patient was painful on palpation of the thoracic spine at this time. The diagnosis at the later healing stage is more difficult since the disc spaces are filled with new bone. Diagnosis can be confirmed by positive blood or urine culture. Comments Discospondylitis is an inflammatory, usually infectious, lesion resulting in collapse of the disc space, destruction of the vertebral end plates, and destruction of the subchondral bone adjacent to the end plates. In the mid-thoracic region, the lesions are usually hematogenous and secondary to a primary lesion such as, urogenital infection, periodontal infection, or valvular disease. Clinical signs do not relate directly to the radiographic appearance and it is often difficult to determine whether the lesions are a source of pain at the time of radiography - Activity of the lesion can not be determined from the radiographic appearance. Multiple radiographic views often make the diagnosis more easy to make - but it remains a diagnosis made only following careful examination of the radiograph. Differential diagnosis Primary bone tumors are not polyostotic and do not center on disc spaces. Metastatic bone tumors may be polyostotic but do not center on disc spaces. Destructive lesions may follow disc fenestration or puncture wounds but are not often seen in the midthoracic region without a specific clinical history. Lesions of this appearance could follow a fracture-luxation but would only be located at a single disc space and usually include segmental malalignment. Congenital lesions do not have the destructive appearance with periosteal response.
