hip joint anatomy and biomechanics .

1. J.R.P S.C.P.T

2. THE HIP JOINT
SUBMITTED TO –
Dr. Kaynat Hassan Mam
Mam
(ASSIST. PROF J.R.P.S.C.P.T)
S.C.P.T)
SUBMITTED BY – BPT 17TH BATCH
MD.FURQUAN

3. INTRODUCTION
 The hip joint is the articulation of the acetabulum of pelvis and the head of the
femur.
 It is the analogous of shoulder joint.
TYPE OF JOINT
 Diathrodial ball and socket joint.
PRIMARY FUNCTION
 The primary function of the hip joint is to support the weight of the
head , arm and trunk (HAT) both in static and erect posture.

4. INTRODUCTION
DEGREE OF FREDOM = 3
1. Sagittal plane - Flexion & extension
2. Frontal plane – abduction & adduction
3. Transverse plane – medial rotation & lateral rotation

5. INTRODUCTION

6. STRUCTRE OF THE JOINT
PROXIMAL ARTICULATING SURFACE
 The proximal articulating surface is formed by cup like concave socket knows as acetabulum

7. STRUCTRE OF THE JOINT
(PROXIMAL ARTICULATING SURFACE)
ACETABULUM
 Acetabulum if formed by three pelvis bone I.e (ilium ischium &pubis).
 The acetabulum id directed laterally anteriorly and inferiorly.
 The pubis forms 1/5th of acetabulum.
 The ischium forms 2/5th of acetabulum.
 And the rest of acetabulum is formed by ilium .
 The periphery of acetabulum is known as knows as lunate surface.
 The lunate surface is covered with hyaline cartilage.
 The lunate surface is horse-shoe shaped which articulate with
the head of femur.
 The acetabulum is deepened by fibrocartilaginous acetabular labrum.

8. STRUCTRE OF THE JOINT
(PROXIMAL ARTICULATING SURFACE)
ACETABULAR NOTCH
 The inferior aspect of the lunate surface is interrupted by deep notch known as acetabular notch
 The acetabular notch is spanned by a fibrous band i.e transverse acetabular ligament that connect the two
end of horse-shoe

9. STRUCTRE OF THE JOINT
(PROXIMAL ARTICULATING SURFACE)
ACETABULAR LABRUM
 The entire periphery of the acetabulum is rimmed by a ring of wedge-shaped fibrocartilage called as
acetabular labrum.
 It is attached to the periphery of aceteabulum by the zone of calcified cartilage .
 It is analogous to the meniscus of knee and labrum of glenohumeral joint .
 The acetabular labrum not only deepens the socket but also increases the concavity of the acetabulum
.
 It also act as seal to maintain the negative intra-articular pressure .
 The nerve ending within the labrum provide proprioceptive feed back as well as the source of pain .

10. STRUCTRE OF THE JOINT
(PROXIMAL ARTICULATING SURFACE)

11. STRUCTRE OF THE JOINT
(PROXIMAL ARTICULATING SURFACE)
CENTER EDGE ANGLE OF WIBERG
 It is formed by a line connecting the lateral rim of the acetabulum and the centre of
femoral head and a vertical line from the centre of femoral head.
 Centre edge angle are classified as follow –
1. DEFINITE DYSPLASIA – 16 degree .
2. POSIBILE DYSPLASIA – 16-25 degree .
3. NORMAL DYSPLASIA – greater than 25 degree .
 Center edge angle greater than 40 degree may indicate excessive acetabular over
coverage .

12. STRUCTRE OF THE JOINT
(PROXIMAL ARTICULATING SURFACE)
CENTER EDGE ANGLE OF WIBERG

13. STRUCTRE OF THE JOINT
(PROXIMAL ARTICULATING SURFACE)
CENTER EDGE ANGLE OF WIBERG

14. ACETABULUMABNORMALITIES
1. ACETABULAR DYSPLASIA
 It is abnormally shallow acetabulum that results in a lack of femoral head coverage .

15. ACETABULUMABNORMALITIES
2. COXA PROFUNDA & ACETABULAR PROTUSION
 These are the term used describe the condition in which
acetabulum excessively cover the acetabular head .
 Acetabular over-coverage can lead to limit ROM and
internal impingment between the femoral head-neck
junction and acetabulum .

16. ACETABULUMABNORMALITIES
2. COXA PROFUNDA & ACETABULAR PROTUSION

17. COMMON TERMS
1. ANTEROVERSION - anteroversion of acetabulum exist when acetabulum is shifted far anteriorly in
transverse plane.
2. RETROVERSION – retroversion of acetabulum exist when acetabulum is shifted far posteriorly in transverse
plane .

18. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
 The distal articulating surface of the hip joint is formed by the proximal part of femur .
THE FEMUR

19. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)

20. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
FEMORAL HEAd
 It is fairly rounded and the surface is covered with hyaline cartilage
 The articular area of the femoral head forms approximately 2/3rd of sphere and
is more circular then acetabulum.
 The radius of curvature of femoral head is smaller in women then men.
 Just inferior to the most medial point of the femoral head a small rouged pit is
present called fovea or fovea capitis .
 The fovea is not covered with hyaline cartilage
 Fovea capitis is the point where the ligament of head of femur is attached .

21. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)

22. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
ANGULATION OF FEMUR
 There are two angulation is made by the head and neck of the femur in relation to the shaft.
1. Angle of inclination- it occur in frontal plane
2. Angle of torsion- it occur in transverse plane .

23. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
ANGLE OF INCLINATIONOF FEMUR
 It occur in frontal plane between an axis through the femoral head & neck
and the longitudinal axis of the shaft.
 Normal angel of inclination of the femur is approximated about 125 degree
but the it ranges from 110 to 144 degree .
 In women the angle of inclination is smaller than that of man .
 The angle of inclination of femur changes across the life span ,At birth its
about 150 degree and the gradually decreases to 125 degree as the skeleton
mature.

24. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
ANGLE OF INCLINATION OF FEMUR

25. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
ANGLEOF INCLINATIONOF FEMUR

26. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
PATHOLOGICAL ANGLEOF INCLINATION
 There are two pathological angle of inclination
1. COXA VALGA- angle of inclination is greater than 125
degree in adult.
2. COXA VARA- angle of inclination is smaller than 125
degree in adult.
 Both coxa vara and valga can lead to abmormal lower
extremity biomechanics & alterd muscle function

27. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
1. COXAVALGA
 In coxa-valga the angle of inclination in the femur is greater than 125 degree (normal
adult angle)
 The increased angle bring the vertical weight bearing line closer to the shaft of femur
that causes bending force across the femoral neck.
 Coxa valga also decreases the amount of femoral articulation

28. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
COXAVALGA

29. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
COXAVARA
 In coxa vara the angle of inclination in the femur is smaller than
125 degree (normal adult angle) .
 Coxa vara is consider to give the advantage of hip joints stability ,
but if the reduction of angle is not too extreme.
 Coxa vara has disadvantage of increasing the bending moment
along the femoral head and neck .

30. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
COXA VARA

31. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
ANGLE OF TORSIONOF FEMUR
 A line parallel to the posterior femoral condyles and align through the head and neck to femur making
an angle which is known as angle of torsion .
 The angle of torsion of femur can be best viewed by looking down to the length of the femur from top
to bottom .
 Normal angle of torsion ranges from 10 to 20 degree.
 In male it is up to 20degree .
 In female it is up to 15 degree .

32. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
ANGLE OF TORSIONOF FEMUR

33. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)
 FEMORAL ANTEROVERSION – The angle of torsion is greater than 10to20 degree.
 FEMORAL RETROVERSION- The angle of torsion is smaller than 10to20

34. STRUCTRE OF THE JOINT
(DISTAL ARTICULATING SURFACE)

35. STRUCTRE OF THE JOINT
(ligaments)
 There are seven ligaments present in the hip joint .
1. The fibrous capsule
2. The iliofemoral ligament
3. The pubofemoral ligament
4. The ischiofemoral ligament
5. Ligament of the head of the femur
6. Acetabular labrum
7. Transverse acetabular labrum
1.

36. STRUCTRE OF THE JOINT
(ligaments)
1. THEFIBROUS CAPSULE
 It is attached on the hip bone to the acetabular labrum including the transverse
acetabular labrum and to the bone above and behind the the acetabulum and on
the femur to the intertrochanteric line in front .
 Anterosuperiorly the capsule is thick and firmly attached .
 Posteroinferiorly the capsule is thin and loosely attached .
 The capsule is made up of two fibre outer fibre is longitudinal and inner fibre is
circular
 These fibre is known as ZONA ORBICULARIS

37. STRUCTRE OF THE JOINT
(ligaments)
1. THE FIBROUSCAPSULE

38. STRUCTRE OF THE JOINT
(ligaments)
2. ILIOFEMORALLIGAMENT
 It is inverted Y shaped ligament of bigelow .
 It is one of the strongest ligament in the body
 It take origin from the ilium I .e ASIS and extending the two
arm along intertrochantic line
 Its major function is to provide the resistance in excessive
motion in medial as well as lateral rotation of the hip

39. STRUCTRE OF THE JOINT
(ligaments)
2. ILIOFEMORALLIGAMENT

40. STRUCTRE OF THE JOINT
(ligaments)
3. PUBOFEMORALLIGAMENT
 Superiorly it is attached to iliopubic eminence
 Inferiorly it merge with the anteroinferior part of the capsule .
 It is also triangular in shape .
 It supports the joint inferomedially .

41. STRUCTRE OF THE JOINT
(ligaments)
3. PUBOFEMORAL LIGAMENT

42. STRUCTRE OF THE JOINT
(ligaments)
4. ISCHIOFEMORAL LIGAMENT
 This is the posterior ligament which take origin from the acetabular rim and labrum and end over the
femoral neck
 It is comparatively weak
 Its fibre is twisted

43. STRUCTRE OF THE JOINT
(ligaments)
5. LIGAMENTOF HEADOF FEMUR
 It is also knows as ligamentum teres
 It is triangular and flat in shape .
 Its apex it attached to fovea capitis and its base is attached to base of transverse ligament
 It may be very thin .

44. STRUCTRE OF THE JOINT
(ligaments)
5. LIGAMENT OF HEADOF FEMUR

45. STRUCTRE OF THE JOINT
(ligaments)
6. TRANSVERSACETABULARLIGAMENT
 It is the part of acetabular labrum which bridge the acetabular labrum

46. BLOODSUPPLY OF HIP JOINT
 Lateral & medial circumflex of femoral artery
 Two gluteal artery
 Obturator artery

47. NERVE SUPPLY OF HIP JOINT
 Femoral nerve
 Nerve to rectus femoris
 Anterior division of obturator nerve
 Superior gluteal nerve

48. STRUCRAL ADAPTATION
 The internal architecture of the pelvis and the femur reveals the remarkable interaction between the
mechanical stress and the structural adaptation created by the transmission of forces between femur and
pelvis .
 In standing or upright weight bearing activities at least half of the weight of HAT passes down through the
pelvis to the femoral head ,
 The GRF travel up the shaft
 These two forces are parallel and opposite to each other ,and they create a bending moment (shear force)
across the femoral neck.
 The bending stress creates a tensile force on the superior aspect of femoral neck and compressive stress on
the inferior aspect
 A complex set of forces prevents the rotation and resist the shear force that the force couple causes .

49. STRUCRAL ADAPTATION
TRABECULAR SYSTEM
 There are 2 major and 3 minor trabecular system
 Major trabecular system
1. Medial or principal compressive trabecular system
2. Lateral or principal tensile trabecular system
 Minor trabecular system (secondary trabecular system )
a. secondary compressive system .
b. secondary tensile system .
c. another secondary trabecular system is confined to trochanteric area of femur .

50. STRUCRAL ADAPTATION
 Medial trabeculae system is oriented along the vertical compressive
force passing through the hip joint
 Lateral trabeculae system is oblique and may develop in response
to shear force of the weight of HAT and GRF
 According to HELLER and its colleagues
 The area in which trabecular system cross each other at right angle
offer greatest resistance to stress and strain
 The area in the femoral neck in which trabeculae is relatively thin
and does not cross each other is known as zone of weakness