College of Veterinary Medicine

Purpose

The purpose of this study is to compare the effectiveness of cemented versus cementless canine total knee replacement.

Background

In this study, we would like to perform a side-by-side comparison of two types of canine total knee replacement (TKR) implant, one of which is a standard implant that is secured to bone with bone cement, while the other is intended for use without bone cement ("cementless fixation"). Cementless fixation has a long and successful history in human joint replacement, and we have been using cementless hip replacements at OSU for several years in dogs, with excellent clinical results. We have no reason to believe that a cementless TKR will behave any differently to a cemented TKR, and the safety of the cementless implant has been established in a research study that we performed at OSU. However, there are no published reports on the effectiveness of cementless canine TKR in clinical patients. In the research study that we have designed, your dog will be randomized to receive either a cemented TKR implant or a cementless TKR implant. The surgical procedure will be the same, except for minor changes that relate only to insertion of the implant with or without cement. Post-operative care will be exactly the same for both cemented and cemented TKR animals. Recovery times are expected to be the same for the two groups.

Inclusion Criteria

To qualify for enrollment in this study, dogs must have either:

• Skeletally mature dogs with moderate to severe arthritis of the knee joint and clinical signs of pain and/or lameness that are not significantly improved by the use of joint supplements (e.g. glucosamine-chondroitin sulfate, Adequan), non-steroidal anti-inflammatory drugs (e.g. Rimadyl, Deramaxx) or other standard medical treatments.

Study Design/Treatment Schedule

The overall goal of this study is to document clinical function and the long-term performance of the implant. Clinical function will be assessed at 6, 12, 26 and 52 weeks through clinical examinations supplemented by the use of a computerized force platform that allows us to document how much your dog is using each leg after surgery, objectively assessing his/her degree of lameness. We will assess bone healing using standard X-rays and a bone mineral density scan (essentially, a modified X-ray). The additional procedures that are required will not pose a significant risk to your dog. No additional drugs will be administered since we will collect our data while your animal is under sedation for regular radiographs routinely taken during recheck evaluations.

We would like to follow your animal for the duration of his/her normal lifespan. Our goal is to develop a TKR implant that lasts the duration of the animal's life. The interval between the time of TKR surgery and any subsequent revision surgery (if needed) will be used as a measure of implant survival. If the implant lasts for the duration of your animal's life, or if a second surgery is needed to replace the implant, we would ask that you provide us with an opportunity to examine the retrieved implant so that we can evaluate the implant for evidence of mechanical wear or damage.

Client Compensation

• The implants for this study will be provided at no cost; as a result, the cost of TKR performed under this clinical trial will be $4,500 to $5,000 (a saving of $1,000 over the standard cost of TKR).

Client Cost

• The owner is responsible for all standard fees associated with TKR surgery and post-operative assessments, including office visits and examinations.

Contact

Dr. Matthew Allen, e-mail, for further information.