Total Joint Replacement in Dogs and Cats

Patient function, quality of life and return to a normal life ultimately define the animal owners’ satisfaction following total joint replacement surgery. Rapid recovery and high performance are expected—not just hoped for—in current veterinary orthopedic surgery. Joint replacements are a suitable option for joint pain. Intervention in young patients is feasible and becoming more common because new technology has provided implants with a longer life-expectancy than that of dogs and cats.

Canine joint replacement technology and surgeon expertise have advanced greatly over the past 20 years, and the management of pre-operative, peri-operative, post-operative and chronic pain have received considerable attention. Only a few relatively small companies worldwide supply the technology for joint replacement surgery, and a relatively low number of surgeons have the expertise and high-volume joint replacement practices to consistently perform the procedure with a high degree of proficiency and success.

Treatment Options for Arthritis and Chronic Joint Pain

Dogs with chronic osteoarthritis and presumable chronic joint pain have few options available, including physical therapy and medical management. Pain management of osteoarthritis will always be the first treatment option. A femoral head ostectomy (FHO) for the hip is an option that was described in the scientific literature about 50 years ago, but no conclusive studies with objective evidence, such as recent reliable force plate gait analysis data, are available that document a return to “normal” function as is available following total hip replacement (THR) surgery.

A paradigm shift is in order in recommending total hip replacement surgery from “wait until it is absolutely necessary because nothing else works any longer” to “perform hip replacement surgery sooner rather than later.” Months and even years of oral anti-inflammatory medication, joint health support product injections, acupuncture, holistic medicine and chiropractic have been used in some dogs. Hip replacement implants are expected to outlive the patient so delaying surgery over concerns about implant wear is not justified.

Total Hip Replacement Surgery Patients Expected to Have Rapid Recovery

Animals should return to high levels of activity following total hip replacement surgery. Even older animals with chronic arthritis or other diseases are expected to have a rapid recovery and regain pain-free full function exceeding levels previously never considered possible. In most instances, expectations of outcomes for dogs appear to be higher than what human patients expect for themselves if they undergo the same procedure. Some human patients undergoing hip replacement expressed concerns about the ability to continue with certain recreational and sporting activities or to begin new activities after the procedure. The total number of patients exercising following joint replacement increased post-operatively, but the total amount of vigorous activity decreased¹. This kind of decrease in vigorous activity levels is not acceptable for dogs and is generally not necessary after full rehabilitation.

Many dogs resume normal activity, including weekend warriors, hunting, performance in the show ring and field trials. They also return to duty as service dogs, return to work as law enforcement dogs and participate in endurance activities like running with owners many miles per week. Expectations should be realistic, and owners should not expect dogs to compete at elite levels of activity, such as competing in events like the Iditarod Sled Dog Race, which is a 1,049-mile race, or to accompany their human owners in competitive racing. High expectations for performance activity should be discussed with the surgeon and understood by animal owners before surgery.

The ideal joint prosthesis would mimic the anatomy and motion of a normal joint. Implant design, surgical technique and surgeon judgment affect proper restoration of the new prosthetic joint. Incomplete restoration creates the possibility of biomechanical dysfunction, subtle functional deficits, accelerated implant wear and ultimately the potential for complications or joint replacement failure. This is particularly true in the patient that is expected to return to strenuous, high-impact and/or endurance activity².

Rehabilitation Determines Positive Outcomes

The patient’s aftercare and rehabilitation are critical in defining ultimate performance outcomes after surgery. Rehabilitation and a realistic prognosis should be part of the pre-operative conversation and preparation, and rehabilitation should continue throughout patient recovery. Risks and complications should clearly be discussed and be well understood by the client. All of these factors take a considerable amount of effective and consistent communication between the doctor/hospital staff and the client. In conclusion, high performance by the surgeon and hospital staff is necessary to produce high performance from our patients.

How to Ensure Animals Lead an Active Life with Joint Replacements

• Perform surgery sooner than later, i.e., before muscle and bone atrophy (loss) is present.
• The implants must be stable immediately and for the life of the animal.
• The implants are made of the same materials used in human hip replacements so they do not wear out in a dog’s or cat’s lifetime.
• Implants are placed in a perfect position to match the animal’s anatomy.
• Activity during recovery and physical therapy instructions must be followed carefully.
• Follow-up examinations include stitch removal at approximately six weeks after surgery and annually thereafter to ensure expectations are being met.

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References:

1.  Chatterji U, Ashworth MJ, Lewis PL, Dobson PJ: Effect of total hip arthroplasty on recreational and sporting activity. ANZ J Surg. 2004 Jun;74(6):446-9

2. Markel D C, Kester M: High Performance: What is it and why we need it, Seminars in Arthroplasty Vol 17:2, p 31, June 2006