{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T00:37:20Z","timestamp":1768437440796,"version":"3.49.0"},"reference-count":30,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2021,11,24]],"date-time":"2021-11-24T00:00:00Z","timestamp":1637712000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Anneliese Pohl-Habilitationsfoerderung","award":["---"],"award-info":[{"award-number":["---"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biomolecules"],"abstract":"<jats:p>The most common spinal disorder in elderly is lumbar spinal stenosis (LSS), resulting partly from ligamentum flavum (LF) hypertrophy. Its pathophysiology is not completely understood. The present study wants to elucidate the role of estrogen receptor \u03b1 (ER \u03b1) in fibroblasts of hypertrophied LF. LF samples of 38 patients with LSS were obtained during spinal decompression. Twelve LF samples from patients with disk herniation served as controls. Hematoxylin &amp; Eosin (H&amp;E) and Elastica stains and immunohistochemistry for ER \u03b1 were performed. The proportions of fibrosis, loss and\/or degeneration of elastic fibers and proliferation of collagen fibers were assessed according to the scores of Sairyo and Okuda. Group differences in the ER \u03b1 and Sairyo and Okuda scores between patients and controls, male and female sex and absence and presence of additional orthopedic diagnoses were assessed with the Mann\u2013Whitney U test. There was a tendency towards higher expression of ER \u03b1 in LF fibroblasts in the hypertrophy group (p = 0.065). The Sairyo and Okuda scores were more severe for the hypertrophy group but, in general, not statistically relevant. There was no statistically relevant correlation between the expression of ER \u03b1 and sex (p = 0.326). ER \u03b1 expression was higher in patients with osteochondrosis but not statistically significant (p = 0.113). In patients with scoliosis, ER \u03b1 expression was significantly lower (p = 0.044). LF hypertrophy may be accompanied by a higher expression of ER \u03b1 in fibroblasts. No difference in ER \u03b1 expression was observed regarding sex. Further studies are needed to clarify the biological and clinical significance of these findings.<\/jats:p>","DOI":"10.3390\/biom11121752","type":"journal-article","created":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T04:01:28Z","timestamp":1637812888000},"page":"1752","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Expression of Estrogen Receptor Alpha and Evaluation of Histological Degeneration Scores in Fibroblasts of Hypertrophied Ligamentum Flavum: A Qualitative Study"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6812-3563","authenticated-orcid":false,"given":"Christina C.","family":"Westhoff","sequence":"first","affiliation":[{"name":"Institute of Pathology, Philipps University, and University Hospital Giessen and Marburg, 35033 Marburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christian-Dominik","family":"Peterlein","sequence":"additional","affiliation":[{"name":"Center for Orthopedics and Trauma Surgery, Philipps University, and University Hospital Giessen and Marburg, 35033 Marburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hanna","family":"Daniel","sequence":"additional","affiliation":[{"name":"Institute of Medical Biometry and Epidemiology, Philipps University, 35037 Marburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juergen R.","family":"Paletta","sequence":"additional","affiliation":[{"name":"Center for Orthopedics and Trauma Surgery, Philipps University, and University Hospital Giessen and Marburg, 35033 Marburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Roland","family":"Moll","sequence":"additional","affiliation":[{"name":"Institute of Pathology, Philipps University, and University Hospital Giessen and Marburg, 35033 Marburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Annette","family":"Ramaswamy","sequence":"additional","affiliation":[{"name":"Institute of Pathology, Philipps University, and University Hospital Giessen and Marburg, 35033 Marburg, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stefan","family":"Lakemeier","sequence":"additional","affiliation":[{"name":"Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center G\u00f6ttingen, 37075 G\u00f6ttingen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2649","DOI":"10.1097\/01.brs.0000188117.77657.ee","article-title":"Pathomechanism of ligamentum flavum hypertrophy: A multidisciplinary investigation based on clinical, biomechanical, histologic, and biologic assessments","volume":"30","author":"Sairyo","year":"2005","journal-title":"Spine"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1592","DOI":"10.1002\/jor.21431","article-title":"Hypertrophy of ligamentum flavum in lumbar spine stenosis associated with the increased expression of connective tissue growth factor","volume":"29","author":"Zhong","year":"2011","journal-title":"J. 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