What is a total hip replacement (THR)?
Both the ball (head of the femur) and socket (acetabulum) of a hip joint are replaced with prosthetic implants. The ball is made from a cobalt-chrome metal alloy. The cobalt chrome shaft is inserted down the center of the femur to secure the implant and forms the neck that the ball is impacted onto. The cup that replaces the socket is made from ultra-high molecular weight polyethylene plastic. If a cementless cup is implanted the plastic part of the cup is backed with a cobalt chrome liner that has a beaded surface that bone grows into. Both of these materials are used in human total hip replacements. The implants used at Oregon Veterinary Referral Associates (OVRA) are especially made for dogs by BioMedtrix, LLC. If we put in a cemented hip replacement we use the same special bone cement used in human total hips to hold these implants in place.

Since the expertise of the surgeon is very important, what experience do the surgeons OVRA have with the procedure?
Dr. Marvin L. Olmstead, who was a Professor at Ohio State University's, College of Veterinary Medicine for 26 years, began evaluating the effectiveness of the total hip replacements in the dog in 1976. About 3,000 total hip replacements have been performed by Dr. Olmstead at Ohio State and various other veterinary practices across the United States and around the world. Dr. Olmstead is a Diplomat and Past President of the American College of Veterinary Surgeons and one of the world’s leaders in developing and writing about total hip replacement surgery. He is a consultant for BioMedtrix, LLC. Dr. Curt Daly, who also performs total hip replacement surgery, is a Diplomat of the American College of Veterinary Surgeons, and works with Dr. Olmstead.

Do you use a cementless or cemented total hip replacement?
Both types of implants are used at OVRA. Dr. Olmstead started implanting cemented total hip replacements at the Ohio State University (OSU) College of Veterinary Medicine in August of 1976. He has considerable experience and a high success rate. The prosthesis we use has many of the design features found in hip replacements used in people. For many years the cemented hip was the main hip used in dogs. A cementless prosthesis has been recently developed by BioMedtrix, LLC and has gained world wide acceptance and use. This prosthesis gives the surgeons at OVRA many more choices for treating our patients. Each hip has two areas where a prosthetic implant will be placed. The socket will be replaced and a stem will be placed in the shaft of the femur. The ball with fits on the stem can be used with either cemented or cementless implants. We can use an all cemented prosthesis, all cementless prosthesis or both types of prosthesis (called a hybrid) in a given hip. This allows us to select the implant combination that is best for each individual patient. We have found no difference in the results from implanting any of the combinations.

Can you tell from my dog’s x-rays (radiographs) if he/she is a good candidate for THR?
Radiographs show abnormalities in the hip joint and are used for choosing the proper sized prosthesis but they are the only part of the picture. To decide what is best for your pet, the surgeon must evaluate your pet’s history, perform a complete physical exam, evaluate your pet’s radiographs, and interpret laboratory data. Many factors must be considered before your pet is determined to be a good total hip candidate.

How do you determine is my dog is a candidate for THR?
A painful hip(s) that is affecting your dog’s comfort, locomotion and activity levels is the primary indication for a THR. Stiffness, lameness, and reluctance to exercise are often signs of a problem. Your pet must be in good general health. There must be no other joint or bone problems, no nerve disease and no other medical issues. Your dog must be skeletally mature which means, that your pet has finished growing bone length. Generally this occurs by nine months of age. Giant breed dogs may not be skeletally mature until 11 months of age. Radiographs of the hips are used to determine skeletal maturity. The size of the bones as determined by radiographs must be large enough to fit the available sizes of prosthesis. Total hips can generally be placed in dogs weighing 30 pounds or greater. A dog with arthritic hips that has pain-free normal function is not a candidate for THR.

What is the earliest age my dog can have this procedure done?
In most dogs nine months old is the earliest the procedure will be done. There are only a few giant breeds where it will be necessary to delay the surgery for one or two months while the dog’s skeleton reaches maturity.

What can I expect from this surgery?
The goal of the surgery is to return your pet to pain-free mechanically sound normal hip function. Generally dogs are found to be more comfortable and have an improved quality of life. Many owners report that their pet can do things they have not done since they were a puppy. Increase in muscle mass, improved hip motion, and increased activity levels have been observed in most patients. Working dogs have returned to full activity including field trials. Some aggressive dogs have even developed a pleasant personality when the pain was eliminated from their hips. We have found that 95% of the hips that have been replaced return to normal or near normal function. More than 95% of owners feel that their dog’s quality of life is improved or markedly improved.

My dog is on medication. Should I stop giving this?
Medications for health conditions such as diabetes or low thyroid function should not be stopped. Medications for hip pain should be stopped prior to the initial examination. Oral steroids (even for skin conditions) should be stopped one week before the exam while other anti-inflammatory drugs including aspirin should be stopped three days before the exam and any elective surgeries.

Is surgery performed the day of admission?
No. Your pet must be carefully screened before surgery. This entails a complete history and physical examination. Radiographs of the hips will be taken pre-operatively. A complete blood count and chemistry profile (if indicated) will be obtained to screen your dog for evidence of infection, anemia, or problems with internal organs before surgery is performed. Your pet’s skin will be carefully examined for signs of infection. Abnormalities noted on these examinations may indicate that your dog is not a good candidate for a THR or needs other treatments before total hip surgery can be performed. If the pre-operative evaluations reveal no abnormalities, surgery is scheduled for the next day Dr. Olmstead is available to perform the surgery and that is also convenient for the pet's owner.

How long will my pet stay in the hospital?
The routine length of hospitalization for patients with THR is the day of surgery and the next day when the release occurs at a time determined during the telephone call by the doctor following the surgery. If it is determined that your pet is a good candidate for the procedure and you agree to have the procedure done, he/she may be admitted to the hospital at the initial examination for surgery the next day.

What is the success rate of THR?
In reviewing the records of patients that have had THR, a little over 95% of dogs have had good to excellent function with this procedure. These patients have normal pain-free function, increased muscle mass, no limping, and increased activity. Dr. Olmstead has published scientific articles about the functional results observed in total hip replacement patients.

What are the complications of this surgery?
As with any surgery, total hip replacements have their own set of complications. The complications that have been reported include dislocations, fractures of the femur, infection, loosening of the implants, nerve damage and very rarely clinically significant pulmonary embolism. Because the procedure has been continuously evaluated and improved, the risk of a complication occurring is low. Some complications seen in the early stages of development of the technique have been totally eliminated, while the risk for other complications has been greatly reduced. Methods of treating the few complications that do occur are also being developed and evaluated. Most complications can now be successfully resolved, preserving the THR. Thus, in the unlikely event your pet does have a complication, it is best to have it dealt with by a surgeon at OVRA because we are very used to dealing with total hip patients and their potential problems.
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What is the postoperative care for my pet?
The postoperative care for your pet is critical. The surgical incision must be monitored daily for redness, swelling or discharge. Your pet must be discouraged from licking the incision. This sometimes requires placement of a special collar to prevent your pet from reaching the incision. Your pet’s attitude and appetite should be monitored daily while the incision heals. The sutures may be removed from the incision 10 to 14 days after surgery. This may be done by your local veterinarian or at OVRA. An appointment for suture removal is required at OVRA.

The activity level of your pet must be strictly controlled. For the first two months after surgery your pet should only be allowed outside on a leash to urinate and defecate and for a short five to ten minute walk. Your pet should be immediately returned to the house afterward. Inside the house your pet should avoid stairs and slippery floors. If your pet must go up and down some stairs, you should go with the pet using a leash or your hand on the collar to control the speed of your pet on the stairs. Good footing is important. Absolutely no running, jumping or playing is allowed in the first two months after surgery. When your pet is not under your direct control, he/she should be kept confined to a small room or a kennel. Some owners find that a large crate or an airline crate is the ideal place to confine their pet when they are not at home.. After the end of the second month, you may gradually return your pet to full activity over a four week period.

Do I have to bring my dog back to OVRA for a check up?
If possible we would like to evaluate our patients at OVRA. We understand that people come to us from long distances, so if it is not convenient for you to return to OVRA, we ask that you have your veterinarian evaluate your pet two months after surgery. We also ask that a report on your pet’s function be sent to us so that we may record that information in your pet’s medical record. Any time your pet is having a problem it should be evaluated at OVRA since we are very used to dealing with total hip patients and their potential problems.

Both of my dog’s hips are affected. Will both need to be replaced? How do you decide which hip to replace?
Four out of five dogs or 80% of the patients with arthritis in both hips only require one side to be operated upon to return them to a satisfactory and comfortable life. The decision on which hip to replace is based on the owners’ observations, the physical examination findings, and the hip radiograph. Your knowledge of your pet’s disability is important in making this decision. Owner observation of the pets function and examination by Dr. Olmstead or Dr. Daly is used to determine if a second hip replacement is needed. This decision is never based on the radiographs alone. In the 20% that need both hips replaced, there will be at least eight weeks between the surgeries. The average time between surgeries in the 20% that need both sides done is six months and Dr. Olmstead has seen periods as long as seven years before a second hip is done.

What is included in the cost for the procedure?
At OVRA we are committed to offering our clients the best possible care for their pets. We use the most modern techniques and best equipment available to provide this service. Many things go into the cost of this procedure including but not limited to the examination, laboratory fees, radiographs, hospitalization fees, antibiotics, anesthesia, surgical fees, special surgical equipment and draping material, technician time and the cost of the implants. To successfully perform the procedure in a manner that will make it most efficient, and has the greatest success potential, we have at least one to two doctors and four to five staff involved directly with the surgery. The implants we use meet the same standards used for human implants, even though they are specifically designed for use in dogs. We feel that although this procedure may be more costly than some other procedures done for the treatment of disabling hip conditions, it is in almost all cases, the best technique available to restore the pain-free, mechanically sound ball and socket joint that “mother nature” intended the hip to be. The results obtained from a normally functioning THR is worth the cost.

How do I make an appointment for a total hip replacement consultation?
Your veterinarian may already have consulted with OVRA about your pet's condition. If not, please have them do so because a referral is needed for your pet to be seen at OVRA. Call OVRA at (541) 726-1100 to make a consultation appointment.

Is the THR the only treatment available for my pet?
No, besides THR, other possibilities for the treatment of your pet include non-surgical therapy and several other surgical options. Which treatment should be used on your pet depends on many factors. An OVRA doctor will discuss the different treatment options with you after we have taken a history, evaluated radiographs and completed an orthopedic examination of your pet.

We hope your questions about total hip replacement have been answered. If you have other questions, please be sure to ask them at the time of your appointment, or call (541) 726-1100 for more information.

Canine Total Hip Replacement: Questions & Answers