Surgical management of osteomyelitis of the sustentaculum tali in a horse.

The research discusses a case of a 2-year-old gelding horse diagnosed with osteomyelitis of the sustentaculum tali (a bone in the horse’s hock joint), which was successfully treated with surgical debridement, drainage, and antimicrobial therapy.

Background and Diagnosis

• The horse was initially presented to the Rural Veterinary Centre with severe lameness in the left hind limb, which had been persistent despite treatment with various antimicrobial agents over four months.
• An examination of the horse’s tarsus (hock), revealed it was enlarged, firm, and hot, signalling possible inflammation or infection.
• Further investigations involving blood samples, radiographs, and an analysis of the synovial fluid from the horse’s tarsal sheath (a protective structure surrounding the tendons in the hock), revealed an increase in white cells suggestive of an infection, and irregular bone proliferation at the distal medial aspect of the sustentaculum tali. The synovial fluid was cloudy and tested positive for Streptococcus equi bacteria, a common cause of joint infections in horses.
• Based on these findings, the researchers diagnosed the horse with a septic synovitis of the tarsal sheath (an inflamed, infected joint) and osteomyelitis of the sustentaculum tali (bone infection).

Treatment and Recovery

• The researchers recommended surgery to debride (clean out) the infected bone, drain the area, and administer appropriate antimicrobial therapy.
• In the surgical procedure, the researchers removed the exostosis (abnormal bone growth), drained the synovial sheath, and flushed it with a saline solution. The sheath was then sutured and left to heal.
• Post-surgery, the horse was given antibiotics and non-steroidal anti-inflammatory therapy for 10 days, and the horse’s lameness improved significantly.
• Radiographs confirmed the exostosis was successfully removed and 5 weeks after the surgery the area had healed well, with reduced swelling.
• Six months post-operation, the gelding was performing light work without evidence of lameness and showed no recurrence of the original bony lesion.

The study presents a successful management of osteomyelitis of the sustentaculum tali in a horse, highlighting the beneficial effect of surgery in resolving this infection, along with antimicrobial therapy.