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SCIENTIFIC EVALUATION OF AUTOGRAFT ACL RECONSTRUCTION

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Professor & Vice Chair, Orthopaedics. Director, Vanderbilt Sports Medicine & Ortho PCC ... Is There Evidence in Literature Supporting EBM Approach for ORTHOPAEDICS? ... – PowerPoint PPT presentation

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Title: SCIENTIFIC EVALUATION OF AUTOGRAFT ACL RECONSTRUCTION


1
Orthopaedic Interest Group www.mc.vanderbilt.edu/
medschool/OIG
2
How to Read the Literatureand Formulate
Hypothesis
Vanderbilt Medical Student Journal Club September
18, 2003
  • Kurt P. Spindler, MD
  • Professor Vice Chair, Orthopaedics
  • Director, Vanderbilt Sports Medicine Ortho PCC
  • Head Team Physician, Vanderbilt University

3
How is this Relevant?
  • 1. Time efficient way to read literature
  • 2. Teach YOU how to evaluate studies
  • 3. Develop clinical practice solid ground
  • 4. IMPROVE PATIENT CARE!
  • 5. Stimulate better clinical research in future
  • 6. Avoid wasting economic resources

4
Is There Evidence in Literature Supporting EBM
Approach for ORTHOPAEDICS?
  • 1. JBJS-A, Jan 2003 Editorial (Heckman)
  • Introducing levels of evidence
  • Five levels
  • Four study types
  • 2. AJSM, 2002 Abstract Format (Reider)
  • Background
  • Hypothesis
  • STUDY DESIGN list
  • Methods / Results / Conclusion
  • Clinical relevance

5
Goal TEACH
  • Evidence-based framework review clinical
    literature
  • How to use WORKSHEET !

6
Basics
  • Title
  • Author
  • Reference
  • HYPOTHESIS
  • PRIMARY
  • SECONDARY

7
Type of Study
  • Treatment
  • Diagnosis
  • Screening
  • Prognosis
  • Causation

8
Type StudyPreferred Design
  • 1 HYPOTHESIS OR
    PREFERRED
  • TOPIC RESEARCH EXAMPLES RESEARCH
    DESIGN
  • Treatment drug, prevention, RCT
  • surg
  • Diagnosis dx test Cross-sect
    survey
  • Screening value of test Cross-sect survey
  • Prognosis disease, injury, Longitudinal
    cohort
  • condition
  • Causation exposure to . . . Cohort or
    case-control

9
Common Sports Medicine Clinical Questions
  • 1. Treatment ACL Graft Ham vs PT
  • Operative Approach Endo vs Rear Entry
  • Meniscus Repair Inside-Out Sut vs All In
  • Grade IV Defect Microfx vs Autologous
  • 2. Diagnosis SLAP PE vs MRI
  • Meniscus tear PE vs MRI
  • ACL tr Lachman vs Ant Draw
  • 3. Prognosis Natural hx ACL tear Identify risk
    factors
  • Risk OA ACL recon Function and/or OA
  • Partial meniscectomy Function and/or OA
  • stable knee

10
Traditional Hierarchy ofClinical Treatment
Studies
  • 1. RCT (randomized controlled trials) only
    computer or random table acceptable
  • 2. Cohort two or more groups selected basis
    differences exposure to agent and f/u
  • 3. Case control pts particular
    disease/condition identified matched control
  • 4. Cross-sectional data collected single
    timepoint
  • 5. Case reports/series medical hxs one or more
    patients with condition/tx reported on

11
Methods
  • CONTROL or COMPARISON GROUP in treatment study?
  • Control for major known variables that could BIAS
    result?
  • Identify GOLD STANDARD in diagnostic study?
  • Prospective or retrospective?

12
Why do Treatment Studies Need Control Group?
  • 1. Basics Scientific Method!
  • 2. If no control group tx is same, better, or
    worse than what?
  • 3. Quality of control group one measure of
    validity of results
  • 4. Unfortunately majority orthopaedic literature
    lack control group -- case series

13
Data Collection
  • 1. Prospective study -- data
  • collection planned in advance
  • 2. Retrospective study -- review data
  • normally collected (examples
  • include case control or chart reviews
  • 3. Prospective design better control
  • confounding variables

14
How to Identify Bias
  • Study BIAS
    Example
  • Allocation groups Selection Fail randomize
  • Intervention Performance Fail control
    confounding variables
  • Follow-up Exclusion Not uniform or
  • (or Transfer) inadequate (lt70)
  • Outcomes Detection Dissimilar evaluation
  • independent examiner?
  • Validated question-
  • naire?

15
Definition of Bias
  • 1. SELECTION or SUSCEPTIBILITY difference in
    comparison groups secondary to incomplete
    randomization
  • 2. PERFORMANCE differences in care provided
    apart from intervention being evaluated
  • 3. EXCLUSION or TRANSFER differences in
    withdrawal from trial
  • 4. DETECTION different evaluation for outcomes
    best independent examiner or blinding examiner or
    validated outcome questionnaire self-administered

16
Sports Medicine Examples Bias
  • 1. Selection
  • ACL tr pt self-select OR vs Nonop tx
    evaluate OA
  • Soccer teams self-select ACL inj prevention
    training,
  • then report difference incidence ACL tr
  • 2. Performance
  • Report outcome of meniscal allograft or
    autologous
  • chondrocytes fail control concomitant ACL
    recon or HTO!
  • 3. Exclusion or Transfer
  • Report conclusions based lt70 f/u outcome
    variable

17
Methods
  • 1. Did author demonstrate
  • demographics (age, gender,
  • etc) equal in groups?
  • 2. Length of f/u
  • Min ______
  • Avg ______

18
Basic Statistics
  • A. Continuous (ht, age) ? normality tested OK
  • Yes ? parametric tests
  • No ? nonparametric tests
  • B. Discrete (Yes, No, ) ? nonparametric
  • C. See handout for Common Statistical Tests
  • D. Stats are acceptable Y / N / unknown
  • E. Stats consultation requested Y / N /
  • Who __________________________

19
Statistical and Clinical Significance Outcomes
  • Absolute
    If ns power ( ) Clinically
  • Outcome/Result Difference P for (
    ) diff significant
  • a.
  • b.
  • c.
  • d.

20
Statistical vs Clinical Significance
  • 1. Primary hypothesis determines sample size by a
    clinically meaningful difference in single
    outcome variable chosen.
  • 2. Example -- ACL graft choice detect 1 mm side
    to side difference, n ? 60-70. If differences
    are significant but could be 1 vs 2 vs 3 mm, what
    would change your practice?
  • 3. Thus clinical significance both common but
    individual!
  • 4. Power set 80 to detect clinically
    meaningful stat difference.
  • 5. Other examples . . . .

21
Summary
  • A. If no comparison group or control group in
    TREATMENT STUDY ? READ FOR INFORMATION ONLY --
    no evidence-
  • based reason or data to change practice pattern
  • B. If no comparison of groups that equal
    PreTREATMENT ? RESULTS MAY NOT BE CAUSED BY
    TREATMENT BUT BY
  • DIFFERENCES IN GROUPS
  • C. If INTERVENTION contains additional proven or
    suspected variables other than 1 hypothesis
    indicating Performance Bias, results NOT
    SPECIFIC TO INTERVENTION ?
  • RESULTS UNCLEAR SIGNIFICANCE TO TREATMENT

22
Summary
  • D. Inadequate follow-up (lt70) indicates
    EXCLUSION or TRANSFER BIAS ? RESULTS COULD
    CHANGE IF
  • ADEQUATE FOLLOW-UP
  • E. Are STATS acceptable?
  • F. Are absolute values which are statistically
    significant also CLINICALLY SIGNIFICANT?

23
Conclusion
  • If A ? F acceptable
  • If your patient population similar to study
  • If you can perform technique/treatment
  • CHANGE YOUR PRACTICE ACCORDINGLY!

24
Requirements Research Study Design
  • 1. HYPOTHESIS (Ho)
  • Measured outcome strength, stability,
    function
  • Comparison or control group
  • 2. AIMS
  • Specific statistical measurements between
    groups at defined intervals (KT1000 _at_ 2 yr)
  • 3. METHODS
  • 4. RESULTS and STATISTICS
  • 5. BUDGET and TIMELINE
  • 6. Discussion strengths, weaknesses, alternative
    approaches

25
Steps Research Design
  • First Read the literature EBM
  • Second Develop working hypothesis
  • Third Write Aims/Methods/Results, etc.
  • Fourth Establish Budget/Timelines/Team
  • Finally Initiate study!

26
Pearls
  • 1. Develop ideas methods, results, statistics
    from best EBM in literature review
  • 2. Retrospective review your cases!
  • Establish sample size
  • Timelines to complete
  • Generate methods
  • 3. Consult statistician BEFORE begin study!

27
Examples EBM ReviewsClinical Questions Sports
Medicine
  • Shoulder
  • 1. How do you treat Type 3 AC sprains?
  • 2. Which treatment do you prefer midshaft
    clavicle fracture?

28
EBM Type III AC Sprains
  • 1. RCT (randomized controlled trials) Nonop vs
    Op
  • Bannister G JBJS-B 1989 (n84, 13 mo f/u)
  • Larsen E JBJS-A 1986 (n60, 48 mo f/u)
  • Results clinical outcomes equal!
  • Rehabilitation faster nonoperative
  • 2. Meta-Analysis 24 Articles Tx
  • Phillips A CORR 1998
  • AROM and strength same
  • No signif benefit surg outcome analysis
  • 3. Strength Evaluation Nonop Tx
  • Tibone J AJSM 1992 (retrospective 4.5 yrs)
  • No strength deficits

29
EBM Clavicle Fx
  • 1. Nowak J Injury 2000 (Sweden)
  • 101 fx/100,000
  • Male female 21 (71 males, 30 females)
  • 75 middle third
  • 95 healed without problem
  • 2. Anderson K Acta Orthop Scand 1987
  • RCT Fig 8 vs Sling n 61
  • Clinical and XR EQUAL
  • 100 union
  • Initial displacement -- UNCHANGED!

30
EBM Clavicle Fx
  • 1. Nordqvist A J Orthop Trauma 1998
  • Avg 17 yo f/u 225 nonop mid clav Fx
  • Sx 82 (185) none, 17 (39) moderate
  • Union 97 (218) healed, 3 (7) nonunion
  • Position 68 (153) nl, 24 (53) malunited
    (displaced)
  • FYI -- 40 malunions, 3 nu clinically rated good

31
Why ACL Reconstruction 2003?
  • 1. Primary repair?
  • 2. Augmentation?
  • 3. Meniscus tears?
  • 4. Higher function?
  • 5. Prevent arthritis?

32
Why ACL RECONSTRUCTION 2003Evidence Based
Literature
  • 1. Primary repair no better nonoperative tx
  • Sandberg RCTs. JBJS-A, 1987
  • 2. PT ACL recon better than repair and
    augmentation
  • Engebretsen. AJSM, 1990
  • Grontvedt. JBJS-A, 1996
  • 3. Reconstruction significant decrease meniscus
    tear rate from 27 (nonoperative) to 3 (ACL
    recon)
  • Anderson. JBJS-A, 1989

33
ACL Reconstruction Techniques
  • 1. Which autograft do you choose?
  • Reasons . . .
  • 2. Approach endoscopic (single- incision) or
    rear entry (two- incision)?
  • Reasons . . .

34
Summary Six RCTs in 2000
  • 1. Function No difference
  • 2. ROM ? PT 1.5 - 3.0 in 33
  • 3. KT1000 PT more stable 1-3.4 mm (50)
  • 4. Ant or PF pain No difference 83
  • 5. Kneeling pain PT greater 3/3 (100)
  • 6. Isokinetic Ham weaker 7-11 (50)

35
Operative Technique
  • 1. Arthroscopic vs Mini Open
  • (patella stays in trochlea)
  • -- Raab 93 Cameron 95 -- No difference !
  • 2. Endoscopic (single inc) vs
  • Rear-Entry (two inc)
  • -- Brandsson 99, Reat 97, Garfinkel 93,
  • ONeill 96, Gerich 97
  • No major differences trend better rear-entry

36
Decision Making Meniscus Surgery
  • 1. Op vs Nonop treatment?
  • 2. Repair vs Excision?
  • 3. Partial vs Complete?
  • 4. Technique Repair?
  • Inside-out sutures
  • All-inside arrows

37
EBM Meniscus
  • 1. RCTs (Cochrane database 2001)
  • a. Surgery vs nonoperative -- none
  • b. Repair vs excision -- none
  • c. Partial vs complete equal long-term XRs
  • 2. RCTs and Prospective Comparative?
  • Inside-Out Suture EQUALS All-Inside Arrows
  • a. Albrecht-Olsen.? Kn Surg Spt Traum Arth 1999
  • b. Kirkley? in preparation
  • c. Spindler? AJSM, in press

CAVEAT All NWB five weeks!!
38
Summary First Steps Research
  • 1. Review literature EBM
  • 2. Generate hypothesis
  • 3. Construct preliminary aims
  • 4. Retrospective review clinical cases sample
    size
  • CAVEAT Basic science requires lab usually
    university

39
Thank you
40
References
  • Wright JG JBJS-Am 2000
  • Hurwitz SR JBJS-Am 2000
  • McLeod RS Surgery 1996
  • Greenhalgh T How to Read a Paper. Br Med J
    2001
  • Lang TA and Secic M How to Report Statistics in
    Medicine. ACP 1997
  • Spindler K, Johnson R, Reider B ICL AOSSM 2002

41
Orthopaedic Interest Group www.mc.vanderbilt.edu/
medschool/OIG
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