Mitani Sugao, Shimizu Masato, Abo Masahiro, Hagino Hiroshi, Kurozawa Youichi
Division of Health Administration and Promotion, University of Tottori, 86 Nishimachi Yonago, Tottori, 683-8503, Japan.
J Orthop Sci. 2010 Mar;15(2):192-7. doi: 10.1007/s00776-009-1440-x. Epub 2010 Apr 1.
Hip fractures following falls by the elderly, which increase with age, are increasing in number annually. The incidence of refracture (second hip fractures) has been reported to be 5%-10% in Japan and is expected to increase with the aging of the population in the future. Therefore, through a retrospective cohort study, we attempted to clarify the risk factors associated with second hip fractures.
A total of 400 patients were consecutively treated for hip fracture at a single orthopedic hospital between January 2001 and December 2007. We excluded 16 subjects: 11 patients who died within a year after a hip fracture and 5 who were <50 years of age. The remaining 384 patients, consisting of 64 men and 320 women, were chosen as the study subjects. The mean age of the subjects at the time of the initial fracture was 83.1 +/- 9.0 years (range 51-102 years). Age, sex, interval between the two fractures, body mass index (BMI), length of bed-rest periods and of rehabilitation periods, living place after an initial fracture, and complicating diseases were determined from medical records. Furthermore, effectors of second hip fractures were extracted using the Cox proportional hazard model.
In all, 384 patients were observed for 1140.0 person-years (mean: 3.0 +/- 1.4 years per patient) following the initial hip fracture. During the observation period, 49 second hip fractures were identified, giving an overall incidence of 0.043 per person-year. The second fracture occurred within 3 years in 85.7% (42 patients). Dementia and respiratory disease were recognized as being significantly related to refracture. Using a Cox proportional hazard model, dementia showed a significant influence, with the hazard ratio (HR) 1.87 [95% confidence interval (CI) 1.02-3.41; P = 0.042]. Respiratory diseases also were associated with second hip fracture (HR 4.41, 95% CI 2.33-8.34; P < 0.001).
In this study, 85.7% of refractures occurred within 3 years of the first fracture, with dementia and respiratory disease being the complicating factors that influenced refracture.
老年人跌倒后发生的髋部骨折随年龄增长而增加，且每年的数量都在上升。据报道，日本再次骨折（第二次髋部骨折）的发生率为5%-10%，预计未来随着人口老龄化还会上升。因此，我们通过一项回顾性队列研究，试图阐明与第二次髋部骨折相关的危险因素。
2001年1月至2007年12月期间，一家骨科医院连续收治了400例髋部骨折患者。我们排除了16名受试者：11例在髋部骨折后一年内死亡的患者和5名年龄小于50岁的患者。其余384例患者，包括64名男性和320名女性，被选为研究对象。初次骨折时受试者的平均年龄为83.1±9.0岁（范围51-102岁）。从病历中确定年龄、性别、两次骨折之间的间隔、体重指数（BMI）、卧床休息时间和康复时间、初次骨折后的居住地点以及并发疾病。此外，使用Cox比例风险模型提取第二次髋部骨折的影响因素。
总共对384例患者在初次髋部骨折后进行了1140.0人年的观察（平均：每位患者3.0±1.4年）。在观察期内，发现49例第二次髋部骨折，总体发生率为每人年0.043。85.7%（42例患者）的第二次骨折发生在3年内。痴呆和呼吸系统疾病被认为与再次骨折显著相关。使用Cox比例风险模型，痴呆显示出显著影响，风险比（HR）为1.87[95%置信区间（CI）1.02-3.41；P = 0.042]。呼吸系统疾病也与第二次髋部骨折有关（HR 4.41，95%CI 2.33-8.34；P < 0.001）。
在本研究中，85.7%的再次骨折发生在第一次骨折后的3年内，痴呆和呼吸系统疾病是影响再次骨折的并发因素。
