Castaño-Betancourt Martha C, Rivadeneira Fernando, Bierma-Zeinstra Sita, Kerkhof Hanneke J M, Hofman Albert, Uitterlinden Andre G, van Meurs Joyce B J
Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands.
Arthritis Rheum. 2013 Mar;65(3):693-700. doi: 10.1002/art.37792.
The atrophic type of hip osteoarthritis (OA) is characterized by cartilage degradation without the formation of osteophytes. Individuals with atrophic OA have been less well studied, and it is unknown whether this OA type differs from the osteophytic types with regard to bone tissue. The purpose of this study was to examine bone mineral density (BMD), hip structural properties, and fracture risk in individuals with the atrophic type of OA as compared to those with the osteophytic types (normotrophic/hypertrophic) as well as individuals without OA.
This study is part of the Rotterdam Study, a large prospective population-based cohort study. We examined 5,006 participants who had been assessed for OA, BMD, and geometric measures at baseline and for incident nonvertebral osteoporotic fractures (mean followup 9.6 years). We estimated the differences in bone characteristics between the OA groups and the controls (no joint space narrowing or osteophytes). Cox proportional hazards regression was used to calculate osteoporotic fracture risk.
Participants with atrophic OA had systemically lower BMD as compared to those with normotrophic OA and as compared to the controls (6.5% and 9% for total body BMD; 4% and 5% for skull BMD, respectively). Participants with osteophytic OA had ∼4% and ∼5% higher total body and skull BMD, respectively, a wider femoral neck, and greater bone strength (12% and 5% higher section modulus, respectively) as compared to the controls or to those with atrophic OA. The risk of osteoporotic fractures was almost 50% higher in those with atrophic OA as compared to the controls (hazard risk 1.48, P = 0.008). This difference was not explained by differences in the BMD, number of falls, degree of disability, or use of corticosteroids.
Individuals with atrophic hip OA have an increased risk of osteoporotic fractures that is not fully explained by systemically lower BMD as compared to controls.
萎缩型髋骨关节炎（OA）的特征是软骨退化且无骨赘形成。对萎缩型OA患者的研究较少，尚不清楚这种OA类型在骨组织方面是否与有骨赘的类型有所不同。本研究的目的是比较萎缩型OA患者与有骨赘的类型（正常营养型/肥大性）患者以及无OA的个体之间的骨密度（BMD）、髋部结构特性和骨折风险。
本研究是鹿特丹研究的一部分，这是一项基于人群的大型前瞻性队列研究。我们检查了5006名参与者，他们在基线时接受了OA、BMD和几何测量评估，并对非椎体骨质疏松性骨折的发生情况进行了随访（平均随访9.6年）。我们估计了OA组与对照组（无关节间隙变窄或骨赘）之间骨特征的差异。采用Cox比例风险回归计算骨质疏松性骨折风险。
与正常营养型OA患者和对照组相比，萎缩型OA患者的全身BMD系统性降低（全身BMD分别降低6.5%和9%；颅骨BMD分别降低4%和5%）。与对照组或萎缩型OA患者相比，有骨赘的OA患者的全身和颅骨BMD分别高出约4%和5%，股骨颈更宽，骨强度更大（截面模量分别高出12%和5%）。与对照组相比，萎缩型OA患者发生骨质疏松性骨折的风险高出近50%（风险比1.48，P = 0.008）。这种差异不能用BMD、跌倒次数、残疾程度或使用皮质类固醇的差异来解释。
与对照组相比，萎缩型髋OA患者发生骨质疏松性骨折的风险增加，而全身BMD降低并不能完全解释这一现象。
