A 16 month Quarter horse colt The colt had been lame in the pasture with “bleeding” from the right hind leg - 3 days later he was nonweightbearing and purulent material was noted to drain from an open tract over the tarsus The colt was transported to the clinic and radiographs were made of the affected joint. Right tarsus on day 1 Right tarsus on day 1 Radiographic diagnosis on day 1
- Poorly defined destructive lesion on the distal portion of the lateral trochlea tali
- The base of the lesion is poorly defined and does not contain osteochondral fragments as would be expected with an OCD lesion
- The clinical history supports a radiographic diagnosis of osteomyelitis
Clinical history
- Joint swelling was noted throughout hospitalization
- Leucocytosis of 17,000 and 48,000 white cells within the joint fluid
- The joint was repeatedly flushed
- Radiographs were made on day 11
Right tarsus on day 11 Radiographic diagnosis on day 11 The destructive lesion is larger with the possibility of fragmentation (sequestration). Right tarsus on day 23 post op Radiographic diagnosis on day 23 Following surgery, the size of the cavity is larger following curettage and removal of the sequestrum. Comments
- Usually, radiographs are made immediately following a traumatic joint injury and are prior to bone lysis
- In this colt, the lesion is probably 7-10 days old at the time of the first radiograph and bone destruction is evident and the studies only confirm the clinical diagnosis -
- Despite repeated joint lavage, the bony destruction increases with the suggestion of development of a sequestrum
- Following the surgery, the colt was discharged without follow up
- The affected bone in this colt is intra-articular and is not covered with a strong periosteum - consequently, a pattern of periosteal new bone that is so characteristic of bone infection in a tubular bone is not seen - only bone destruction is evident on the radiograph - thus a diagnostic feature of bone infection prominent in a long bone is not present on the radiograph
