AAOS 2009:退化性椎盤症-腰椎盤全置換術優於脊椎融合


  February 27, 2009(內華達州拉斯維加斯) —根據於美國整形外科醫學會2009年會中發表的兩篇食品藥物管理局(FDA)研發裝置免許前溯隨機多中心研究結果,在緩解失能與改善病患生活品質上,一種腰椎盤全置換術系統(ProDisc-L)優於脊椎融合,且較少需要再度手術。兩篇研究都顯示病患對於人工椎間盤的手術結果比脊椎融合還要滿意。
  
  ProDisc與融合術治療L3與S1間脊椎疼痛之比較研究的主要作者、Texas Back研究中心研究員Jack Zigler醫師表示,ProDisc是安全而有效的,在我們的研究中,Oswestry失能指數(ODI)、SF-36分數、二度手術比率、使用止痛藥、病患滿意度等改善均顯著優於融合術。
  
  在前溯研究中,16家中心的237名病患被隨機以2比1的比率指派接受人工椎間盤或者融合術,於術後6週與3、6、12、18、24個月時評估結果。所有病患都有兩個鄰近的椎間出現失能退化性椎間盤症,主要有背部與腳痛,且保守治療6個月以上失敗。排除規範包括之前有腰椎融合手術、涵蓋的椎間超過兩個、DEXA分數小於–1.0、身體質量指數超過40 kg/m2。兩組病患的特徵相似。
  
  結果顯示,在兩種手術之後,ODI指數都顯著立即下降,但是人工椎間盤組改善較明顯,在24個月時,有53.1%的病患達成平均ODI指數改善34.4分,而41.3%的融合手術病患達到平均改善26.7分(P< .05)。而且,73%人工椎間盤組病患以及60.3%融合手術病患的ODI改善都至少有15分(P< .05)。以視覺類比評分表(VAS)測量,人工椎間盤組之疼痛也有較大的改善,不過,只在18個月時還有明顯改善。
  
  兩組都沒有椎間盤高度損失,但人工椎間盤組的病患在24個月時較少使用止痛藥。同樣的術後時間,人工椎間盤組病患的滿意度較高。24個月之後,再度手術比率—兩組皆低 — 在融合手術組顯著較高,有8.2%的病患接受二度手術,人工椎間盤組的病患只有2.4% 二度手術(P<.05)。
  
  另一篇研究比較人工椎間盤置換與脊椎融合手術,但是是1名椎間盤疼痛的病患,研究發現人工椎間盤組的VAS疼痛分數、ODI指數、 SF-36 數在追蹤五年時都有持續改善。人工椎間盤組的再度手術比率也顯著較脊椎融合組低。此研究開始於2001年,於2006年8月FDA核准ProDisc時告終。此處報告的前溯隨機試驗目標,在於評估最初的研究結果是否和兩年後的追蹤報告相似。加州洛杉磯Cedars-Sinai醫學中心的脊椎中心醫療主任Rick Delamarter 醫師表示,我們希望可以回答這個問題:五年後會如何?
  
  該研究將17個不同中心的161名病患隨機分組到脊椎融合手術或者人工椎間盤置換,兩組在60個月期間,ODI指數以及VAS疼痛分數都維持改善。24個月時,人工椎間盤組的VAS滿意分數顯著高於脊椎融合組(P= .015),且在評估之後60個月仍有穩定的滿意度。至於24個月之後,當被問到如果再度手術時,人工椎間盤組有81%病患表示願意,而融合手術組只有69%。五年後,人工椎間盤組有80% 病患、融合手術組63%病患表示他們願意再度手術。而實際上,在60個月時,融合手術組再度手術的比率(13.3%)仍高於人工椎間盤組 (4.2%)。
  
  不過,主持這兩篇研究發表的Steven Garfin醫師表示,和脊椎融合手術相較時,人工椎間盤置換的正面結果可以視為今日健康照護環境的結果。
  
  Garfin醫師指出,當今的問題是,雖然我們在頸椎置換的研究上有許多好的結果,但保險公司並不給付。或許這些資料可以起決定性的作用;Garfin醫師是加州大學聖地牙哥分校整形外科主任、教授。
  
  Synthes, Inc.公司資助這兩篇研究。Zigler醫師宣稱接受Synthes公司的發表費用以及顧問費用。Delamarter 醫師宣稱接受Synthes公司的版稅、發表費用以及顧問費用。Garfin醫師宣稱接受Johnson & Johnson 集團的DePuy公司的版稅、發表費用、顧問費用以及研究支持。
  
  美國整形外科醫學會2009年會:摘要106與108。發表於2009年2月25日。

AAOS 2009: Lumbar Total Disc Replacement Superior to Spinal Fusion for Degenerative Disc Disease

By Barbara Boughton
Medscape Medical News

February 27, 2009 (Las Vegas, Nevada) — A lumbar total disc replacement system (ProDisc-L) is superior to spinal-fusion surgery in relieving disability and improving patient quality of life, and it resulted in fewer reoperations, according to 2 US Food and Drug Administration (FDA) investigational device exemption prospective randomized multicenter studies presented here at the American Academy of Orthopedic Surgeons 2009 Annual Meeting. Both studies also showed that patients experienced greater satisfaction with surgery results with the artificial disc than with spinal fusion.

"The ProDisc is a safe and effective alternative to fusion, and showed statistically significant improvements over fusion in our study in Oswestry Disability Index (ODI), SF-36 scores, reoperation rates, narcotic usage, and patient satisfaction," said Jack Zigler, MD, fellowship codirector at the Texas Back Institute, in Plano, and lead investigator of a study of ProDisc vs fusion for treatment of disc pain at 2 vertebral levels between L3 and S1.

In the prospective study, 237 patients at 16 centers were randomly assigned in a 2:1 ratio to the artificial disc or to fusion, and results were evaluated postoperatively at 6 weeks and at 3, 6, 12, 18, and 24 months. All patients had disabling degenerative disc disease in 2 adjacent segments with primary back and leg pain, and had failed 6 months or more of conservative care. Exclusion criteria included prior lumbar fusion surgery, more than 2 levels of vertebral involvement, a DEXA score of less than –1.0, and a body mass index of more than 40 kg/m2. Patient characteristics in both groups were similar.

Results indicated that ODI scores decreased immediately and significantly after both types of surgery. Yet there was significantly more improvement in the artificial-disc group, with 53.1% of patients achieving a mean ODI improvement of 34.4 points at 24 months and 41.3% of fusion-surgery patients achieving a mean 26.7 point improvement (P?< .05). Also, 73% of patients in the artificial-disc group and 60.3% in the fusion-surgery group had an ODI improvement of at least 15 points (P?< .05). There was also a trend toward greater improvement in pain, measured by mean visual analog scale (VAS) scores, in the artificial-disc group, although this was significant only at 18 months.

There was no disc height loss in either group, although patients in the artificial-disc group reported significantly less use of narcotics at 24 months. Patients also had significantly higher satisfaction with their surgery after the same time period. After 24 months, reoperation rates — although low in both groups — were significantly higher in the fusion-surgery group, with 8.2% of patients undergoing a second surgery, compared with 2.4% of those in the artificial-disc group (P?< .05).

Another study comparing artificial-disc replacement and spinal-fusion surgery, but in patients with disc pain at 1 vertebral level, found that improvements in VAS pain scores, ODI index, and SF-36 scores in the artificial-disc group were sustained after 5 years of follow-up. There were also significantly fewer reoperations in the artificial-disc group than in the spinal-fusion group. The study, which began in 2001, culminated with the FDA approval of ProDisc in August 2006. The prospective randomized trial reported here aimed to assess whether the initial study's results were similar to those reported at 2-year follow-up. "We wanted to answer the question: What are the trends after 5 years?" said Rick Delamarter, MD, medical director of the Spine Center at Cedars-Sinai Medical Center, in Los Angeles, California.

The study randomized 161 patients at 17 different centers to either spinal-fusion surgery or artificial-disc replacement. Improvements in ODI scores and VAS pain score assessments were maintained through 60 months in both treatment groups. At 24 months, the VAS satisfaction score was significantly higher in the artificial-disc group (P?= .015) than in the spinal-fusion group, and levels of satisfaction remained constant after 60 months of evaluation. When asked, after 24 months, if they would have the surgery again, 81% of patients in the artificial-disc group indicated they would, compared with 69% in the fusion-surgery group. After 5 years, 80% of patients in the artificial-disc group and 63% in the fusion-surgery group indicated they would have the surgery again. Reoperations after 60 months were also significantly higher (13.3%) in the fusion-surgery group than in the artificial-disc group (4.2%).

The positive results seen with artificial-disc replacement when evaluated against spinal-fusion surgery should be considered in the context of today's healthcare environment, however, cautioned Steven Garfin, MD, who moderated the session at which both studies were presented.

"The problem in today's world is that although we have seen a barrage of good results in studies on cervical disc replacements, insurers won't pay for them," Dr. Garfin pointed out. "But perhaps data like these may eventually tip the scale." Dr. Garfin is professor and chair of orthopedics at the University of California, San Diego.

Both studies were funded by Synthes, Inc. Dr. Zigler has disclosed paid presentations and consulting fees from Synthes. Dr. Delamarter has disclosed royalties, paid presentations, and consulting fees from Synthes. Dr. Garfin has disclosed royalties, paid presentations, consulting fees, and research support from DePuy, a Johnson & Johnson Company.

American Academy of Orthopaedic Surgeons (AAOS) 2009 Annual Meeting: Abstracts 106 and 108. Presented February 25, 2009.

    



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