Osteochondral fracture of the proximal palmar middle phalanx in a Thoroughbred.

This study discusses a rare case of an osteochondral fracture in the proximal palmar middle phalanx of a Thoroughbred horse and elaborates on the clinical approach, treatment, and eventual recovery.

Introduction

• The paper begins by highlighting that fractures of the middle phalanx are common in horses used for western performance events. However, osteochondral fractures at the site mentioned are rare and if they do occur, they are usually found incidentally with no associated lameness.
• The authors reveal that such lesions can occur bilaterally, and surgical intervention is often based on clinical response to intra-articular anaesthesia.
• The fracture incident discussed is a surgical excision of an osteochondral fragment from the proximal palmar aspect of the second phalanx.

Case History

• The subject is a three-year-old Thoroughbred colt that was taken to the Texas Veterinary Medical Center for the evaluation of a proximal palmar fracture of the middle phalanx of the right forelimb.
• The horse had raced successfully two months prior but was experiencing a decline in performance. Other than this, physical examination revealed no abnormalities.
• After a four-week stall confinement and hand-walking exercise recommended by the referring vet, the horse did not gain back its previous performance level.
• Radiographs indicated a fracture of the proximal medial palmar aspect of the middle phalanx, after which the horse was referred for further evaluation.

Clinical Examination

• No abnormalities were identified by physical examination.
• A grade II of V lameness was detected on the right forelimb while being circled to the right at the canter, but not apparent at walk or trot in a straight line. The lameness was resolved by injecting local anaesthetic into the affected joint.
• The radiographic examination confirmed the presence of a minimally displaced osteochondral fragment at the medial proximal palmar aspect of the middle phalanx. It was decided that the fragment would be surgically excised.

Treatment and Course of Condition

• The horse was sedated and put under general anaesthesia and positioned in right lateral recumbency for surgery.
• A 7 cm longitudinal skin incision was made centered over the palmar aspect of the proximal interphalangeal joint.
• The osteochondral fragment was navigated to and finally removed using a periosteal elevator and bone rongeurs.
• The joint was then lavaged with physiological saline and, post-excision, radiographs confirmed complete removal of the fragment.
• The wound was sutured up, 20 mg of sodium hyaluronate was injected into the affected joint and tendon sheath, and a sterile non-adhesive pad was applied.