Jenny Toonstra, PhD, ATC Mid-Atlantic Athletic Trainers Association (MAATA) Student Educational Program May 20, 2017

Transcription

1 Jenny Toonstra, PhD, ATC Mid-Atlantic Athletic Trainers Association (MAATA) Student Educational Program May 20, 2017

2 Appreciate the role of evidence-based medicine in relation to clinical examination and diagnosis Understand sensitivity and specificity and their application to diagnostic accuracy Practice common special tests for the knee and shoulder in the context of sensitivity and specificity values

3 What clinical test(s) will you administer to a patient suspected of having a knee injury? Shoulder injury? WHY???

4 Which diagnostic techniques should I include in my clinical examination? Useful? Does it successfully identify the presence or absence of pathology? Tradition or science? Does evidence support the use of this technique, or am I only using it because I learned it in class? Bias? I invented the test, so it must work.

5 Confirm a tentative diagnosis Differentiate between structures Understand unusual-difficult signs and symptoms

6 Does every known orthopedic test need to be performed on each patient? Symptoms Special Tests Pathology Clinical exam components should be supported by evidence

7 How often do the results correctly identify whether or not the pathology is present? Steps to assessing diagnostic accuracy: Identify a population to test Perform the test Compare results to diagnostic gold standard (reference standard)

8 Lower Leg Injury; Possible fibular fracture Special Test(s)? Diagnostic Gold Standard

9 The outcome variable of a diagnostic test falls into one of four situations: TRUE-POSITIVE: the test is (+) and the patient has the condition FALSE-POSITIVE: the test is (+), but the patient does not have the condition FALSE-NEGATIVE: the test is (-)but the patient has the condition TRUE-NEGATIVE: the test is (-) and the patient does not have the condition

10 Highest diagnostic accuracy Generally more expensive, less accessible, slower, invasive, requires more personnel Clinical Test Positive Gold Standard Gold Standard Positive True Positive (TP) Gold Standard Negative False Positive (FP) e.g. arthroscopy=gold standard for diagnosing ACL tears Clinical Test Negative False Negative (FN) True Negative (TN) Best diagnostic accuracy=high rate of true positives AND a high rate of true negatives

11 AKA True Positive Rate Proportion of people with the pathology who have a (+) test Represents the ability of a test to recognize when a condition is present A highly sensitive test means that there are few false negative results, and fewer cases of disease are missed Formula: # of injuries diagnosed by exam # of injuries diagnosed by gold standard SnNout: high sensitivity means that a negative test is useful for ruling out a condition

12 Compression Test Test (+) Compression Test Test (-) Compression Test Sensitivity= Gold Standard: X-Ray Condition Present Cell A Compression Test (+), Fractured Fibula 30 patients Cell C Compression Test (-), Fractured Fibula 70 patients A A+C Condition Absent Cell B Compression Test (+), Fibula Intact Cell D Compression Test (-), Fibula Intact =0.30 Alonso A, J Orthop Sports Phys Ther, 1998

13 AKA True Negative Rate Proportion of people without the pathology who have a (-) test Represents the ability of a test to recognize when a condition is absent A highly specific test means that there are few false positive results Formula: # of diagnoses w/o injury based on exam # of true diagnoses based on gold std. SpPin: high specificity means that a positive test is useful for ruling in a condition

14 Compression Test Test (+) Compression Test Test (-) Compression Test Gold Standard: X-Ray Condition Condition Absent Present Cell A Compression Test (+), Fractured Fibula Cell C Compression Test(-), Fractured Fibula Cell B Compression Test (+), Fibula intact 94 patients Cell D Compression Test (-), Fibula intact 6 patients Specificity= D B+D =0.94 Alonso A, J Orthop Sports Phys Ther, 1998

15 SnNout: when a test has a high SeNsitivity, a Negative result (-) typically rules OUT the diagnosis Very few false negatives A highly sensitive test would definitely catch anyone that is positive. So if they re not positive, you can be sure they re negative

16 SpPin: when a test has a high SPecificity, a Positive result (+) typically rules IN the diagnosis Very few false positives A highly specific test would definitely catch anyone that is negative. So if they re not negative, you can be sure they re positive

17 If a test has a 100% specificity, there are NO false positives, therefore a positive test means the disease is present. If a test has a 100% sensitivity, there are NO false negatives, therefore a negative test means the disease is not present. Is it better to have high sensitivity or high specificity?

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19 Compression Test Sensitivity 30% Specificity 94% How would you interpret this? Alonso A, J Orthop Sports Phys Ther, 1998

20 ImPACT Testing Sensitivity 81.9% Specificity 89.4% How would you interpret this? Schatz P, Arch Clin Neuropsych, 2005

21 Homan s Sign Sensitivity 33% Specificity 79% How would you interpret this? Urbano, FL. Hospital Phys, 2001

22 Finkelstein s Test Sensitivity 99% Specificity 29% How would you interpret this? Goubau JF, J Hand Surg, 2014

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24 Anterior Drawer Pivot Shift Lachman

25 Anterior Drawer Pivot Shift Lachman Sensitivity 49% 32% 94% Specificity 58% 100% 97% Benjaminse A, J Orthop Sports Phys Ther, 2006

26 Anterior Drawer Pivot Shift Lachman Sensitivity 49% 32% 94% Specificity 58% 100% 97% Benjaminse A, J Orthop Sports Phys Ther, 2006

27 McMurray s Test Thessaly Test Apley s Test Joint Line Tenderness

28 McMurray s 1 Apley s 1 Thessaly 2 JLT 1 Sensitivity 70% 60% 89% 63% Specificity 71% 70% 96% 77% 1: Hegedus EJ, J Orthop Sports Phys Ther, : Karachalios T, J Bone Joint Surg, 2007

29 McMurray s 1 Apley s 1 Thessaly 2 JLT 1 Sensitivity 70% 60% 89% 63% Specificity 71% 70% 96% 77% 1: Hegedus EJ, J Orthop Sports Phys Ther, : Karachalios T, J Bone Joint Surg, 2007

30 Painful Arc Hawkins-Kennedy Test Neer Impingement Test

31 Hawkins- Kennedy Neer Painful Arc Sensitivity 79% 72% 53% Specificity 59% 60% 76% Hegedus EJ, Br J Sports Med, 2012

32 Hawkins- Kennedy Neer Painful Arc Sensitivity 79% 72% 53% Specificity 59% 60% 76% Hegedus EJ, Br J Sports Med, 2012

33 Apprehension Test Jobe Relocation & Surprise Test

34 Apprehension Jobe Relocation Surprise Sensitivity 53% 46% 64% Specificity 99% 54% 99% Lo IKY, Am J Sports Med, 2004

35 Apprehension Jobe Relocation Surprise Sensitivity 53% 46% 64% Specificity 99% 54% 99% Lo IKY, Am J Sports Med, 2004

36 O Brien Test Speed s Test Yergason s Test Crank Test

37 O Brien Crank Yergason Speed Sensitivity 63% 40% 9% 18% Specificity 73% 73% 93% 87% Guanche CA, J Arthrosc Related Surg, 2003

38 O Brien Crank Yergason Speed Sensitivity 63% 40% 9% 18% Specificity 73% 73% 93% 87% Guanche CA, J Arthrosc Related Surg, 2003

39 Sensitivity and specificity are values that may guide you in your clinical examination. Special tests are only one part of the examination puzzle and should not be the only method used to determine pathology. Utilizing evidence-based medicine and a comprehensive clinical examination is the best way to arrive at a correct working diagnosis.

40 Thank You!