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DOI: 10.1055/s-0032-1330325
Assessment of Cam-Type Femoroacetabular Impingement by Ultrasonography: Value of Anterior Femoral Distance Measurements
Beurteilung des „cam-type“ femoroacetabulären Impingement durch Ultrasonografie: Wert der Messung der anterior-femoralen DistanzPublication History
25 June 2012
24 October 2012
Publication Date:
13 December 2012 (online)
![](https://www.thieme-connect.de/media/ultraschall/201207/lookinside/thumbnails/10.1055-s-0032-1330325-1.jpg)
Abstract
Purpose: To retrospectively determine the reproducibility and performance of a quantitative measurement for cam-type femoroacetabular impingement (FAI) designated as the anterior femoral distance (AFD) of the femoral head-neck junction identified at ultrasonography (US).
Materials and Methods: 72 patients with clinically suspected FAI were retrospectively evaluated, and US studies were performed during a 20-month period. Of these, we selected 53 patients who underwent subsequent magnetic resonance (MR) arthrography and had adequate recorded US images. All the longitudinal US images of the anterior and anterosuperior contours of the femoral head-neck junction were recorded by a radiologist. 33 of these US images were also recorded by a technician. An alpha angle of > 55° on MR arthrography was indicative of cam-type FAI. Two independent radiology residents blinded to the clinical data and MR arthrography measured the maximal femoral head-neck overgrowth defined as the AFD on US (AFD-US). Reproducibility was assessed using intra-class correlation coefficients (ICCs) and Bland-Altman plots, and diagnostic performance was assessed using receiver operating characteristic (ROC) analysis.
Results: AFD-US showed high intra- and inter-rater agreement (ICC = 0.913 – 0.968) in all measurements and good reproducibility among different operators in the anterior contour measurements (ICC = 0.881) but not in the anterosuperior contour measurements (ICC = 0.196). An AFD-US cut-off value of 4.0 mm in the anterior contour yielded the greatest sensitivity (80.9 %) and specificity (87.5 %) for the diagnosis of cam-type FAI by ROC analysis.
Conclusion: AFD-US of the anterior contour of the femoral head-neck junction is helpful in diagnosing cam-type FAI.
Zusammenfassung
Ziel: Die retrospektive Bestimmung der Reproduzierbarkeit und Leistung der quantitativen Messung beim „cam-type“ femoroacetabulären Impingement (FAI), die als anterior-femorale Distanz (AFD) des Femurkopf-/Schenkelhals-Übergangs im Ultraschall (US) bestimmt wird.
Material und Methoden: Retrospektiv wurden 72 Patienten mit klinischem Verdacht auf FAI bewertet und US-Untersuchungen über einen Zeitraum von 20 Monaten durchgeführt. Davon wählten wir 53 Patienten aus, die sich in Folge einer Magnetresonanz(MR)- Arthrografie unterzogen und die ausreichend dokumentierte US-Bilder besaßen. Alle longitudinalen US-Bilder der anterioren oder anterosuperioren Konturen des Femurkopf-/Schenkelhals-Übergangs wurden durch einen Radiologen aufgenommen; 33 dieser US-Bilder wurden auch durch einen Techniker aufgenommen. Ein Alphawinkel von > 55° in der MR-Arthrografie sprach für ein „cam-type“ FAI. Zwei unabhängige niedergelassene Radiologen bestimmten verblindet zu den klinischen Daten und der MR-Arthrografie die maximale Überwucherung des Femurkopf-/Schenkelhalses, der als AFD im US (AFD-US) definiert wurde. Die Reproduzierbarkeit wurde durch Intraklassen-Korrelationskoeffizienten (ICCs) und durch Bland-Altman-Diagramme bewertet; die diagnostische Leistung wurde mittels Receiver-Operating-Characteristic(ROC)-Analyse ermittelt.
Ergebnisse: AFD-US zeigte bei allen Messungen eine hohe Intra- und Interrater-Übereinstimmung (ICC = 0,913 – 0,968) und eine gute Reproduzierbarkeit zwischen den verschiedenen Anwendern für die anteriore Kontur (ICC = 0,881), jedoch nicht für die anterosuperioren Konturmessungen (ICC = 0,196). Ein AFD-US Grenzwert von 4,0 mm der anterioren Kontur erzielte nach der ROC-Analyse die höchste Sensitivität (80,9 %) und Spezifität (87,5 %) für die Diagnose eines „cam-type“ FAI.
Schlussfolgerung: AFD-US der anterioren Kontur des Femurkopf-/Schenkelhals-Übergangs unterstützt die Diagnose des „cam-type“ FAI.
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References
- 1 Ganz R, Parvizi J, Beck M et al. Femoroacetabular impingement: a cause for osteoarthritis of the hip. Clin Orthop Relat Res 2003; 417: 112-120
- 2 Lavigne M, Parvizi J, Beck M et al. Anterior femoroacetabular impingement: part I. Techniques of joint preserving surgery. Clin Orthop Relat Res 2004; 418: 61-66
- 3 Beck M, Kalhor M, Leunig M et al. Hip morphology influences the pattern of damage to the acetabular cartilage: femoroacetabular impingement as a cause of early osteoarthritis of the hip. J Bone Joint Surg Br 2005; 87: 1012-1018
- 4 Wyss TF, Clark JM, Weishaupt D et al. Correlation between internal rotation and bony anatomy in the hip. Clin Orthop Relat Res 2007; 460: 152-158
- 5 Ito K, Minka 2nd MA, Leunig M et al. Femoroacetabular impingement and the cam-effect. A MRI-based quantitative anatomical study of the femoral head-neck offset. J Bone Joint Surg Br 2001; 83: 171-176
- 6 Pfirrmann CW, Mengiardi B, Dora C et al. Cam and pincer femoroacetabular impingement: characteristic MR arthrographic findings in 50 patients. Radiology 2006; 240: 778-785
- 7 Beaule PE, Zaragoza E, Motamedi K et al. Three-dimensional computed tomography of the hip in the assessment of femoroacetabular impingement. J Orthop Res 2005; 23: 1286-1292
- 8 Kassarjian A, Yoon LS, Belzile E et al. Triad of MR arthrographic findings in patients with cam-type femoroacetabular impingement. Radiology 2005; 236: 588-592
- 9 Ganz R, Gill TJ, Gautier E et al. Surgical dislocation of the adult hip a technique with full access to the femoral head and acetabulum without the risk of avascular necrosis. J Bone Joint Surg Br 2001; 83: 1119-1124
- 10 Notzli HP, Wyss TF, Stoecklin CH et al. The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement. J Bone Joint Surg Br 2002; 84: 556-560
- 11 Kassarjian A, Brisson M, Palmer WE. Femoroacetabular impingement. Eur J Radiol 2007; 63: 29-35
- 12 Blankenbaker DG, De Smet AA. Hip injuries in athletes. Radiol Clin North Am 2010; 48: 1155-1178
- 13 Malanga GA, Dentico R, Halperin JS. Ultrasonography of the hip and lower extremity. Phys Med Rehabil Clin N Am 2010; 21: 533-547
- 14 Buck FM, Hodler J, Zanetti M et al. Ultrasound for the evaluation of femoroacetabular impingement of the cam type. Diagnostic performance of qualitative criteria and alpha angle measurements. Eur Radiol 2011; 21: 167-175
- 15 Lohan DG, Seeger LL, Motamedi K et al. Cam-type femoral-acetabular impingement: is the alpha angle the best MR arthrography has to offer?. Skeletal Radiol 2009; 38: 855-862
- 16 Kubiak-Langer M, Tannast M, Murphy SB et al. Range of motion in anterior femoroacetabular impingement. Clin Orthop Relat Res 2007; 458: 117-124
- 17 Clohisy JC, Knaus ER, Hunt DM et al. Clinical presentation of patients with symptomatic anterior hip impingement. Clin Orthop Relat Res 2009; 467: 638-644
- 18 Davies AG, Clarke AW, Gilmore J et al. Review: imaging of groin pain in the athlete. Skeletal Radiol 39: 629-644
- 19 Sutter R, Dietrich TJ, Zingg PO et al. Femoral antetorsion: comparing asymptomatic volunteers and patients with femoroacetabular impingement. Radiology 2012; 263: 475-483
- 20 Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; 1: 307-310
- 21 Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977; 33: 159-174
- 22 Aamodt A, Terjesen T, Eine J et al. Femoral anteversion measured by ultrasound and CT: a comparative study. Skeletal Radiol 1995; 24: 105-109
- 23 Kulig K, Harper-Hanigan K, Souza RB et al. Measurement of femoral torsion by ultrasound and magnetic resonance imaging: concurrent validity. Phys Ther 2010; 90: 1641-1648
- 24 Robben SG, Lequin MH, Diepstraten AF et al. Anterior joint capsule of the normal hip and in children with transient synovitis: US study with anatomic and histologic correlation. Radiology 1999; 210: 499-507