Fractures of the Second and Fourth Metatarsal Bones in Horses
Fractures of the second and particularly the fourth metatarsal bones are common and usually arise from direct trauma (eg, kick from another horse). Simple, comminuted, and displaced fractures occur and are often associated with overlying wounds. Diagnosis is confirmed by radiography.
Most second and fourth metatarsal bone fractures will heal with conservative treatment despite comminution and infectious osteitis with appropriate antimicrobial therapy, wound care bandaging, and rest. Rest of 4–6 mo may be necessary in horses with open or infected fractures. Segmental ostectomy may be indicated in horses with chronic discharging wounds and sequestrum development. Complete removal of severely comminuted fourth metatarsal bones has been reported as successful, although persistent lameness may result. Internal fixation of the fractures of the proximal end of the second metatarsal bone may be indicated in some cases with marked displacement and instability of the fracture fragments. Open fractures of the proximal end of the second and fourth metatarsal bones may result in sepsis of the tarsometatarsal joints, which requires aggressive antimicrobial therapy and appropriate treatment.
Simple fractures of the distal end of the second and fourth metatarsal bones, just above the “button of the splint bone,” are usually associated with desmitis of the branches of the suspensory ligament.