Severe Bilateral Physitis with Instability and Salter Harris Type 1 Fractures in Two Foals

Introduction
Physitis is an enlargement of the physeal region of the long bones and is part of the DOD syndrome (developmental orthopedic disease). The present report describes the clinical and radiological findings of two foals with severe physitis of both distal metatarsi (Mt3) with secondary instability and fracture (Type-1 Salter Harris).

Case description
Case 1: A 3-months-old Warmblood foal was presented to the clinic because of difficulty in rising. The clinical examination revealed an enlarged physeal region of the distal Mt3 and a bilateral hind limb lameness with a decreased cranial phase of stride. The radiological examination of both fetlocks showed irregular growth plates of distal Mt3, sclerosis of the surrounding bone and confirmed the diagnosis of physitis. The foal was treated with NSAID’s and mineral supplementation. The foal went home and two months later was presented to the clinic because of suddenly worsening clinical signs. The radiological examination revealed severe bone proliferation and deformation of both distal Mt3 contours, with severe areas of radiolucency at the level of the growth plates. On the lateral views, a caudal subluxation of both epiphyses, with displacement between the distal epiphysis and metaphysis on the bone at the level of the physis could be seen. A CT examination revealed a pathologic Salter Harris fracture Type-1 on both sides. Because of the poor prognosis the owner elected to euthanize the foal. Case 2: A 4-months old Friesian filly was presented to the clinic because of severe bilateral hindlimb lameness of 5 weeks duration. On clinical examination, both physeal region of the distal MtIII were enlarged, warm and painful on palpation. Radiographs showed massive bone proliferation at the level of the growth plates with sclerosis of the surrounding bone and periosteal proliferation. On lateral radiographic views, plantar displacement of both epiphyses through the growth plate was evident. The owner elected euthanasia of the foal because of a poor prognosis.  [...]