Przejdź do treściPolish version: Abaloparatyd po złamaniu miednicy — brak potwierdzenia szybszego zrostu
Could an anabolic osteoporosis treatment also accelerate healing of an acute pelvic fracture? This is an attractive hypothesis for older adults with fragility fractures. A double-blind phase 2 randomized trial, however, found no benefit from abaloparatide for radiographic healing, pain or physical performance at 3 months.
Why this study matters
Pelvic fractures in older adults can cause prolonged pain, impaired mobility and loss of independence. Because PTH receptor agonists stimulate bone formation, there is interest in whether they can promote healing as well as prevent future fractures. This trial used a prospective, randomized, placebo-controlled, double-blind design and CT assessment of the primary endpoint, making its negative findings more informative than uncontrolled observations.
Study design
Postmenopausal women and men aged at least 50 were enrolled within 4 weeks of pelvic fracture. Forty-eight participants were randomized to abaloparatide 80 µg subcutaneously once daily or matching placebo for 12 weeks. Mean age was 82 years; 93% were women, 98% had multiple pubic ramus fractures, 67% had an associated sacral fracture, and 36% had at least one displaced fracture.
The primary outcome was healing at 3 months, assessed by two radiologists using cortical bridging on CT. Pain and physical performance were also measured, including the Short Physical Performance Battery (SPPB) and Timed Up and Go (TUG).
The planned sample was 78, but recruitment stopped at 48 when funding ended. Three participants allocated to abaloparatide did not begin treatment and were excluded from analyses. CT at 3 months was available for 40 patients.
Main results
- The distribution of CT cortical bridging scores did not differ significantly at 3 months (P = 0.15).
- In the patient-level healed/not-healed analysis, 39% of the abaloparatide group and 64% of the placebo group met the healing criterion: RR 0.61 (95% CI 0.33–1.12).
- Among 81 individual fractures, healing rates were 47% and 53%, respectively: RR 0.88 (95% CI 0.55–1.40).
- Changes in pain did not differ between groups.
- SPPB and TUG improved over time in both groups, without an advantage for abaloparatide.
Bone turnover markers increased with abaloparatide, demonstrating a biochemical response. The absence of clinical benefit therefore did not reflect a complete lack of pharmacodynamic activity.
Clinical interpretation for an orthopaedic surgeon
The trial does not support prescribing abaloparatide solely to accelerate healing of a recent pelvic fracture. In this population and regimen, no radiographic, functional or analgesic benefit emerged during the first 3 months. This question is separate from treating osteoporosis and preventing subsequent fractures; the trial does not challenge abaloparatide’s established role in osteoporosis treatment for appropriately selected patients.
Limitations and disclosures
- The trial randomized 48 rather than the planned 78 patients; the authors reported a reduction in statistical power to approximately 75%.
- The population was highly specific: mean age 82 years, 93% women and all participants White, limiting generalisability.
- Healing was principally assessed at one time point, 3 months.
- Treatment began approximately 3 weeks after fracture on average, so the study does not address very early initiation.
- Three participants assigned to abaloparatide did not start treatment and were excluded from analyses.
Radius Pharmaceuticals supplied the drug and placebo. According to the publication, the company did not participate in trial conduct, interpretation or manuscript preparation. Funding came primarily from the NIH. Some authors disclosed financial relationships with pharmaceutical manufacturers, including Radius.
Implications for practice
These results temper expectations for routinely using PTH receptor agonists to accelerate pelvic fracture healing. They provide no reason to start abaloparatide solely because a recent fracture might heal faster. Conversely, the numerically lower patient-level healing rate does not prove that abaloparatide impairs union: confidence intervals were wide, recruitment was insufficient, and the authors regarded the findings as exploratory. Other fracture sites and age groups were not addressed.
References
Nieves JW, Cosman F, McMahon D et al. Abaloparatide and pelvic fracture healing: a phase 2 randomized placebo-controlled trial. Osteoporosis International. Published online 20 August 2026. DOI: 10.1007/s00198-026-08176-2. PubMed: PMID 42618812.
The full text is legally available through the publisher, Springer Nature.
Related resources
For Doctors and Physiotherapists · Research Updates, Literature and Evidence-Based Medicine
Content prepared by: Tomasz Poboży - orthopaedic surgeon.