Success rates with the new artificial disc replacements (ADRs) vary depending on who is doing the study and how it’s being done. The definition of success with this procedure is not always the same from study to study either.
Success can be measured by pain relief or improved function. Other measures can include change in spinal motion, quality of life, patient satisfaction, or even amount of pain medication taken each day. If more than one measure of success is used at a time, then overall success rates may go down.
When reviewing studies using the FDA-required definition, about half of the patients receiving the new ProDisc ADR had success. This definition was used with similar patients who had lumbar spinal fusion. The fusion group had a success rate of 40.8 per cent.
Using a more lenient definition of success, the developer of the ADR reported success for 63.5 per cent of patients in the same ADR group. The same fusion group rated 45 per cent success.
Although the manufacturer knows the ADRs can last 40 to 50 years, there are no long term studies yet (20 years or more) to guide us. With two ADRs on the market more and more patients will benefit from this new treatment. In time, success rates may be better defined and improve — however they are measured.