The most common orthopedic problem found in the Boston Terrier is the dislocation of the patella, which can lead to rupture of the anterior cruciate ligament.

The canine patella is equivalent to the human knee.

The cause of the problem may be by trauma or genetic cause (most common).

Traumatic injury can occur when the dog's leg is trapped in some way and fight for freedom or for an overly enthusiastic playtime when the playmate grabs the foot and holds tight while the excited puppy tries to escape. Any similar accident can permanently damage the joint.

When the dislocation is genetic, is due to abnormal development of the leg. There is a small groove which is a part of the structure which allows the ball to move freely. When this slot is too low or when the leg is slightly bent, the ligaments that hold the patella can be damaged, weak ligaments, etc.. The heritability is polygenic.

Signs of patellar luxation are lameness, pain and the dog may stop frequently to stretch the back leg behind him. This straightening of the leg is done to allow the patella appear again in its normal slot.

There are varying degrees of dislocation (0 to 4). "0", no dislocation, "1" intermittent "2" not permanent "3" permanent and reducible and "4" permanent non-reducible. In grades 3 and 4, the surgery is a necessity.

In Spain there are still no guidelines on the degree of dislocation of limpets allowed to breed, countries such as Germany permit to grade 1.

Important in Boston with dislocated kneecaps maintain a healthy weight.

It is recommended that proof of the patella can be done every two years due to changes that may occur in the patella. Most importantly, do so before to breed your dog. The dog must be reviewed every two years if regularly used as a stallion. It has been suggested that a dog should not breed if more than 25% of their littermates are unaffected.

The first test may be performed when the puppy is 6-8 weeks, but only when it is 12 months old can be certified with accuracy.