My Grandma has always had a low BMI

This was one of the largest cohort studies on the topic and included almost 65000 individuals diagnosed with hip or knee OA.¹

Of the 65000, the average risk of receiving a total hip replacement was 14% and a total knee replacement was 30%.

In other words, although diagnosed with OA, the odds are in favour that the patient will never require or receive hip or knee arthroplasty.

I can’t stand it when patients tell me that they’ve been told by a surgeon, “You have arthritis and you’ll eventually need a joint replacement”.

Seriously? Are they psychic? Cause the majority do not need a replacement and may get better. In fact by telling them that they will need a replacement eventually, they are more likely to reduce their walking, running or participation in sports thinking that they don’t want to accelerate their OA progression. When in fact…

“There is strong evidence that … running and regular performance of sports are not associated with knee OA progression.” ²

As PTs we MUST inform patients of the above-motioned facts.

It must be said that the strongest predictor of needing a joint replacement is BMI.² My grandma has always had a low BMI, which may partly explain why at 92 she remains symptom free and can still go into a deep squat!

References:

1. Burn E et al Lifetime risk of knee and hip replacement following a GP diagnosis of osteoarthritis: a real-world cohort study. Osteoarthritis Cartilage. 2019 Jun 17. pii: S1063-4584(19)31088-X.

2. Bastick AN et al What Are the Prognostic Factors for Radiographic Progression of Knee Osteoarthritis? A Meta-analysis. Clin Orthop Relat Res. 2015 Sep;473(9):2969-89.