Moe is a one and a half year old domestic short hair that presented for a two week duration of right pelvic limb (right hind limb) lameness. The owners had been resting him for two weeks and did not see an improvement with strict rest. Moe is an otherwise healthy, indoors only cat, and is current on all vaccinations.
On physical exam Moe was weight bearing lame on his right pelvic limb and had mild muscle wasting of that limb. He weighed 14.5 lbs. All other physical exam findings were normal.
Moe was sedated for x-rays of his right pelvic limb and of his pelvis. His x-rays revealed a fracture across his right femoral head (the ball portion of the ball and socket hip joint). His fracture is classified as a capital physeal fracture or a Salter Harris Type I fracture and is a common fracture in young male neutered, overweight, cats. You can see the subtle difference between the hip on your left (with the fracture) and the hip on your right (normal) in this x-ray.
There appears to be a correlation between neutering early in life and delayed closure of the growth plates in male overweight cats. Although no one can classify as to what the “early” cut off is or when is an appropriate time to neuter kittens. Some professionals are electing to wait until the patient is 6 months of age but no published research confirms whether or not that decreased the incidence of spontaneous fractures. The same process and fracture type appears in male adolescent overweight boys.
Moe had surgery to address his fracture with a femoral head and neck ostectomy to remove the head of his femur. Here is an x-ray after surgery and you can see the hip on your left is now no longer attached. Moe is now able to get around pain free and should do well long term.