BACKGROUND While a large volume of literature has focused on risk factors for anterior shoulder instability, the rates of recurrence are inconsistent and require additional population-based epidemiologic data. PURPOSE/HYPOTHESIS The purpose was to report the effect of patient age on the number of instability events before physician consultation, rate of surgical stabilization, recurrent instability, and progression to osteoarthritis in patients <40 years old with anterior shoulder instability, utilizing an established US geographic population. We hypothesized that younger patients would be more likely to experience multiple episodes of instability before evaluation, undergo surgery, and experience recurrent instability after surgical intervention. STUDY DESIGN Descriptive epidemiologic study. METHODS An established geographic database of more than 500,000 patients was used to identify patients <40 years of age with anterior shoulder instability between 1994 and 2016. Medical records were reviewed to obtain patient characteristics, history, imaging, surgical details, and outcomes. Patients were divided into 5 groups based on age (≤15, 16-20, 21-25, 26-30, and 31-40 years) at initial instability. Comparative analysis was performed to identify differences between groups. RESULTS The study population consisted of 654 patients with a mean follow-up of 11.1 years (range, 2.0-25.2 years). This resulted in 118 patients (18%) ≤15 years of age at initial instability; 250 (38%), 16 to 20 years; 110 (17%), 21 to 25 years; 80 (12%), 26 to 30 years; and 96 (15%), 31 to 40 years. Of patients ≤15 years old at initial instability 47% had 3+ instability events, compared with 12% of patients aged 31 to 40 years (P < .001). At 10 years of follow-up, patients ≤15 and 16 to 20 years old demonstrated the highest recurrent instability rates of 38.8% and 47.1% after nonoperative management, respectively. Patients 16 to 20 years old demonstrated the highest rates of both surgical intervention (40.4%) and recurrence after surgery (24.8%). Patients 31 to 40 years of age were significantly more likely to develop clinically symptomatic osteoarthritis (15.6%) than all other age groups. CONCLUSION In a US epidemiologic population of patients <40 years old, the rate of recurrent anterior shoulder instability was roughly one-third after initial physician consultation. Younger patients, particularly those ≤15 and 16 to 20 years of age, were more likely to have experienced multiple instability events at the time of initial evaluation, require surgery, and experience recurrent instability compared with older patients. For every year of decrease in age at initial instability, the risk of recurrent instability or surgical intervention after physician consultation increased by 4.1% and 2.8%, respectively.

中文翻译：

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一种基于年龄的40岁以下患者前肩不稳的方法：美国人群的分析。

背景技术虽然大量文献集中在肩部前部不稳定的危险因素上，但复发率并不一致，需要更多的基于人群的流行病学数据。目的/假设目的是利用已建立的美国方法，在医师咨询之前报告患者年龄对不稳定事件数量，手术稳定率，复发性不稳定以及进展为骨关节炎进展情况的影响，该方法已建立于美国。地理人口。我们假设年轻的患者在评估之前更可能经历多次不稳定性事件，接受手术治疗，并在手术干预后经历复发性不稳定性现象。研究设计描述性流行病学研究。方法使用建立的超过500,000名患者的地理数据库来识别1994年至2016年间<40岁的前肩不稳定患者。对患者的病历进行回顾，以获得患者的特征，病史，影像学，手术细节和结局。根据初始不稳定时的年龄（≤15岁，16-20岁，21-25岁，26-30岁和31-40岁）将患者分为5组。进行比较分析以识别组之间的差异。结果研究人群包括654名患者，平均随访时间为11。1年（范围为2。0-25。2年）。最初不稳定时，导致≤15岁的118例患者（18％）≤15岁；250（38％），16至20年；110（17％），21至25岁；80（12％），26至30岁；和96（15％）岁，年龄在31至40岁之间。≤15岁的患者在初次不稳定时有47％发生了3次以上的不稳定事件，而31岁至40岁的患者中有12％发生了这种情况（P <.001）。在10年的随访中，≤15岁和16至20岁的患者在非手术治疗后表现出最高的复发不稳定性率，分别为38.8％和47.1％。16至20岁的患者在外科手术干预（40.4％）和术后复发率（24.8％）上均最高。与所有其他年龄组相比，年龄在31至40岁之间的患者出现临床症状性骨关节炎的可能性更高（15.6％）。结论在40岁以下的美国流行病学人群中，在最初的医生咨询后，复发性前肩不稳定性的发生率约为三分之一。年轻的患者，尤其是年龄在15岁以下和16至20岁的患者，与年龄较大的患者相比，在初次评估时，他们更有可能经历过多次不稳定事件，需要手术并且经历了反复不稳定。最初不稳定时，年龄每降低一年，经医生咨询后复发不稳定或手术干预的风险分别增加4.1％和2.8％。