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Surgery Library


Canine Hip Dysplasia
Matt G. Oakes, DVM, ACVS
Kimberly R. Cox, DVM, ACVS

What is Hip Dysplasia?
Hip dysplasia is the medical term for an incorrectly formed hip joint that can lead to debilitating arthritis. The exact cause of hip dysplasia in dogs is thought to arise from a number of factors, including inherited traits from their parents, rate of growth, and other environmental factors.

Signs of hip dysplasia in dogs can vary greatly. Many signs may go unrecognized in the early stages. Puppies affected with hip dysplasia may have difficulty rising from a sitting position, lameness of one or both rear legs, a "bunny-hopping" gate while running, or they may have an audible clicking sound from the hip as it slips in and out of the socket. As arthritis develops in the joint, there may be stiffness or lameness of the rear legs and decreased stamina.

In general terms, there are two broad categories of treatment for canine hip dysplasia: Medical management and surgical management. Medical management of canine hip dysplasia centers around three concepts: 1.) weight control, 2.) moderation of exercise, 3.) control of pain or discomfort with anti-inflammatory medication. By maintaining your dog's weight at or slightly below the ideal, you will reduce the overall load applied to the hip joint, and consequently improve the function of the joint. Moderation of exercise is implemented and designed to maintain muscle mass and strength. This helps reduce the wear and tear on the joint caused by bursts of uncontrolled activity. Finally, controlling any discomfort or pain with anti-inflammatory medication will improve the comfort level of your pet and allow him or her to return to a higher level of activity.

The simple measures described above can result in significant improvement in many dogs level of comfort and function. Some dogs, however, have advanced changes that can limit the effectiveness of medical management. There are also some young dysplastic dogs that may be good candidates for a surgical procedure to prevent the development of arthritis.

Femoral Head Ostectomy (FHO)
The femoral head ostectomy, or femoral head and neck excision, is a surgery that is designed to eliminate the joint as a source of pain. By removing the "ball" portion, the joint is eliminated. Weight is transmitted around the joint through the gluteal musculature and joint capsule. Small dogs and cats function quite well with this procedure. Large dogs can also function well; however, the results are less consistent than with other procedures such as a Triple Pelvic Osteotomy or Total Hip Replacement.

Triple Pelvic Osteotomy (TPO)
The triple pelvic osteotomy surgery is designed to improve the biomechanical function of a hip joint that suffers from early hip dysplasia. The goal of the procedure is to prevent the formation of arthritis in the joint by improving the congruency of the joint. Three cuts (osteotomies) of the pelvis are made to allow the cup portion of the joint to rotate and cover the ball portion of the joint. The osteotomies are stabilized with a specially designed bone plate and screws. After healing is complete, normal function can be expected. To ensure a successful procedure, careful screening is important before surgery. For example, if arthritis is present in the joint before surgery, this procedure may have limited effectiveness. The most common complication after surgery is implant loosening. The risk of this complication is minimized by restriction of activity during the healing period.

Canine Total Hip Replacement Surgery

BACKGROUND:
Debilitating arthritis of the coxofemoral joint is very common in dogs. To date, no single treatment enjoys the success of hip replacement surgery. By eliminating the source of discomfort and providing a durable, functional arthroplasty, greater than 90% of patients treated with a hip replacement return to a normal level of function and activity.

INDICATIONS:
Hip replacement is most commonly indicated for debilitating arthritis of the coxofemoral joint as a result of hip dysplasia. However, arthritis resulting from malunion fractures of the capital physis, acetabulum, and chronic coxofemoral luxation can sometimes be treated with hip replacement.

CONTRAINDICATIONS:
Patients less than 10 months of age are too young to receive a hip replacement because the femur is still growing, which may result in loosening of the femoral component and failure of the arthroplasty. Other concurrent orthopedic, neurologic and infectious conditions should be addressed and treated prior to recommending a hip replacement. In addition, implant size availability generally limits hip replacement to patients more than 40 pounds. Occasionally, severe remodeling changes to the acetabulum may preclude secure fixation of the cup. Loss of the dorsal acetabular rim results in inadequate coverage of the acetabular cup and subsequent loosening and arthroplasty failure.

SURGICAL PROCEDURE:
Utilizing a craniolateral approach to the coxofemoral joint, an ostectomy of the femoral head and neck is made. The acetabular cartilage and subchondral bone is removed in preparation for accepting the acetabular cup prosthesis, which is secured in place with bone cement. The formal cavity is then prepared to accept the femoral component which is also secured with bone cement. The stainless steel head is attached and the joint is reduced. Accurate positioning of the implant and secure closure of the joint capsule and deep musculature ensure immediate stability of the arthroplasty. The surgical incision is closed routinely. Postoperative radiographs are taken to ensure proper positioning and fixation of the arthroplasty.

PREIOPERATIVE CARE:
Intravenous antibiotics are given at anesthetic induction and continued orally for 7 days postoperatively. Activity is restricted for the first 3 months after surgery. During the first month short leash walks are allowed, but steps and slippery surfaces are avoided unless closely supervised. Activity is increased gradually over the second and third months with leash walking and swimming, but running and jumping are not allowed.

FOLLOW-UP EVALUATION:
Two weeks postoperatively: evaluate the healing of the surgical site. Six weeks postoperatively: assess early postoperative use of the leg. Twelve weeks postoperatively: assess completeness of recovery, return to full levels of activity. Pelvis radiographs are taken 3 and 12 months postoperatively and annually thereafter or as otherwise indicated. Expedient treatment of infectious diseases, such as dental disease, bacterial cystitis, and bacterial pyoderma is imperative as infection of the orthopedic implant can occur at any time following surgery.

COMPLICATIONS:
Complications of hip replacement are uncommon (less than 10%), however, when complications occur, they can be devastating. Case selection and client education regarding postoperative care are of utmost importance to minimize the chance of complications and ensure a successful outcome. Potential complications include dislocation of the joint, fracture of the femur, infection of the implants, and aseptic loosening of the implants.

SCHEDULING AND COST:
Currently we perform hip replacement surgery on Wednesdays. We like to see first time cases at any time during the week and schedule surgery within the next 3 weeks. This allows for operative planning and ensures the cleanest environment for this procedure. The cost of uncomplicated hip replacement surgery at Tampa Bay Veterinary Specialists is approximately $3,400-$3,500.

MOST FREQUENTLY ASKED QUESTIONS ABOUT HIP REPLACEMENT SURGERY

1. HOW MUCH WILL IT COST? $3,400-$3,500 as of January, 2004.

2. HOW LONG WILL THE SURGERY TAKE? 1 ½ TO 2 ½ hours.

3. HOW LONG WILL IT TAKE TO RECOEVER FROM ANESTHESIA?
Following the surgery, your pet will return to his/her kennel for a supervised recovery. Their body temperature, vital signs, and pain management will be monitored until they are fully awake and warm. This generally takes 30-90 minutes.

4. WHO WILL DO THE SURGERY?
We use a team approach to provide the most efficient procedure for your dog. Dr. Matt Oakes performs the procedure with 2 certified veterinary technicians assisting. One assistant is scrubbed in to help with the procedure while the other monitors anesthesia and provides supplies and equipment as needed. We eliminate any unnecessary personnel from entering or leaving the room during the procedure to reduce the chance of contamination and infection.

5. WHAT IS THE "ARTIFICIAL HIP" MADE OF?
The hip socket (acetabular cup) component is made of a very hard polyethylene plastic. The thigh bone component (ball and stem) is composed of a special stainless steel (colbalt chromium). Bone "cement" is used to secure these components. This material is an epoxy-like acrylic called polymethylmethacrylate, which hardens completely 10 to 12 minutes after mixing.

6. I HAVE DECIDED TO HAVE MY DOG EVALUATED FOR A POSSIBLE HIP REPLACEMENT. WHAT HAPPENS NEXT?
Candidates for hip replacement surgery will need an appointment at Tampa Bay Veterinary Specialists with Dr. Matt Oakes. During that time our staff will do a physical exam of your dog, evaluate any x-rays your vet may have sent, and if necessary take additional x-rays. After reviewing this information, Dr. Oakes will discuss your treatment options. If it is decided that a hip replacement is the best choice, and you wish to proceed, your dog will be scheduled for surgery (usually the following Thursday). Routine blood work and urinalysis will be performed. We will ask that you give your dog a bath the night before the surgery.

7. WHAT HAPPENDS THE DAY OF SURGERY?
On the day of surgery, your dog will be anesthetized and will arrive in the operating room 15 to 20 minutes later. After surgery, radiographs of the "new hip" are taken to ensure proper positioning of the implants and recognize any potential problems. Your dog will probably be discharged Friday or Saturday morning.

8. WHAT THINGS COULD CAUSE MY DOG TO NOT BE AN IDEAL CANDIDATE FOR HIP REPLACEMENT SURGERY?
Pre-existing disease in other joints or organs (such as liver, kidney, heart, etc.), neurological disease, or infections of the skin, mouth, or urinary tract could temporarily or permanently eliminate your pet as a candidate for hip replacement surgery.

9. WHAT SORT OF SCREENING CAN BE DONE BY MY FAMILY VETERINARIAN TO PREVENT ANY DELAYS OF SURGERY?
Even if your pet is ideal candidate for total hip replacement, any sign of infection will postpone or cancel surgery. Disappointment can be avoided if your family veterinarian can screen your pet for any signs of infection by closely scrutinizing skin, teeth, ears, etc. In older dogs, basic blood chemistry and urinalysis may be done to assess overall state of health.

10. WHAT WILL I HAVE TO DO TO HELP WITH MY DOG'S RECOVER AT HOME? WILL MY DOG BE ABLE TO DO "NORMAL" ACTIVITIES?
Your dog may be willing to walk on his "new hip" immediately following surgery; however, special restrictions must be adhered to for the first 90 days to ensure proper healing and stability, and therefore a successful outcome for the future. Although the "bone cement" which holds the components in place is solid, the joint capsule and muscles which hold the ball in the cup are cut and then sutured back together during surgery. During the first 30 days while the tissues heal, excess exercise or a fall could break the stitches and result in dislocation of the joint.

For the first 30 days following surgery, your pet must be confined (preferably to a crate, kennel or small area on the ground floor of your home) and leash walked outside only for elimination purposes. ABSOLUTELY NO OTHER EXERCISE AND NO STAIRS WITHOUT DIRECT SUPPORT OF HIS BODY WEIGHT. Watch out for slippery surfaces.

During the second 30 day period you may begin to slowly resume leash controlled walking and swimming, but NO unsupervised stairs, slippery surfaces, or running.

As the muscle strength builds back up during the third 30 day period following surgery, you may slowly return your dog to normal levels of activity. After the 3rd month there are no limitations on activity.

11. WHEN DOES A VETERINARIAN NEED TO EVALUATE MY DOG FOLLOWING SURGERY?
Initial postoperative evaluations should be performed at TBVS by Dr. Oakes. We recommend rechecks at 2 weeks, 6 weeks, and 12 weeks following surgery. The 2 week check-up is to evaluate the healing of the surgical site. The 6 week evaluation is to assess how well your dog is using the leg and take x-rays if there are any potential problems. The 12 week check-up is to make sure your dog is fully recovered before returning to full levels of activity. X-rays will be taken at the 12 week recheck. After these follow-up exams, we recommend that x-rays of the hips be taken annually by TBVS or your veterinarian.

12. WHAT COMPLICATIONS SHOULD I WATCH FOR?
At the surgical incision site, watch for signs of redness, swelling, tenderness or discharge of fluid. Any of these symptoms would be a good reason to seek veterinary attention. DO NOT let your dog lick at the surgery site. If your dog has been using the leg well, then suddenly or over time begins to favor the leg, your veterinarian needs to examine the leg.

13. IF MY DOG HAS HIP DYSPLASIA IN BOTH HIPS, DO I NEED TO HAVE SURGERY DONE ON BOTH?
If hip dysplasia is present in both hips, the most painful hip will be operated first. Only about 10 to 20% of our clients elect a hip replacement on both hips. The rest do well with medical treatment or a different surgery (femoral head and neck excision). If a second hip replacement is required, 3 months is the minimum recovery time between surgeries.