Researchers studied 21 older adults who experienced unusual hip fractures without taking bisphosphonates—drugs commonly used to strengthen bones. They found that most of these patients were women with low vitamin D levels and weak bones. Interestingly, the study suggests that unusual hip fractures might happen for different reasons: some people get them because their bones are too weak, while others might get them because their bones stop remodeling properly. This research helps doctors understand that these rare fractures aren’t just caused by one thing, and more research is needed to figure out exactly what causes them.

The Quick Take

  • What they studied: Why some older adults get unusual hip fractures even though they’re not taking bone-strengthening medications
  • Who participated: 21 older adults (age 65 and up) who came to the hospital with unusual hip fractures between 2019 and 2024. Most were women.
  • Key finding: About 77% of patients had low vitamin D levels, and 67% had osteoporosis (weak bones). These fractures happened without bisphosphonate drugs, suggesting multiple causes rather than one single reason.
  • What it means for you: If you’re an older adult, especially a woman, maintaining good vitamin D levels and bone health may be important. However, this is a small study, so talk to your doctor about your individual fracture risk rather than making changes based on this research alone.

The Research Details

This was a retrospective study, meaning researchers looked back at medical records from patients who had already been treated. They reviewed 932 patients who came to the hospital with hip fractures between January 2019 and September 2024. From these cases, they identified 36 that met the criteria for unusual hip fractures, and 21 of those patients had never taken bisphosphonates (bone-strengthening drugs). Two independent doctors reviewed each case to make sure it was truly an unusual fracture type.

The researchers collected information about each patient’s age, sex, bone density, vitamin D levels, and other blood markers that show how bones are being built and broken down. They used a statistical technique called principal component analysis to find patterns in how different bone-related measurements connected to each other.

Understanding how unusual hip fractures happen in people not taking bone drugs is important because doctors previously thought these fractures were mainly caused by the medications. By studying patients without this medication exposure, researchers can identify other risk factors and causes, which helps doctors better predict who might be at risk and how to prevent these injuries.

This study has some important limitations to consider: it’s a small group (only 21 patients), it looked backward at existing medical records rather than following patients forward in time, and it was done at a single hospital. The findings are interesting but preliminary. The researchers themselves note that more research is needed to confirm these patterns.

What the Results Show

Among the 21 patients without bisphosphonate exposure, the researchers found that most were women. The fractures typically occurred in the middle section of the thighbone (called the diaphysis). When the researchers looked at blood tests and bone scans, they discovered that 77% of patients had insufficient or deficient vitamin D levels—meaning their bodies didn’t have enough of this important nutrient. Additionally, 67% of patients had osteoporosis, a condition where bones become weak and brittle.

The study also found strong connections between different bone-related measurements. For example, patients with low vitamin D tended to have high levels of parathyroid hormone (PTH), which is a chemical messenger that helps control calcium and bone health. Similarly, patients with high PTH often had high levels of alkaline phosphatase (ALP), an enzyme related to bone turnover.

When the researchers compared their findings to the smaller group of patients who had taken bisphosphonates, they noticed some differences. The bisphosphonate-treated patients tended to have higher vitamin D levels and lower ALP levels, suggesting their bones were being remodeled differently.

The statistical analysis identified four main patterns in the bone-related measurements, which together explained 88% of the variation between patients. These patterns represented: (1) how the body regulates minerals and hormones, (2) how quickly bones are being broken down and rebuilt, (3) kidney function, and (4) bone density as a separate factor. This suggests that unusual hip fractures might develop through different biological pathways depending on the individual.

Previous research established that bisphosphonates—drugs that slow bone breakdown—were linked to unusual hip fractures in some patients. This study adds important new information by showing that these fractures can also occur in people who have never taken these drugs. This suggests that the causes are more complex than previously understood. The findings align with the idea that both weak bone quality and overly suppressed bone remodeling might lead to these unusual fractures, but through different mechanisms.

This study is small (only 21 patients), which means the findings might not apply to all older adults. It looked at medical records after the fact rather than following patients over time, so it can’t prove cause and effect. The study was done at one hospital, so the results might be different in other populations. The researchers didn’t have complete information on all patients’ medical histories, medications, or lifestyle factors that might affect bone health. Finally, without a comparison group of older adults without fractures, it’s hard to know if the vitamin D levels and other findings are truly unusual or just normal for this age group.

The Bottom Line

Based on this research, maintaining adequate vitamin D levels appears important for bone health in older adults (moderate confidence). Regular bone density screening may be helpful for older women (moderate confidence). However, this is a small preliminary study, so these recommendations should be discussed with your doctor who knows your individual health situation. Do not make major changes to medications or supplements based solely on this research.

This research is most relevant to older adults (65+), particularly women, who are concerned about bone health and fracture risk. It’s also important for doctors who treat hip fractures and want to understand different causes. People currently taking or considering bisphosphonates should discuss this research with their doctor. This research is less relevant to younger adults or those without bone health concerns.

Vitamin D deficiency correction typically takes several weeks to months of supplementation to show effects on bone health. Improvements in bone density from lifestyle changes or supplements usually take 6-12 months to become measurable. Fracture prevention benefits would take even longer to assess.

Want to Apply This Research?

  • Track vitamin D levels quarterly through blood tests and log supplementation doses daily. Monitor any bone pain or unusual aches, and record falls or near-falls to identify patterns.
  • Set reminders to take vitamin D supplements consistently, log sun exposure time (which helps your body make vitamin D), and track calcium-rich foods consumed daily to ensure adequate intake.
  • Review bone density scan results annually if recommended by your doctor. Track vitamin D blood levels every 3-6 months. Monitor for any new bone pain or changes in mobility. Share this data with your healthcare provider during regular check-ups.

This research describes a small group of 21 patients with unusual hip fractures and should not be used for self-diagnosis or self-treatment. Unusual hip fractures are rare and complex medical conditions. If you have concerns about bone health, fracture risk, or have experienced a hip fracture, consult with your healthcare provider or an orthopedic specialist. Do not start, stop, or change any bone-related medications or supplements without discussing this research with your doctor first. This article is for educational purposes and does not replace professional medical advice.