My father-in-law is going to have a total knee replacement next week. Call me a pessimist but I think he's going to have problems. He's old (83 years old) and frail. Is it possible to predict who will and who won't have a good result?

Researchers are studying many problems patients face with the idea of predicting who will have a good/poor result. The hope is to give the right care to each group to get the most benefit.

When it comes to total knee replacements (TKRs), there are quite a few studies already done on this topic. One of the most recent ones looked at over 200,000 patients who had a TKR between 1991 and 2001. Rates of infection, blood clots, and death were compiled. Factors such as age, gender, health, and type of insurance were matched against the data.

They reported that age over 65 was a risk factor for problems. Likewise, patients with more than one other health problem had worse outcomes. High blood pressure, diabetes, and a previous history of blood clot(s) are all risk factors for problems after surgery.

Previous studies have shown that surgeon experience makes a difference. Surgeons who do more TKRs have the best results. It turns out that hospitals have similar track records. High volume hospitals have the lowest death rate and rate of infection after TKRs.

Your father-in-law's best chances for a good recovery depend on his health, his surgeon's skill, and the type of hospital he will be staying at. Type of insurance seems to have an impact, too. Medicare patients have worse results than patients covered by private insurance.