Do You Have a Patient that is a Potential Candidate for Total Hip Replacement?
Sending a client for a consultation regarding hip replacement is a large commitment by the client and patient. Even with a diagnosis of hip dysplasia, some patients are very good candidates for hip replacement and others are not. A client must consider many things including cost, aftercare, expected function, and potential complications. This document is intended to answer many of these questions, and also serve as a check list for the primary care clinician who is referring the case. Iowa State University School of Veterinary Medicine and the Lloyd Veterinary Medical Center are proud to offer total hip replacement (Total Hip Arthroplasty - THA) to our referring veterinarians for the benefit of their patients and clients. We have been offering this service for over 25 years and with the recent addition of new orthopedic surgeons and with the support of industry leaders, are expanding our service into being a regional center for hip and other joint replacements. Our surgeons have extensive experience in orthopedics including hip replacements. We offer both cemented and uncemented Biomedtrix THA systems.
What is a typical history for a potential candidate?
The typical candidate is a middle age to older dog with increasing soreness and lameness referable to their hip joints. Typically these patients are slow to rise after sleeping, will tire or become more lame with increased exercise, and can exhibit pain when climbing stairs. The other category are young dogs that are no longer a candidate for a triple pelvic osteotomy, exhibit significant pain and lameness, and are large enough so that FHO may not return them to acceptable function.
What physical examination findings are common?
The neurologic examination should be within normal limits with no loss of placing deficits, or proprioceptive deficits to the caudal limbs. There will be decreased range of motion, especially in internal rotation and extension of the hip joints. Normal extension should be about 170 degrees and internal rotation is 45 degrees Flexion and external rotation can be normal or decreased. Abduction is often decreased.
Should the referring hospital take radiographs?
Even though ISU will take radiographs, these will be very precise radiographs, taken under anesthesia, with several specialized views for surgical planning. Prior to referral, it is best to confirm a diagnosis of hip dysplasia before having a client make a trip. In addition, these images are often helpful during the initial visit as they may suggest the candidacy of the patient, prognosis, and potential for operating the contralateral side.
What should I be looking for in my radiographs?
Hip dysplasia is demonstrated radiographically as laxity of the coxofemoral joints at an early age, and secondary osteoarthritic changes in the adult. This instability results in osteophyte formation, thickened femoral neck, and a shallow acetabulum. The severity of the arthritic changes is not a primary differentiating factor for candidacy for THA. Some patients with mild radiographic changes are candidates due to pain and dysfunction.
The patient has not been on NSAID medications. Should I try this first?
Most surgeons will try a trial period of conservative treatment before recommending THA. Some, if not many, patients will respond very well and may resume a more comfortable life without surgical intervention. Conservative treatment consists of weight management, exercise moderation, high quality chondroprotectives, and the use of NSAID medications, either continuously or intermittently for a few days during periods of increased lameness. Exercise should be in the form of low-impact activities such as leash walking and swimming.
What other conditions should I rule out?
Many conditions may look like hip dysplasia. What can be confusing is that many dogs have radiographic signs of hip dysplasia, but their lameness or dysfunction is primarily cause by another condition. This happens frequently. Here is a list of other conditions and how to exclude them.
- Degenerative Myelopathy - This spinal cord degenerative condition occurs frequently in German Shepherds (as does hip dysplasia). The signs you should look for are ataxia, placing deficits, wear on the tops of the toe nails, exaggerated patellar reflexes. I often ask the clients to choose the word “Sore” or “Drunk” in the back end to describe their pet's problem. Other spinal cord conditions including compressive tumors may also present with these signs. Patients with DM are not candidates for THA.
- Rupture of the Cranial Cruciate Ligaments - CCL conditions are common, often bilateral, and can have a slow onset of clinical signs, just like OA from hip dysplasia. Radiographs may demonstrate hip OA while most of the lameness is due to knee problems. This is VERY common. The patient should be checked for signs of stifle instability including the bump on the inside of the knee some call a “Medial Buttress”. The patient should be checked for drawer and cranial tibial thrust. Radiographs of the stifle can also be taken.If a dog has both severe hip dysplasia and a CCL rupture, the CCL rupture is addressed before the THA.
- Caudae Equina Syndrome - Instability of the lumbosacral joint may result in compression of nerve roots at that area. Since compression of nerve roots can cause pain and dysfunction to the caudal limbs, this can mimic hip dysplasia. The tail may be held very low and the patient may resist being petted around the LS area. Lifting of the tail, palpating over the lumbosacral area, and extending the lower back while not extending the hip joints may elicit pain. Radiographs are often difficult to interpret since many older dogs have radiographic changes including ossifying spondylosis at the LS junction. If we suspect a LS condition, we may request an MRI prior to performing a THA.
How Much Does a Total Hip Replacement Cost?
The average cost is $6,000. This includes the examination, laboratory work, x-rays, hospitalization, antibiotics, anesthesia/analgesics, surgery, special surgical drapes and the cost of the implants (which accounts for about 35% of the fee). Charges for follow up evaluations range from $200-$300. These costs vary, depending on what needs to be done.
Will both hip joints need to be replaced?
Eighty percent of the patients with arthritis in both hips only require one side be operated upon to return them to a satisfactory and comfortable life. The decision on which hip to replace is based on the owner's observations, the physical examination findings and the hip x-rays. Only one hip is operated at first, usually the clinically most effected side. The decision to operate the second side is made after recovery from the first.
What is the Success/Complication rate at ISU?
Successful return to good to excellent function occurs in 95% of our cases. Complications can and do occur, and with a total hip replacement can be severe. These include infection, luxation of the hip joint, damage to the sciatic nerve, and fractures of the femur. Most complications can be successfully resolved.
How do I schedule an appointment?
Appointments can be made by calling the Small Animal Reception desk at:
Phone: (515) 294-4900
Fax: (515) 294-7520