lower limb

1. THE HIP JOINT
Dr M Idris Siddiqui

2. Hip Joint
• Hip Joint is a synovial joint which is
ball and socket type, that is located
between:
• Hip bone’ s acetabulum and
• Head part of femur.
• This is considered as biggest ball and
socket joint in the body.

4. Articulating Surfaces
acetabulum
• The acetabulum is a cup-like depression located on
the inferolateral aspect of the pelvis. Its cavity is
deepened by the presence of a fibrocartilaginous
collar – the acetabular labrum.
• The acetabulum (Latin acetabulum = vinegar cup)
presents 3 features:
– A horseshoe-shaped lunate surface,
– Acetabular notch, and
– Acetabular fossa.
• Out of these, only lunate surface is articular and covered by an
articular cartilage.

6. Articulating Surfaces
Head of femur
• The head of femur is hemispherical, and
fits completely into the concavity of the
acetabulum.
• Both the acetabulum and head of femur
are covered by articular hyaline cartilage
which is thicker at the places of weight
bearing(with the exception of a small pit-
the fovea capitis for ligamentum teres)

7. CAPSULE OF HIP JOINT
• The capsular ligament is a powerful.
• On the hip bone, it is connected 5-6 millimeter
beyond the acetabular margin, outer aspect of the
acetabular labrum and transverse acetabular
ligament.
• On the femur, it is connected anteriorly to the
intertrochanteric line and posteriorly 1 cm in front
of (medial to) the intertrochanteric crest.
• The capsule is thicker anterosuperiorly.
Posteroinferiorly it is thin and loosely connected.

9. CAPSULE OF HIP JOINT
• The capsule is made up 2 types of fibres-
inner circular fibres and outer longitudinal
fibres.
• The inner circular fibres create collar around
the femoral neck (zona orbicularis). These
fibres are not directly connected to the
bones.
• The outer longitudinal fibres are represented
along the neck toward the head to create the
retinacula

10. The synovial membrane
• The synovial membrane lines:
• Inner aspect of the fibrous capsule,
–The intracapsular portion of the femoral neck,
–Glenoid labrum (both surfaces),
–Transverse acetabular ligament,
–Ligamentum teres, and
–Fat in the acetabular fossa.
• It is thin on the deep surface of the
iliofemoral ligament where it is compressed
against the head.

11. Ligaments
• The ligaments of the hip joint act to increase stability.
• Joint capsule itself is a powerful ligament .
• The ligaments of the hip joint can be divided into two
groups – intracapsular and extracapsular:
Intracapsular
• Ligament of head of femur. It is a relatively small
structure, which runs from the acetabular fossa to the
fovea of the femur.
– It encloses a branch of the obturator artery (artery to head
of femur), a minor source of arterial supply to the hip joint.
• Transverse acetabular ligament.
• Acetabular labrum.

12. Ligaments
Extracapsular
• There are three main extracapsular
ligaments, continuous with the outer
surface of the hip joint capsule:
1. Iliofemoral ligament
2. Pubofemoral
3. Ischiofemoral.

14. ILIOFEMORAL LIGAMENT
• The iliofemoral ligament is inverted Y-shaped ligament, which is
located anteriorly and closely combined with the capsule.
• Its apex is connected to the lower half of the anterior inferior iliac
spine and area between it and above acetabular margin.
• Its base is connected to the intertrochanteric line. This ligament
includes 3 parts-
– A Lateral thick group of oblique fibres,
– A medial thick group of vertical fibres, and
– A large central thin portion.
• Iliofemoral ligament prevents the trunk from falling backwards in
the standing position.
– It prevents hyperextension of the hip joint. It is the strongest of
the three ligaments.

15. PUBOFEMORAL LIGAMENT
• It spans between the superior pubic rami and the
intertrochanteric line of the femur, reinforcing the
capsule anteriorly and inferiorly.
• The pubofemoral ligament is a triangular ligament
– Base above i.e. iliopubic eminence, superior pubic ramus,
and obturator crest.
– Apex i.e. intertrochanteric line of the femur below.
• It is located inferomedially and supports the joint on
this particular aspect.
• Inferiorly it combines with all the anteroinferior part
of the capsule and medial group of the iliofemoral
ligament.
– It has a triangular shape, and prevents excessive abduction and extension.

16. ISCHIOFEMORAL LIGAMENT
1. It spans between the body of the ischium and the
greater trochanter of the femur, reinforcing the
capsule posteriorly.
2. The ischiofemoral ligament is comparatively feeble
and supports the capsule posteriorly.
3. Above it isconnected to the ischium posteroinferior
to the acetabulum.
– From ischium its fibres spiral behind the femoral neck to
be connected into the greater trochanter deep to the
iliofemoral ligament.
– It prevents hyperextension and holds the femoral head in the
acetabulum.

18. Ligamentum teres /foveal ligament
(Round ligament of head of femur)
• This ligament is also termed ligamentum teres of the
head of femur. It is a flat triangular ligament with apex
connected to the fovea of the head, and its base to the
Transverse acetabular ligament.
• The ligamentum teres is a round ligament that
connects the femoral head with the acetabulum. The
ligament contains a blood vessel, originated from the
acetabular branches of the obturator and medial
circumflex femoral arteries which contribute the blood
supply of the femoral head during childhood.
– Transverse acetabular ligament. It is ensheathed by a conical
reflection of the synovial membrane.

20. ACETABULAR LABRUM
• Acetabular labrum is a fibrocartilaginous
rim connected to the acetabular margin.
• It is triangular in cross section.
• The labrum not only deepens the
acetabulum (socket) but takes the head
of femur softly to hold it in position.

21. TRANSVERSE ACETABULAR LIGAMENT

22. TRANSVERSE ACETABULAR LIGAMENT
• It is a part of acetabular labrum,
which bridges the acetabular notch.
• It is devoid of cartilage cells.
• The acetabular notch so becomes
converted in the foramen which
carries the acetabular vessels and
nerves to the hip joint.

23. SOLIDITY OF THE HIP JOINT
• The firmness of the hip joint is supplied by the
following factors which help prevent its
dislocation:
• Depth of the acetabulum and narrowing of its
mouth by the acetabular labrum.
• 3 powerful ligaments (iliofemoral, pubofemoral,
and ischiofemoral) reinforcing the capsule of the
joint.
• Strength of the surrounding muscles, example,
gluteus medius, gluteus minimus, etc.
• Length and obliquity of the neck of femur.

24. RELATIONSHIPS

25. ANTERIORLY Tendon of iliopsoas divided from joint by a synovial
bursa, pectineus (lateral part), straight head of rectus
femoris.
Femoral nerve in the groove between the iliacus and the
psoas.
Femoral artery in front of the psoas tendon.
Femoral vein in front of the pectineus.
POSTERIORLY Piriformis, obturator externus, obturator internus, superior
and inferior gemelli, quadratus femoris, and gluteus
maximus.
Superior gluteal nerve and vessels above the piriformis.
Inferior gluteal nerve and vessels below the piriformis.
Sciatic nerve, posterior cutaneous nerve of the thigh, and
nerve to quadratus femoris.
SUPERIORLY Reflected head of rectus femoris medially.
Gluteus minimus, gluteus medius, and gluteus maximus
laterally.
INFERIORLY Pectineus.
Obturator externus.

26. BURSAE AROUND THE HIP JOINT

27. BURSAE AROUND THE HIP JOINT
• These are 7 in number:
• 4 under glutens maximus,
• Between gluteus maximus and smooth area of the ilium being
located between the posterior curved line and the outer lip of
the iliac crest.
• Between gluteus maximus and lower part of the outer aspect of the
higher trochanter (trochanteric bursa).
• Between gluteus maximus and ischial tuberosity (ischial bursa).
• Between the tendon of gluteus maximus and vastus
lateralis (gluteofemoral bursa).
• 1 under gluteus medius, 1 under gluteus minimus,
• 1 under psoas tendon as under:
– i.e. between the iliopubic eminence and the psoas tendon.
It’s termed subpsoas bursa.

28. ARTERIAL SUPPLY
• The arterial supply of the head and neck of the femur
medically really essential. It is originated from the
following three sources:
1. Acetabular branches of the obturator artery and the
medial circumflex femoral arteries. These arteries get
to the head via the round ligament of the head.
2. Retinacular vessels (the main source) originate from
the medial circumflex femoral artery, run along the
neck of the femur via the retinaculum of the capsule.
3. Nutrient artery of the femur supplies few branches to
the neck and head of femur

29. Arterial Supply
• The arterial supply to the hip joint is largely via the medial
and lateral circumflex femoral arteries – branches of the
profunda femoris artery (deep femoral artery).
– These anastomose at the base of the femoral neck to form a ring,
from which smaller arteries arise to supply the hip joint itself.
• The medial circumflex femoral artery is responsible for the
majority of the arterial supply via Retinacular vessels (the
lateral circumflex femoral artery has to penetrate through the
thick iliofemoral ligament).
– Damage to the medial circumflex femoral artery can result
in avascular necrosis of the femoral head.
• The artery to head of femur (acetabular branches of
obturator artery) and the superior/inferior gluteal arteries
provide some additional supply.

30. NERVE SUPPLY
The hip joint is supplied by the following nerves:
The hip joint is innervated primarily by
the sciatic, femoral and obturator nerves.
• 4 spinal nerves (L2, L3, L4, L5) control the
movements of the hip joints as below:
– L2 and L3 modulate flexion, adduction, and medial
rotation.
– L4 and L5 modulate extension, abduction, and lateral
rotation.
• These same nerves innervate the knee, which
explains why pain can be referred to the knee from
the hip and vice versa

33. Flexion Iliopsoas , rectus femoris, and sartorius and also
by the adductor muscles
Extension
(a backward movement
of the flexed thigh)
Gluteus maximus and the hamstring muscles
Abduction Gluteus medius and minimus, assisted by the
sartorius, tensor fasciae latae, and piriformis
Adduction Adductor longus and brevis and the adductor
fibers of the adductor magnus. These muscles are
assisted by the pectineus and the gracilis
Lateral rotation Piriformis , obturator internus and externus,
superior and inferior gemelli, and quadratus
femoris, assisted by the gluteus maximus
Medial rotation Anterior fibers of the gluteus medius and gluteus
minimus and the tensor fasciae latae
Circumduction
(combination of all movements)
Note: The extensor group of muscles is more powerful than the flexor group, and the lateral
rotators are more powerful than the medial rotators.

34. DISLOCATION OF THE HIP JOINT
• (a) Congenital dislocation: The congenital dislocation
of the hip joint is much more common than every
other joint within the body. It happens because of
two reasons:
• The joint capsule is loose at birth.
• Hypoplasia of the acetabulum and femoral head: In
this state, the head of femur slips upward into
the gluteal region since the upper margin of the
acetabulum is developmentally deficient.
• Medically, it presents as:
– Inability of the newborn to abduct the thigh.
– Affected limb is shorter in length and externally rotated.
– Asymmetry of skin folds of the thighs.
– Lurchinggait with positive Trendelenburg’s hint

35. Stabilising Factors
• The primary function of the hip joint is to weight-bear. There are a
number of factors that act to increase stability of the joint.
1. The first structure is the acetabulum. It is deep, and
encompasses nearly all of the head of the femur.
2. There is a horseshoe shaped fibrocartilaginous ring around the
acetabulum which increases its depth, known as the acetabular
labrum. The increase in depth provides a larger articular surface.
3. The iliofemoral, pubofemoral and ischiofemoral ligaments are
very strong, and along with the thickened joint capsule, provide a
large degree of stability. These ligaments have a unique spiral
orientation; this causes them to become tighter when the joint is
extended.
4. In addition, the muscles and ligaments work in a reciprocal
fashion at the hip joint:
– Anteriorly, where the ligaments are strongest, the medial flexors
(located anteriorly) are fewer and weaker.
– Posteriorly, where the ligaments are weakest, the medial rotators are
greater in number and stronger .

36. REFERRED PAIN OF THE HIP JOINT
• In diseases of the hip joint like
tuberculosis, the pain is referred
to the knee joint due to the
common nerve supply of these
two joints.

37. FRACTURES OF THE NECK OF THE
FEMUR
• These fractures are generally
common in people of more
than 60 years of age notably in
females because their femoral
necks become weak and fragile
as a result of osteoporosis.
• The fractures of the neck of
femur are of 4 types:
• Subcapital (near the head).
• Cervical (in the middle).
• Basal (near the trochanters).
• Pretrochanteric fracture (just
distal to 2 trochanters).

38. Hip Joint Stability and Trendelenburg's Sign
• The stability of the hip joint when a person stands on
one leg with the foot of the opposite leg raised above
the ground depends on three factors:
– The gluteus medius and minimus must be functioning
normally.
– The head of the femur must be located normally within the
acetabulum.
– The neck of the femur must be intact and must have a
normal angle with the shaft of the femur.
• If any one of these factors is defective, then the pelvis
will sink downward on the opposite, unsupported side.
The patient is then said to exhibit a positive
Trendelenburg's sign