Joints Of The Lower Limb

Joints Of The Lower Limb

Which muscles are chief flexors of hip joint?

1. Iliacus,

2. Psoas major, and

3. Pectineus.

Hip Anatomy Muscles

What is the nerve supply of hip joint?

Hip Joint Nerve supply: The three nerves of the pelvic girdle and lower limb supply the hip joint (Hilton’s law).

1. Femoral nerve via the nerve to rectus femoris,

2. Sciatic nerve via the nerve to quadratus femoris, and

3. Obturator nerve directly from its anterior division.

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Name the articulating surface participating in formation of hip joint

There are two bones taking part in hip joint. They are

1. Head of femur, and

2. Articulating surface of acetabular cavity of hip bone.

Lower Extremity Joints

Dislocation of hip joint

 

Attachments of capsule of hip joint

1. Attachments of the capsule: The fibrous capsule is attached on the

1. Hip bone to the

1. Acetabular labrum including the transverse acetabular ligament, and to
2. Bone above and behind the acetabulum;

2. Femur to the

1. Intertrochanteric line in front, and
2. One cm medial to the intertrochanteric crest behind.

3. Variation of thickness of capsule

1. The capsule is thick and firmly attached anterosuperiorly. This part is subjected to maximum tension in the standing posture.
2. It is thin and loosely attached posteroinferiorly

Lower Extremity Joints

Hip Anatomy Muscles

Describe Hip Joint under following heads

1. Hip Joint Classification,

2. Hip Joint Ligaments,

3. Hip Joint Relations,

4. Hip Joint Blood supply,

5. Hip Joint Nerve supply,

6. Hip Joint Movements,

7. Hip Joint Muscles bringing movements, and

8. Hip Joint Applied anatomy.

1. Classification of hip joint:

Axis: Multiaxial. There are three axes.

No. of Bones taking part: There are two bones taking part in formation of hip joint.

Hence it is classified as simple joint. The bones are

1. Head of femur, and
2. Articulating surface of acetabular cavity of hip bone.

Surfaces of articulating bones are spherical and socket like. Hence, it is classified as
ball and socket type of synovial joint.

2. Ligaments

1. Capsule

1. Attachments

1. Superiorly: It is attached superiorly 5 to 6 mm above the acetabular margin of hip bone.
2. Inferiorly Anteriorly: On the intertrochanteric line. Posteriorly: One cm medial to intertrochanteric crest.

Lower Extremity Joints

2. Variation in thickness

1. Anterosuperiorly: It is thick and attached firmly. It is subjected to maximum tension in standing.
2. Posteroinferiorly: It is thin and loosely attached to bone.

3. Types of fibres: There are two types of fibres

1. The outer fibres are longitudinal and are best developed anterosuperiorly. They are called retinacula. The blood vessel supplying head and neck of femur travel along these retinacula.
2. The inner fibres are circular and are called zona orbicularis.

4. Capsule is re-enforced by

1. Iliofemoral,
2. Pubofemoral,
3. Ischiofemoral ligaments,
4. Acetabular labrum,
5. Transverse acetabular ligament, and
6. Ligament of the head of the femur (ligamentum teres)

5. Synovial membrane: It lines

1. The inner surface of fibrous capsule,
2. Intracapsular portion of neck of femur,
3. Both surfaces of acetabular labrum,
4. Transverse acetabular ligament, and
5. Fat in the acetabular fossa.

6. Acetabular labrum (labrum—edge, brim). It is fibrocartilage.

1. Functions:
2. Deepens the acetabular cavity.
3. Accommodates distal end of the head of femur. Thus, it protects the socket in case of pulling the head of the femur.
4. Maintains the bony contacts
5. Protects the edges.

Lower Extremity Joints

2. Iliofemoral ligament (ligament of Bigelow)

1. It is Y-shaped, strongest ligament in the body.
2. It extends from the anterior inferior iliac spine to the intertrochanteric line.
3. It prevents backwards falling.

3. Pubofemoral ligament

1. It is lar.
2. It extends from iliopubic eminence, obturator crest and obturator membrane to inferior part of capsule.

4. Ischiofemoral ligament

1. It should be ideally called ischiocapsular because it is attached to inner layer of capsule.

2. It is weak and almost horizontal across the capsule of hip joint.

1. It extends from

1. Posterior inferior surface of acetabular margin to
2. Posterior part of neck of femur.

2. It is continuous with zona orbicularis.

Hip Anatomy Muscles

5. Ligament of head of femur (ligamentum teres or round ligament)

1. It is flat and lar.

2. Its apex is attached to the depression present on the head of femur called fovea centralis, and

3. Base is attached to

1. Transverse acetabular ligament, and
2. Margins of acetabular notch by two bands.

4. It transmits arteries of head of femur (from acetabular branches of the obturator and medial circumflex femoral arteries).

6. Transverse ligament of the acetabulum

1. Transverse ligament of the acetabulum is a part of acetabulum, and
2. Transverse ligament of the acetabulum bridges the notch.

3. Relations

1. Posterior

1. Tendon of

1. Obturator externus, and
2. Obturator internus.

2. Gemelli, and

3. Piriformis.

2. Superior

1. Reflected head of rectus femoris, and
2. Gluteus minimus.

3. Inferior

1. Pectineus and cover of gluteus maximus, and
2. Obturator muscle.

4. Transverse ligament of the acetabulum Nerve supply: There are three nerves of the pelvic girdle and lower limb that supply the hip joint (Hilton’s law).

1. Femoral nerve via the nerve to rectus femoris,
2. Sciatic nerve via the nerve to quadratus femoris, and
3. Obturator nerve directly from its anterior division.

5. Transverse ligament of the acetabulum Blood supply

1. Obturator artery branch of anterior division of internal iliac artery.
2. Ascending branches of medial circumflex femoral artery branch of profunda femoris artery.
3. Ascending branches of lateral circumflex femoral branch of profunda femoris artery.
4. These supply the neck and head of the femur.

Hip Anatomy Muscles

6. Transverse ligament of the acetabulum Movements

1. Axis

1. Transverse axis of hip joint

1. Flexion:

1. Psoas major, and
2. Iliacus are powerful flexors.

2. Extension: Muscles

1. Gluteus maximus, and

2. Hamstring muscles.

1. Ischial fibres of adductor magnus,
2. Biceps femoris,
3. Semimembranosus, and
4. Semitendinosus.

2. Sagittal axis of hip joint

1. Adduction

1.  Adductor magnus,
2. Adductor longus, and
3. Adductor brevis.

2. Abduction

1. Gluteus medius, and
2. Gluteus minimus.

3. Longitudinal axis of hip joint

1. Medial rotation

1. Tensor fascia lata, and
2. Anterior fibres of gluteus medius.

2. Lateral rotation

1. Gluteus maximus,
2. Obturator internus and externus,
3. Superior and inferior gemelli,
4. Piriformis, and
5. Quadratus femoris.

7. Applied anatomy

1. Congenital dislocation is more common in hip joint than in any other joint.
2. The position of the hip joint is weak in flexion and lateral rotation of femur. Hence posterior dislocation (dashboard injury) is more common.
3. Anterior dislocation is less common.
4. Central dislocation is very rare.
5. Fracture of neck of femur occurs between 40 and 60 years.
6. Disease of hip joint may produce shortening of limb.
7. Disease of hip may cause referred pain to knee joint.

Classify Knee Joint (Genual)

1. Structurally:

1. Axis: Uniaxial
2. Modified hinge joint: The movements are in transverse axis. The movements permitted are flexion, extension hence hinge joint. The transverse axis is not fixed, so it is modified hinge joint.
3. Number of Bones: There are three bones in the knee joint sharing a common capsule. Hence, it is a compound joint.
4. Complex: Joint is divided into two compartments by a fibrocartilage structure— menisci.
5. Condylar: Medial and lateral condyles of femur and tibia are taking part.
6. Shape: Saddle-shaped: Between femur and patella, the surface of which is concave convex and reciprocating convex concave.

2. Functionally: Diarthrosis (freely movable).

Capsule of Knee Joint

1. Attachments

1. To femur: It is attached to the peripheral margin of articular surface of lower end of femur.

1. It excludes articulating area of patella.
2. It includes tendon of popliteus.

2. To tibia: It is attached 1 cm distal to articular margin.

1. Anteriorly, it is attached along the upper margin of the tibial condyles.
2. Posteriorly, it is attached to the intercondylar ridge.

3. Deficient at

1. Tibial tuberosity on tibia, and
2. Gap for popliteal tendon behind the lateral condyle of tibia for the passage of tendon of popliteus.

4. Strengthened by

1. Anteriorly by medial and lateral patellar retinacula,
2. Posteriorly by oblique popliteal ligament,
3. Laterally by iliotibial tract, and
4. Medially by tendon of sartorius and semimembranosus.

Draw and label the diagram showing anastomosis around knee joint

Five genicular branches of the popliteal artery

1. Descending

1. Genicular branch of the femoral artery, and
2. Branch of the lateral circumflex femoral artery.

2. Two recurrent branches of the anterior tibial artery, and

3. Circumflex fibular branch of the posterior tibial artery.

Enumerate intra-articular structures of knee joint

The most important structure is cruciate ligament. The other intra-articular structures include the menisci, and the femoral tendon of popliteus.

The other structures are: The intra-articular structures start with the first letters of days of the week.

Menisci (Mon),

Tendon of popliteus (Tue),

Meniscofemoral ligament (Wed—the first letter of Wednesday is inverted M),

Transverse ligament (Thu),

Haversian pad of fat (Fri),

Synovial membrane (Sat), and

Coronary ligament (Cun) (The pronunciation of c and s is similar)

Cruciate Ligament

Cruciate Ligament Introduction: The ligaments connecting the femur and tibia are in the form of cross. Hence, they are called cruciate ligaments. The nomenclature is based on the attachments to the part of upper surface of tibia.

1. Cruciate Ligament Functions

1. It is key stabilizer of knee joint.
2. It checks anterior and posterior movements of the femur on tibia.

2. Cruciate Ligament Attachments

Lateral condyle gives attachment to Anterior cruciate ligament. Medial condyle gives attachment to Posterior cruciate ligament.

Anterior cruciate ligament extends from anterior part of upper surface of tibia to the lateral condyle of femur.

Posterior cruciate ligament extends from posterior part of upper surface of tibia to the medial condyle of femur.

3. Cruciate Ligament Morphology: The posterior cruciate ligament is stronger, shorter and less oblique. In weight-bearing, flexed knee, posterior cruciate ligament is the only stabilizing factor.

4. Cruciate Ligament Functions

1. Anterior cruciate ligament prevents the anterior displacement of tibial condyle on femur. It prevents sliding of the femur backwards on tibia.

2. Posterior cruciate ligament prevents the posterior displacement of tibial condyle on femur. It prevents femur from sliding forward. Both cruciate ligaments prevent side-to-side displacement of tibia and femur.

Compare Anterior And Posterior Cruciate Ligaments

Meniscus

(Menisco—crescent, half moon)

Meniscus Introduction: It is a semilunar, fibrocartilaginous ring, lar in cross-section, covers the articular surfaces of the condyles of tibia.

1. Meniscus Functions: The chief role of meniscus is to

1. Rotate the femur, and to
2. Spread the synovial fluid uniformly.

• Maintains the bony contact and potential joint space.
• Escorts the articular surfaces.
• Nourishes the articular surface.
• Increases the concavity of tibial condyle.
• Serves as a cushion.
• Deepens the joint cavity.
• Spreads the synovial fluid uniformly.
• Saves from the shock during weight transmission.

2. Meniscus Number: There are two menisci—medial and lateral.

3. Meniscus Attachment

1. Each meniscus has anterior and posterior horns. Both the horns of both the menisci are attached to the anterior and posterior intercondylar areas, respectively.

2. The medial margin of the medial meniscus and lateral margin of lateral meniscus are attached to the capsule of the knee joint.

3. The medial margin of the medial meniscus is also attached to the tibial collateral ligament.

4. The posterior horn of lateral meniscus provided attachment to

1. The meniscofemoral ligament, and
2. Fibres of the popliteus.

4. Meniscus Movements

1. The flexion and extension movements occur in the upper compartment.

2. The rotation movement occurs in the lower compartment.

5. Meniscus Applied anatomy: The medial meniscus is more prone for injury as it is more firmly attached to the capsule and tibial collateral ligament.

Meniscofemoral Ligaments

Meniscofemoral Ligaments Introduction: They connect the lateral meniscus to medial condyle of femur.

1. Attachments

1. They arise from posterior horn of lateral meniscus and get attached to medial condyle of the femur.

2. They are named anterior and posterior meniscofemoral ligaments. The anterior meniscofemoral ligament passes anterior to the posterior cruciate ligament and posterior meniscofemoral ligament passes posterior to the posterior cruciate ligament.

2. Meniscofemoral LigamentsFunction: They regulate the forward movement of the lateral meniscus during extension of the knee.

Lower Extremity Joints

Oblique popliteal ligament

The oblique popliteal ligament is an expansion of tendon of semimembranosus muscle. It extends from posterior surface of medial condyles of tibia to lateral part of intercondylar line of femur. This forms the floor of popliteal fossa. It is pierced by

1. Middle genicular vessels and nerves, and

2. Genicular branch of posterior division of obturator nerve.

 

Transverse ligament (transverse meniscal ligament)

It connects anterior horn of medial meniscus to anterior margin of lateral meniscus. It is present in 40% of individuals.

Synovial membrane of knee joint

Synovial membrane of knee joint Introduction: It lines the inner surface of capsule and extends on patella. It is a mere capillary film.

1. Synovial membrane of knee joint Amount of synovial fluid—0.5 ml.

2. Synovial membrane of knee joint Features

1. Infrapatellar synovial fold: It is a flattened hollow cone of synovial membrane.

It has a base and an apex.

1. Base is opened. It extends from articular cartilage of patella to the anterior intercondylar area of tibia.
2. Apex: It is attached to the most anterior point of the intercondylar notch of femur.

2. Synovial cavity: There are three cavities—a patellar and two condylar.

C. Bursae: There are three bursae

1. Suprapatellar bursa: It is deep to quadriceps femoris tendon.
2. Popliteal bursa: It opens into lateral condylar cavity. It is below the meniscus.
3. Gastrocnemius bursa: It is deep to medial head of gastrocnemius.

Coronary ligament

Coronary ligament Introduction: It is a part of fibrous capsule.

Coronary ligament connects

1. Convex margins of medial and lateral menisci to

2. Upper end of tibia.

Arcuate Ligament

Arcuate Ligament Introduction: It is Y-shaped fibrous band.

1. The stem of the arcuate ligament is fixed to styloid process of fibula.

2. The anterior band is attached to lateral condyle of femur.

3. The posterior band is attached to lateral condyle of tibia.

Ligamentum Patellae

Introduction: Ligamentum patellae derived from tendon of quadriceps femoris and extend from the apex of patella to the tibial tuberosity.

Collateral Ligaments

The collateral ligaments are present on the medial and lateral side of knee joint. These can be described as follows

Relations of Knee Joint

1. Anterior: Quadriceps femoris.

2. Posterior

1. Popliteal vessels,
2. Tibial nerve, and
3. Lateral and medial head of gastrocnemius.

3. Medially

1. Medial patellar retinaculum,
2. Sartorius,
3. Gracilis,
4.  Semimembranosus, and
5. Semitendinosus.

4. Laterally

1. Common peroneal nerve,
2. Lateral patellar retinaculum, and
3. Tendon of biceps femoris.

Movements of knee joint and muscles bringing the movements of knee joint

1. Flexion

1. Main muscles

1. Hamstring muscles,

1. Semimembranosus,
2. Semitendinosus, and
3. Biceps femoris.

2. Sartorius, and

3. Gracilis.

2. Accessory muscles

1. Gastrocnemius, and
2. Plantaris.

2. Extension

1. Main muscles

1. Quadriceps femoris, and
2. Tensor fascia lata.

2. Accessory muscle

3. Muscular slips of articularis genu

3. Rotation of the knee joint: May be adjuvant or conjunct.

1. Adjuvant (aiding, assisting, independent of flexion and extension) rotation. Rotation around the vertical axis independent of flexion and extension, e.g. when foot is off the ground and knee in semiflexed position, tibia rotates medially and laterally around the vertical axis.

2. Conjunct (associated and integrated with flexion and extension) rotation

1. It takes place along with flexion and extension of knee joint.
2. In last 30° of extension, the anterior cruciate ligament is stretched.
3. It acts as a vertical axis around which the medial condyle of femur rotates in backwards and medially.
4. It (medial condyle of femur) reaches the anterior horn of medial meniscus and completely obliterates the medial meniscofemoral compartment.
5. This completes the last 30° of extension.
6. It is achieved by conjunct rotation of medial condyle of femur on tibia.
7. This mechanism locks the knee joint.
8. During unlocking, the popliteus contracts. It causes the lateral rotation of medial condyle of femur on tibia.

4. Locking: The key word is for locking

1. Definition: It is

1. Medial Rotation of the Femur on fixed tibia, or
2. Lateral rotation of tibia on fixed femur.

2. Muscle: Quadriceps femoris

3. Medial rotation: Semimembranosus, semitendinosus, gracilis and sartorius.

4. Lateral rotation: Biceps femoris.

5. Unlocking

1. Definition: It is

1. Lateral rotation of femur on fixed tibia, or
2. Medial rotation of tibia on fixed femur.

2. Muscle: Popliteus.

Stability of knee joint

The stability of knee joint is maintained by following structure

1. The cruciate ligaments are indispensable for anteroposterior stability in flexion.

2. Vastus medialis is indispensable to the stability of patella.

3. Spines of tibia prevent side way gliding.

4. Ilio-tibial tract, gluteus maximus and tensor fascia lata stabilizes slightly flexed knee joint.

5. Bones do not play any role.

Bursae Around Knee Joint

1. Anterior bursae: They are anterior to knee joint. They are

1. Subcutaneous: It is present beneath the skin. They may be

1. Subcutaneous pre-Patellar, e.g. Housemaid’s knee—PPH
2. Subcutaneous infrapatellar, e.g. Clergyman’s Knee—SICK.

B. Deep

1. Suprapatellar, and
2. Infrapatellar.

2. Lateral bursae between

1. Lateral condyle of tibia and tendon of popliteus,
2. Popliteus and fibular collateral ligament,
3. Fibular collateral ligament and biceps femoris, and
4. Deep to lateral head of gastrocnemius.

3. Medial

1. Deep to medial head of gastrocnemius,

2. Anserine bursa

1. It is a complicated bursa,
2. It separates the members of guy ropes from one another. The members of the guy ropes are sartorius, semitendinosus, and gracilis, and
3. It also separates from tibia and tibial collateral ligament.

3. Deep to tibial collateral ligament,

4. Deep to semimembranosus, and

5. Between semimembranosus and semitendinosus.

Locking and Unlocking of Knee Joint

Introduction: The function of locking and unlocking of knee joint is to keep the knee in full extension without muscular effort. It is brought by

1. Medial rotation of femur on fixed tibia during terminal stage of extension.
2. Lateral rotation of femur on fixed tibia during early stage of flexion.

1. Necessity of the movements of locking and unlocking

1. The surface area of articular surfaces of tibia and femur are not proportionate.
2. The articular surfaces of tibia and femur are incongruent.
3. During the terminal part of extension of knee joint, the small articular surface of the tibia is used up by the femur. To accommodate the unused articular surface of femur on tibia, the femur or tibia is required to rotate. This is done to have the stable movement.

Lower Extremity Joints

2. Difference between locking and unlocking