I’m trying to get up enough courage to have one of my knees replaced. Are there any studies to show who should really have this operation? Maybe I’m not a good candidate.

Lots of studies have been done on the results of total knee replacements (TKRs). Unfortunately, most surgeons focus on which operation works best and which implant has the fewest problems.

Very few studies look at the characteristics of patients. Does age make a difference? Do patients with rheumatoid arthritis do better or worse than patients with osteoarthritis? Does it matter if you’re overweight when you have the operation?

These are just a few of the questions patients raise when thinking about having a TKR. A recent review conducted by the University of Minnesota reported no evidence that age or type of arthritis was linked to results.

The biggest factor in success was how much pain the patient had before the operation. Those with the greatest pain had the best improvement in function.