3-Year-Old Female Spayed DSH

Signalment & History

  • This patient presents to your clinic with pain and swelling in the right thigh, and one-week history of lameness.
  • You order pelvis radiographs.

Findings

  • There is a smoothly marginated, ill-defined, transverse fracture of the proximal physis of the right femur with mild to moderate cranial, medial, and dorsal displacement of the distal fragment.
  • There is mild osseous proliferation along the cranial margin of the femoral neck. Multiple open physes are identified. The right gluteal and thigh musculature is mildly thin compared to the contralateral limb.

Diagnosis

  • Right capital physeal fracture¬†and disuse muscular atrophy.

Capital fractures

  • The proximal femur has two physes, one associated with the capital epiphysis, which becomes the head of the femur, and the other with the greater trochanter.
  • The closure of these physeal growth plates normally occurs between 7 and 10 months-old in non neutered cats.\
  • The blood supply of the femoral head is given by the medial and lateral circumflex femoral arteries

  • The fracture line passes through the proximal femoral physis and may affect cats older than 2 years that have a delay of physeal closure, but they occur more commonly in cats between 4 and 11 months. The highest incidence is reported in cats 6 to 9 months old.
  • Male, neutered and overweight cats are predisposed.
  • Femoral capital physeal fractures are most commonly a result of trauma in cats, but there are also spontaneous cases reported.

VD pelvis projections of adults cats with different appearance of capital fractures (McNcicholas et al, 2002): 

References

  • Perez-Aparicio, F., and Fjeld, T.O. Femoral neck fractures and capital epiphyseal separations in cats. Journal of Small Animal Practice (1993) 34: 445-449.
  • Craig, L. E. Physeal dysplasia with slipped capital femoral Epiphysis in 13 cats. Veterinary Patology (2001) 38:92-97.
  • McNicholas, W.T. et al. spontaneous femoral capital physeal fractures in adult cats: 26 cases (1996-200). JAVMA (2002) vol 221, No. 12: 1731-1736