August 2014 Small animal case

Small Animals Case of the Month

Dog
Golden Retriever
Male intact
10 years of age
Referred with severe bilateral hip displasia and for total hip replacement ( THP Zurich cementless).
Pre (not shown) and post OP radiographs were taken.

Radiographic examination

 

Faux profile of the left femur and left lateral projection of the pelvis post THR.

Radiographic examination

  • The radiographs are normal with no signs of acute complications.
  • 2 days later, the dog was suddenly severly lame on the same leg with no anamnesis of trauma.
  • A lateromedial oblique view of the left femur was taken.

Radiographic findings

Faux profile of the left femur.

  • The implants look stable. There is a small step formation and irregularity of the caudal cortex of the femur at the level of the mid diaphysis (arrow).
  • A second orthogonal view was recommended.

Radiographic Diagnosis

Craniocaudal view of the left femur.

  • There is a complete oblique fracture of the left femur, running from distomedially, at the level of the distal part of the stem, to proximolateral.
  • There is a cortical fragment visible medially and severe shortening with displacement proximolateral.
  • The dog underwent a second surgery.
  • Post OP radiographs were taken.

Radiographic Diagnosis

Faux profile of the left femur and left lateral projection of the pelvis after fixation of the femoral fracture.

Comments

  • Complication after Zurich cementless total hip replacement have been described in a study with retrospective evaluation of the technique in 60 dogs(1)
  • Postoperative complications occurred in 11 dogs, with one having a long oblique fracture (1 week after surgery) extending from the 4th screw hole to the midfemoral diaphysis.
  • The fracture was stabilized with a broad dynamic compression plate and additional 5 cerclage wires, similarly as in the case reported here.
  • Post OP fractures are well –reported complications after THP dogs and if not traumatic, appears to be more common in old animals because of nonuse of the leg or other pahologic conditions.

...To be continued...

(1) Guerrero and Montavon, Veterinary Surgery, 2009