Denosumab vs. Oral Bisphosphonates: Impact on Osteoarthritis Risk

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Clinical Overview: Denosumab Versus Oral Bisphosphonates and Osteoarthritis Risk

A target trial emulation study published in the Journal of Bone and Mineral Research investigated whether older adults with osteoporosis initiating therapy with denosumab experience a decreased risk of osteoarthritis compared with those initiating oral bisphosphonates. The study also evaluated outcomes among patients switching from oral bisphosphonates to denosumab.

In the primary analysis of new medication users, adults initiating denosumab exhibited a 17% lower overall risk of new-onset osteoarthritis compared to those starting oral bisphosphonates. Commenting on these results, Masaki Hatano, MD, MPH, of the Department of Orthopedic Surgery at the Faculty of Medicine at the University of Tokyo, stated:

“Our findings raise the possibility that denosumab may be associated with a lower observed risk of osteoarthritis in addition to its established role in osteoporosis treatment.”

Dr. Hatano added:

“They also suggest that this association may vary according to prior bisphosphonate exposure. Further evidence is needed before these findings can inform treatment decisions.”

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Target Trial Emulation Design and Results

Researchers utilized administrative claims data from adults aged 50 years or older diagnosed with osteoporosis. Propensity score matching was implemented across two core analyses:

• New User Cohort: 13,485 new denosumab users were matched 1:4 with 51,629 new oral bisphosphonate users. In a per-protocol analysis, denosumab initiation was associated with a lower risk for new-onset osteoarthritis (RR = 0.83; 95% CI, 0.73–0.91; absolute risk reduction, 2%; 95% CI, 1.1%–3.2%).
• Switching Cohort: 4,309 adults who switched from an oral bisphosphonate to denosumab were matched 1:4 to 16,546 adults who continued using an oral bisphosphonate. There was no significant difference in overall osteoarthritis risk between patients who switched to denosumab and those who maintained continued bisphosphonate therapy.

When evaluating specific joint sites, denosumab initiation in new users reduced the risk of knee osteoarthritis (RR = 0.84; 95% CI, 0.71–0.92; absolute risk reduction, 1.5%; 95% CI, 0.7%–2.8%) and hip osteoarthritis (RR = 0.87; 95% CI, 0.52–0.98; absolute risk reduction, 0.2%; 95% CI, 0%–0.8%). No significant differences in hand osteoarthritis risk were observed between new users. Among patients who switched therapies, only knee osteoarthritis risk showed a reduction (RR = 0.85; 95% CI, 0.71–1; absolute risk reduction, 1.3%; 95% CI, 0%–2.8%), with no differences noted for hip or hand osteoarthritis.

Regarding the lack of overall risk reduction in patients who switched therapies, Dr. Hatano noted:

“One possible explanation is that prior bisphosphonate exposure may have altered the subchondral bone-remodeling environment.”

Furthermore, Dr. Hatano explained:

“Differences in treatment persistence and adherence-related characteristics between patients starting osteoporosis treatment for the first time and those already receiving oral bisphosphonates may also have contributed to this difference.”

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Summary Tables of Osteoarthritis Risk Data

Table 1: New Users — Denosumab vs. Oral Bisphosphonates

Clinical Outcome	Relative Risk (RR)	95% Confidence Interval (CI)	Absolute Risk Reduction	95% CI (Absolute Risk)
Overall Osteoarthritis	0.83	0.73 – 0.91	2.0%	1.1% – 3.2%
Knee Osteoarthritis	0.84	0.71 – 0.92	1.5%	0.7% – 2.8%
Hip Osteoarthritis	0.87	0.52 – 0.98	0.2%	0% – 0.8%
Hand Osteoarthritis	No difference	N/A	N/A	N/A

Table 2: Treatment Switchers — Switch to Denosumab vs. Continued Bisphosphonates

Clinical Outcome	Relative Risk (RR)	95% Confidence Interval (CI)	Absolute Risk Reduction	95% CI (Absolute Risk)
Overall Osteoarthritis	No difference	N/A	N/A	N/A
Knee Osteoarthritis	0.85	0.71 – 1.0	1.3%	0% – 2.8%
Hip Osteoarthritis	No difference	N/A	N/A	N/A
Hand Osteoarthritis	No difference	N/A	N/A	N/A

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Interactive Osteoarthritis Risk Explorer Widget (CLS-Optimized Code)

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<div class="osteo-risk-widget">
  <h4>Osteoporosis Therapy & Osteoarthritis Risk Explorer</h4>
  <p style="font-size: 0.9rem; color: #666;">Select patient cohort and joint site to review comparative clinical outcomes from Hatano et al. (2026):</p>

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    <label for="cohortSelect">Patient Cohort:</label>
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      <option value="switcher">Switchers (Switch to Denosumab vs. Continued Bisphosphonates)</option>
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    <label for="jointSite">Joint Site / Category:</label>
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      <option value="overall">Overall Osteoarthritis Risk</option>
      <option value="knee">Knee Osteoarthritis Risk</option>
      <option value="hip">Hip Osteoarthritis Risk</option>
      <option value="hand">Hand Osteoarthritis Risk</option>
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    <div class="orw-result-title">Clinical Finding Summary</div>
    <div id="orwOutputText" class="orw-result-text">New denosumab users had a 17% lower overall osteoarthritis risk compared to new oral bisphosphonate users (RR = 0.83; 95% CI, 0.73-0.91).</div>
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      if (joint === 'overall') {
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        output.textContent = 'Denosumab initiation was linked to reduced risk for knee osteoarthritis among new users (RR = 0.84; 95% CI, 0.71-0.92; absolute risk reduction, 1.5%).';
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        output.textContent = 'Denosumab initiation showed a reduced risk for hip osteoarthritis among new users (RR = 0.87; 95% CI, 0.52-0.98; absolute risk reduction, 0.2%).';
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        output.textContent = 'No significant difference in hand osteoarthritis risk was observed between new users of denosumab and oral bisphosphonates.';
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        output.textContent = 'No significant difference in hip osteoarthritis risk was observed between patients who switched therapies and those who continued bisphosphonates.';
      } else {
        output.textContent = 'No significant difference in hand osteoarthritis risk was observed between switchers and continued users.';
      }
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</script>
<!-- END: CLS-Optimized Interactive Widget -->

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Clinical Trials & Guidelines Resource Summary (CLS-Optimized HTML)

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<div class="osteo-trials-card">
  <h3>Bone Mineral Research & Clinical Trials Hub</h3>
  <p>Access published literature, target trial emulation studies, and database resources concerning osteoporosis therapies and joint outcomes:</p>

  <div class="osteo-trials-grid">
    <a href="https://pubmed.ncbi.nlm.nih.gov/" target="_blank" rel="noopener" class="osteo-trial-link">PubMed Literature Database</a>
    <a href="https://clinicaltrials.gov/" target="_blank" rel="noopener" class="osteo-trial-link">ClinicalTrials.gov Registry</a>
    <a href="https://academic.oup.com/jbmr" target="_blank" rel="noopener" class="osteo-trial-link">Journal of Bone & Mineral Research</a>
    <a href="https://www.healio.com/" target="_blank" rel="noopener" class="osteo-trial-link">Healio Clinical News</a>
  </div>
</div>
<!-- END: CLS-Optimized Clinical Trials Component -->

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Video Overview Container (CLS-Optimized Code)

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