Signalment & History
An 8 year old MN Greyhound presented for running in the yard and becoming acutely non-weight bearing lame.
Findings
USING THE “ABCS”
• A for Alignment
• B for Bone
• C for “Cartilage” / Joint
• S for Soft tissues
A for Alignment
A complete, comminuted, spiral fracture of the distal tibial diaphysis is seen, with presence of several fracture fragments, with the largest one being located medially to the fracture site and measuring approximately 56 mm in length. There is cranial, medial, and proximal displacement of the distal main fracture fragment. A transverse fracture of the distal left fibula diaphysis is also noted.
B for Bones
Centered on the left distal tibial metaphyseal region, a mixed osteolytic (moth-eaten to permeative lysis) and osteoproliferative (irregular and interrupted osseous proliferation) process is noted, with ill-defined zone of transition. Associated to that, a complete, comminuted, spiral fracture of the distal tibial diaphysis is seen, with presence of several fracture fragments, with the largest one being located medially to the fracture site and measuring approximately 56 mm in length. A transverse fracture of the distal left fibula diaphysis is also noted. Adjacent to that, multiple irregular gas lucencies are seen, which are likely related to the open nature of this fracture.
C for “Cartilage” / Joint
There is no evidence of articular involvement.
S for adjacent Soft tissues
Mild amount of surrounding soft tissue swelling is noted around the distal crus.
Diagnosis
Centered on the left distal tibial metaphyseal region, a mixed osteolytic (motheaten to permeative lysis) and osteoproliferative (irregular and interrupted osseous proliferation) process is noted, with ill-defined zone of transition. Associated to that, a complete, comminuted, spiral fracture of the distal tibial diaphysis is seen, with presence of several fracture fragments, with the largest one being located medially to the fracture site and measuring approximately 56 mm in length. There is cranial, medial, and proximal displacement of the distal main fracture fragment. A transverse fracture of the distal left fibula diaphysis is also noted. Adjacent to that, multiple irregular gas lucencies are seen, which are likely related to the open nature of this fracture. Surrounding soft tissue swelling is noted around the distal crus.
Conclusions
Aggressive bone lesion centered on the left distal tibial metaphysis with secondary pathologic, comminuted and open fracture of the distal tibial diaphysis, and transverse fracture of the distal fibular diaphysis, and surrounding soft tissue edema and/or hemorrhage. The primary differential is primary bone neoplasia, such as osteosarcoma. Other differentials include metastatic osseus neoplasia, round cell tumor or infeccious disease, such as fungal osteomyelitis.
