X-rays: Pelvis, Hip & Shoulder

1. X-rays:Pelvis, Hip & Shoulder Feb. 22, 2006 J. Huffman, PGY-1 Thanks to Dr. J. Lord Also thanks to Moritz, Adam and Steve Lan for some borrowed slides and images

2. Goals: As per instructions, this is a radiology talk ONLY. The focus is on reading as many films as possible. Therefore, try your best to describe what you see as you would when on the phone with a consultant. • No epidemiology • No management • No associated injuries (i.e. vascular injury with pelvic #)

3. Pelvis Anatomy Views Classification of fractures Practice Hip Anatomy Views Fractures Dislocations Practice Shoulder Anatomy Views Dislocations Fractures Practice Outline

4. Pelvis = sacrum, coccyx + 2 inominate bones Inominate bones = ilium, ischium, pubis Strength from ligamentous + muscular supports Pelvis: Anatomy

5. Anterior Support: ~40% of strength Symphysis pubis Fibrocartilaginous joint covered by ant & post symphyseal ligaments Pubic rami Posterior Support: ~60% of strength Sacroiliac ligament complex Pelvic floor Sacrospinous ligament Sacrotuberous ligament Pelvic diaphragm Pelvis: Anatomy

6. Pelvis: Anatomy • Very strong posterior ligaments • Disruption of these is the cause of mechanical instability • Arteries and veins lie adjacent to posterior arch

7. Divided into 3 columns: Anterior superior column (= ilium) Anterior inferior column (= pubis) Posterior Column (= ischium) Pelvis: Anatomy

8. Pelvis: Imaging • Plain films • AP • Inlet view / Outlet view • Judet view (oblique – shows columns, acetabulum) • AP alone ~90% sensitive; combined w/ inlet/outlet views ~94% • Limited in ability to clearly delineate posterior injuries • Pelvic films are NOT necessary in pts with normal physical exam, GCS >13, no distracting injury and not intoxicated • At least one study shows clinical exam reliable in EtOH • Gonzalez et al. J Am Coll Surg. 2002; 194: 121-5 • CT scans • Evaluates extent of posterior injury better • Superior imaging of sacrum and acetabulum • More detailed info about associated injuries

11. Pelvis: Imaging - Acetabulum • Arcuate line • Ileoischial line • Radiographic U (teardrop) • Acetabular roof • Anterior lip of acetabulum • Posterior lip of acetabulum

12. Pelvis: Imaging - Acetabulum

13. Pelvis: Imaging – Normal Inlet

14. Pelvis: Imaging – Normal Outlet

15. Pelvis: Imaging • Radiographic clues to posterior arch fractures: • L5 transverse process avulsion* (iliolumbar ligament) • Avulsion of the lower, lateral sacral lip* (sacrotuberous ligament) • Ischial spine avulsion* (sacrospinous ligament) • Assymmetry of sacral foramina • Displacement at the site of a pubic ramus fracture

16. Pelvis: Fracture Classification Systems • 2 most common are Tile and Young systems • Tile Classification system: • Advantages • Comprehensive • Predicts need for operative intervention • Disadvantages • Does NOT predict morbidity or mortality • Young Classification System: • Advantages • Based on mechanism of injury  predicts ass’d injury • Estimates mortality • Disadvantages • Excludes more minor injuries

17. Tile Classification System Type A: • Stable: Posterior structures intact Type B: • Partially stable: Posterior structures incompletely disrupted Type C: • Unstable: Posterior structures completely disrupted *Each type further classified into 3 sub-types based on fracture.

18. Type A: Stable pelvis: post structures intact A1: avulsion injury A2: iliac wing or ant arch # A3: Transverse sacrococcygeal # Tile Classification System

19. Type B: Partially stable pelvis: incomplete posterior structure disruption B1: open-book injury B2: lateral compression injury B3: contralateral / bucket handle injuries Tile Classification System

20. Type C: Unstable pelvis: complete disruption of posterior structures C1: unilateral C2: bilateral w/ one side Type B, one side Type C C3: bilateral Type C Tile Classification System

21. Young Classification System • Lateral Compression • Anteroposterior Compression • Vertical Shear • Combination *LC and APC further classified into 3 sub-types based on fracture

22. Lateral Compression (50%) transverse # of pubic rami, ipsilateral or contralateral to posterior injury LC I – sacral compression on side of impact LC II – iliac wing # on side of impact LC III – LC-I or LC-II on side of impact w/ contralateral APC injury Young Classification System:

23. AP Compression (25%) Symphyseal and/or Longitudinal Rami Fractures APC I – slight widening of the pubic symphysis and/or anterior SI joint APC II – disrupted anterior SI joint, sacrotuberous, and sacrospinous ligaments APC III – complete SI joint disruption w/ lateral displacement and disruption of sacrotuberous and sacrospinous ligaments Young Classification System:

24. Vertical Shear (5%) Symphyseal diastasis or vertical displacement andteriorly and posteriorly Combined Mechanism combination of injury patterns Young Classification System:

25. Young Classification System: Morbidity and Mortality

26. Tile A1

27. Tile B1 / Young APC II

28. Tile C1/ Young VS

29. Tile A1

30. No Fracture, just an IUD

31. Tile B3 / Young APC

32. Tile A2 / Young LC II

33. No #, just SC air from rib fractures

34. Pelvis: Acetabular Fractures • Four Categories: • Posterior lip fracture • Commonly assoc. w/ posterior hip dislocation • Central or transverse fracture • Fracture line crosses acetabulum horizontally • Anterior column fracture • Disrupts arcuate line, ileoischial line intact, U displaced medially • Posterior column fracture • Ileoischial line disrupted and separated from the U • Judet (oblique views) or CT helpful if suspicious

35. Pelvis: Imaging - Acetabulum

36. Focus on the acetabular fractures. Posterior Column #

37. Posterior Column #

38. Anterior Column #

39. Bilateral Anterior Column #

40. Posterior Lip #

41. Central (Transverse) fracture

42. Proximal Femur & Hip

43. Proximal Femur & Hip: Injuries • Fractures: • Femoral neck, intertrochanteric, femoral head, greater & lesser trochanter, subtrochanteric • Dislocations: • Anterior, posterior, central, (inferior)

44. Proximal Femur: Anatomy Ward’s Triangle

45. Proximal Femur: Images • AP • Internal rotation! • Lateral • Cross-table Lateral • Frog-leg Lateral

46. Proximal Femur: Images Cross-table lateral view * = ischial tuberosity

47. Proximal Femur: Fracture Classification • Relationship to capsule • Intracapsular, extracapsular • Anatomic location • Neck, trochanteric, intertrochanteric, subtrochanteric, shaft • Degree of displacement

48. Proximal Femur: Approach to the film • Shenton’s Line • Femoral neck # • Dislocation • ‘S’ and ‘Reverse S’ patterns • Position of lesser trochanter • Dislocation • Femoral head size • Dislocation • Trace trabecular groups

49. Left posterior dislocation – note Shenton’s line

50. Proximal Femur: Approach to the film Lowell’s ‘S’ patterns