Romosozumab Enhances Implant Stability in Glucocorticoid-Induced Osteoporotic Bone - A Rabbit Model Study

Sep 30, 2026

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Implant fixation in osteoporotic bone is difficult because reduced bone mass and impaired microarchitecture undermine screw stability. This rabbit model study evaluated whether romosozumab, a sclerostin inhibitor, improves osseointegration and mechanical stability of cancellous bone screws under glucocorticoid-induced osteoporosis. Fifty-five rabbits received glucocorticoid-based osteoporosis induction and were treated across control, osteoporosis, PTH, PTH plus denosumab, and romosozumab groups, followed by histomorphometry and biomechanical pull-out testing to assess fixation performance.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages11

Reading Time28 min

AccessFree to download

Objective

Methods

Results

Conclusion

Introduction

Background on osteoporosis and implant stability

Rationale for romosozumab and glucocorticoid effects

Neurospine 2025;22(4):880-890. [https://doi.org/10.14245/ns.2550774.387](https://doi.org/10.14245/ns.2550774.387) Neurospine pISSN 2586-6583 eISSN 2586-6591 Original Article Corresponding Author Byung Ho Lee [https://orcid.org/0000-0001-7235-4981](https://orcid.org/0000-0001-7235-4981) Department of Orthopedic Surgery, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea [Email: bhlee96@yuhs.ac](Email: bhlee96@yuhs.ac) Received: May 29, 2025 Revised: July 16, 2025 Accepted: July 26, 2025 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ([https://creativecom](https://creativecom)[mons.org/licenses/by-nc/4.0/](mons.org/licenses/by-nc/4.0/)) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © 2025 by the Korean Spinal Neurosurgery Society Romosozumab Enhances Implant Stability in Glucocorticoid-Induced Osteoporotic Bone: A Rabbit Model Study Ji-Won Kwon, Seong-Hwan Moon, Kyung-Soo Suk, Si Young Park, Hak-Sun Kim, Sub-Ri Park, Namhoo Kim, Byung Ho Lee Department of Orthopedic Surgery, Yonsei University College of Medicine, Seoul, Korea Objective: Implant fixation in osteoporotic bone presents substantial challenges due to reduced bone mass and compromised microarchitecture. This study investigated whether romosozumab, a sclerostin inhibitor, improves osseointegration and mechanical stability of cancellous bone screws in glucocorticoid-induced osteoporosis . Methods: Fifty-five New Zealand white rabbits were enrolled. Osteoporosis was induced via either bilateral ovariectomy or weekly intramuscular glucocorticoid injections (4–8 mg/kg) . Based on bone mineral density results, glucocorticoid injection was selected for experimental induction . Rabbits were divided into 5 groups: control, untreated osteoporosis, parathyroid hormone (PTH), PTH combined with denosumab, and romosozumab. Cancellous bone screws (4.0-mm diameter, titanium alloy) were bilaterally inserted into the iliac bones . Antiosteoporosis treatments were administered for 3-week postimplantation . Histomorphometric evaluation of bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) was performed using nondecalcified sectioning and Goldner trichrome staining. Biomechanical pull-out testing measured resistance at 1-mm displacement using a standardized setup on the MTS system . Results: The romosozumab-treated group exhibited superior outcomes. BIC reached 21.2% ± 18.1%, and BAFO was 56.9% ± 9.9%. Pull-out strength significantly increased to 275 ± 55 Nin the romosozumab group, outperforming PTH (184 ± 61 N), PTH+denosumab (202 ± 23 N), and untreated osteoporosis (120 ± 33 N) . Enhanced collagen structure and neobone formation were observed histologically around implants. Conclusion: Romosozumab significantly enhances cancellous bone screw fixation strength and osseointegration in glucocorticoid-induced osteoporotic bone . These findings suggest its clinical potential as an adjuvant therapy in improving spinal implant outcomes in osteoporotic patients. Keywords: Glucocorticoid, Implant, Osteoporosis, Romosozumab, Rabbit INTRODUCTION Osteoporosis, a systemic skeletal disorder, leads to a gradual reduction in bone density and quantity. Primary osteoporosis, the major form including postmenopausal and age-related osteoporosis, is a worldwide public health issue.1 The methods used to treat osteoporosis have greatly expanded, enabling clinicians to provide patients with individualized treatment plans.2-5 However, stronger therapy regimens may be essential for individuals with extremely low bone mineral density (BMD) and a new therapeutic objective is to develop osteoporosis medicines that raise BMD T-scores to > 2.5 within 5 years. Successful spine surgery implant treatment relies on achieving optimal primary stabil

FAQs

What problem does the study address in osteoporotic bone implants?

Osteoporotic bone has reduced mass and compromised microarchitecture, which limits primary stability and increases the risk of implant failure.

How was osteoporosis induced in the rabbit model?

Osteoporosis was induced using either bilateral ovariectomy or weekly intramuscular glucocorticoid injections, with glucocorticoid injection selected based on bone mineral density results.

What outcomes were used to evaluate implant performance?

Bone-to-implant contact and bone area fraction occupancy were assessed by histomorphometry, and mechanical pull-out strength was measured at 1-mm displacement.

Sep 30, 2026

Uploaded by Pentious