This case study followed 3 kittens, ages 3.5 to 4.5 months, that developed growth abnormalities of the distal radius after falling from a height. Only one of the cats had a radiographically visible fracture through the distal radial physis on initial examination. Both of the other cats had fractures of the ulnar styloid process and 1 also had metacarpal fractures. All cats developed varying degrees of shortening of the radius subsequent to damage of the distal radial physis. Widening of the lateral aspect of the radiocarpal joint space due to asymmetric closure was observed in 2 cats. Unlike dogs, which frequently develop elbow incongruity after premature closure of the distal radius, all of the cats in this study showed carpal joint incongruity. Treatment included osteotomy of the radius and ulna and realignment of the radius with external skeletal fixation in one cat, ostectomy in another cat, and radius and ulna osteotomies and distraction osteogenesis of the radius in the third cat. Clinical outcome was considered good for all 3 cats, with none showing obvious lameness at the final examination, although the range of carpal flexion was reduced in all 3.

COMMENTARY: The distal radial physis closes between ages 14 and 20 months in intact cats, but later in neutered cats. If the physis closes at 5 months of age or younger, clinically significant loss of radial length can occur. These case studies illustrate the importance of watching for premature closure of the distal radial physis in kittens that have had trauma to the distal forelimb-and to follow up with radiographs 2 to 3 weeks after trauma, as compression injury to the growth plate may not be initially visible on radiographs. The surgical options to correct subsequent growth abnormalities depend on the type and severity of the injury as well as the age of the animal. The techniques used yielded clinically satisfactory results in all 3 patients.

Trauma-induced growth abnormalities of the distal radius in three cats. Voss K, Lieskovsky J. J Feline Med Surg 9:117-123, 2007.