Lacey Rosie J, Thomas Elaine, Duncan Rachel C, Peat George
Primary Care Musculoskeletal Research Centre, Keele University, Keele, Staffordshire ST5 5BG, UK.
BMC Musculoskelet Disord. 2008 Jun 11;9:82. doi: 10.1186/1471-2474-9-82.
A recent study of adults aged >or=50 years reporting knee pain found an excess of radiographic knee osteoarthritis (knee ROA) in symptomatic males compared to females. This was independent of age, BMI and other clinical signs and symptoms. Since this finding contradicts many previous studies, our objective was to explore four possible explanations for this gender difference: X-ray views, selection, occupation and non-articular conditions.
A community-based prospective study. 819 adults aged >or=50 years reporting knee pain in the previous 12 months were recruited by postal questionnaires to a research clinic involving plain radiography (weight-bearing posteroanterior semiflexed, supine skyline and lateral views), clinical interview and physical examination. Any knee ROA, ROA severity, tibiofemoral joint osteoarthritis (TJOA) and patellofemoral joint osteoarthritis (PJOA) were defined using all three radiographic views. Occupational class was derived from current or last job title. Proportions of each gender with symptomatic knee ROA were expressed as percentages, stratified by age; differences between genders were expressed as percentage differences with 95% confidence intervals.
745 symptomatic participants were eligible and had complete X-ray data. Males had a higher occurrence (77%) of any knee ROA than females (61%). In 50-64 year olds, the excess in men was mild knee OA (particularly PJOA); in >or=65 year olds, the excess was both mild and moderate/severe knee OA (particularly combined TJOA/PJOA). This male excess persisted when using the posteroanterior view only (64% vs. 52%). The lowest level of participation in the clinic was symptomatic females aged 65+. Within each occupational class there were more males with symptomatic knee ROA than females. In those aged 50-64 years, non-articular conditions were equally common in both genders although, in those aged 65+, they occurred more frequently in symptomatic females (41%) than males (31%).
The excess of knee ROA among symptomatic males in this study seems unlikely to be attributable to the use of comprehensive X-ray views. Although prior occupational exposures and the presence of non-articular conditions cannot be fully excluded, selective non-participation bias seems the most likely explanation. This has implications for future study design.
最近一项针对年龄≥50岁且报告有膝关节疼痛的成年人的研究发现，有症状的男性与女性相比，膝关节影像学骨关节炎（膝关节ROA）更多。这与年龄、体重指数及其他临床体征和症状无关。由于这一发现与许多先前的研究相矛盾，我们的目标是探究造成这种性别差异的四种可能原因：X线视图、选择因素、职业和非关节疾病。
一项基于社区的前瞻性研究。通过邮寄问卷招募了819名年龄≥50岁且在过去12个月内报告有膝关节疼痛的成年人，让他们到一家研究诊所，接受普通X线摄影（负重后前半屈曲位、仰卧天际线位和侧位）、临床访谈及体格检查。使用所有三种X线视图来定义任何膝关节ROA、ROA严重程度、胫股关节骨关节炎（TJOA）和髌股关节骨关节炎（PJOA）。职业类别根据当前或最后工作职位确定。有症状的膝关节ROA的各性别比例以百分比表示，并按年龄分层；性别差异以百分比差异及95%置信区间表示。
745名有症状的参与者符合条件并拥有完整的X线数据。男性中任何膝关节ROA的发生率（77%）高于女性（61%）。在50 - 64岁人群中，男性多出的是轻度膝关节骨关节炎（尤其是PJOA）；在年龄≥65岁人群中，多出的是轻度和中度/重度膝关节骨关节炎（尤其是合并的TJOA/PJOA）。仅使用后前位视图时，男性多出的情况依然存在（64%对52%）。诊所中参与度最低的是65岁及以上有症状的女性。在每个职业类别中，有症状的膝关节ROA的男性比女性更多。在50 - 64岁人群中，非关节疾病在两性中同样常见，不过，在65岁及以上人群中，其在有症状的女性（41%）中比男性（31%）中更频繁出现。
本研究中有症状男性中膝关节ROA较多，似乎不太可能归因于使用了全面的X线视图。虽然不能完全排除既往职业暴露和非关节疾病的存在，但选择性不参与偏倚似乎是最有可能的解释。这对未来的研究设计有影响。
