Evidence map›Paper›PMID 40858317›Full record

ArticleAsian spine journal2026

Gender-specific patterns of external occipital protuberance hyperplasia: associations with nuchal ligament ossification and cervical sagittal imbalance in myelopathy patients.

Zhaoyang Gong, Hanqiu Sun, Dachuan Li, Xiao Lu, Siyang Liu, Ximeng Wang, Xinlei Xia, Feizhou Lyu, Jianyuan Jiang, Fei Zou and 2 more

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Article in Asian spine journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

Authors and funding

12 authors.

Zhaoyang GongDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Hanqiu SunDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Dachuan LiDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Xiao LuDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Siyang LiuDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Ximeng WangDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Xinlei XiaDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Feizhou LyuDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Jianyuan JiangDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Fei ZouDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Hongli WangDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.
Xiaosheng MaDepartment of Orthopaedics, Huashan Hospital, Fudan University, Shanghai, China.

Funding

National Key Research and Development Program of China 2022YFC2407203
6 · The paper itself

Abstract

STUDY

designRetrospective cross-sectional analysis of 187 consecutive patients undergoing surgical treatment for cervical spondylotic myelopathy (CSM). PURPOSE: To investigate sexual dimorphism in external occipital protuberance (EOP) hyperplasia morphology and elucidate its clinical correlation with ossification of the nuchal ligament (ONL) and cervical sagittal imbalance. OVERVIEW OF LITERATURE: Emerging evidence implicates EOP hyperplasia as potential biomarker of chronic neck strain, yet its relationship with ONL and cervical sagittal imbalance remains underexplored in surgical CSM cohorts.

methodsCervical radiographs were analyzed. EOP hyperplasia was classified into three subtypes with standardized length measurements. Variables encompassed demographics, ONL-related indices, and sagittal parameters. Subtype comparisons and multivariate regression analyses (with EOP length as dependent variable) were conducted.

resultsAnalysis of 187 CSM patients (64.2% male) identified gender-specific patterns: males exhibited greater EOP length (9.4±6.8 mm vs. 4.6±3.4 mm, p<0.001). Type III EOP demonstrated male predominance (82.4% vs. type I 31.8%, type II 51.4%; p<0.001), with associated longer hyperplasia length (11.6±6.6 mm vs. type II 5.1±1.9 mm, p<0.001). Type III EOP was associated with higher ONL prevalence (type III 64.8% vs. type I 45.5%, type II 41.9%; p=0.010) and longer ONL osteophyte length (type III 18.8±9.8 mm vs. type I 14.2±8.1 mm, type II 14.2±9.4 mm; p=0.046). Multivariate regression confirmed male sex (β=-3.82, p=0.009), ONL osteophyte length (β=0.16, p=0.017), T1 slope (β=0.27, p=0.041), and spino-cranial angle (β=-0.19, p=0.009) as factors independently associated with EOP length (adjusted R²=0.382).

conclusionsSevere EOP hyperplasia exhibits a male-predominant distribution pattern and demonstrates significant radiological associations with ONL and cervical sagittal imbalance in CSM patients. These findings advocate for EOP evaluation in clinical evaluations to identify high-risk biomechanical profiles.

Indexed as

Cervical sagittal imbalanceCervical spondylotic myelopathyExternal occipital protuberance hyperplasiaOssification of the nuchal ligamentSex characteristics

Identifiers

PMID40858317
PMCPMC12960429

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