Przejdź do treściPolish version: Kołnierz trzpienia a ryzyko złamania okołoprotezowego po bezcementowej endoprotezie biodra
An analysis of the Swiss National Joint Registry, published in The Journal of Arthroplasty on 24 August 2026, examined periprosthetic fracture risk after uncemented hip arthroplasty in older women. Its most notable finding concerned the presence of a stem collar.
Why this study matters
Uncemented stems are widely used in older women, a group in whom periprosthetic femoral fracture is a particular concern. The relevant question is therefore not only whether to use cemented or uncemented fixation, but whether a specific stem design feature affects the safety of uncemented implantation.
Study design
The authors analysed Swiss National Joint Registry (SIRIS) data from 2012–2024 for women aged at least 70 undergoing total hip arthroplasty (THA) for osteoarthritis. Nine uncemented stem models, each with more than 1,000 implantations, were included. The cohort comprised 32,874 women, with a mean age of 76 years and mean BMI of 26.5.
Design variables included collared versus collarless stems, standard versus increased offset, neck–shaft angle and relative stem length. The endpoint was revision for periprosthetic femoral fracture (PFF). THAs with cemented stem fixation provided an additional reference population. Multivariable analysis adjusted for patient and implant characteristics.
Main results
- Revision for PFF: 0.5% after uncemented THA versus 0.2% with cemented fixation (P < 0.001).
- Variation between uncemented models: revision for PFF ranged from 0.1% to 1.1%.
- Collared stems: 0.1% underwent revision for PFF, compared with 0.6% of collarless stems.
- Adjusted odds ratio for a collared stem: OR 0.08 (95% CI 0.03–0.27; P < 0.001).
- Offset, neck–shaft angle and relative stem length were not associated with PFF risk in this analysis.
Clinical interpretation for an orthopaedic surgeon
Among women aged ≥70 receiving uncemented THA, a stem collar was strongly associated with a lower risk of revision for PFF. The absolute difference was small, but relevant given the severity of this complication and the substantial revision surgery it often requires.
The crude comparison still favoured cemented fixation over uncemented fixation for this endpoint. The study mainly helps inform stem selection when uncemented fixation has been chosen for an older woman.
Limitations
- This registry study was observational, so it cannot establish causation.
- Residual confounding may involve bone quality, surgical technique, implant selection and patient selection.
- The endpoint was revision for PFF, rather than every periprosthetic fracture.
- The results concern women aged ≥70 treated for osteoarthritis and should not automatically be extrapolated to younger patients, men or other indications.
- The analysis included specific models in the Swiss registry; a collar is not the only difference between implants on the market.
Implications for practice
The findings encourage caution when choosing a collarless uncemented stem for an older woman and support considering a collared design if uncemented fixation is selected. They do not prove that a collared stem is superior to a cemented stem or that a collar eliminates fracture risk. Other outcomes, including aseptic loosening, patient-reported outcomes and long-term implant survival, remain unresolved.
References
Ladurner A, Kramer M, Giesinger K, Zdravkovic V. Collared, Uncemented Stems Markedly Reduce Periprosthetic Femoral Fracture Risk in Women ≥ 70 Years: A Swiss National Registry Study. The Journal of Arthroplasty. Published online 24 August 2026. DOI: 10.1016/j.arth.2026.08.037. PMID: 42637028. Article in The Journal of Arthroplasty.
This summary is based on the publicly available abstract and metadata from PubMed and the publisher.
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Content prepared by: Tomasz Poboży - orthopaedic surgeon.