Case Study

CT- Elbow osteoarthritis with joint incongruity and kissing lesion, moderate hip dysplasia in a FS dog

History of progressive aggression attributed to suspect elbow pain. Concern for decreased range of motion in hind end as well.

Physical Exam: unable to examinine awake due to aggression. No abnormalities on PE under anesthesia

CBC/: WNL

Chemistry: elevated phosphorus (8.7)

U/A: USG 1.013

History of progressive aggression attributed to suspect elbow pain. Concern for decreased range of motion in hind end as well.

Physical Exam: unable to examinine awake due to aggression. No abnormalities on PE under anesthesia

CBC/: WNL

Chemistry: elevated phosphorus (8.7)

U/A: USG 1.013

DX

The computed tomographic findings are compatible with moderate right-sided complex elbow joint incongruity with a long ulna and secondary medial coronoid pathology with a radioulnar fissure. Moreover the findings indicate an emerging kissing lesion of the humeral trochlea. Mild osteoarthritis is evident. The findings of the left elbow are consistent with mild complex elbow joint incongruity with long ulna and medial coronoid pathology without fragmentation or fissuring. Yet the findings at the tip have been found to correlate with avitality of the MCP tip arthroscopically. Emerging osteoarthritis is evident. There is bilateral moderate hip dysplasia with moderate secondary osteoarthritis

Image Interpretation

CT of elbows, pelvis and stifles-
Right elbow:
An incomplete fissure line separates a flake shaped fragment positioned within the
radioulnar space at medial coronoid process (MCP). The tip of the MCP is
heterogenous in attenuation and the base reveals marked sclerosis. There is a 2.5 mm
radioulnar step formation. The humeroulnar joint space is asymmetric with central
widening. The radioulnar incisure is irregular in width with craniad tapering. The
subchondral bone of the humeral trochlea reveals a zone of focal sclerosis. A
subchondral bone defect is not seen. There are osteophytes emerging from the
periarticular margins. Multiple small cystic bone lesions were noted within the
subchondral bone of the apposing joint surfaces.
Left elbow:
The MCP presented marked overall sclerosis with irregular outline and focally
decreased attenuation at its tip. An isolated fragment or fissure was not seen. There is a
1 mm radioulnar step formation. The humeroulnar joint space was mildly asymmetric.
The radioulnar incisure was irregular in width and tapering cranially. Several small
cystic bone lesions were noted within the subchondral bone of the apposing joint
surfaces as well as emerging osteophytes.
Pelvis:
Symmetric findings of dysplasia and osteoarthritis are noted for both hip joints with
shallow acetabular grooves, marked joint space divergence, reduced femoral heal
coverage and dorsolateral subluxation. The femoral heads are small and shallow, their
necks are stunted and broad.
Moderate amounts of osteophytes are noted at the periarticular margins including
appositional new bone at the dorsolateral acetabular margins as well as caudolateral
and curvilinear femoral head and neck osteophytes.
Both stifle joints are within normal limits.

Outcome

Multifocal skeletal pain is a potential based on the CT findings. Correlate with the
clinical presentation to define the most relevant manifestation of joint dysplasia here.
A diagnostic challenge with potent medical pain management may be considered to
verify the relationship between the skeletal changes and the aggressive behaviour.
There was no evidence of Panosteitis at this point.