Authors of section


Denis Marcellin-Little

Executive Editor

Amy Kapatkin

General Editor

Noel Moens

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Comminuted fracture

General considerations

Comminuted patellar fractures are debilitating and require surgical intervention.

Comminuted patellar fracture in a dog


Comminuted patellar fractures can result from strenuous exercise in athletic dogs or from direct impact to the patella.

Due to its proximity to the skin surface patellar fractures can be open and require immediate attention.

Clinical signs

Most common clinical signs are:
  • Weight bearing lameness of the affected limb
  • Skin bruising over the patella
  • Pain response to palpation of the stifle joint
  • Proximal displacement of the patella is most often palpable
  • Lack of tension in the patellar ligament
  • Edema over the patella
  • Stifle joint effusion
  • Crepitus during flexion/extension of the stifle joint
Clinical signs of patellar fracture in a cat


High quality craniocaudal and mediolateral radiographs of the stifle joint are acquired.

Radiographs of the stifle joint
Small fragments or comminution may be visible on a tangential ("skyline") view of the patella or a CT scan.
Tangential ("skyline") radiograph of a comminuted patellar fracture in a dog