A total hip or total knee replacement is something that is performed when someone’s quality of life is impaired. There are many factors that go into deciding the timing of when you should see an orthopaedic surgeon to consider a hip or knee replacement. Lifestyle factors, quality of life, optimisation of non operative measures are some of those factors.
Whilst we always like to wait as long as possible before considering a joint replacement, the data is positive when we look at how long hip and knee replacements last. A recent analysis is on this site on Longevity of a hip replacement and knee replacement longevity. These are useful to look at the past and what failure mechanisms there are for hip and knee replacements.
What is the optimal weight before surgery?
Whilst weight is a factor, in general patients with a BMI under 30 are optimal. And acceptable with a BMI from 30-40. Patients with a BMI over 40 are deemed high risk for all failure mechanisms for hip and knee replacements, and high risks for anaesthetic complications. The main mode of failure with BMI > 40 is infection, where the soft tissue envelope is not optimal for healing.
I don't like taking pain relief - do I have to?
Whilst pain relief can be a good way to cope with the pain from arthritis, some of the more effective ones, such as anti-inflammatories can cause more side effects than benefits, so some patients cannot take them. Whilst things like Panadol Osteo, Glucosamine and Fish oil can be excellent ways to minimise the discomfort, they have variable success rates. You do not have to maximise pain relief before deciding to have a joint replacement performed, as long as other aspects of the disability such as quality of life impairment and lifestyle modifications show that you need a joint replacement.