ISSN 2398-2977      

Bone: osteitis - septic

pequis

Synonym(s): Osteomyelitis


Introduction

  • Cause: open fracture, open reduction of fracture, extension from septic arthritis   Joint: septic arthritis - adult  , laceration, puncture wounds that damage bone.
  • Signs: heat, pain, reduced weightbearing, pyrexia, poor wound healing, sinus tract.
  • Diagnosis: radiography, microbiology.
  • Treatment: surgical debridement, implant removal, bone graft, antibiotics.
  • Prognosis: guarded - osteomyelitis secondary to fractures and septic arthritis; fair - sequestration secondary to wounds.
  • See also:
Print off the Owner factsheet Penetrating foot injuries to give to your clients.
 

Pathogenesis

Etiology

  • Trauma.
  • Iatrogenic.
  • Extension from joint infection/fracture.

Specific

  • Open and/or comminuted fractures.
  • Open reduction of fracture.
  • Surgical implants.
  • Wounds.
  • Joint infection.
  • Incomplete fractures

Pathophysiology

  • Loss of blood supply plus introduction of bacteria (traumatic or hematogenous)   →   death of bone   →   bacteria proliferate   →   inflammation and formation of a sequestrum.
  • Joint infection   →   bacteria spread via epiphyseal vascular channels or through defects in articular cartilage to bone.
  • Definitions:
    • Osteitis: inflammation of bone.
    • Osteomyelitis: inflammation of bone involving the medullary cavity.
Loss of blood supply
  • Blood is circulated in the bone from the medulla out toward the cortex.
  • Periosteal blood supply is best at the attachments of ligaments and tendons and at the extremities of the bone.
  • There is some continuity of the periosteal vessels with the medullary circulation.
  • Loss of periosteum   →   ischemic death of the outer third of the cortex.
  • Loss of blood supply   →   osteocytic death   →   necrotic bone.

Infection

  • Bacteria introduced during trauma or surgery, by hematogenous spread to an area of minor but chronic bone pathology, or by extension from joint infection.
  • Bacteria adhere to damaged endothelium   →   proliferate   →   inflammatory response   →   osteitis (inflammation in the periosteum and superficial cortex).
  • Inflammation   →   interstitial edema and capillary rupture   →   increased pressure in the osteonal system and trabecular space   →   pain and further disruption of blood supply.
  • Bacteria produce a protective layer of extra polysaccharide polymers suitable for adhesion of more bacteria and reducing susceptibility to antibiotics   →   loss of tissue viability.
  • Pieces of dead bone   →   good substrate for further colonization   →   infection penetrates deeper cortex and medulla   →   osteomyelitis.

Bone response

  • Granulation tissue proliferates   →   osteonal, trabecular and periosteal mesenchymal cells produce new bone   →   isolates infected bone.
  • Isolated abscess and necrotic bone = sequestrum.
  • New bone surrounding sequestrum = involucrum.
  • Formation of a sinus tract which drains exudate and sequestrum fragments   →   potentially spreads to joint(s) and/or overlying soft tissues   →   prevents healing.

Diagnosis

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Kilcoyne I, Nieto J & Vaughan B (2014) Tibial osteomyelitis caused by Rhodococcus equi in a mature horse. Equine Vet Educ 26 (6), 283-286 VetMedResource.
  • Werpy N (2014) The use of magnetic resonance imaging for the diagnosis of osteomyelitis. Equine Vet Educ 26 (1), 15-17.
  • Garcia E B et al (2014) Navicular bone osteomyelitis and navicular bursitis with associated fistula diagnosed with magnetic resonance fistulography in the horse. Equine Vet Educ 26 (1), 10-14 VetMedResource.
  • Koch C & White S (2013) Septic osteitis and osteomyelitis in foals - are antimicrobials alone enough? Equine Vet Educ 25 (2), 60-62 VetMedResource.
  • Lawrence C P & Fraser B S L (2013) Septic osteitis of the axial border of the proximal sesamoid bones in two foals. Equine Vet Educ 25 (2), 63-66 VetMedResource.
  • Close K, Gerard M, Davidson G & Schramme M (2011) Successful treatment of infectious (Salmonellatype III44) polyarthritis and osteomyelitis in a 4-week old foal. Equine Vet J 23 (3), 121-126 VetMedResource
  • Dabareiner R M, Watkins J P, Carter G K, Honnas C M & Eastman T (2001) Osteitis of the axial border of the proximal sesamoid bones in horses - eight cases (1993-1999). JAVMA 219 (1), 82 PubMed.
  • Booth LC (1998) Superficial septic osteitis and sequestrum formation in the horse.Equine Vet Educ 10, 233-237 VetMedResource.
  • Fitch G L and Martinelli M J (1998) Conservative and surgical management of a sequestrum involving the radial cortex in two horses. Equine Vet Educ 10, 228-232 VetMedResource.
  • Moore R M et al (1992) Antimicrobial susceptibility of bacterial isolates from 233 horses with musculoskeletal infection during 1979-1989. Equine Vet J 24, 450-456 PubMed.
  • Tulamo R-M and Alitalo I (1986) An unusual case of osteomyelitis in a horse. Equine Vet J 18, 404-407 PubMed.

Other sources of information

  • Ross M W & Dyson S J (2003) Antimicrobial Therapy. In: Diagnosis and Management of Lameness in the Horse. W B Saunders, USA. pp 601-602.

Related Images

Want more related items, why not
contact us

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code