According to Gram Research analysis of a 16-year study of 2,882 adults, maintaining a healthy body weight and avoiding falls are the strongest ways to reduce your risk of needing hip or knee replacement surgery. Only 7.7% of participants needed joint replacement, and those with lower body weight had 4% lower risk per BMI unit, while people who never fell had 26% lower risk than those who fell.
A major study following nearly 3,000 people for over 16 years discovered what actually helps prevent the need for hip and knee replacements. Researchers found that maintaining a healthy weight, avoiding falls, and having good socioeconomic support were among the strongest protective factors. Surprisingly, some factors people worry about—like calcium intake—didn’t show the expected protective effect. The findings suggest that preventing joint replacement isn’t just about one thing, but rather a combination of lifestyle choices, biological factors, and social support that work together to keep joints healthy longer.
Key Statistics
A 2026 cohort study of 2,882 Australian adults followed for an average of 16.7 years found that only 7.7% underwent hip or knee replacement surgery, with lower body weight and absence of falls being the strongest protective factors.
According to research reviewed by Gram, each unit increase in body mass index raised the risk of needing joint replacement by approximately 4% in a study of nearly 3,000 adults followed for over 16 years.
A long-term population study found that people with no history of falls had 26% lower risk of needing hip or knee replacement compared to those with a fall history, suggesting fall prevention is crucial for joint preservation.
In a 16-year follow-up study of 2,882 participants, people with higher socioeconomic status had nearly twice the risk of joint replacement compared to those with lower socioeconomic status, highlighting unexpected social determinants of joint health.
The Quick Take
- What they studied: What factors help people avoid needing hip or knee replacement surgery as they age?
- Who participated: 2,882 Australian adults ranging from age 20 to 96 years old, followed for an average of 16.7 years. About half were men and half were women.
- Key finding: Only 7.7% of participants needed joint replacement surgery. People with lower body weight, no history of falls, no cancer history, and higher socioeconomic status had significantly lower chances of needing the surgery.
- What it means for you: Maintaining a healthy weight and avoiding falls appear to be the most practical ways to reduce your risk of needing joint replacement later in life. However, this is observational research, so these factors may be markers of overall health rather than direct causes.
The Research Details
This was a long-term follow-up study using data from the Geelong Osteoporosis Study, which tracked Australian adults over many years. Researchers measured participants’ body weight, muscle and bone composition, blood markers, and lifestyle factors at the start. They then tracked who eventually needed hip or knee replacement surgery over the next 16-23 years by checking medical records, hospital registries, and asking participants directly.
The researchers used advanced statistical methods to identify which factors were most strongly linked to avoiding joint replacement. They tested multiple factors simultaneously to see which ones truly mattered, rather than looking at each one separately. This approach helps separate real relationships from coincidental patterns.
The study included people of all ages and both sexes, making the results more broadly applicable. The researchers also accounted for competing factors—for example, some people might have died from other causes before needing joint replacement, which could skew the results.
This research approach is valuable because it follows real people over decades, not just weeks or months. This long timeframe allows researchers to see which factors actually predict who will need surgery in the future. The study also measured many different factors—weight, bone density, blood markers, falls, socioeconomic status, and more—to get a complete picture rather than focusing on just one thing.
This study has several strengths: it’s large (nearly 3,000 people), follows participants for a very long time (average 16.7 years), uses objective medical records rather than just asking people to remember, and includes diverse age groups. However, it’s observational research, meaning researchers watched what happened rather than randomly assigning people to different treatments. This means we can identify patterns but can’t prove that one factor directly causes another. The study also comes from Australia, so results may differ in other countries with different healthcare systems or populations.
What the Results Show
Over the 16-year follow-up period, 223 out of 2,882 participants (7.7%) underwent hip or knee replacement surgery. The strongest protective factors were maintaining a lower body weight, avoiding falls, and having no history of cancer. For every unit increase in body mass index (BMI), the risk of needing joint replacement increased by about 4%. People who never fell had about 26% lower risk compared to those who fell.
Socioeconomic status emerged as a surprising factor. People with medium or high income had nearly twice the risk of needing joint replacement compared to those with low income. This counterintuitive finding may reflect that wealthier people have better access to surgery when needed, or that lower-income individuals have different activity patterns or healthcare-seeking behaviors.
Bone mineral density in the spine showed an unexpected relationship: people with lower spine bone density had lower joint replacement risk. Researchers believe this may reflect that people with higher spine bone density also have more spine degeneration, which could affect how joints function overall.
Dietary calcium intake appeared protective in initial analysis, but this effect disappeared when researchers accounted for calcium supplements. This suggests the apparent benefit wasn’t from calcium itself, but from other factors associated with people who eat calcium-rich foods.
A blood marker called P1NP (related to bone turnover) showed that lower levels were associated with reduced joint replacement risk. This is one of the few potentially modifiable biological factors identified. The study also found that having a history of cancer was associated with lower joint replacement risk, though this association weakened when accounting for the fact that some cancer patients may have died before needing surgery. Age-related spine degeneration appeared to be a key mechanism linking higher bone density to increased joint replacement risk.
This study aligns with previous research showing that body weight is important for joint health, but it provides more detailed long-term evidence. The finding about socioeconomic status challenges some assumptions in the field and suggests that social factors may be more important than previously recognized. The unexpected findings about bone density and calcium intake suggest that joint health is more complex than simple ‘stronger bones are better’ assumptions. The study adds to growing evidence that falls prevention is crucial for maintaining joint function in older age.
This is observational research, so it identifies patterns but cannot prove cause-and-effect relationships. For example, people who don’t fall might be healthier overall in ways not measured in the study. The study followed Australian adults, so results may not apply equally to other populations with different genetics, healthcare systems, or activity levels. Some factors were self-reported, which can be less accurate than objective measurements. The study couldn’t measure all possible factors that might influence joint replacement risk, so some important factors may have been missed. Finally, the definition of ‘joint replacement’ included both hip and knee surgery, which may have different risk factors.
The Bottom Line
Based on this research, maintaining a healthy body weight appears to be the most important modifiable factor for reducing joint replacement risk (strong evidence from long-term follow-up). Avoiding falls through balance training, home safety, and appropriate footwear is also important (moderate evidence). There’s no strong evidence that increasing calcium intake specifically prevents joint replacement, so focus on overall nutrition rather than calcium supplementation alone (weak evidence). If you have access to healthcare, regular check-ups may help identify and address joint problems early.
Anyone concerned about joint health as they age should pay attention to these findings, particularly people in their 40s and beyond when joint problems become more common. People with family histories of joint replacement or those who are overweight should find this especially relevant. However, these findings don’t mean that thin people never need joint replacement or that heavier people definitely will—individual variation is large. People with cancer or significant fall risk should discuss joint health with their healthcare provider.
The benefits of maintaining a healthy weight and avoiding falls develop over years and decades, not weeks or months. The study followed people for an average of 16.7 years, suggesting that the protective effects of these factors take many years to become apparent. You might notice improved joint comfort within weeks of weight loss or fall prevention, but the long-term benefit of avoiding surgery develops over a much longer timeframe.
Frequently Asked Questions
What’s the best way to prevent needing a hip or knee replacement?
Maintaining a healthy body weight and avoiding falls are the two strongest protective factors based on a 16-year study of 2,882 adults. Each BMI unit increase raised replacement risk by 4%, while people who never fell had 26% lower risk than those who fell.
Does eating more calcium help prevent joint replacement surgery?
Surprisingly, dietary calcium intake didn’t show a protective effect in this study. The apparent benefit disappeared when accounting for supplements, suggesting other factors associated with calcium-rich diets may be responsible, not calcium itself.
How long does it take to see benefits from maintaining a healthy weight for joint health?
The study followed people for an average of 16.7 years, suggesting protective effects develop over decades. You may notice improved joint comfort within weeks of weight loss, but the long-term benefit of avoiding surgery takes many years to become apparent.
Can I still need joint replacement if I’m thin and don’t fall?
Yes, this study identifies risk factors but doesn’t mean thin people never need replacement or that other factors don’t matter. Individual variation is large, and genetics, previous injuries, and other health conditions also influence joint health significantly.
Why did wealthier people have higher joint replacement rates in this study?
Researchers believe this may reflect better access to surgery among wealthier people, or differences in activity levels and healthcare-seeking behavior. It doesn’t mean wealth causes joint problems, but rather that socioeconomic factors influence who receives surgery.
Want to Apply This Research?
- Track weekly weight trends and monthly fall incidents. Set a goal to maintain a stable weight within a 5-pound range and record any falls or near-falls to identify patterns and hazards.
- Use the app to log daily physical activity focused on balance and strength training (which helps prevent falls), weekly weight check-ins, and nutrition logging to maintain a healthy weight. Set reminders for home safety checks like removing tripping hazards.
- Monitor weight trends over 3-month periods rather than daily fluctuations. Track fall frequency quarterly to identify seasonal patterns or new hazards. Use the app to note any joint discomfort and correlate it with weight changes or activity levels to identify personal patterns.
This research identifies factors associated with joint replacement risk but does not establish cause-and-effect relationships. These findings are observational and should not replace personalized medical advice from your healthcare provider. If you have joint pain, a history of falls, or concerns about joint replacement, consult with a doctor or orthopedic specialist who can evaluate your individual situation. This article is for educational purposes and is not a substitute for professional medical diagnosis or treatment.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.