版權：吳昭慶 / 陳育群 / 新思惟國際
多數國際期刊規範，論文的文字與圖片，屬於原作者，但「排版後」的論文，版權屬於雜誌社。所以，不管是教學或商業使用，散佈下載的論文 PDF，並不在授權範圍內，也就是說，我們過去有時候，直接把論文 PDF 寄給同事參考，這動作事實上是「違法」的。
新思惟國際，尊重各種形式的智慧財。所以，我們取得吳昭慶醫師與陳育群醫師同意後，取得論文的 MS-Word 版本原稿，委請設計師，用不同的風格，重新排版過。版權由「新思惟國際」回贈給吳昭慶醫師與陳育群醫師，並均能獨立使用。
人類的頸椎，會因為姿勢不良或外傷而退化。如果椎間盤突出，產生神經症狀，復健無效，就需要開刀。目前開刀的主流方法，是從前面開，拿掉退化的椎間盤，作減壓，接著打上金屬板固定，避免不穩定的晃動。這個手術，叫做 anterior cervical discectomy and fusion (ACDF)。
但頸椎本來是可以動的，打上金屬板後，被強制固定，力學上，壓力自然是傳到其他幾節的頸椎，這可能會導致附近幾節的頸椎，加速退化，稱之為 adjacent segment disease (ASD)。
過去的文獻，認為開過 ACDF 之後 10 年，會有 25.6% 的人產生 ASD，其中有 2/3 需要手術。不過，吳昭慶醫師在臨床上的經驗，認為這比例有問題。他想作個研究，知道實際的數字是多少，過去文獻的推論到底對或不對。
Wu JC, Liu L, Huang WC, Chen YC, et al. The incidence of adjacent segment disease requiring surgery after anterior cervical diskectomy and fusion: estimation using an 11-year comprehensive nationwide database in Taiwan. Neurosurgery. 2012; 70(3):594-601.
BACKGROUND: The incidence of symptomatic adjacent segment disease (ASD) after anterior cervical diskectomy and fusion (ACDF) was reported as 2.9%/y in a previous cohort of 374 patients. Few other data corroborate the incidence and natural history of ASD.
OBJECTIVE: To calculate the incidence of ASD after ACDF that required secondary fusion surgery.
METHODS: The retrospective study used an 11-year nationwide database to analyze the incidences. All patients who underwent ACDF for cervical disk diseases were identified through diagnostic and procedure codes. Kaplan-Meier and Cox regression analyses were performed.
RESULTS: From 1997 to 2007, covering 241 800 725.8 person-years, 19 385 patients received ACDF and 568 had ≥ 2 ACDF operations. The incidence of secondary ACDF operations was 7.6 per 1000 person-years. At the end of the 10-year cohort, 94.4% of patients who had received 1 ACDF remained free from secondary ACDF. The average time interval between the first and second ACDF was 23.3 months. After adjustment for comorbidities and socioeconomic status, secondary ACDF operations were more likely performed on male patients (hazard ratio = 1.27; P = .008) 15 to 39 years of age (hazard ratio = 1.45; P = .009) and 40 to 59 years of age (hazard ratio = 1.41, P = .002, respectively).
CONCLUSION: Repeat ACDF surgery for ASD cumulated steadily in an annual incidence of approximately 0.8%, much lower than the reported incidence of symptomatic ASD. However, at the end of this 10-year cohort, a considerable portion of patients (5.6%) received a second operation. Younger and male patients are more likely to receive such second operations.