Navicular bone fracture and severe deep digital flexor tendinopathy after palmar digital neurectomy in two horses

Abstract

Background: Navicular syndrome is a common cause of forelimb lameness in the horse. Beyond changes to the navicular bone itself, horses with a clinical diagnosis of navicular syndrome often have pathology associated with other components of navicular apparatus, including the navicular bursa, deep digital flexor tendon, collateral sesamoidean ligaments, and impar ligament. Palmar digital neurectomy (PDN) is often used as a salvage procedure for horses diagnosed with navicular syndrome that become unresponsive to medical management. There are many potential complications associated with PDN, some of which are debilitating. Case Description: This report describes two cases of navicular bone fracture with severe deep digital flexor tendinopathy and distal interphalangeal joint subluxation/hyperextension that occurred 12 and 19 weeks after bilateral forelimb PDN. Conclusion: These two cases highlight the importance of proper patient selection prior to PDN due to the high incidence of undiagnosed soft tissue pathology in conjunction with radiographic evidence of navicular syndrome. Advanced imaging of the digit is recommended to identify and characterize any soft tissue pathology associated with the navicular apparatus prior to pursuing PDN to avoid disease progression and catastrophic injury.