Focal Bone Reaction and Avulsion Fractures of the Third Metatarsal Bone in Horses

Focal bone reaction and avulsion fractures of the third metatarsal bone at the site of the proximal attachment of the suspensory ligament are not uncommon. They may be solitary injuries or, more frequently, are associated with proximal suspensory ligament desmitis. These injuries are frequently found in sports horses. Severity of lameness is variable, and localizing signs are usually not evident. Diagnostic analgesia is necessary to localize the pain. Some fractures may be evident radiologically, whereas in other horses scintigraphy or MRI is necessary to confirm the diagnosis. Conservative treatment with rest and a controlled ascending exercise program is usually recommended. However, recurrence of lameness is common, particularly in horses with concurrent proximal suspensory desmitis; in these horses, neurectomy of the deep branch of the lateral plantar nerve may be the only chance to resume sustained athletic performance.