Search Results

Abstract

Case Description—A 4-month-old Standardbred colt was examined because of a fractured right calcaneus of 8 days' duration with increased distraction of the fracture fragment evident on sequential radiographs.

Clinical Findings—The foal was severely lame with diffuse periarticular tarsal swelling. Radiographically, a complete, displaced long oblique fracture of the right calcaneal body was evident. Because the fracture gap was increasing with time and lameness remained severe, despite medical management, surgical repair was recommended.

Treatment and Outcome—The foal was anesthetized, and minimally invasive fracture reduction and internal fixation were achieved by use of two 4.5-mm cortical screws placed in lag fashion via stab incisions over the lateral aspect of the calcaneus. External coaptation with a Robert-Jones bandage only was used after surgery. The foal recovered well and the fracture healed appropriately, but at 8 weeks following surgery, tenosynovitis of the tarsal sheath had developed. This was attributed to the tip of the distal screw encroaching on the sheath. The screw was removed under anesthesia and the tarsal sheath drained. The tenosynovitis resolved with rest and bandaging. Fourteen months after surgery, the colt was free of lameness.

Clinical Relevance—Findings suggested that a minimally invasive internal fixation technique for treatment of a calcaneus fracture in horses may be successful and may be associated with decreased morbidity, compared with the use of open reduction and plate fixation.

Abstract

Objective—To identify patterns and correlations of gross, histologic, and gene expression characteristics of articular cartilage from horses with osteoarthritis.

Animals—10 clinically normal horses and 11 horses with osteoarthritis of the metacarpal condyles.

Procedures—Metacarpophalangeal joints were opened and digitally photographed, and gross lesions were scored and quantified. Representative cartilage specimens were stained for histologic scoring. Total RNA from dorsal and palmar articular surfaces was processed on an equine gene expression microarray.

Results—Histologic scores were greater in both regions of osteoarthritic joints, compared with corresponding regions in control joints. Cartilage from the palmar aspect of diseased joints had the highest histologic scores of osteoarthritic sites or of either region in control joints. A different set of genes for dorsal and palmar osteoarthritis was identified for high and low gene expression. Articular cartilage from the dorsal region had surface fraying and greater expression of genes coding for collagen matrix components and proteins with anti-apoptotic function, compared with control specimens. Articular cartilage from the palmar region had greater fraying, deep fissures, and less expression of genes coding for glycosaminoglycan matrix formation and proteins with anti-apoptotic function, compared with cartilage from disease-free joints and the dorsal aspect of affected joints.

Conclusions and Clinical Relevance—Metacarpal condyles of horses with naturally occurring osteoarthritis had an identifiable and regional gene expression signature with typical morphologic features.