COMMINUTED FRACTURES OF DISTAL FEMUR IN DOG AND CAT: A CASE SERIES.

Abstract

Comminuted distal fractures of the femur in small animals are complex fractures where the fracture lines commonly pass through the supracondylar and intercondylar regions and have a guarded functional prognosis due to the articular envolvement. The number of lines and fragments are variable and the articular cartilage damage is difficult to assess by simple radiology. The supracondylar fracture line can also pass through the femoral troclea increasing the potencial for cartilage lesion. Hereby, we present a case series of comminuted fractures of distal femur in dogs and cats that were presented to two veterinary hospitals between 2016 and 2018. The objective of this comunication is to assess the functional prognosis of complex fractures with articular component of distal femur after osteosynthesis.

Two cats and one dog were presented with distal fractures of the femur with two or more fracture lines, with at least one of them including the articular surface were include in this case series. Two orthogonal x-ray views of the distal femur were done and the fractures were classified according to the AOvet classification system.

The cats and the dogs included in these case series, had an age range between 1 and 2 years old, the average weight was 3,5 Kg and the femoral fractures were unilateral in the three cases. Falls form heights were considered to be the cause of fractures in the three cases. The classification according the AOvet was 33_C1 (n=1) and 33_C2 (n=2). The osteosynthesis plan consisted in the reduction of the intercondylar component of the fracture by the use of two crossed kirchner pins (n=2) or by the use of one lag screw associated to one kirchner pin (n=1). The supracondylar component of the fracture was addressed either by the use of crossed kirchner pins associated to Rush pins (n=2) or by the application of two lag screws (n=1) due to the condrodystrophic nature of distal femur. In spite of the comminuted and articular component of these fractures the patients made a full recovery exhibiting a complete osseous regeneration at 12 weeks post-surgery without degenerative joint disease and decrease joint range.