We don't know if more patients age 45-64 are getting osteoarthritis or if the rise in sports injuries is driving it. With the baby boomers now reaching Medicare age, it is anticipated that the knee replacement rate will continue to soar.
Total knee replacement is a big surgery. Some have referred to it as "precision carpentry". The recovery period is 4-6 weeks and the full recovery takes about a year. For older, retired people who are more sedentary, this disability time is not such a big deal. But for working adults, it consumes a lot of time. The surgery is usually not done until the patient has tried all of the other treatments but still has severe pain with normal activities.
Non operative treatment options include weight loss, anti-inflammatory meds, joint supplements, cortisone injections, hyaluronic acid injections and activity modification.
One study of 84 patients younger than 55 years old who underwent knee replacement found that 82 of them improved their activity after knee replacement and 18 years later, 94% of the knees were still working well.
There is a forum site where people exchange tips and stories about total knee replacement. The person who started the site was 27 when she had a TKR!