Fragmentation of the extensor process of the distal phalanx is thought to occur due to trauma, osteochondrosis, or, in large fragments, the presence of a separate center of ossification. Forelimbs are more commonly affected than hindlimbs. The fracture fragments are usually intra-articular but are commonly nondisplaced; they may be adhered to the extensor tendon. The fragments may be incidental findings, but they may also cause lameness. The close association of the extensor process with the distal interphalangeal joint results in secondary arthritis if the fragments are not removed. Fractures can be removed by either arthroscopy or arthrotomy; arthroscopic removal of small fragments carries a good prognosis. With large untreated fractures, an enlargement of the toe region just above the coronary band is usually present, which results in the “buttress foot” or pyramidal appearance to the foot. Systemic anti-inflammatory medication may be beneficial.
Last full review/revision March 2012 by Stephen B. Adams, DVM, MS, DACVS; Joerg A. Auer, DrMedVet, Dr h c, MS, DACVS, DECVS; James K. Belknap, DVM, PhD, DACVS; Jane C. Boswell, MA, VetMB, CertVA, CertES (Orth), DECVS, MRCVS; Peter Clegg, MA, Vet MB, PhD, CertEO, DECVS, MRCVS; Andrew L. Crawford, BVetMed, CertES (Orth), MRCVS; Jean-Marie Denoix, DVM, PhD, Agregé; Marcus J. Head, BVetMed, MRCVS; C. Wayne McIlwraith, BVSc, PhD, DSc, FRCVS, DACVS, DACVSMR; James Schumacher, DVM, MS, DACVS, MRCVS; John Schumacher, DVM, MS, DACVIM; Roger K. W. Smith, MA, VetMB, PhD, DEO, DECVS, MRCVS; Chris Whitton, BVSc, FACVSc, PhD