Ultrasound and radiography findings in developmental dysplasia of the hip: a pictorial review Poster No.: C-2542 Congress: ECR 2012 Type: Educational Exhibit Authors: S. P. Ivanoski; Ohrid/MK Keywords: Musculoskeletal joint, Pediatric, Ultrasound, Plain radiographic studies, Education, Diagnostic procedure, Congenital DOI: 10.1594/ecr2012/C-2542 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 25
Learning objectives To explain the ultrasound and radiography examinations for diagnosing developmental dysplasia of the hip (DDH). To get familiar with the degrees and methods of ultrasound evaluation of DDH. To get familiar with standard radiography diagnosis of DDH. Background Developmental dysplasia of the hip is a condition that brings together the following terms: subluxation, luxation, hip instability and antenatal (teratologic) hip dislocation. The major factors for developing this condition are genetic factors (family history), breech presentation and sex (female). There are differences in incidence among different regions and ethnicities worldwide, from 0.06 in Africans to 76.5 per 1000 newborns in Native Americans, in Europe the highest incidence is in Eastern European Countries, Spain and Mediterranean Islands. It is a major factor for early development of osteoarthritis in adults. On time recognition of the condition is essential because the treatment is easier, cheaper and later open reduction surgery could be avoided. Imaging findings OR Procedure details Ultrasound imaging The ultrasound method developed and described by D-r Reinhard Graf is used for assessing the child's hip maturity in our institution. The hip is scanned in a standard coronal plane. To find the standard plane one has to visualize the three important landmarks: the lower limb of iliac bone, the bony rim (middle portion of acetabulum), and the acetabular labrum (fig 1.). The bony rim is defined as the point where the concavity of the bony acetabular roof turns into convexity. It could be angular (fig 2.), blunt (fig 3) or rounded (fig 4) Page 2 of 25
After defining the standard plane and finding the landmarks, 3 straight lines are drawn, and angles are measured for quantitative evaluation of hip maturity. The baseline, that passes through the iliac plane, the bony roof line and the cartilage roof line (inclination line). Alpha is the angle between the baseline and the bony roof line, and it determines the hip type. Beta is the angle between the baseline and the inclination line and it determines the hip subtype (fig 5). The hip maturity is then assessed by the combination of measured values for alpha and beta angles. D-r Graf proposed a classification system based on alpha and beta values, and divided all hips in four types, Type I-mature hip (alpha value over 60 degrees), Type II (alpha values from 43-59), type III and IV (alpha values below 43 degrees). The ultrasonography classification of developmental hip displasia by D-r Graf is given below. Graf's type hip Description # angle (º) # angle (º) Bony rim Age >60 <55 Angular/ slightly blount Any I Normal IIa Physiologically50-60 immature 55-77 rounded 0-12 wks IIb Immature 50-59 55-77 rounded >12 wks IIc Critical stable/ unstable 43-49 >77 Rounded or Any flattened D Decentered hip 43-49 >77 Rounded or Any flattened III Eccentric with acetabular labrum pressed upwards <43 >77 flattened Any <43 >77 flattened Any IV Eccentric with acetabular labrum pressed downwards As described by D-r Graf Page 3 of 25
Below there are some examples of various degrees of developmental hip displasia: Type 1a hip (10 weeks old child), alpha value- 65 degrees, beta value- 43 degrees Fig. 6: Type 1a hip References: S. P. Ivanoski; Radiology, Ohrid, MACEDONIA Type 1b (12 week old child), alpha value- 65 degrees, beta-57 degrees Page 4 of 25
Fig. 7: Type 1b hip References: S. P. Ivanoski; Radiology, Ohrid, MACEDONIA Type 2a physiologically immature hip (8 week old), alpha- 57 degrees, beta- 67 degrees Page 5 of 25
Fig. 8: 2a physiologically immature hip Page 6 of 25
References: S. P. Ivanoski; Radiology, Ohrid, MACEDONIA Type IIc, alpha value- 46, beta-74 Fig. 9: 2c hip References: S. P. Ivanoski; Radiology, Ohrid, MACEDONIA Type D hip example, alpha value- 44 degrees, beta-94 Page 7 of 25
Fig. 10: Type D References: S. P. Ivanoski; Radiology, Ohrid, MACEDONIA Type 4 hip, alpha value- 40 degrees, acetabular labrum is compressed and displaced caudally Page 8 of 25
Fig. 11: Type 4 hip References: S. P. Ivanoski; Radiology, Ohrid, MACEDONIA Radiography findings Page 9 of 25
Plain radiography is an adequate method for asessing congenital hip displasia after ossification centre has occurred, and ultrasound diagnosis is more difficult to perform. To evaluate hips few standard lines are drawn on a standard A-P radiograph of child's pelvis. Hilgenreiner line is a straight horizontal line drawn between the superior aspects of both triangulate cartilages. Perkins line is a vertical line drawn perpendicular to the previously explained line, through the lateral portion of the acetabulum. Both line divide the field into 4 quadrants. In normally developed hip the ossification centre should be in the lower inner quadrant (fig 12). The acetabular index is the angle formed between the Hilgenreiner line and the line drawn between the superior lateral and inferior medial parts of the acetabulum. It's normal values should be less than 30 degrees in infants and vary between 25-29 degrees. Shenton line is a curved line that connects the medial femoral metaphysic and the inferior edge of the inferior pubic ramus. It should be continuous in normally developed hip (fig 12). Left side hip displasia (fig 13) with acetabular index of 35 degrees. The right hip appears normal. Note the less developed epyphiseal femoral ossification center compared to normally developed side. Right side displasia (14), the osification center is in the outher upper quadrant. Notice the irregular Shenton line compared with left side normal Shenton line. Images for this section: Page 10 of 25
Fig. 1: The standard plane: 1. lower limb of iliac bone; 2. acetabular labrum; 3. bony rim; 4. iliac contour; 5. ossification centre 6. Femoral neck; 7. Greater trohanter Page 11 of 25
Fig. 2: angular bony rim Page 12 of 25
Fig. 3: Blunt bony rim Page 13 of 25
Fig. 4: Rounded bony rim Page 14 of 25
Fig. 5: Three standard lines and alpha and beta angles: 1. baseline 2. bony roof line 3. inclination line Page 15 of 25
Fig. 6: Type 1a hip Page 16 of 25
Fig. 7: Type 1b hip Page 17 of 25
Fig. 8: 2a physiologically immature hip Page 18 of 25
Fig. 9: 2c hip Page 19 of 25
Fig. 10: Type D Page 20 of 25
Fig. 11: Type 4 hip Page 21 of 25
Fig. 12: plain radiography normal finding. 1. Hilgenreiner's line 2.Perkin's line 3. Acetabular index 4. Femoral head ossification center 5. Shenton's line Page 22 of 25
Fig. 13: Left side hip dysplasia Page 23 of 25
Fig. 14: Right side developmental hip displasia Page 24 of 25
Conclusion Ultrasound screening of normal population together with clinical examination is important for on time diagnosis and avoiding the complicacies of DDH, especially in countries with high incidence of the condition. Radiography is the first performed examination in older children, where ultrasound is not possible or very difficult to perform, because the epiphysis of the femoral head has ossified. Personal Information References Graf R. (2006). Hip Sonography: Diagnosis and Management of Infant Hip Dysplasia, Heidelberg:Springer Graf R. (1984). Classification of hip joint dysplasia by means of sonography. Arch Orthop Trauma Surg.102:248-55 Randall T. Loder and Elaine N. Skopelja, "The Epidemiology and Demographics of Hip Dysplasia," ISRN Orthopedics, vol. 2011, Article ID 238607, 46 pages, 2011. doi:10.5402/2011/238607 Karnik A. Hip utrasonography in infants and children. Indian J Radiol Imaging [serial online] 2007 [cited 2012 Feb 1];17:280-9. Available from: http://www.ijri.org/text.asp?2007/17/4/280/36879 Kosar P., Ergun E., Unulbay D., & Kosar U. (2009). Comparison of morphologic and dynamic US methods in examination of the newborn hip, Diagn Interv Radiol, 15:284-289 Davies A. M., Johnson K. J. & Whitehouse R. W. (2006) Imaging of the hip & bony pelvis, Berlin:Springer Storer S. K. & Skaggs D. L. (2006), Developmental Dysplasia of the Hip. American Family Physician, 74(8):1310-1316 Norton I. K. & Polin S. A. M. (2011), Imaging in Developmental Dysplasia of the Hip. Medscape http://emedicine.medscape.com/article/408225-overview French L. M., & Dietz F. R., (1999), Screening for Developmental Dysplasia of the Hip. American Family Physician, 60(1):177-184 Castro W. H. M., Jerosch J., & Grossman T.W. (2001). Examination and Diagnosis of Musculoskeletal Disorders, Stuttgart: Thieme Page 25 of 25