{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T14:26:53Z","timestamp":1786112813768,"version":"build-2736575974"},"reference-count":14,"publisher":"MJS Publishing, Medical Journals Sweden AB","license":[{"start":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:00:00Z","timestamp":1785888000000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["ActaO"],"abstract":"<jats:p>Background and purpose:\u00a0We aimed to compare the effect of 2 femoral stem designs on periprosthetic bone mineral density (BMD) after total hip arthroplasty in a randomized controlled trial. We hypothesized that a short collum-fixated stem (Primoris) would better preserve proximal BMD than a conventional metaphyseal-fixated and diaphyseal engaging stem (Echo).Methods:\u00a061 patients with primary osteoarthritis were randomized to receive either the Primoris (n = 31) or Echo (n = 30) uncemented femoral stem. DXA scans were performed preoperatively, at 6 weeks, 12 months, and 24 months. The prespecified primary outcome was periprosthetic BMD at 24 months and patient-reported outcomes (EQ-5D, Oxford Hip Score, FJS-12) were collected preoperatively, and at each follow-up were secondary.Results:\u00a0At 24 months, model-based estimates showed significantly higher BMD in the Primoris group than in the Echo group in Gruen zones 3 (mean difference 0.40 g\/cm\u00b2, 95% confidence interval [CI] 0.26\u20130.53; P &lt; 0.001), 5 (0.20 g\/cm\u00b2, CI 0.07\u20130.33; P = 0.003), and 7 (0.27 g\/cm\u00b2, CI 0.14\u20130.41; P &lt; 0.001). These differences corresponded to relative differences of +19.1%, +9.1%, and +14.3%, respectively, compared with the Echo group. In addition, the increase in BMD from 6 weeks to 24 months was significantly greater in the Primoris group in Gruen zone 7 (mean difference in change 0.18 g\/cm\u00b2, CI 0.04\u20130.32; P = 0.01). PROMs improved similarly in both groups, with no statistically significant between-group differences.Conclusion:\u00a0At 2 years, the collum-fixated Primoris stem preserved more proximal femoral bone than the Echo stem, while PROMs were comparable between groups. The observed preservation of proximal bone stock may be advantageous for long-term bone maintenance and future revision surgery.<\/jats:p>","DOI":"10.2340\/17453674.2026.46481","type":"journal-article","created":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T16:04:58Z","timestamp":1785945898000},"source":"Crossref","is-referenced-by-count":0,"title":["Preservation of periprosthetic bone with a collum-fixated short stem versus conventional metaphyseal-fixated stems in total hip arthroplasty: a randomized controlled trial with 2-year follow-up in 61 patients"],"prefix":"10.2340","volume":"97","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-3416-2054","authenticated-orcid":false,"given":"Anders","family":"Tj\u00f8nneland","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0337-3078","authenticated-orcid":false,"given":"Janus D","family":"Christiansen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Jakobsen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Poul T","family":"Nielsen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1183","published-online":{"date-parts":[[2026,8,5]]},"reference":[{"key":"164918","doi-asserted-by":"crossref","unstructured":"Learmonth I D, Young C, Rorabeck C. The operation of the century: total hip replacement. Lancet 2007; 370(9597): 1508-19. doi: 10.1016\/S0140-6736(07)60457-7.","DOI":"10.1016\/S0140-6736(07)60457-7"},{"key":"164919","doi-asserted-by":"crossref","unstructured":"Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am 2007; 89(4): 780-5. doi: 10.2106\/JBJS.F.00222.","DOI":"10.2106\/JBJS.F.00222"},{"key":"164920","doi-asserted-by":"crossref","unstructured":"Engh C A, Bobyn J D, Glassman A H. Porous-coated hip replacement. The factors governing bone ingrowth, stress shielding, and clinical results. J Bone Joint Surg Br 1987; 69(1): 45-55. doi: 10.1007\/978-1-4471-5451-8_12.","DOI":"10.1302\/0301-620X.69B1.3818732"},{"key":"164921","doi-asserted-by":"crossref","unstructured":"Sheth N P, Nelson C L, Paprosky W G. Femoral bone loss in revision total hip arthroplasty: evaluation and management. J Am Acad Orthop Surg 2013; 21(10): 601-12. doi: 10.5435\/JAAOS-21-10-601.","DOI":"10.5435\/JAAOS-21-10-601"},{"key":"164922","doi-asserted-by":"crossref","unstructured":"Rasmussen MB, El-Galaly A, Daugberg L, Nielsen P T, Jakobsen T. Projection of primary and revision hip arthroplasty surgery in Denmark from 2020 to 2050. Acta Orthop 2022; 93(1): 849-53. doi: 10.2340\/17453674.2022.5255.","DOI":"10.2340\/17453674.2022.5255"},{"key":"164923","doi-asserted-by":"crossref","unstructured":"Stulberg S D, Patel R M. The short stem: promises and pitfalls. Bone Joint J 2013; 95-B(11): 57-62. doi: 10.1302\/0301-620X.95B11.32936.","DOI":"10.1302\/0301-620X.95B11.32936"},{"key":"164924","doi-asserted-by":"crossref","unstructured":"Tj\u00f8nneland A, Nielsen P T, Jakobsen T. Biomechanics of a collum-fixated short stem in total hip arthroplasty. J Orthop 2024; 52: 61-6.doi: 10.1016\/j.jor.2024.02.027.","DOI":"10.1016\/j.jor.2024.02.027"},{"key":"164925","doi-asserted-by":"crossref","unstructured":"Nielsen M P, Christensen J D, Jakobsen T, Nielsen P T. An ultra-short stemless femoral hip prosthesis. J Bone Joint Surg 2025; 107(14): 1590-7. doi: 10.2106\/JBJS.24.00844.","DOI":"10.2106\/JBJS.24.00844"},{"key":"164926","doi-asserted-by":"crossref","unstructured":"Christiansen J D, Laursen M, Blunn G W, Nielsen P T. Stable fixation of an ultra-short femoral neck-preserving hip prosthesis: a 5-year RSA, DXA, and clinical prospective outcome study of 48 patients. Acta Orthop 2024; 95: 138-46. doi: 10.2340\/17453674.2024.40074.","DOI":"10.2340\/17453674.2024.40074"},{"key":"164927","doi-asserted-by":"crossref","unstructured":"Salemyr M, Muren O, Ahl T, Bod\u00e9n H, Eisler T, Stark A, et al. Lower periprosthetic bone loss and good fixation of an ultra-short stem compared to a conventional stem in uncemented total hip arthroplasty. Acta Orthop 2015; 86(6): 659-66. doi: 10.3109\/17453674.2015.1067087.","DOI":"10.3109\/17453674.2015.1067087"},{"key":"164928","doi-asserted-by":"crossref","unstructured":"Kold S, Rahbek O, Vestermark M, Overgaard S, S\u00f8balle K. Bone compaction enhances fixation of weightbearing titanium implants. Clin Orthop Relat Res 2005; 431(431): 138-44. doi: 10.1097\/01.blo.0000150461.69142.f3.","DOI":"10.1097\/01.blo.0000150461.69142.f3"},{"key":"164929","doi-asserted-by":"crossref","unstructured":"Christiansen J D, Ejaz A, Nielsen P T, Laursen M. An ultra-short femoral neck-preserving hip prosthesis: a 2-year follow-up study with radiostereometric analysis and dual X-ray absorptiometry in a stepwise introduction. J Bone Joint Surg Am 2020; 102(2): 128-36. doi: 10.2106\/JBJS.19.00104.","DOI":"10.2106\/JBJS.19.00104"},{"key":"164930","doi-asserted-by":"crossref","unstructured":"Khanuja H S, Banerjee S, Jain D, Pivec R, Mont M A. Short bone-conserving stems in cementless hip arthroplasty. J Bone Joint Surg Am 2014; 96(20): 1742-52. doi: 10.2106\/JBJS.M.00780.","DOI":"10.2106\/JBJS.M.00780"},{"key":"164931","doi-asserted-by":"crossref","unstructured":"Rosenthall L, Bobyn J D, Brooks C E. Temporal changes of periprosthetic bone density in patients with a modular noncemented femoral prosthesis. 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