Many patients wish to gauge their chance for a successful artificial disc replacement surgery by looking at success rates. While this is perfectly reasonable, it can be misleading and it is certainly complicated. Some experienced surgeons report audited success of 90%, yet the world-wide figure is about 65% for ADR surgery. Always deal with a surgeon who has audited results.
First, we must ask, what is success? If the patient has a technically perfect surgery, which restores the disc height, decompresses all the nerves and prevents paralysis, but the patient still has pain, is the surgery a success? Well, the patient is the judge and if the patient is still in pain they may say the surgery was not a success and this is how success rates are measured in studies. But the surgeon has done that he/she can do. ADR surgery does repair spinal nerves, which have suffered from compression, only by time and the bodies healing mechanisms. Even in a perfectly performed surgeries, a minority of patients post surgical back pain can result as from distraction or pain chronification (a brain function). These conditions usually subside in 3 months.
Second, patients expectations play a role in success scoring. While the vast majority of patients report a successful outcome from ADR surgery, especially with an experienced and successful surgeon, if the 65 year patient, who has suffered from back pain most their life, expects their entire spine to feel like it did when there were a teenager, they maybe disappointed. But then again no surgery can do that.
Third, we must understand that statistics include all patients, some for which the surgery was their last hope. It is almost a universal aspect of medicine that once the procedure moves from research to the general public patient selection becomes wider. (Sicker and older patients with more comorbidities will be included in the treatment groups.) Younger, healthier single-level patients without comorbidities will do better than other patients. How much better depends on how wide the patient population is and how skilled the surgeon. Success rates can vary widely by surgeon. The best hope for a patient is to find a surgeon with peer verified results. These surgeons are usually involved in some kind of research with a manufacturer.
Fourth, we must realize that artificial disc replacement is a relatively new surgical procedure. Any medical doctor can legally do this procedure and some begin doing the procedure after a two-day course. Their success rates become part of the world-wide success rate of the procedure.
Fifth, there is every reason to believe that artificial disc replacement in the hands of skilled and experienced surgeon has a much higher initial success rate than fusion and a higher success rate than other surgeons. Also, ADR will have a better long-term outlook than fusion, because of the lack of orthopedic stresses that fusion places on the spine.