Q: Is my dog too young/old for total hip replacement?  What is the ideal age for THR?
A: Total hip replacement (THR)is routinely performed in dogs over 6 months of age. In young dogs with severe hip pain, 10 months is usually the earliest, as this is when the bones have finished growing. However, if the hip has dislocated from the socket, earlier surgery may be warranted.  There is no upper age limit for THR. For dogs near the end of their life with hip dysplasia, it is often other issues that cause them to slow down or appear weak. It is very important to thoroughly evaluate all other systems before considering THR. If no other issues are present, and the dog has the energy and desire to be more active, then THR is a good option.

Q: Is my dog too small/big for THR?
A: The modular system developed by Biomedtrix can accommodate dogs of just about any size. For toy and some giant breed dogs, cemented components may be needed. The BFX ® system can usually be used in dogs from 20 –80 kg. Since body weight is not strictly correlated with bone (and thus implant) size, radiographs must be performed to determine the exact implant size.

Q: What is the cost of THR and why is it expensive?
A: The cost for a total hip replacement varies according to the region of the country, surgical practice, and other factors. Prices are generally from $4,000 to $5,000. Approximately $1,500 of this cost is for the implants. These are manufactured to very high standards, with top quality medical grade materials. The cost is comparable to other complex, elective veterinary orthopedic procedures.

Q: What can I do if I can't afford a THR?
A: Medical management can work well in many dogs to make them comfortable despite significant hip arthritis. It is important to ensure that the dog is not overweight and that activity is modified to reduce stress on the joints. Anti-inflammatory and analgesic drugs can also be helpful for improving quality of life. Femoral head and neck excision is also an option to treat hip osteoarthritis.

Q: Why should I spend all that money on a total hip replacement instead of doing a femoral head osteotomy?
A: Following a successful total replacement of the ball and socket of the hip joint, limb function can return to 100 percent. Following an FHO, the pain in the area is greatly reduced, but the limb will only regain 75 to 80 percent of function. In larger, active dogs, this will be evident as lameness.

Q: If I choose an FHO and my dog doesn’t recover well, can a THR be done after that?
A: An FHO can be converted into a total hip replacement, however it is a technically demanding procedure with a higher complication rate than primary total hip replacement.  The longer the interval from the FHO to the total hip, the more difficult the total hip replacement becomes, with the best results occurring if the total hip replacement is performed early (4-6 weeks) after the FHO.

Q: My vet said it will "wear out" in 5 years, but my dog is only 2 yrs old and in pain. What do I do?
A: Since total hip replacement results in normal function and activity, if medical treatment does not alleviate clinical symptoms, then surgical treatment is recommended.  The young dog will immediately benefit from the surgery during its most active period of life.  Loosening of the implants is a possibility in the THR.  Because the bond between the bone and the metal in porous coated implants involves direct ingrowth of bone, the chances of this interface failing is much less than for cemented components.  For this reason, the uncemented system is preferred by most surgeons for younger dogs.

Q: Will my dog be able to return to a completely normal active life-style after THR surgery?
A: In most cases, dogs will return to normal activity following total hip replacement.

Q: What are the potential complications?
 A: Most dogs can bear weight on the operated leg the same day or the day after surgery.  Recovery to full activity typically takes 3-4 months. Approximately 5–10 percent of patients experience a complication in the first 3 months following surgery Dislocation of the components can occur if the patient is too active, or slips or falls. There is a small risk of bone fracture around the stem if too much load is placed on the implants before the bone has adapted to the components. After 4 weeks, the risk of these problems drops off rapidly—though activity restriction is still important until around 12 weeks after surgery. In addition, infection around the implants may require removal of all hardware and cement. In a healthy patient with no active infection, the risk is less than 1 percent, and even lower with the uncemented system. Late infection is a possibility if bacteria spread from an active site elsewhere in the body. Loosening without infection is very unlikely in the uncemented system. With cemented components, gradual changes to the interface between the cement and the bone can lead to loss of implant stability.

Q: What can I do to reduce the chances of complications?
A: The best way to avoid complications is to strictly adhere to the suggested protocol for exercise restriction and return to normal activity outlined by your surgeon.  Since the majority of complications occur during the first 3 months following surgery, it is during this period that activity should be limited and closely monitored. No running, jumping or playing is allowed. The patient must be kept under control on a leash at all times. A sling to support the hind end can help protect the limb during risky times. Late infections can be avoided by aggressive treatment of any infections.

Q: What is involved during the recovery period?
A: Initially, exercise restriction is recommended for the first 4 weeks; this means no running, no jumping, no climbing stairs, leash walks only outside to eliminate, and confinement to a crate or small room.  During weeks 5–8, respective  leash walks of 5, 10, 15 and 20 minutes are allowed.  During weeks 9–12, leash walks of 20 minutes duration 2–3 times per day are recommended.  Follow-up radiographs are obtained at 12 weeks post-operatively, and gradual return to normal activity is allowed during weeks 13–16.
 
Q: If both hips are abnormal, do both need to be replaced?
A: In most cases, the hip with the worse function is operated on first. This results in good function in about 75 percent of dogs. The other 25 percent remain somewhat lame on the opposite hip, and total hip replacement of the other side is considered in these cases.

Q: Why can’t both hips be treated at the same time?
A: Bilateral surgery increases discomfort and the risk of complications.  For this reason the two surgeries are separated by approximately 3-4 months in most cases. If function is good after the worse hip is replaced, the second hip may not need surgery.

Q: What sort of long-term follow-up is needed?  
A: Follow up radiographs are obtained at 12 weeks and then yearly thereafter.  The radiographs are very important to evaluate the response of the bone to the implants and to detect any abnormalities.  The earlier abnormalities are detected, the more likely they can be successfully treated.

Q: What is Hip Dysplasia?

Hip Dysplasia is an abnormal development and growth of the hip joint. Both hips are usually affected, but only one hip may show symptoms. The onset of clinical signs may not occur in both hips simultaneously. Hip Dysplasia is manifested by varying degrees of laxity (looseness) of the muscles and ligaments around the hip joint with instability and malformation of the joint components. Arthritis is the long term consequence of hip joint looseness.

A. Young dog with normal hips; note how the head of the femur sits tightly within the acetabulum.

B. Young dog with CHD (Canine Hip Dysplasia); note how joint laxity allows the head of the femur to subluxate.

C. Old dog with CHD and severe arthritis; note the flattening of the head of the femur and added bone fillings around the neck of the femur and within the acetabulum.