Contributors: Michael Guilliard

 Species: Canine   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading

Introduction

  • Cause: chronic inflammation of the sesamoid bones.
  • Cause of lameness and incidental finding in the racing greyhound.
  • Lameness in large pet breeds, eg Rottweiler.
  • Signs: often an insidious onset, progressive forelimb lameness in young dogs, or can also be acute onset lameness in adults.
  • Diagnosis: clinical signs and radiography.
  • Treatment: conservative, or surgical removal of sesamoids.
  • Prognosis: guarded for resolution.

Presenting Signs

Age Predisposition

  • Young growing dogs (3-4 months) but may present at any age.

Breed Predisposition

Cost Considerations

  • Often require chronic conservative management.

Pathogenesis

Etiology

  • Lytic lesions possible manifestation of osteochondrosis Osteochondrosis.
  • Inflammatory changes seen with enthesiophyte formation, possible traumatic etiology.
  • Degenerative secondary changes may be present in the metacarpo-phalangeal joint.

Pathophysiology

  • Fragmentation of the sesamoid bone may be result of abnormal endochondral ossification, ie a manifestation of osteochondrosis.
  • Multiple exostoses within the soft tissue attachments of the sesamoid may have a traumatic etiology.
  • There may be calcification around the sesamoid bones or osteophytosis around the metacarpo-phalangeal joint.
  • These changes may be secondary to joint trauma or instability.
  • Repeated stress on palmar surface of sesamoids by digital flexor tendons during hyperextension of metacarpo-phalangeal joints may → fatigue fractures and degeneration of the underlying bone and soft tissues.
  • Digits 2 and 5: flexor tendon pressure solely on inner sesamoids 2 and 7.
  • Digits 2 and 5: metacarpal bones are asymmetrical so axial condyle bears more load.
  • Histologically see bone fracture and necrosis supporting vascular compromise theory.

Timecourse

  • Slow, progressive lameness seen over weeks to months in the young dog.

Diagnosis

Presenting Problems

  • Pain and soft tissue swelling around joint.

Client History

  • Lameness (usually forelimb).
  • Joint swelling.

Clinical Signs

  • Localized soft tissue swelling around affected palmar aspect of the metacarpo-phalangeal joint.
  • Pain on metacarpophalangeal joint flexion.
  • Reduced range of flexion.

Diagnostic Investigation


Radiography
  • Dorsopalmar radiographs of manus Radiography: carpus and forefoot Foot sesamoid disease - radiograph Foot: sesamoid disease (Rottweiler) - radiograph :
    • Lysis of affected sesamoid.
    • Multiple calcified masses replacing sesamoid.
    • In some cases, calcification around sesamoid bones and metacarpo-phalangeal joint osteophytosis.

Differential Diagnosis

Treatment

Initial Symptomatic Treatment

  • Acute stage:
    • Restricted exercise, with or without non-steroidal anti-inflammatory treatment Analgesia: NSAID for 4-8 weeks is often successful.
    • Pentosan polysulfate sodium Pentosan polysulfate recommended during the period of inactivity.
  • Surgical excision is a possible treatment for chronic sesamoiditis not responding to conservative management.
    Surgical treatment carries a similar prognosis to conservative management and may not be beneficial.

Monitoring

  • Conservative management, by monitoring lameness and pain on direct palpation of sesamoid bones and by manipulation of MCP joint.
  • If still lame after 12 weeks rest, consider surgical excision of affected sesamoid bone and associated calcified bodies.

Subsequent Management

Treatment

  • Unresolved lameness will require restricted exercise and pain management Pain: management.
  • Surgical cases require of 1 week of bandage support post-surgery; then 3 weeks of lead exercise before returning to normal exercise if sound.

Outcomes

Prognosis

  • Conservative treatment usually adequate for pet dog.
  • If significant degenerative joint disease, may need long-term non-steroidal anti-inflammatory treatment or digit amputation for sporting dogs Amputation: digit Greyhound: digit injuries.
    Check for lameness elsewhere.

Expected Response to Treatment

  • Lameness should improve over 4-6 weeks in conservatively managed cases.
  • If lameness persists after surgery, this may be due to degenerative changes at the MCP joint.

Reasons for Treatment Failure

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.
  • Matthews K G, Koblick P D, Whitehair J G & Bradley C (2001) Fragmented palmar metacarpo-phalangeal sesamoids in dogs: a long-term evaluation. Vet Comp Ortho Traumatol 14 (1), 7-14 UCDavis.
  • 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) W B Saunders Company, Philadelphia, pp 255-264.
  • Robins G M & Read R A (1993)diseases of the sesamoid bones.In:Disease mechanisms in small animal surgery.2nd edn. pp 1094.

Other Sources of Information