Background Cam morphology, a distinct bony morphology of the hip, is prevalent in many athletes, and a risk factor for hip-related pain and osteoarthritis. Secondary cam morphology, due to existing or previous hip disease (eg, Legg-Calve-Perthes disease), is well-described. Cam morphology not clearly associated with a disease is a challenging concept for clinicians, scientists and patients. We propose this morphology, which likely develops during skeletal maturation as a physiological response to load, should be referred to as primary cam morphology. The aim of this study was to introduce and clarify the concept of primary cam morphology. Design We conducted a concept analysis of primary cam morphology using articles that reported risk factors associated with primary cam morphology; we excluded articles on secondary cam morphology. The concept analysis method is a rigorous eight-step process designed to clarify complex ‘concepts’; the end product is a precise definition that supports the theoretical basis of the chosen concept. Results We propose five defining attributes of primary cam morphology—tissue type, size, site, shape and ownership—in a new conceptual and operational definition. Primary cam morphology is a cartilage or bony prominence (bump) of varying size at the femoral head-neck junction, which changes the shape of the femoral head from spherical to aspherical. It often occurs in asymptomatic male athletes in both hips. The cartilage or bone alpha angle (calculated from radiographs, CT or MRI) is the most common method to measure cam morphology. We found inconsistent reporting of primary cam morphology taxonomy, terminology, and how the morphology is operationalised. Conclusion We introduce and clarify primary cam morphology, and propose a new conceptual and operational definition. Several elements of the concept of primary cam morphology remain unclear and contested. Experts need to agree on the new taxonomy, terminology and definition that better reflect the primary cam morphology landscape—a bog-standard bump in most athletic hips, and a possible hip disease burden in a selected few. All data relevant to the study are included in the article or uploaded as supplementary information.

中文翻译：

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初级凸轮形态；颠簸、负担还是沼泽标准？概念分析

背景 Cam 形态是髋关节的一种独特骨形态，在许多运动员中很普遍，并且是髋关节相关疼痛和骨关节炎的危险因素。由于现有或以前的髋关节疾病（例如，Legg-Calve-Perthes 病），继发性凸轮形态得到了很好的描述。与疾病没有明确关联的凸轮形态对临床医生、科学家和患者来说是一个具有挑战性的概念。我们建议这种形态可能在骨骼成熟过程中作为对负荷的生理反应而发展，应称为初级凸轮形态。本研究的目的是介绍和阐明初级凸轮形态的概念。设计 我们使用报告与主要凸轮形态相关的风险因素的文章对主要凸轮形态进行了概念分析；我们排除了关于二次凸轮形态的文章。概念分析方法是一个严格的八步过程，旨在阐明复杂的“概念”；最终产品是支持所选概念的理论基础的精确定义。结果 我们在新的概念和操作定义中提出了主要凸轮形态的五个定义属性——组织类型、大小、部位、形状和所有权。主要凸轮形态是股骨头颈交界处大小不一的软骨或骨突起（隆起），它将股骨头的形状从球形变为非球形。它通常发生在双髋无症状的男性运动员身上。软骨或骨 α 角（根据 X 光片、CT 或 MRI 计算）是测量凸轮形态的最常用方法。我们发现主要凸轮形态分类法、术语、以及形态是如何操作的。结论 我们介绍并阐明了主要凸轮形态，并提出了新的概念和操作定义。主要凸轮形态概念的几个要素仍然不清楚和有争议。专家们需要就新的分类法、术语和定义达成一致，以更好地反映主要的凸轮形态景观——大多数运动臀部的沼泽标准凸起，以及选定的少数髋部疾病负担。与研究相关的所有数据都包含在文章中或作为补充信息上传。更好地反映主要凸轮形态景观的术语和定义——大多数运动臀部的沼泽标准颠簸，以及选定的少数髋关节疾病负担。与研究相关的所有数据都包含在文章中或作为补充信息上传。更好地反映主要凸轮形态景观的术语和定义——大多数运动臀部的沼泽标准颠簸，以及选定的少数髋关节疾病负担。与研究相关的所有数据都包含在文章中或作为补充信息上传。