Malleolus: shearing injury in Cats (Felis) | Vetlexicon
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Malleolus: shearing injury

ISSN 2398-2950

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Introduction

  • Cause: HBC (RTA) - abrasion of prominences of medial (most common and more severe) and lateral malleoli.
  • Signs: soft tissue loss, hock instability, intra-articular contamination.
  • Treatment: open wound management followed by repair of collateral ligaments or talocrural/pantarsal arthrodesis.
  • Prognosis: generally good if arthrodesis can be avoided and skin loss in not severe.

Presenting signs

  • Acute onset, hindlimb, non-weight bearing lameness.
  • Extensive soft tissue loss.
  • Pain.
  • Swelling.

Pathogenesis

Etiology

  • Trauma, eg HBC (RTA): limb is abraded along road surface causing loss of skin, underlying soft tissue and bone.

Diagnosis

Presenting problems

  • Hindlimb lameness.

Client history

  • Acute onset non-weight bearing hindlimb lameness following trauma.

Clinical signs

  • Intra-articular contamination.
  • Extensive soft tissue loss.
  • Severe hock instability.
  • Pain.
  • Swelling.

Diagnostic investigation

Radiography

  • Plain and stressed:
    • Demonstration of bony damage and joint instability.

Confirmation of diagnosis

Discriminatory diagnostic features

  • History and clinical signs.

Definitive diagnostic features

  • Radiographic findings.

Differential diagnosis

Treatment

Initial symptomatic treatment

  • Open wound management: meticulously remove ischemic tissue and debris from wound, lavage Wound: lavage copiously and perform deep wound culture.

Standard treatment

  • Following open wound management, prosthetic repair of deficient collateral ligaments using non-absorbable material - short and long functional components should be repaired independently to give stability to the joint in flexion and extension respectively.
  • More extensive wounds are best managed with supportive external skeletal fixation until granulation tissue has covered the defect - delayed primary closure or skin grafting is then appropriate +/- prosthetic replacement of collateral ligament Skin graft: free.
  • If axial part of trochlear ridge is involved or joint stability cannot be achieved, talocrural or pantarsal arthrodesis Arthrodesis: pantarsal may be indicated.
  • Open wound management plus surgical repair plus external skeletal fixation plus antibiotic therapy specific to culture results Therapeutics: antimicrobial drug.

Subsequent management

Treatment

  • Rigid coaptation or transarticular external skeletal fixation is required for several weeks following prosthetic repair Fracture fixation: external skeletal fixator.
  • Dressing and wound management may be required for several weeks.

Prevention

Outcomes

Prognosis

  • Generally good despite extensive soft tissue loss, severe hock instability and intra-articular contamination.

Further Reading

Publications

Refereed papers