1. Imaging adult hip pain
James F Griffith
Department of Imaging and Interventional Oncology
Prince of Wales Hospital

2. What’s hip in hip imaging
º Early onset OA
º Hip dysplasia
º Femoroacetabular impingement (FAI)
º Non-FAI impingement syndromes of hip
º Abductor tendon problems (greater trochanteric pain syn.)

3. Acetabular lines
Sourcil ‘eyebrow’ [Fr]
Acetabulum
‘vinegar bowl’ [Lt]

4. Hip dysplasia - too shallow
Mild
Moderate
Severe
Acetabulum should cover ~ 80% of the femoral head

5. Hip dysplasia - too deep
normal
profunda
º Floor of acetabular fossa extends beyond ilioischial line

6. Centre-edge (CE) angle
º Normal centre-edge (CE) angle 25 - 400
º Abnormal < 200 or > 400
Beltran LS et al AJR 2012

7. Acetabular index
º Normal acetabular index 0 -10 degrees
º Negative value indicates profunda

8. Acetabular retroversion
Three radiographic signs of acetabular retroversion

9. Proximal femoral morphology
head-neck junction
‘pistol-grip deformity’
Osseous bump
Os supra-acetabulare
º These radiographic abnormalities are reliable

10. Femoroacetabular Impingement
(FAI)
º Not as common in the East
º Leads to premature labral injury & premature OA
º Cam-type, pincher-type & mixed type

11. Cam-type

12. Cam-type
α=39°
Normal alpha angle < 550
α=64°

13. Cam-type
Insert Movie 1
Most severe cam-type deformity at anterosuperior plane →
renewed interest in radial hip imaging (should use 600 as cutoff)
Sutter R et al Radiology 2012

14. Pincher (protrusio)
global overcoverage
Normal
Protrusio

15. Pincher (retroversion)
Focal overcoverage

16. Femoral torsion
↓ femoral torsion
Impingement in
internal rotation
↑ femoral torsion
Impingement in
external rotation
Sutter R et al Radiology 2012

17. Femoral torsion
Normal femoral torsion = 12- 150
Sutter R et al Radiology 2012

18. FAI – controversy
º Very high no. of asymptomatic radiographic deformity
º Only small number → osteoarthritis
º
º
º
º
Level of activity clearly important
Considerable inherent variability in imaging assessment
FAI is a clinical diagnosis
“Acetabular ±femoral morphological tendency to FAI”
Hartofilakidas G et al JBJS 2011
Hartofilakidis G et al JBJS 2011
deBruin F et al Eur Radiol 2013

19. Pelvic tilt
>Pelvic tilt ↑ acetabular coverage → ↑ likelihood of impingement
Sutter R et al AJR 2013

20. Morphology – so what ??
Shallow
acetabulum
Deep
acetabulum
Retroverted
acetabulum
Proximal
femoral
dysplasia
º Very little can be done
º Operative success questionable
º Helps to explain symptoms
º Potential for prevention
Hip pain,
Labral injury
Premature OA

22. Labral tear description
Degenerate
Frayed
Partial thickness
Full thickness

23. Labral tear description
Degenerate
Frayed

24. Labral tear description
Partial thickness
Full thickness

25. Labral / paralabral cyst

26. Labral tear localisation
12
3
9
6
• Anterior
• Superior
• Posterior
Reverse clock-face

27. Labral tears
55% tears occur just
between 3 – 12 o’clock
95% occur between
3-12 o’clock & beyond
12
3

28. Sublabral sulcus in 20%
At anteroinferior & posteroinferior aspects

29. Iliopsoas impingement
º Isolated anterior labral tear at 3 o’ clock
º Considered due to iliopsoas impingement
Blankenbaker DG et al AJR 2012

30. Articular cartilage
Hip cartilage very thin (3.5mm - 4mm in total)

31. Articular cartilage
Cartilage delamination
& ligamentum teres tear

32. Hip Traction
No traction
Traction
Llopis E et al AJR 2008

33. Arthrography – Yes or No
º Direct arthrography more sensitive
º Loose effect of seeing hip joint effusion
º Moderate post-arthropathy pain is common,
delayed & lasts~2 days
º Non-invasive → invasive investigation
º Time consuming, ↑ cost, ↓ unit productivity

34. 3.0T
or
1.5T
Cardiac
coil
(6
element
SENSE)
T2
SPIR
obl
cor
PD
obl
cor
PD
FS
obl
ax
PD
FS
obl
sag
±
T2
FS
(whole
pelvis)
±PD
axial
(whole
pelvis)

35. Ischiofemoral impingement
º Impingement of quadratus femoris m.
º More common in women
º Deep-seated buttock pain
º Often bilateral, but only one side symptomatic
º Can respond to steroid/ long acting LA injection

36. Ischiofemoral impingement
º Ischiofemoral distance
º 13.5mm ±5mm in patients vs 23 ±8mm controls
Torriani M et al AJR 2009

37. Ischiofemoral impingement
Insert Movie 2

38. Gr. trochanter - facets
Anterior facet

39. Gr. trochanter - facets
Lateral
facet

40. Gr. trochanter - facets
Posterosuperior
& Posterior
facets

41. Gr. trochanter – tendon insertions
Glut. minimus
Glut medius

42. Gr. trochanter – tendon insertions

43. Gr. trochanter – bursa
Glut. Min. bursa
Glut med bursa
Trochanteric

44. Abductor tendons
Gluteus minimus
Gluteus medius

45. Abductor tendon tears
Peritendinitis
Gluteus minimus tear

46. Abductor tendon tears
Gluteus minimus avulsion

47. Abductor tendinosis & tears
º Very high % are bilateral & asymptomatic
º Tears much more likely to be symptom indicative
Blankenbaker DG et al Skel Radiol 2008

48. 45 volunteers (38 years)… 3T MRI
º 69% had labral tears
º 13% has labral / paralabral cysts
º 24% had chondral defects
º 11% acetabular bone oedema
º 22% has fibrocystic change in head/neck region
º 20% had osseous bumps
º 16% had subchondral cysts
º Overall, 73% has some abnormality
Register B et al Amer Jour Sports Med 2013

49. Hip imaging is hip!
º Things might look a bit messy
º Plenty to be happy about!
Thank you!