Lower Limb

Lower Limb

31. Describe Femoral Triangle under the following headings.

(A) Boundaries

(B) Contents

(C) Femoral Sheath

(D) Femoral Hernia

Answer:

(A, B)

(10 marks)

Table summary: This table provides a detailed anatomical overview of the femoral triangle, specifying its precise location on the upper thigh and defining its boundaries, roof components, and floor muscles.

Table summary: The table outlines the anatomical components and clinical significance of the femoral triangle, detailing the specific arteries, veins, nerves, and lymph nodes contained within the region, while noting its importance as a conduit for these structures and a location for medical interventions and herniation.

Image summary: This is an anatomical diagram. The figure illustrates the anatomical structures within the femoral triangle, labeling the boundaries and the neurovascular bundle. It identifies the relationship between muscles such as the sartorius and adductor longus, the inguinal ligament, and various vessels including the common femoral artery, femoral vein, and femoral nerve. The diagram demonstrates that the femoral nerve is positioned most laterally, followed by the femoral artery and then the femoral vein medially, showing the organized spatial arrangement of these critical structures as they pass under the inguinal ligament into the thigh.

(C) Femoral Sheath

○ This is a funnel-shaped sleeve of fascia enclosing the upper 3 to 4 centimeters of the femoral vessels.

○ The sheath is formed by downward extension of two layers of the fascia of the abdomen.

○ The anterior wall of the sheath is formed by the fascia transversalis which lies in the anterior abdominal wall deep to the transversus abdominis.

○ The posterior wall is formed by the fascia iliaca, which covers the iliacus muscle.

O Inferiorly, the sheath merges with connective tissue around the femoral vessels.

○ The femoral sheath is asymmetrical.

○ The sheath is divided into the following three compartments by septa:

The lateral or arterial compartment contains the femoral artery and the femoral branch of the genitofemoral nerve.

The intermediate or venous compartment contains the femoral vein.

The medial or lymphatic compartment is the smallest of all, and is known as the femoral canal.

(D) Femoral Hernia

○ The femoral canal is an area of potential weakness in the abdominal wall through which abdominal contents may bulge out forming a femoral hernia.

○ A femoral hernia is more common in females because the femoral canal is wider. This is associated with the wider pelvis, and the smaller size of the femoral vessels, in the female.

○ It is never congenital.

○ The course of an enlarging hernial sac is typical. First it passes downwards through the femoral canal, then forwards through the saphenous opening, and finally upwards along with the superficial epigastric and superficial circumflex iliac vessels.

○ In cases of strangulation/choke of a femoral hernia, the surgeon has to enlarge the femoral ring. This is possible only by cutting the lacunar ligament; which forms the medial boundary of the ring.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis Volume 2, B.D Chaurasia, 8th Edition, Page No. 51 to 54

32. Short note on Femoral Artery.

(3 marks)

Table summary: The table provides a detailed anatomical overview of the femoral artery, describing its point of origin, its downward course through specific anatomical regions, and its various superficial and deep branches. Additionally, it outlines the clinical significance of the artery, highlighting its utility for pulse assessment, bleeding control, and medical access.

Femoral arteries

Anterior view

Image summary: This figure is an anatomical diagram. It illustrates the arterial system of the human hip and thigh, detailing the branching patterns of the common femoral artery and its subsequent divisions. The diagram shows the distribution of blood vessels, including the superficial epigastric, superficial external pudic, femoral profunda, and superficial femoral arteries, along with various perforating and circumflex branches. The layout demonstrates that the femoral artery serves as the primary conduit, branching into smaller vessels that provide blood supply to the pelvic region, the thigh muscles, and the knee joint through an extensive network of anastomoses.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis, Volume 2, B.D Chaurasia, 8th Edition, Page No. 55 to 57

33. Describe Adductor Canal under following headings.

(A) Features

(B) Boundaries

(C) Contents

Answer:

Adductor/Hunter's/Sub Sartorial Canal

Features

- O Adductor canal is also called the subsartorial canal or Hunter's canal.

○ The adductor canal is an intermuscular space situated on the medial side of the middle one-third of the thigh.

Extent

○ The canal extends from the apex of the femoral triangle, above; to the tendinous opening in the adductor magnus, below.

Boundaries

○ Adductor canal has anterolateral, posteromedial and medial walls.

○ The anterolateral wall is formed by the vastus medialis.

○ The posteromedial wall or floor is formed by the adductor longus, above, and the adductor magnus, below.

○ The medial wall or roof is formed by a strong fibrous membrane joining the anterolateral and posteromedial walls. The roof is overlapped by the sartorius.

○ The subsartorial plexus of nerves lies on the fibrous roof of the canal under cover of the sartorius.

The plexus is formed by branches from the medial cutaneous nerve of the thigh, the saphenous nerve, and the anterior division of the obturator nerve.

It supplies the overlying fascia lata and the neighboring skin.

Image summary: This figure is an anatomical diagram. It illustrates the relative positioning of several muscles in the thigh area, specifically labeling the vastus medialis, adductor longus, and sartorius, while also indicating the location of the adductor magnus. The diagram shows that the vastus medialis is positioned superiorly and medially relative to the adductor longus, while the sartorius is located more laterally. The arrangement suggests a complex overlapping of muscle groups that converge toward the lower portion of the depicted region.

Contents of Adductor Canal

○ The femoral artery enters the canal at the apex of the femoral triangle.

❖ Within the canal it gives off muscular branches and a descending genicular branch.

The descending genicular artery is the last branch of the femoral artery. It divides into a superficial saphenous branch that accompanies the saphenous nerve, and a deep muscular branch that enters the vastus medialis and reaches the knee.

❖ Femoral artery leaves the adductor canal through the opening in the adductor magnus muscle to continue as a popliteal artery in the popliteal fossa.

○ Femoral vein lies posterior to the femoral artery in the upper part, and lateral to the artery in the lower part of the canal.

○ The saphenous nerve crosses the femoral artery anteriorly from lateral to medial side.

○ The nerve to the vastus medialis lies lateral to the femoral artery, and enters the vastus medialis in the upper part of the canal.

○ Branches of two divisions of obturator nerve:

The anterior division emerges at the lower border of the adductor longus, gives branches to the subsartorial plexus, and ends by supplying the femoral artery.

The posterior division of the obturator nerve runs on the anterior surface of the adductor magnus, accompanies the femoral and popliteal arteries, and ends by supplying the knee joint.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis, Volume 2 B.D Chaurasia, 8th Edition, Page No. 62, 63 34. Write the Structures under the cover of Gluteus Maximus.

Structures Under Cover of Gluteus Maximus

Structures are:

Muscles

○ Gluteus medius

○ Gluteus minimus

○ Reflected head of the rectus femoris

○ Piriformis

Obturator internus with two gemelli

○ Quadratus femoris

○ Obturator externus

○ Origin of the four hamstrings from the ischial tuberosity

O Insertion of the upper or pubic fibers of the adductor magnus.

Vessels

○ Superior gluteal vessels

O inferior gluteal vessels

O Internal pudendal vessels

O Ascending branch of the medial circumflex femoral artery

○ Trochanteric anastomosis

○ Cruciate anastomosis

○ The first perforating artery

Nerves

○ Superior gluteal L.4, 5, S.1

O Inferior gluteal L.5, S.1, 2)

○ Sciatic L.4, 5, S.1, 2, 3)

O Posterior cutaneous nerve of thigh (S.1, 2, 3)

○ Nerve to the quadratus femoris L.4, 5, S.1

○ Pudendal nerve S.2, 3, 4).

○ Nerve to the obturator internus L.5, S.1, 2)

○ Perforating cutaneous nerves S.2, 3)

Bones and Joints

O llium

○ Ischium with ischial tuberosity

O Upper end of femur with the greater trochanter

O Sacrum and coccyx

O Hip joint

○ Sacroiliac joint

Ligaments

○ Sacrotuberous

○ Sacrospinous

○ Ischiofemoral

Bursae

○ Trochanteric bursa of gluteus maximus

○ Bursa over the ischial tuberosity

○ Bursa between the gluteus maximus and vastus lateralis

Now we can also look on to the Structures under the cover of Gluteus Medius and Minimus:

Structures Deep to the Gluteus Medius

○ The gluteus medius covers:

- The superior gluteal nerve

- The deep branch of the superior gluteal artery

- The gluteus minimus

- The trochanteric bursa of the gluteus medius

Structures Deep to the Gluteus Minimus

○ Structures lying deep to the gluteus minimus include the reflected head of the rectus femoris, and the capsule of the hip joint.

Q-How These Three Muscles Are Tested?

While testing gluteus maximus, the patient lies prone. The right hand of the physician presses the patient's right leg downwards. Patient is requested to extend his hip against resistance provided by the physician's right hand; while his left hand feels the contracting gluteus maximus muscle.

○ Gluteus medius and gluteus minimus can be tested together by doing internal rotation of the thigh against resistance. The person lies in supine position with the hip and knee flexed.

Gluteus medius, gluteus minimus and tensor fasciae latae are tested by the abducting lower limb against resistance. The person lies in the supine position and the knee is extended.

Clinical Anatomy

○ When the gluteus maximus is paralyzed as in muscular dystrophy, the patient cannot stand up from a sitting posture without support.

○ Intramuscular injections are given in the anterosuperior quadrant of the gluteal region, that is in the gluteus medius and minimus, to avoid injury to large vessels and nerves which pass through the lower part of this region.

When the gluteus medius and minimus (of the right side) are paralyzed, the patient cannot walk normally. He bends or waddles on the right side or paralyzed side to clear the opposite foot, that is left, off the ground. This is known as lurching gait. When bilateral, it is called waddling gait.

○ Normally, when the body weight is supported on one limb, the glutei of the supported side raise the opposite and unsupported side of the pelvis.

○ However, if the abductor mechanism is defective, the unsupported side of the pelvis drops, and this is known as a positive Trendelenburg's sign.

○ The sign is positive in defects of power, that is paralysis of the gluteus medius and minimus that is congenital or pathological dislocation of the hip.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis, Volume 2, B.D Chaurasia, 8th Edition, Page No. 76, 79, 80, 81 35. Describe Popliteal fossa under the following headings.

(A) Location

(B) Boundaries

(C) Contents

Answer:

Table summary: This table provides a comprehensive anatomical overview of the popliteal fossa, detailing its diamond-shaped location behind the knee, the specific muscles forming its boundaries, the layers of fascia comprising the roof, the bony and ligamentous structures of the floor, and the various arteries, veins, nerves, and lymph nodes contained within the space.

Image summary: This is an anatomical diagram. The figure illustrates the posterior view of the knee joint, labeling various muscles and the popliteal fossa. Key structures identified include the biceps femoris, semimembranosus, semitendinosus, plantaris, and the medial and lateral heads of the gastrocnemius. The diagram demonstrates the spatial arrangement of these muscles, showing how they converge to form the boundaries of the popliteal fossa, with the hamstring muscles located superiorly and the gastrocnemius heads located inferiorly.

Arrangement of the structures in popliteal fossa

○ Upper part, from medial to lateral side A V N

A—Popliteal artery

V—Popliteal vein

N—Tibial nerve

○ Middle part, from behind to forwards N V.A

N—Tibial nerve

V—Popliteal vein

A—Popliteal artery

O Lower part, from medial to lateral side N V.A

N—Tibial nerve

V—Popliteal vein

A—Popliteal artery

Image summary: This figure is an anatomical diagram. It illustrates the neurovascular structures of the popliteal region, specifically detailing the arrangement of the popliteal artery, popliteal vein, and the tibial and common peroneal nerves in relation to the knee joint and the short head of the biceps femoris muscle. The diagram demonstrates that the popliteal artery and vein run parallel to the tibial nerve, while the common peroneal nerve diverges laterally. It further shows the branching of the common peroneal nerve into the superior lateral genicular nerve, the lateral cutaneous nerve of the calf, and the inferior lateral genicular nerve, eventually connecting to the sural communicating nerve.

Other Important Points to Be Remembered

Branches of Popliteal Artery

O Several large muscular branches: Supply the adductor magnus, hamstrings and terminate by anastomosing with the fourth perforating artery.

○ Cutaneous branches: One branch usually accompanies the small saphenous vein.

○ Genicular branches: They are five in number - two superior, two inferior and one middle.

Clinical Importance of Popliteal Artery

○ Blood pressure in the lower limb is recorded from the popliteal artery.

○ The popliteal artery is fixed to the capsule of the knee joint by a fibrous band present just above the femoral condyles. This may be a source of continuous adhesion or stretching on the artery, causing primary thrombosis of the artery in young individuals.

Tibial Nerve Injury

O Damage to the tibial nerve causes motor and sensory loss.

Motor loss: Superficial and deep muscles of calf and intrinsic muscles of sole.

Sensory loss: Loss of sensation on whole of sole of foot, plantar aspect of digits and nail beds on dorsum of foot.

○ The medial side of the nerve is safe as most of the muscular branches of the tibial nerve arise from the lateral side except to the medial head of gastrocnemius muscle.

Common Peroneal Nerve Injury

○ The Common peroneal nerve may be injured in the posterolateral side of the neck of the fibula.

○ It is the most frequently injured nerve in the lower limb.

○ This nerve is relatively unprotected.

○ It may get trapped between the attachments of peroneus longus to the head and shaft of the fibula. Patients present 'foot drop' which is usually painless.

There is weakness of dorsiflexion of ankle and of eversion of the foot. Inversion and plantar flexion are normal and the ankle jerk is intact.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis, Volume 2, B.D Chaurasia, 8th Edition, Page No. 87, 88, 89 36. Discuss in detail about the Arches of Foot and its anomalies also. (10 marks)

O Arches of the foot help in fast walking, running and jumping.

○ These help in weight-bearing and in providing upright posture.

○ Arches are supported by intrinsic and extrinsic muscles of the sole in addition to ligaments, aponeurosis and shape of the bones.

O Footprints are not complete due to the arches.

Classification of Arches

○ Longitudinal

- ❖ Medial

- ❖ Lateral

- O Transverse

- ✿ Anterior

- Posterior

Formation or Structure of Arches

Medial Longitudinal Arch

○ This arch is higher, more mobile and resilient than the lateral.

○ It is considered as a big arc of a small circle with more bones and more joints.

○ Bones involved are calcaneus, talus, navicular, all three cuneiform bones and 1st-3rd metatarsals.

O Anterior end-1st, 2nd, 3rd metatarsal.

O Posterior end-Medial tubercle of calcaneus

Key stone-Talus

O Summit (Highest point) - Superior articular surface of body of talus.

O Pillars-

❖ Anterior pillar-Long and weak - Talus, 3 Cuneiforms, Navicular and 1st three metatarsal bone

Posterior pillar-Medial part of Calcaneus

O Suspension-Slings formed by Tibialis anterior and peroneus Longus.

O Main Joint-Talocalcaneonavicular Joint

○ Bony factor-Wedge Shaped

O Intersegmental Ties-Spring Ligament

○ Tie Beams

- Plantar aponeurosis

- Abductor Hallucis and Flexor digitorum brevis

Slings

- Tibialis posterior

- Flexor Hallucis Longus

- ❖ Flexor digitorum longus

Image summary: This figure is an anatomical diagram. It illustrates the internal structure of the human foot and ankle, specifically labeling various bones such as the tibia, talus, navicular, medial cuneiform, and calcaneum, as well as soft tissue structures including the spring ligament, plantar aponeurosis, and tendons of the tibialis posterior and flexor hallucis longus. The diagram demonstrates the spatial relationship between the skeletal framework and the supporting ligaments and tendons, showing how these components integrate to support the arch of the foot and facilitate movement.

Lateral Longitudinal Arch

○ This arch is with less bones, less joints and has limited mobility, and is built to transmit weight and thrust to the ground.

○ It is considered as a small arc of a big circle. This is in contrast to the medial longitudinal arch which acts as a shock absorber.

○ Bones forming this arch are part of calcaneus, cuboid and 4th, 5th metatarsals.

O Anterior end-4th and 5th metatarsals

O Posterior end-Lateral tubercle of calcaneus

O Summit-Articular facet on superior surface of Calcaneus

O Anterior pillar-4th and 5th metatarsals, Cuboid

Posterior pillar-Lateral half of Calcaneus

O Main joint-Calcaneocuboidal joint

O Key stone-Cuboid

O Intersegmental Ties-Long and short plantar ligament

Slings-Peroneus Longus and brevis

O Suspension-Slings formed by Tibialis anterior and peroneus Longus

○ Tie Beams-Plantar aponeurosis, Abductor digiti minimi, Flexor digitorum brevis (lateral part).

Anterior Transverse Arch

○ The anterior transverse arch is formed by the heads of the five metatarsal bones.

○ It is complete because the heads of the first and fifth metatarsals come in contact with the ground, and form the two ends of the arch

Posterior Transverse Arch

○ The posterior transverse arch is formed by the greater parts of the tarsus and bases of metatarsus.

○ It is incomplete because only the lateral end comes in contact with the ground, the arch forming a 'half dome' which is completed by a similar half dome of the opposite foot.

Factors Responsible for Maintenance of Arches

O Shape of the bones concerned

O Intersegmental ties/staples or ligaments (and muscles) that hold the different segments of the arch together

○ Tie beams that connect the two ends of the arch

Slings that keep the summit of the arch pulled up

Functions of Arches

○ The arches of the foot distribute body weight to the weight-bearing areas of the sole, mainly the heel and the toes.

○ The arches act as springs (chiefly the medial longitudinal arch) which are of great help in walking and running.

○ They also act as shock absorbers in stepping and particularly in jumping.

○ The concavity of the arches protects the soft tissues of the sole against pressure.

Clinical Anatomy

○ Absence or collapse of the arches leads to flat foot (pes planus).

The effects of a flat foot are as follows:

O Loss of spring in the foot leads to a clumsy, shuffling gait.

○ Loss of shock absorbing function makes the foot more liable to trauma and osteoarthritis.

○ Loss of the concavity of the sole leads to compression of the nerves and vessels of the sole.

○ Compression of the communication between the lateral and medial plantar nerves causes neuralgic pain in the forefoot (metatarsalgia).

Exaggeration of the longitudinal arches of the foot is known as pes cavus. This is usually a result of contracture at the transverse tarsal joint. When dorsiflexion of the metatarsophalangeal joints, and plantar flexion of the interphalangeal joints are superadded, the condition is known as clawfoot.

○ The common causes of pes cavus and claw foot are spina bifida and poliomyelitis.

Club Foot

O Commonest deformity of the foot is talipes equinovarus (club foot).

○ In this condition, the foot is inverted, adducted and plantar flexed.

○ The condition may be associated with spina bifida.

Talipes (club foot) may be of two types:

- O Talipes calcaneovalgus—foot is dorsiflexed at ankle joint, everted at midtarsal joints.

- O Talipes equinovarus—foot is plantar flexed at ankle joint and inverted at midtarsal joints.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis, Volume 2, B.D Chaurasia, 8th Edition, Page No. 289 to 293

37. Describe Venous Drainage of Lower Limb under the following headings.

(A) Factors that help venous return

(B) Veins of Lower limb

(C) Varicose Veins

(D) Trendelenburg's Test

Answer:

Venous Drainage

○ Venous drainage is of great importance because in the lower limb venous blood has to ascend against gravity.

Factors Helping Venous Return

General Factors

O Negative intrathoracic pressure

O Arterial pressure and overflow from the capillary bed

O Compression of veins accompanying arteries by arterial pulsation

○ The presence of valves

Local Factors

○ These are venous, muscular and fascial.

Venous: They have a greater number of valves. Superficial veins are connected to deep veins by perforators.

Muscular: When the limb is active, muscular contraction compresses the deep veins and drives the blood in them upwards. It is helped by the suction action of the diaphragm.

Fascial: The tight sleeve of deep fascia makes muscular compression of the veins much more effective by limiting outward bulging of the muscles.

Veins of Lower Limb

The veins may be classified into three groups:

○ Superficial

Deep

○ Perforating

Superficial Veins

○ They include the great and small saphenous veins, and their tributaries.

○ They are thick-walled because of the presence of smooth muscle and some fibrous and elastic tissues in their walls.

Deep Veins

These are the medial plantar, lateral plantar, dorsalis pedis, anterior and posterior tibial, peroneal, popliteal, and femoral veins, and their tributaries.

○ They are supported by powerful surrounding muscles.

○ The valves are more numerous in deep veins than in superficial veins.

○ They are more efficient channels than the superficial veins because of the driving force of muscular contraction.

Perforating Veins

○ They connect the superficial with the deep veins.

○ Valves of perforating veins permit only one way flow of blood, from the superficial to the deep veins.

○ There are about five perforators along the great saphenous vein, and one perforator along the small saphenous vein.

Long Saphenous Vein

O Formed by the union of medial end of dorsal venous arch with the medial marginal vein which drains the medial side of great toe.

○ It contains 10 to 15 valves which prevent the backflow of venous blood which tend to occur because of gravity.

○ The vein is also connected to the deep veins of the limb by perforating veins.

○ Perforating veins are also provided with valves which permit flow of blood only from the superficial veins to the deep veins.

Small or Short Saphenous Vein

○ The vein is formed on the dorsum of the foot by the union of the lateral end of the dorsal venous arch with the lateral marginal vein.

○ It drains the lateral border of the foot, the heel, and the back of the leg.

○ It is connected with the great saphenous and with the deep veins, and is accompanied by the sural nerve.

Image summary: This is an anatomical diagram. The figure illustrates the arterial and venous systems of the human lower limb from both anterior and posterior perspectives, labeling the major blood vessels from the pelvic region down to the toes. The diagram shows that the blood supply originates from the common iliac artery, which branches into internal and external iliac arteries, eventually leading to the femoral artery and its subsequent divisions. It can be inferred that the vascular network becomes more complex and branched as it extends distally, transitioning from large primary arteries in the thigh to smaller, specialized vessels in the lower leg and foot to ensure comprehensive blood distribution to the extremities.

Perforating Veins

○ These connect the superficial with the deep veins.

Indirect Perforating Veins

○ Indirect perforating veins connect the superficial veins with the deep veins through the muscular veins

Direct Perforating Veins

Direct perforating veins connect the superficial veins directly with the deep veins.

○ The great and small saphenous veins are the large direct perforators.

Various perforators are

○ Adductor Canal perforator-Connect the great saphenous vein with the femoral vein.

○ A perforator is there which connects the great saphenous vein with the posterior tibial vein.

O Lateral Perforator-Connects small saphenous vein with the peroneal vein.

○ Medially, there are three perforators which connect the posterior arch vein with the posterior tibial vein.

The upper medial perforator

The middle medial perforator

The lower medial perforator

Varicose Veins

Varicose veins and ulcers:

○ If the valves in perforating veins or at the termination of superficial veins collapse, the damaged veins turn into “high pressure leaks” via which the high pressure of the deep veins due to muscular contraction is transmitted to the superficial veins.

○ This results in dilatation of the superficial veins and to gradual degeneration of their walls producing varicose veins and varicose ulcers.

○ In pregnancy, varicose veins often occur during the third trimester, as the iliac vein gets pressed due to an enlarged uterus.

Trendelenburg's test

○ This test is done to find out the site of leak or defect in a patient with varicose veins.

○ Only the superficial veins and the perforating veins can be tested, not the deep veins.

Q-How to Perform This Test?

○ The patient is made to lie down, and the veins are emptied by raising the limb and stroking the varicose veins in a proximal direction.

○ Then pressure is applied with the thumb at the saphenofemoral junction and the patient is asked to stand up quickly.

○ To test the superficial veins, the pressure is released. Quick filling of the varicose veins from above indicates incompetency of the superficial veins.

○ To test the perforating veins, the pressure at the saphenofemoral junction is not released, but maintained for about a minute. Gradual filling of the varices indicates incompetency of the perforating veins, allowing the blood to pass from deep to superficial veins.

○ Perthe's test is done to check for the deep veins.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis, Volume 2, B.D Chaurasia, 8th Edition, Page No. 148 to 152

38. Explain knee joint under the following headings.

(B) Ligaments of the joint

(C) Relations and Blood Supply

(D) Locking and unlocking of Knee Joint

(E) Clinical Anatomy

Answer:

Features

○ The knee is the largest and most complex joint of the body.

Type

○ It is a condylar synovial joint, incorporating two condylar joints between the condyles of the femur and tibia, and one saddle joint between the femur and the patella.

Articular Surfaces

○ The knee joint is formed by:

○ The condyles of the femur

○ The patella

○ The condyles of the tibia.

Ligaments

Ligaments of knee joint are:

○ Fibrous capsule

O Ligamentum patellae

○ Tibial collateral or medial ligament

○ Fibular collateral or lateral ligament

Oblique popliteal ligament

O Arcuate popliteal ligament

O Anterior cruciate ligament

Posterior cruciate ligament

○ Medial meniscus

O Lateral meniscus

○ Transverse ligament

Synovial Membrane

○ The synovial membrane of the knee joint lines the capsule, except posteriorly where it is reflected forwards by the cruciate ligaments.

○ In front, it is absent from the patella.

Bursae Around the Knee

○ There are 12 bursae around the knee—four anterior, four lateral, and four medial. Anterior

○ Subcutaneous prepatellar bursa

○ Subcutaneous infrapatellar bursa

Deep infrapatellar bursa

○ Suprapatellar bursa

Lateral

○ A bursa deep to the lateral head of the gastrocnemius.

○ A bursa between the fibular collateral ligament and the biceps femoris.

○ A bursa between the fibular collateral ligament and tendon of the popliteus.

○ A bursa between the tendon of the popliteus and the lateral condyle of the tibia.

Medial

○ A bursa deep to the medial head of the gastrocnemius.

○ The anserine bursa which separates the tendons of the sartorius, the gracilis and the semitendinosus from one another.

○ A bursa deep to the tibial collateral ligament.

○ A bursa deep to the semimembranosus.

Relations of Knee Joint

Anteriorly

- O Anterior bursae, ligamentum patellae and plexus of nerves around patella.

Posteriorly

○ At the middle: Popliteal vessels, tibial nerve.

Posterolaterally: Lateral head of gastrocnemius, plantaris, and common peroneal nerve.

Posteromedially: Medial head of gastrocnemius, semitendinosus, semimembranosus, gracilis.

Medially

O Sartorius, gracilis and semitendinosus

○ Great saphenous vein with saphenous nerve.

O Semimembranosus

Laterally

- Biceps femoris, and tendon of origin of popliteus.

Image summary: This figure is an anatomical diagram. It illustrates the internal and external structures of a human knee joint, labeling key components including the femur, tibia, fibula, patella, various ligaments such as the anterior and posterior cruciate ligaments and collateral ligaments, the meniscus, articular cartilage, and the associated muscles and tendons. The diagram shows the spatial relationship and connectivity between the thigh bone, shin bones, and the connective tissues that stabilize the joint, demonstrating how the quadriceps tendon and patellar ligament link the muscles to the lower leg.

Blood Supply

Five genicular branches of the popliteal artery.

○ Branches of the femoral artery.

○ The descending branch of the lateral circumflex femoral artery.

○ Two recurrent branches of the anterior tibial artery.

○ The circumflex fibular branch of the posterior tibial artery.

Nerve Supply

○ Femoral nerve

○ Sciatic nerve

Obturator nerve

Locking and Unlocking of the Knee Joint

Locking is a mechanism that allows the knee to remain in the position of full extension as in standing without much muscular effort.

Locking occurs as a result of medial rotation of the femur during the last stage of extension.

○ The medial condyle of the femur has a larger anteroposterior diameter than the lateral condyle. Therefore, when the medial condylar surface of the lateral condylar articular surface is 'used up' by extension, the lateral condylar articular surface remains partially unused.

○ At this point, the medial condyle rotates backward around the lateral condyle, or the medial rotation of the femur, such that the remaining portion of the medial condylar surface is likewise “taken up.”

○ This movement locks the knee joint.

Locking is aided by the oblique pull of ligaments during the last stages of extension. When the knee is locked, it is completely rigid.

Locking is produced by continued action of the same muscles that produce extension, that is the quadriceps femoris, especially the vastus medialis part.

○ The locked knee joint can be flexed only after it is unlocked by lateral rotation of the femur. Unlocking is brought about by the action of the popliteus muscle.

Clinical Anatomy

O Structurally, the knee is a weak joint because the articular surfaces do not have exactly the same shape and sizes.

○ So the stability of the joint is maintained by a number of factors:

- The cruciate ligaments maintain anteroposterior stability.

- The collateral ligaments maintain side-to-side stability.

- The idiotibial tract plays an important role in stabilizing the knee

Injuries to the Knee

Q-Why medial meniscus is more vulnerable to injury than the lateral meniscus?

○ Because of its fixity to the tibial collateral ligament, and because of greater excursion during rotatory movements.

○ The lateral meniscus is protected by the popliteus which pulls it backwards so that it is not crushed between the articular surfaces.

Injuries to cruciate ligaments are also common.

○ The anterior cruciate ligament is more commonly damaged than the posterior. It may be injured in violent hyperextension of the knee or in anterior dislocation of the tibia.

○ The posterior ligament is injured in posterior dislocation of the tibia.

O Tear of the ligaments leads to abnormal anteroposterior mobility.

○ In the tear of anterior cruciate ligament, the tibia is pushed anteriorly, while in the tear of posterior cruciate ligament, it is pushed posteriorly.

Injuries to collateral ligaments are less common

○ Baker's cyst is a central swelling, occurring due to osteoarthritis of the knee joint. The synovial membrane protrudes through a hole in the posterior part of the capsule of the knee joint.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis Volume, 2 B.D Chaurasia, 8th Edition, Page No. 167, 172, 173, 174 000

39. Describe Hip joint under the following headings.

(B) Ligament

(C) Relations

(D) Movements at the joint

Answer:

Type

○ Ball and socket variety of synovial joint.

○ It is a multiaxial joint.

Articular Surfaces

○ The head of the femur articulates with the acetabulum of the hip bone to form the hip joint.

○ The hip joint has a high degree of stability as well as mobility. The stability or strength depends upon:

- Depth of the acetabulum

- Tension and strength of ligaments.

- Strength of the surrounding muscles.

- ❖ Length and obliquity of the neck of the femur.

- Atmospheric pressure

Ligaments of Hip Joint

○ The ligaments are:

- The fibrous capsule

- The iliofemoral ligament

- The pubofemoral ligament

- The ischiofemoral ligament

- The ligament of the head of the femur

- The acetabular labrum

- The transverse acetabular ligament.

Relations of the Hip Joint

Anterior Relations ○ Tendon of the iliopsoas

Posterior Relations

○ Tendon of obturator externus covered by the quadratus femoris

Obturator internus and gemelli, piriformis, sciatic nerve and the gluteus maximus muscle.

Superior Relations

○ Reflected head of the rectus femoris covered by the gluteus minimus, gluteus medius and partly by gluteus maximus.

Inferior Relations

○ Fibers of the pectineus and the obturator externus.

Image summary: This is an anatomical diagram. The figure illustrates the anatomical relations of the hip joint, depicting the surrounding muscles, nerves, and blood vessels. It identifies various muscle groups such as the gluteal muscles, tensor fasciae latae, iliopsoas, adductors, and hamstrings, as well as key neurovascular structures including the sciatic nerve, femoral nerve, femoral artery, and femoral vein. The diagram shows that the hip joint is encased by a complex network of musculature, with the gluteal muscles positioned posteriorly and superiorly, and the adductors and femoral vessels located anteriorly and medially.

Blood Supply

The hip joint is supplied by

○ The obturator artery

○ Two circumflex femorals

○ Two gluteal arteries.

Nerve Supply

○ The hip joint is supplied by

The femoral nerve

The nerve to the rectus femoris

The anterior division of the obturator nerve

The nerve to the quadratus femoris

The superior gluteal nerve

Movements

O Flexion and extension occur around a transverse axis.

○ Adduction and abduction occur around an anteroposterior axis.

O Medial and lateral rotations occur around a vertical axis.

O Circumduction

Clinical Anatomy

○ Congenital dislocation is more common in the hip than in any other joint of the body. The head of the femur slips upwards onto the gluteal surface of the ilium because the upper margin of the acetabulum is developmentally deficient. This causes lurching gait, and Trendelenburg's test is positive.

○ Dislocation of the hip may be:

Posterior (more common)

❖ Anterior (less common), or

Central(rare).

The sciatic nerve may be injured in posterior dislocations.

O Shenton's line, in an X-ray picture, is a continuous curve formed by the upper border of the obturator foramen and the lower border of the neck of the femur. In fracture of the neck of the femur, line becomes abnormal.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis, Volume 2, B.D Chaurasia, 8th Edition, Page No. 162 to 166

40. Describe Sciatic Nerve under the following headings.

(A) Origin

(B) Course and Relation

(C) Branches

(D) Nerve Injury

Answer:

Sciatic Nerve

○ The sciatic nerve is the thickest nerve in the body.

○ It begins in the pelvis and terminates at the superior angle of the popliteal fossa by dividing into the tibial and common peroneal nerves.

Origin and Root Value

○ This is the largest branch of the sacral plexus.

O Its root value is L.4, 5, S.1, 2, 3.

○ It has two parts—the tibial part and the common peroneal part.

○ The tibial part is formed by the ventral divisions of the anterior primary rami of L.4, 5, S.1, 2, 3.

○ The common peroneal part is formed by the dorsal divisions of the anterior primary rami of L.4, 5, S.1, 2.

Course and Relations

○ In the pelvis: The nerve lies in front of the piriformis,under cover of its fascia.

○ In the gluteal region: The sciatic nerve enters the gluteal region through the greater sciatic foramen below the piriformis.

○ It has the following relations in the gluteal region.

Superficial or posterior: Gluteus maximus

Deep or anterior:

* Body of the ischium.

★ Tendon of the obturator internus with the gemelli.

★ Quadratus femoris, obturator externus.

★ The capsule of the hip joint.

★ The upper, transverse fibers of the adductor magnus.

O Medial: Inferior gluteal nerve and vessels

○ In the thigh: The sciatic nerve enters the back of the thigh at the lower border of the gluteus maximus. It runs vertically downwards up to the superior angle of the

popliteal fossa, at the junction of the upper two-thirds and lower one-third of the thigh, where it terminates by dividing into the tibial and the common peroneal nerves.

It has the following relations in the thigh.

○ Superficial or posterior: The sciatic nerve is crossed by the long head of the biceps femoris.

Deep or anterior: The nerve lies on the adductor magnus.

O Medial: The semimembranosus, and the semitendinosus.

Lateral: Biceps femoris.

Image summary: This is an anatomical diagram. The figure illustrates the posterior view of the hip and upper thigh region, detailing the relationship between the sciatic nerve and surrounding musculature. It labels key structures including the piriformis, obturator internus, quadratus femoris, adductor magnus, and the hamstring muscles such as the semitendinosus, semimembranosus, and biceps femoris, as well as bony landmarks like the ischial spine and greater trochanter. The diagram demonstrates that the sciatic nerve originates from the pelvic region, passes beneath the piriformis muscle, and subsequently divides into the tibial nerve and the common peroneal nerve as it descends through the posterior compartment of the thigh.

Q - Sciatic Nerve Is Accompanied By Which Artery?

○ The sciatic nerve is accompanied by a small companion artery—arteria nervi ischiadica. It is a branch of the inferior gluteal artery.

Branches

○ Articular branches to the hip joint arise in the gluteal region.

○ Muscular branches: The tibial part of the sciatic nerve supplies

The semitendinosus

The semimembranosus

The long head of the biceps femoris

❖ The ischial head of the adductor magnus from its medial side.

The common peroneal part supplies only the short head of the biceps femoris.

Sciatic Nerve Injury

Sciatic Nerve Compression

○ The compression of the sciatic nerve can occur due to various factors, including herniated discs, spinal stenosis, muscle spasms, or injury.

○ The sciatic nerve may be injured by penetrating wounds, dislocation of the hip.

This results in loss of all movements below the knee with foot drop

○ Sensory loss on the back of the thigh, the whole of the leg, and the foot except the area innervated by the saphenous nerve.

Motor loss includes loss of hamstring muscles, loss of dorsiflexors, plantar flexors, evertors and muscles of the sole.

Sciatica

○ Shooting pain along the cutaneous distribution of the sciatic nerve and its terminal branches, chiefly the common peroneal, is known as sciatica.

○ Pain usually begins in the gluteal region, and radiates along the back of the thigh, and the lateral side of the leg, to the dorsum of the foot.

This is usually due to compression of one or more nerve roots forming the sciatic nerve. The cause may be disc prolapse, neuritis, etcetera

○ 'Sciatic nerve block' is done by injecting an anesthetic agent 1.5 centimeters below the midpoint of the line joining posterior superior iliac spine and upper border of greater trochanter.

Reference: Human Anatomy Lower Limb and Pelvis, Volume 2, B.D Chaurasia, 8th Edition, Page No. 99, 100, 101

41. Write about Ankle Joint under the following headings.

(B) Ligaments

(C) Relations

(D) Movements and Blood supply

Answer:

Type

○ This is a synovial joint of the hinge variety.

Articular Surfaces

There are two articular surfaces: Upper and Inferior/Lower

○ The upper articular surface is formed by:

The lower end of the tibia including the medial malleolus

The lateral malleolus of the fibula

The inferior transverse tibiofibular ligament.

○ The inferior articular surface is formed by articular areas on the upper, medial and lateral aspects of the talus.

○ Structurally, the joint is very strong. The stability of the joint is ensured by:

Close interlocking of the articular surfaces.

Strong collateral ligaments on the sides.

The tendons that cross the joint.

Ligaments

Ligaments of the joint are:

○ Fibrous capsule: It surrounds the joint but is weak anteriorly and posteriorly.

○ The deltoid or medial ligament: This is a very strong triangular ligament present on the medial side of the ankle

○ The deltoid ligament is crossed by the tendons of the tibialis posterior and flexor digitorum longus.

○ A lateral ligament: This ligament consists of three bands:

The anterior talofibular ligament

The posterior talofibular ligament

The calcaneofibular ligament

Image summary: This figure is an anatomical diagram. It illustrates the skeletal structure of the human ankle and foot, specifically highlighting the various ligaments and tendons that provide stability to the joint. The diagram labels key bones including the fibula, tibia, and talus, alongside connective tissues such as the Achilles tendon, the anterior and posterior inferior tibiofibular ligaments, the anterior and posterior talofibular ligaments, and the calcaneofibular ligament. The arrangement of these structures indicates that the ankle joint is supported by a complex network of ligaments that connect the lower leg bones to the foot, ensuring joint integrity and restricting excessive movement.

Relations of the Ankle Joint

Anteriorly

○ From medial to lateral side

Tibialis anterior

The extensor hallucis longus

The anterior tibial vessels

The deep peroneal nerve

The extensor digitorum longus

The peroneus tertius

Posteromedially

○ From medial to lateral side

The tibialis posterior,

The flexor digitorum longus,

The posterior tibial vessels,

The tibial nerve,

The flexor hallucis longus.

Posterolaterally

○ The peroneus longus, and the peroneus brevis

Movements

O Major movements around the ankle joint are dorsiflexion and plantar flexion.

Dorsiflexion is brought about by Tibialis anterior.

○ Plantar flexion is brought about by Gastrocnemius and Soleus muscle.

Blood Supply

O Anterior tibial artery

Posterior tibial artery

○ Peroneal artery

Nerve Supply

- O From deep peroneal and tibial nerves.

Clinical

Dislocations of the ankle are rare because the joint is very stable due to the presence of a deep tibiofibular socket. Whenever dislocation occurs, it is accompanied by fracture of one of the malleoli.

○ Acute sprains of the lateral ankle occur when the foot is plantar flexed and excessively inverted.

○ Acute sprains of medial ankle occur in excessive eversion, leading to tear of strong deltoid ligament but these cases are less common.

Reference: Human Anatomy Lower Limb Abdomen and Pelvis, Volume 2, B.D Chaurasia, 8th Edition, Page No. 175 to 178

You have reached the end of the document.