Younger Age has higher risk of short term Failure after Total Knee Arthroplasty

Total knee arthroplasty or total knee as it is commonly called, is surgery that is being performed more and more frequently, with more and younger people opting for a total knee.

It is estimated that by 2030 people younger than 65 will make up one million of the total knee replacement surgeries performed. It has been established that intermediate and long-term failure rates are higher in younger patients with a total knee, however not much is known about the short-term failure rates. The purpose of this study was to determine if patients younger than 55 years old where at a higher risk of getting an infection at the total knee site or having a mechanical failure of the knee prosthetic (hardware breaking anywhere in the total knee) one year after the surgery. After a total knee failure a revision surgery is performed.

The examiners used report information from California hospitals of patients that had only one total knee surgery from 2005-2009. Patients could be any age and male or female. They found that at one year, 1.36 per cent (5301 patients and 72 revisions) of those younger than 50 had a major knee infection and 3.49 per cent (5301 patients and 185 revisions) had a mechanical failure that needed revision surgery. The revision percentage decreased as age increased and those older than 65 had .73 per cent failure rate (74,570 patients and 545 revisions) due to knee infection and .75 per cent failure rate (74,570 patients and 560 revisions) due to mechanical failure. In all age groups men had slightly higher infection rate compared to women (1.04 per cent vs. .68 per cent), but there was no difference in percentages of mechanical failure. People that had multiple (four or more) health issues such as diabetes, anemia, depression, and peripheral vascular disease had higher chances of revision then those without other health issues.

This study demonstrated younger age (less than 50 years old) is a higher risk age for getting infection around a total knee or having it break due hardware failure with one year. While long-term failure rates due to the total knee breakdown are typically attributed to the younger total knee population being more active than their older counterparts, less is known about short-term breaking of the hardware. The examiners give a possible explanation for the higher percentage of revision with the younger population is that revision may be due to the greater amount of arthritis after a major injury that younger patients have. Whereas older patients do not typically have arthritis from a traumatic event in the knee to be replaced. The study also found that hospitals that performed greater than 200 total knee arthroplasties per year had lower infection rates compared with lower volume hospitals. If you are debating getting a total knee and are under fifty, you should discuss this with your health care provider.