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
- Lameness (usually in the forelimbs) Lameness: general - investigation Lameness: forelimb - investigation.
- Pain on flexion of metacarpo-phalangeal joints.
- Reduced range of motion.
- Joint swelling/effusion in acute stage; fibrosis and degenerative joint disease in later stage.
Age Predisposition
- Young growing dogs (3-4 months) but may present at any age.
Breed Predisposition
- Large breed, eg Rottweiler Rottweiler.
- Racing Greyhounds Greyhound.
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
:
- Lysis of affected sesamoid.
- Multiple calcified masses replacing sesamoid.
- In some cases, calcification around sesamoid bones and metacarpo-phalangeal joint osteophytosis.
Differential Diagnosis
- Sesamoid fractures Sesamoid: fracture.
- Bipartite or multipartite sesamoid bones (developmental malformation) Sesamoid: developmental malformation.
- Metacarpo-phalangeal joint dislocation/ligament damage Greyhound: digit injuries.
- Septic arthritis or cellulitis Arthritis: septic.
- Neoplasia of bone or soft tissue Bone: neoplasia.
- Hypertrophic osteodystrophy Hypertrophic osteopathy.
- LAMENESS ELSEWHERE! Rottweilers are prone to elbow and shoulder lameness.
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.