Relationship between the FABER Distance Test and the radiographic alpha-angle in patients with FAI

Transcription

1 Relationship between the FABER Distance Test and the radiographic alpha-angle in patients with FAI Christiano A.C. Trindade, MD Karen K. Briggs, MPH Kiyokazu Fukui, MD, PhD Marc J. Philippon, MD

2 Christiano A. C. Trindade, MD Karen K. Briggs, MPH Kiyokazu Fukui, MD, PhD Disclosure We have no financial relationships to disclose. Marc J. Philippon, MD I have financial relationships with the following companies: Research support, Paid Consultant, Royalties Stockholder, Consultant Ownership, Stockholder Stockholder, Royalties Research Support Research Support Research Support Royalties Royalties Royalties Royalties Smith and Nephew Endoscopy Arthrosurface HIPCO MIS Ossur Arthrex Siemens Bledsoe DonJoy SLACK Inc. Elsevier

3 Introduction FABER (Flexion Abduction External Rotation) test is a clinical exam used to screen patients for sacroiliac joint and hip joint pathology 1.This test is widely used by orthopedic surgeons, with good sensitivity but low specificity for detection of intra-articular pathologies 2. The FABER distance test (FDT) has been used as a diagnostic test for CAM impingement 3.

4 Purpose The purpose of this study was to determine the correlation between the FABER distance test (FDT) and CAM impingement

5 Patients and Methods FABER distance test(fdt) supine position affected leg flexed and its heel posiotioned on the contra-lateral knee, above the patella. distance from the lateral epicondyle to the exam table is measured while stabilizing the pelvis Positive test: >3cm difference between sides

6 FABER Distance Test

7 Patients and Methods Prospective data registry unilateral FAI Cross-table radiographies on affected hips alpha angle measured Exclusion criteria Patients with bilateral symptoms Patients with bilateral surgery Patients with bilateral alpha angles > 55

8 Results 648 patients met the inclusion criteria Average age: 36.1ys(18 to 71ys) Average alpha angle: 69.8 (30 to 110 ) Average FDT: 5.9cm(-11 to 26cm) +FDT -FDT p-value Alpha angle 72.4(SD=12) 64.6(SD=11) The diagnostic odds ratio of the FDT were 3.1 times more likely to have an alpha angle 55 degrees or greater compared to those with a negative test [95CI:1.8 to 5.3]. The FDT had a positive predictive value of 93% [95%CI: 91% to 95%].

9 Results Range of motion also associated with a positive FABER distance test +FABER -FABER p-value Flexion Abduction Adduction n.s. n.s. Internal Rotation External Rotation n.s.

10 Discussion FAI: recognized as a source of intra-articular hip pain in athletes 4 drop in performance or even retirement is sport The impact of the cam-type was detected in young athletes in sports such as soccer, hockey, skating and dance 5 Theory: the increase in alpha angle in these young athletes would be caused by repeated injury to the growth plate while performing movements considered at-risk 6 This theory was confirmed by a study 7 using MRI in individuals before and after closure of the physis. Cam morphology was observed only in patients with closed physis and those with high activity levels Other imaging study 8 suggests that the cam-type deformity in athletes is due to changes in growth plate ("ephyseal extensions") instead of the theory of formation of reactive bone

11 Discussion Young athletes who have their hips at risk should be protected through screening and prevention protocols 9 FDT and range of motion should be assed in this population in screening programs detect abnormal morphologies of the hip in a preclinical phase of FAI patients with negative tests are not exposed to unnecessary imaging tests o avoid the risk of cumulative radiation doses and spending on other costly exams like MRI Patients with positive tests could follow prevention programs avoiding "dangerous" positions such as squatting or not doing extreme movements in their respective sports o

12 Conclusion This study demonstrated that the FABER distance test is associated with the alpha angle. The use of the FABER distance in screening programs can predict higher alpha angles without the use of expensive diagnostic imaging or radiation from radiographs.

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