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2014년 1월 20일 월요일

Survivorship analysis of 150 consecutive patients with DIAM™ implantation for surgery of lumbar spinal stenosis and disc herniation

Brief review

*Title: Survivorship analysis of 150 consecutive patients with DIAM™ implantation for surgery of lumbar spinal stenosis and disc herniation
요추 협착증과 디스크 탈출증으로 DIAM 이식술을 시행한 150명의 환자에 대한 생존 분석

*Authors: Yoo-Joon Sur, Chae-Gwan Kong, Jong-Beom Park

Background of data
The Device for Intervertebral Assisted Motion (DIAM™) has been introduced for surgery of degenerative lumbar disc diseases.

To determine the survivorship of DIAM™ implantation for degenerative lumbar disc diseases and risk factors for reoperation.

▶Subjects: 150 patients who underwent laminectomy or discectomy with DIAM™ implantation (84 males + 66 females)
Mean age: 46.5 years;
Mean follow-up period: 23 months (range 1–48 months)
Indications: 96 spinal stenosis and 54 disc herniations
Index level: 146 one-level (L4–5: 115/ L5–6: 31) and 4 two-level (L4–5 and L5–6)
Evaluating methods:
1. Kaplan–Meier analysis: To determine the cumulative reoperation rate and survival time
2. The log-rank test and Cox regression model: To evaluate the effect of age, gender, diagnosis, location, and level of DIAM™ implantation

-Reoperations of the DIAM™ implantation level or adjacent levels were defined as a failure and used as the end point for determining survivorship.

Reoperation rate: 4.7% (total 7 patients- only implantation level)

The causes of reoperation:
1. recurrent spinal stenosis (n=3)
2. recurrent disc herniation (n=2)
3. post-laminectomy spondylolisthesis (n=1)
4. delayed deep wound infection (n=1)

The mean time interval (from 1st to 2nd surgery): 13.4 months (range 2–29 months)

Kaplan–Meier analysis: predicted an 8% cumulative reoperation rate 4 years post-operatively.
Survival time was predicted to be 45.6 ± 0.9 months.

In Log-rank test, the reoperation rate: L5–6 > L4–5 (p = 0.002)
two-level > one-level (p = 0.01)

-Gender, age, diagnosis did not significantly affect the reoperation rate of DIAM™ implantation.

-Based on a Cox regression model, L5–6 and two-level DIAM™ implantation were also significant variables associated with a higher reoperation rate.
(L5–6: hazard ratio (HR) 10.3, 95% CI, 1.7–63.0; p = 0.01 / HR, 10.4; 95% CI, 1.2–90.2; p = 0.04)

-Survival time was significantly lower in L5–6 (47 vs. 22 months, p = 0.002) and two-level DIAM™ implantation (46 vs. 18 months, p = 0.01) compared with L4–5 and one-level DIAM™ implantation.

-8% patients who have a DIAM™ implantation for primary lumbar spinal stenosis or disc herniation are expected to undergo reoperation at the same level within 4 years after surgery.

-DIAM™ implantation at L5–6 and two-level are significant risk factors for reoperation.

2014년 1월 14일 화요일

Lumbar Facet Joint Tropism Does Not Accelerate Degeneration of the Facet Joints

Brief review

이 논문은 1997년에 출판된 논문으로, 논지는 양쪽 후관절의 비대칭성과 후관절의 퇴행과는 관련성이 없다는 것 입니다.

카데바의 CT, MR에서 총 104개의 요추 후관절을 측정하였고, 측정항목은 연골퇴행의 중증도와 뼈의 경화된 정도, 후관절의 비대칭 정도 입니다.

연골의 퇴행 정도는 후관절의 비대칭이 없는 경우와 심한 경우 사이에 유의한 차이가 없었습니다. 그리고 뼈의 경화된 정도는 후관절의 비대칭이 없는 경우가 심한 경우에 비해 약간 더 높았습니다. 또한 연골의 퇴행과 골 경화는 나이와 수술레벨에서 유의한 차이를 보였습니다.

후관절 퇴행에 있어, 전체적인 후관절각과 나이 및 수술레벨이 후관절의 비대칭성 보다 중요한 요소라는 결론 입니다.

17년 전에 출판된 논문이라는 점과, 실제 사람이 아닌 카데바의 MR, CT라는 점에서 한계점이 있지만 연골 퇴행과 골 경화를 grade로 나누어 놓은 사진이 본문에 있으므로 참고하시기 바랍니다. (아래 서지정보에 링크된 사이트로 가시면 원문파일을 보실 수 있습니다)

*Title: Lumbar Facet Joint Tropism Does Not Accelerate Degeneration of the Facet Joints
요추 후관절의 비대칭은 후관절의 퇴행을 가속화시키지 않는다.

*Authors: John Grogan, Bruce H. Nowicki, Timothy A. Schmidt, and Victor M. Haughton

To study the relationship of lumbar facet joint tropism to degeneration of the cartilage
and subcortical bone in the facet joints and the effect of tropism in intervertebral disk degeneration.

-on CT scans (sagittal plane): Measured the lumbar facet joints
-on MR: measured the severity of cartilage degeneration and bony sclerosis
(total 104 cadevaric facet joints)

degree of tropism
1. joint having no tropism
2. mild tropism
3. severe tropism.

-The correlation between tropism and degeneration was calculated, as was the relationship among
age, spinal level, and degeneration.

degree of tropism
Having no tropism: 94
Mild tropism: 6
Severe tropism: 4

-Cartilage degeneration: Not significantly between severe joint tropism and no tropism.
-Sclerosis: slightly greater in having tropism joint than no tropism.
-Sclerosis and cartilage degeneration were significantly related to age and spinal level.


-Age, spinal level, and overall facet joint angle are more important factors than facet joint tropism in facet joint degeneration.

2014년 1월 12일 일요일

Do Authors Report Surgical Expertise in Open Spine Surgery Related Randomized Controlled Trials?

Brief review
이 논문은 개방척추수술에 대한 무작위대조연구(RCT)에서 보고하는 수술적 기술의 quality를 체계적 문헌고찰을 통해 평가하는 논문 입니다.

2005년부터 2010년에 출판된 RCT논문 중 MEDLINE, Cochrane Library, EMBASE을 통해 검색된  논문을 가지고 사전에 설정한 inclusion, exclusion criteria에 맞추어 총 99개의 논문을 정했습니다 (method에 첨부된 flow chart참고).

이 99개의 RCT논문을 토대로 13개의 질문을 통해 논문에 보고된 내용의 quality를 평가하였습니다 (질문내용: 연구참여자들은 적절히 blinded 되었는가? 모든 치료법들은 무작위로 배정된 그룹에 동일하게 적용되었는가?등. 아래 bibliography에 링크된 사이트로 가서 본문 내용을 참고하세요).

평가결과, 전체의 10%에 해당하는 논문만이 learning curve와 관련하여 수술적 기술 및 경험을  설명한 것으로 나타났습니다.

개방척추수술에 대한 RCT논문에서 수술기술과 논문에 대한 정보는 거의 보고되어 있지 않으며, 이렇게 저자들이 기초적인 안전성 보호에 대해 보고하지 않으면 전문기술의 편차가 나타날 수도 있다는 결론 입니다.

*Title: Do Authors Report Surgical Expertise in Open Spine Surgery Related Randomized Controlled Trials?: A Systematic Review on Quality of Reporting
저자들은 무작위대조연구와 관련된 개방척추수술에서 수술적인 전문기술을 보고하는가?: 보고의 질에 대한 체계적 고찰.

*Authors: Jakob van Oldenrijk, Youri van Berkel, Gino M. M. J. Kerkhoffs, Mohit Bhandari, Rudolf W. Poolman

A systematic review of published trials in orthopedic spine literature.

To determine the quality of reporting in open spine surgery randomized controlled trials (RCTs) with special focus on the reporting of surgical skill or expertise (2005~2010).

In spine surgery, a surgeon's skill and expertise is important role in the outcome of the procedure.
To appraise the reported treatment effect of spine surgery related RCTs adequately, any potential skill or experience bias must be reported.

-MEDLINE, Cochrane Library, EMBASE were systematically searched for open spine surgery RCTs published (2005.1.1~2010.12.31)
>searching word: spine, surgery, spine surgery

>Inclusion criteria:
1) nonpharmaceutical RCT dealing with open surgical interventions of the spine on patients in an operating room.
(2) published between 2005.1.1~2010.12.31 in the English, French, German, or Dutch language.

>Exclusion criteria:
1) Percutaneous techniques
2) Studies dealing with animals, cadavers, manipulation, or acupuncture.
3) Studies summarizing results of a previously published study.

-To determined the quality of reporting eligible studies, using the checklist.
-The reporting of surgeons' skill and experience was scored additionally.
-Subsequently, all authors were surveyed to determine if any information on methodological safeguards was omitted from their reports.
-All data were analyzed in 2-year time frames.

-99 RCTs were included.
10 studies (10%) described surgical skill or experience, mostly as a description of the learning curve.
-The majority of publications were unclear about "concealment of treatment allocation" (77%), "blinding of participants" (68%), "blinding of outcome assessors" (77%), and "adhering to the intention-to-treat principle" (67%).
-Of the 99 surveys, we received 22 (22%) completed questionnaires.
In these questionnaires, information about essential methodological safeguards was often available, although not reported in the primary publication.

-In open spine surgery RCTs information on skill and experience is scarcely reported.
-Authors often fail to report essential methodological safeguards.

-Therefore these studies may be prone to expertise bias.

2014년 1월 6일 월요일

Fusion risk score: evaluating baseline risk in thoracic and lumbar fusion surgery

Brief review

이 논문은 척추유합술의 위험도를 score로 나타내는 FRS(Fusion Risk Score)와 관련된 내용 입니다. 두 가지 만성질환이 동시에 나타나는 범위와 수술적 요소(접근방법, 레벨, 골절술) 등이 수술 위험도의 예후인자로서 증명되었다는 사실을 바탕으로  후향적 연구를 진행하였습니다. 
해당기간 내에 흉추 혹은 요추에 유합술을 시행한 364명의 환자를 대상으로 신장, 폐, 심장등에서의 만성질환과 나이, 당뇨병, approach방법, level등을 조사하였고 FRS scale로 나타냈습니다.
그 결과, 위의 항목들은수술에 대한 예후인자로서 통계적으로 유의한 값을 나타내었습니다. (p값이 모두 0.05보다 작았다)
FRS는 유합술을 받은 후의 위험성을 예측하며, FRS 를 환자에게 적절히 이용하면 외과의는 수술 전후의 위험성을 통제할 수 있다는 결론 입니다.

*Title: Fusion risk score: evaluating baseline risk in thoracic and lumbar fusion surgery.
유합술 위험도 지수: 흉추와 요추 유합술의 기준 위험치 평가

*Authors: Nathan L. Hartin, Amir A. Mehbod, Siddharth B. Joglekar, Ensor E. Transfeldt

Retrospective cohort study.

Fusion Risk Score (FRS)
-To assess the risk of spine fusion surgery preoperatively.
-To control risk through tailoring intervention and explain differences in complication profile in high-complexity practice (for surgeon)

-Research has identified and elevated risk of fusion surgery in elderly, yet the rate of such surgery continues to increase.
-A range of comorbidities and the surgical factors are demonstrated predictors of perioperative risk.

Retrospective review
Subject number: 364 fusion patient (over 65yrs)
Follow-up period: 18-month
-Logistic regression analysis: To identify factors predictive for perioperative events.
-The predictive variables: incorporated into the FRS scaled from 1 to 20.
-Patient demographics and comorbidities: incorporated into the FRS patient score (maximum 10)
-surgical approach, levels, and osteotomies: FRS procedure score (maximum 10).

Multivariate analysis demonstrated those(1~8) are predictive of perioperative events.
1. chronic kidney disease (odds ratio [OR] = 5.3, 95% confidence interval [CI]: 1.5-18.6, P = 0.008),
2. chronic obstructive pulmonary disease (OR = 5.3, 95% CI: 2.0-14.2, P < 0.001),
3. ischemic heart disease (OR = 4.1, 95% CI: 2.0-8.4, P < 0.001)
4. open anterior approach (OR = 3.6, 95% CI: 1.4-9.3, P = 0.010)
5. diabetes (OR = 3.0, 95% CI: 1.4-6.4, P = 0.004)
6. previous spinal surgery at the same site (OR = 2.6, 95% CI: 1.3-4.9, P = 0.005)
7. age (OR = 1.07, 95% CI: 1.01-1.13, P = 0.019)
8. the number of motion segments fused (P = 0.049)

- FRS was highly predictive of 1)perioperative events, 2)intensive care unit admission, 3)operative time, 4)blood loss, 5)length of stay(all P < 0.0001).

-A score over threshold 9 carries a greater than 50% risk of perioperative events.

(처음에 연구대상 환자가 436명이었으나 동의서 받지 못한 환자, missing data, 연구제외기준에 해당하는 환자를 차례로 제외하고 나니 364명이 남았음)

-The FRS predicts the risk of complications after spine fusion surgery and risk of intensive care unit admission, operative time, blood loss, and postoperative length of stay.
-By balancing the FRS procedure score to the patient, the surgeon can quantify and control perioperative risk.

Odds ratio [OR]: 두 집단(실험군, 대조군)의 이항변수(성공, 발병 등)에 관한 승산 비를 나타내는 단위(배율)
예) 수술 성공 비, 질병 발병률 등.
이 논문의 result에 나온 내용을 예로 들어보면, 
choronic kidney disease(만성 신장 질환)의 Odds ratio (OR )=5.3 일 때
만성신장질환을 함께 가지고 있는 환자가 척추유합술을 시행했을 경우, 신장질환이 없는 환자에 비해 수술전후의 위험도가 5.3배 높다는 것 입니다.
odds ratio에 관한 자세한 내용은 빠른 시일 내에 정리하여 포스팅 하겠습니다.