Species: Canine   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading

Introduction

  • Cause: developmental malformation of the plantar or palmar sesamoid bones. May arise from multiple centers of ossification. Included under the general heading sesamoid disease in some texts.
  • Signs: generally asymptomatic: usually incidental finding on radiography of the pes. More commonly found in the manus.
  • Diagnosis: radiography. The sesamoid can be bipartite or multipartite.
  • Treatment: if lame: rest and analgesia.
  • Prognosis: good.

Presenting Signs

  • Generally incidental finding on radiographs of the pes or manus.
  • Occasionally displace causing pain on direct palpation and on flexion of the digits.

Age Predisposition

  • Incidental finding when radiographed for another reason, so identified at any age.
  • Assumed to be developmental, so probably occurs at stage of ossification of the sesamoid bones.

Breed Predisposition

Cost Considerations

  • If problems arise they often resolve with rest and analgesia.

Pathogenesis

Etiology

  • Two possible mechanisms suggested:
    • Multiple centers of ossification that failed to unite; or
    • Incomplete ossification of cartilage template.
  • Sesamoid bones 2 and 7 most commonly affected, numbering medial to lateral. This is thought to be from pressure from the overlying flexor tendons during hyperextension as the metacarpo/metatarso-phalangeal joints 2 and 5 are slightly outwardly rotated.

Pathophysiology

  • Developmental disorder, detailed pathogenesis unknown.
  • Sesamoid bones located in tendon of insertion of the interosseous muscles at the metacarpo-phalangeal joints.
  • Multiple centers of ossification during development may result in multipartite or bipartite sesamoid bone formation.
  • Incomplete ossification of a cartilage template would also be a possible etiology.
  • Restriction of vascular foramina in sesamoids 2 and 7 was found in dogs with sesamoid disease and not in clinically normal dogs.
  • There is an over-representation in the right manus of the racing Greyhound suggesting a traumatic component.

Diagnosis

Client History

  • Usually asymptomatic.
  • May manifest as pain on manipulation of the foot.

Clinical Signs

  • Incidental finding on radiography, generally no lameness.
  • Occasionally displaced causing discomfort and pain on direct palpation.

Diagnostic Investigation


Radiography
  • See radiography of the manus Radiography: carpus and forefoot and pes Radiography: tarsus and hindfoot.
  • Differentiate from fractures radiographically:
    • A fracture has a sharp, irregular well-defined fragment outline Foot: sesamoid fracture - radiograph DPa Foot: sesamoid fracture - radiograph ; bipartite sesamoids have smooth outlines Foot sesamoid disease - radiograph Foot: bipartite sesamoid - radiograph.
  • Differentiate from degenerative disease radiographically:
    • Degenerative disease has pain on palpation, joint swelling or thickening, calcified periarticular bodies and osteophytosis.

Differential Diagnosis

Treatment

Initial Symptomatic Treatment

  • No treatment in most cases.
  • If painful, rest and anti-inflammatory treatment Analgesia: NSAID in the acute stage resolves most cases.
  • Chronic painful cases, consider surgical removal of the painful sesamoid bone.

Subsequent Management

Monitoring

  • If acutely painful, radiography to monitor any secondary degenerative change development.
  • Conservative management: monitor lameness related to pain on direct palpation → should resolve in 4-6 weeks.
  • Asymptomatic: no further monitoring or treatment needed.

Outcomes

Prognosis

  • Good.

Expected Response to Treatment

  • If painful, surgical excision indicated if lameness persists after conservative management.
  • In the long term surgical treatment has been shown to be no better than conservative management.
  • Incidental finding on survey radiographs: no treatment needed - no further monitoring required.

Reasons for Treatment Failure

  • Incorrect diagnosis. Eliminate other causes of lameness especially elbow dysplasia in young Rottweilers Elbow: dysplasia.
  • Osteoarthritis of the metacarpo/metatarso-phalangeal joint Arthritis: osteoarthritis.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Harasen G (2009) Sesamoid disease. Can Vet J 50 (10), 1095 PubMed.
  • Daniel A, Read R A & Cake M A (2008) Vascular foramina of the metacarpophalangeal sesamoid bones of Greyhounds and their relationship to sesamoid disease. Am J Vet Res 69 (6), 716-721 PubMed.
  • Vaughan L C & France C (1986) Abnormalities of the volar and plantar sesamoid bones in Rottweilers. JSAP 27 (9), 551-8 VetMedResource.
  • Bennett D & Kelly D F (1985) Sesamoid disease as a cause of lameness in young dogs. JSAP 26 (10), 567-79 VetMedResource.
  • Bateman J K (1959) Fractured sesamoids in the greyhound. Vet Rec 71, 101.

Other sources of information

  • Robins G M & Read R A (1998)diseases of the sesamoid bones.In:Canine Sports Medicine and Surgery.Bloomberg M S, Dee J F & Taylor R A (eds). Saunders W B Company, Philadelphia, pp 255-264.
  • Robins G E & Read R A (1993)diseases of the sesamoid bones.In:Disease mechanisms in small animal surgery.pp 1094.

Other Sources of Information