CUTANEOUS NERVES, SUPERFICIAL VEINS, AND LYMPHATICS
CUTANEOUS NERVES
Lateral femoral cutaneous nerve
• Arises from the lumbar plexus (L2-L3), emerges from the lateral border of the psoas major, crosses the iliacus, and passes under the inguinal ligament near the anterior-superior iliac spine.
• Innervates the skin on the anterior and lateral aspects of the thigh as far as the knee.
Clunial (buttock) nerves
• Innervate the skin of the gluteal region.
• Consist of superior (lateral branches of the dorsal rami of the upper three lumbar nerves), middle (lateral branches of the dorsal rami of the upper three sacral nerves), and inferior
(gluteal branches of the posterior femoral cutaneous nerve) nerves.
Posterior femoral cutaneous nerve
• Arises from the sacral plexus (S1-S3), passes through the greater sciatic foramen below the
piriformis muscle, runs deep to the gluteus maximus muscle, and emerges from the inferior border of this muscle.
• Descends in the posterior midline of the thigh deep to the fascia lata and pierces the fascia
lata near the popliteal fossa.
• Innervates the skin of the buttock, thigh, and calf.
Saphenous nerve
• Arises from the femoral nerve in the femoral triangle and descends with the femoral vessels through the femoral triangle and the adductor canal.
• Pierces the fascial covering of the adductor canal at its distal end in company with the
saphenous branch of the descending genicular artery.
• Becomes cutaneous between the sartorius and the gracilis and descends behind the condyles of the femur and tibia and medial aspect of the leg in company with the great saphenous vein.
• Innervates the skin on the medial side of the leg and foot.
• Is vulnerable to injury (proximal portion) during surgery to repair varicose veins.
Lateral sural cutaneous nerve
• Arises from the common peroneal nerve in the popliteal fossa and may have a communicating branch that joins the medial sural cutaneous nerve.
• Innervates the skin on the posterolateral side of the leg.
Medial sural cutaneous nerve
• Arises from the tibia/ nerve in the popliteal fossa and may join the lateral sural nerve or its communicating branch to form the sural nerve.
• Innervates the skin on the back of the leg and the lateral side of the ankle, heel, and foot.
Surat nerve
• Is formed by the union of the medial sural and lateral sural nerves (or the communicating branch of the lateral sural nerve).
• Innervates the skin on the back of the leg and the lateral side of the ankle, heel, and foot.
Superficial peroneal nerve
• Passes distally between the peroneus muscles and the extensor digitorum longus and pierces the deep fascia in the lower third of the leg to innervate the skin on the lateral side of the lower leg and the dorsum of the foot.
• Divides into a medial dorsal cutaneous nerve, which supplies the medial sides of the foot and ankle, the medial side of the great toe, and the adjacent sides of the second and third toes, and an intermediate dorsal cutaneous nerve, which supplies the skin of the lateral sides of the foot and ankle and the adjacent sides of the third, fourth, and little toes.
Deep peroneal nerve
• Supplies anterior muscles of the leg and foot and the skin of the contiguous sides of the first and second toes.
Superficial Veins
Great saphenous vein
• Begins at the medial end of the dorsal venous arch of the foot.
• Ascends in front of the medial malleolus and along the medial aspect of the tibia along with the saphenous nerve, passes behind the medial condyles of the tibia and femur, and then ascends along the medial side of the femur.
• Passes through the saphenous opening (fossa ovalis) in the fascia lata and pierces the femoral sheath to join the femoral vein.
• Receives the external pudendal, superficial epigastric, superficial circumflex ilia, lateral femoral cutaneous, and accessory saphenous veins.
• Is a suitable vessel for use in coronary artery bypass surgery and for venipuncture.
C.A The greater saphenous vein: accompanies the saphenous nerve, which is vulnerable to injury when it is harvested surgically. It is commonly used for coronary artery bypass surgery, and the vein should be reversed so its valves do not obstruct blood flow in the graft. This vein and its tributaries become dilated and varicosed and varicose veins are common in the posteromedial parts of the lower limb.
Small (short) saphenous vein
• Begins at the lateral end of the dorsal venous arch and passes upward along the lateral side of the foot with the sural nerve, behind the lateral malleolus.
• Ascends in company with the sural nerve and passes to the popliteal fossa, where it perforates the deep fascia and terminates in the popliteal vein.
C.A Thrombophlebitis: is a venous inflammation with thrombus formation, which occurs in the superficial veins in the lower limb, leading to pulmonary embolism. However, most pulmonary emboli originate in deep veins, and the risk of embolism can be reduced by anticoagulant treatment.
Varicose veins: develop in the superficial veins of the lower limb because of a reduced elasticity and incompetent valves in the veins or thrombophlebitis of the deep veins.
Lymphatics
Vessels
. Superficial lymph vessels
• Are formed by vessels from the gluteal region, the abdominal wall and the external genitalia.
• Are divided into a medial group, which follows the great saphenous vein to end in the inguinal nodes, and a lateral group, which follows the small saphenous vein to end in the popliteal nodes and their efferents accompany the femoral vessels to end in the inguinal nodes.
Deep lymph vessels
• Consist of the anterior tibial, posterior tibial, and peroneal vessels, which follow the course of the corresponding blood vessels and enter the popliteal lymph nodes. The lymph vessels from the popliteal nodes accompany the femoral vessels to the inguinal nodes, which enter the external iliac nodes and ultimately drain into the lumbar (aortic) nodes and vessels.
Lymph nodes
Superficial inguinal group of lymph nodes
• Is located subcutaneously near the saphenofemoral junction and drains the superficial thigh region.
• Receives lymph from the anterolateral abdominal wall below the umbilicus, gluteal region, lower parts of the vagina and anus, and external genitalia except the glans, and drains into the external iliac nodes.
Deep inguinal group of lymph nodes
• Lies deep to the fascia lata on the medial side of the femoral vein.
• Receives lymph from deep lymph vessels (i.e., efferents of the popliteal nodes) that accompany the femoral vessels and from the glans penis or glans clitoris, and drains into the external iliac nodes through the femoral canal.
Fibrous Structures
Iliotibial tract
• Is a thick lateral portion of the fascia lata.
• Provides insertion for the gluteus maximus and tensor fasciae latae muscles.
• Helps form the fibrous capsule of the knee joint and is important in maintaining posture and locomotion.
Fascia lata
• Is a membranous, deep fascia covering muscles of the thigh and forms the lateral and medial intermuscular septa by its inward extension to the femur.
• Is attached to the pubic symphysis, pubic crest, pubic rami, ischial tuberosity, inguinal and
sacrotuberous ligaments, and the sacrum and coccyx.
C.A Gluteal gait (gluteus medius limp): is a waddling gait, characterized by the pelvis falling (or drooping) toward the unaffected side when the opposite leg is raised at each step. It results from paralysis of the gluteus medius muscle, which normally functions to stabilize the pelvis when the opposite foot is off the ground.
The gluteal region is a common site for intramuscular injection of drugs. Injection should always be made in the superior lateral quadrant of the gluteal region.
Piriformis syndrome: is a condition in which the piriformis muscle irritates and places pressure on the sciatic nerve, causing pain in the buttocks and referring pain along the course of the sciatic nerve. This referred pain, called "sciatica," in the lower back and hip radiates down the back of the thigh and into the lower back. (The pain initially was attributed to sciatic nerve dysfunction but now is known to be due to herniation of lower lumbar intervertebral disk compromising nerve roots.) It can be treated with progressive piriformis stretching. If this fails, then a corticosteroid may be injected into the piriformis muscle. Finally, surgical exploration may be undertaken as a last resort.
Positive Trendelenburg's sign: is seen in a fracture of the femoral neck, dislocated hip joint (head of femur), or weakness and paralysis of the gluteus medius and minimus muscle, causing inability to abduct the hip. If the right gluteus medius and minimus muscles are paralyzed, the unsupported left side (sound side) of the pelvis falls (sags) instead of rising; normally the pelvis rises.
Hamstring injury or strains (pulled or torn hamstring): are common in person who are involved in running, jumping, and in quick-start sport the origin of hamstring from the ischial tuberosity may be avulsed, resulting in rupture of blood vessels. Avulsion of the ischial tuberosity may result from forcible flexion of the hip with the knee extended, and tearing of hamstring fibers is very painful.
Congenital dislocation isubluxation) of the hip joint: is characterized by movement of the head of the femur out of the acetabulum through the ruptured capsule onto the gluteal surface of the ilium. It occurs because of faulty development of the upper lip of the acetabulum and results in shortening, adduction, and medial rotation of the affected limb.
Traumatic dislocation of the hip joint: is usually produced by trauma (severe enough to fracture the acetabulum), when the thigh is in the flexed position because the hip joint is less stable.
FIBROUS STRUCTURES OF THE ANTERIOR THIGH
Femoral triangle
• Is bounded by the inguinal ligament superiorly, the sartorius muscle laterally, and the adductor longus muscle medially.
• Has the floor, which is formed by the iliopsoas, pectineus, and adductor long muscles. Its roof is formed by the fascia lata and the cribriform fascia.
• Contains the femoral nerve, artery, vein, and canal from the lateral to medial. The pulsation of the femoral artery may be felt just inferior to the midpoint of the inguinal ligament.
Femoral ring
• Is the abdominal opening of the femoral canal.
• Is bounded by the inguinal ligament anteriorly, the femoral vein laterally, the lacunar ligament medially, and the pectineal ligament posteriorly.
Femoral canal
• Lies medial to the femoral vein in the femoral sheath.
• Contains fat, areolar connective tissue, and lymph nodes.
• Transmits lymphatics from the lower limb and perineum to the peritoneal cavity.
• Is a potential weak area and a site of femoral herniation, which occurs most frequently in women because of the greater width of the superior pubic ramus of the female pelvis.
Femoral hernia: is more common in women than in men, passes through the femoral ring and canal, and lies lateral and inferior to the pubic tubercle and deep and inferior to the inguinal ligament; its sac is formed by the parietal peritoneum. Strangulation of a femoral hernia may occur because of the sharp, stiff boundaries of the femoral ring, and the strangulation interferes with the blood supply to the herniated intestine, resulting in death of the tissues.
Femoral sheath
• Is formed by a prolongation of the transversalis and iliac fasciae in the thigh.
• Contains the femoral artery and vein, the femoral branch of the genitofemoral nerve, and the femoral canal. (The femoral nerve lies outside the femoral sheath, lateral to the femoral artery.)
• Reaches the level of the proximal end of the saphenous opening with its distal end.
Adductor canal
• Begins at the apex of the femoral triangle and ends at the adductor hiatus (hiatus
tendineus).
• Lies between the adductor magnus and longus muscles and the vastus medialis muscle and is covered by the sartorius muscle and fascia.
• Contains the femoral vessels, the saphenous nerve, the nerve to the vastus medialis, and the descending genicular artery.
Adductor hiatus (hiatus tendineus)
• Is the aperture in the tendon of insertion of the adductor magnus.
• Allows the passage of the femoral vessels into the popliteal fossa.
Saphenous opening (saphenous hiatus) or fossa ovalis
• Is an oval gap in the fascia lata below the inguinal ligament that is covered by the cribriform fascia, which is a part of the superficial fascia of the thigh.
• Provides a pathway for the greater saphenous vein.
Innervation of the lower limb.
LEG AND POPLITEAL FOSSA
Popliteal fossa
• Is bounded superomedially by the semitendinosus and semimembranosus muscles and
superolaterally by the biceps muscle.
• Is bounded inferolaterally by the lateral head of the gastrocnemius muscle and inferomedially by the medial head of the gastrocnemius muscle.
• Has a floor that is composed of the femur, the oblique popliteal ligament, and the popliteus muscle.
• Contains the popliteal vessels, the common peroneal and tibial nerves, and the small
saphenous vein.
Pes anserinus
• Is the combined tendinous expansions of the sartorius, gracilis, and semitendinosus muscles at the medial border of the tuberosity of the tibia. It may be used for surgical repair of the anterior cruciate ligament of the knee joint.
Anterior tibial compartment syndrome: is characterized by ischemic necrosis of the muscles of the anterior compartment of the leg. It occurs, presumably, as a result of compression of arteries (anterior tibial artery and its branches) by swollen muscles, following excessive exertion. It is accompanied by extreme tenderness and pain on the anterolateral aspect of the leg.
Intermittent claudication is a condition of limping caused by ischemia of the muscles in the lower limbs chiefly the calf muscles, and is seen in occlusive peripheral arterial diseases particularly in the popliteal artery and its branches. Symptom is the leg pain that occurs during walking and intensifies until walking is impossible, but it is relieved by rest.
Ankle-jerk (Achilles) reflex: is a reflex twitch of the triceps surae (i.e., the medial and lateral heads of the gastrocnemius and the soleus muscles) induced by tapping the tendo calcaneus. It causes plantar flexion of the foot and tests its reflex center in the L5-S1 or
S1-S2 segments of the spinal cord. Both afferent and efferent limbs of the reflex arc are carried in the tibial nerve.
Popliteal (Baker's) cyst: is a firm swelling behind the knee, caused by herniation of synovial membrane of the knee joint with synovial fluid posteriorly through the joint capsule into the popliteal fossa. It impairs flexion and extension of the knee joint, limits the joint mobility, and may be painful.
Shin splint: is a painful condition of the anterior compartment of the leg along the shin bone (tibia) caused by swollen muscles in the anterior compartment, particularly the tibialis anterior muscle following athletic overexertion. It may be a mild form of the anterior compartment syndrome.
ANKLE AND FOOT
Superior extensor retinaculum
• Is a broad band of deep fascia extending between the tibia arid fibula, above the ankle.
Inferior extensor retinaculum
• Is a Y-shaped band of deep fascia that forms a loop for the tendons of the extensor digitorum
longus and the peroneus tertius and then divides into an upper band, which attaches to the medial malleolus, and a lower band, which attaches to the deep fascia of the foot and the plantar aponeurosis.
Flexor retinaculum
• Is a deep fascial band that passes between the medial malleolus and the medial surface of the calcaneus and forms the tarsal tunnel with tarsal bones for the tibial nerve, posterior
tibial vessels, and flexor tendons.
• Holds three tendons and blood vessels and nerve in place deep to it: (from anterior to posterior) the tibialis posterior, flexor digitorum longus, posterior tibial artery and vein, tibial nerve, and flexor hallucis longus (mnemonic device: Tom, Dick ANd Harry or Tom Drives A Very Nervous Horse).
• Provides a pathway for the tibial nerve and posterior tibial artery beneath it.
Tendo calcaneus (Achilles tendon)
• Is the tendon of insertion of the triceps surae (gastrocnemius and soleus) into the tuberosity of the calcaneus.
Plantar aponeurosis
• Is a thick fascia investing the plantar muscles.
• Radiates from the calcaneal tuberosity (tuber calcanei) toward the toes and provides attachment to the short flexor muscles of the toes.
C.A Tarsal tunnel syndrome: is a complex symptom resulting from compression of the tibial nerve or its medial and lateral plantar branches in the tarsal tunnel, with pain, numbless, and tingling sensations on the ankle, heel, and sole of the foot. It may be caused by repetitive stress with activities, flat feet, and excess weight.
Arches
• Consist of medial and lateral longitudinal arches and proximal and distal transverse arches.
• Support the body in the erect position and act as a spring in locomotion.
Medial longitudinal arch
• Is formed and maintained by the interlocking of the talus, calcaneus, navicular, cuneiform
bones, and three medial metatarsal bones.
• Has, as its keystone, the head of the talus, which is located at the summit between the
sustentaculum tali and the navicular hone.
• Is supported by the spring ligament and the tendon of the flexor hallucis longus.
C.A Flat foot (pes planus or talipes planus): is a condition of disappearance or collapse of the medial longitudinal arch with eversion and abduction of the forefoot and causes greater wear on the inner border of the soles and heels of shoes than on the outer border. It causes pain as a result of stretching of the plantar muscles and straining of the spring ligament and the long and short plantar ligaments. Pes cavus exhibits an exaggerated height of the medial longitudinal arch of the foot.
Lateral longitudinal arch
• Is formed by the calcaneus, the cuhoid bone, and the lateral two metatarsal bones. The keystone is the cuboid bone.
• Is supported by the peroneus longus tendon and the long and short plantar ligaments.
• Supports the body in the erect position and acts as a spring in locomotion.
Transverse arch
Proximal (metatarsal) arch
• Is formed by the navicular bone, the three cuneiform bones, the cuhoid bone, and the bases of the five metatarsal bones of the foot.
• Is supported by the tendon of the peroneus longus.
Distal arch
• Is formed by the heads of five metatarsal bones.
• Is maintained by the transverse head of the adductor hallucis.
Superficial Vein
• The greater saphenous vein begins at the medial end of the dorsal venous arch of the foot, passes anterior to the medial malleolus, runs on the medial side of the lower limb, and empties into the femoral vein. The small saphenous vein begins at the lateral end of the dorsal venous arch, passes posterior to the lateral malleolus, ascends on the posterior side of the leg along with the sural nerve and empties into the popliteal vein. Emergency blood transfusion can be performed on the greater saphenous vein anterior to the medial malleolus and a graft of a portion of the greater saphenous vein can be used for coronary bypass operations and also for bypass obstructions of the brachial or femoral arteries.
Arterial Supply
The obturator artery arises from the internal iliac artery and supplies the adductor compartment of the thigh. This artery may arise from the inferior epigastric artery and is at risk in surgical repair of a femoral hernia as it courses over the pelvic brim to reach the obturator foramen.
The femoral artery begins as the continuation of the external iliac artery, descends through the femoral triangle where it is vulnerable to injury, and enters the adductor canal. This artery gives off the superficial epigastric, superficial circumflex iliac, superficial and deep external pudendal, deep femoral, medial and lateral femoral circumflex, and descending genicular arteries. The medial femoral circumflex artery is the most important source of blood to the femoral head and proximal neck and gives off muscular branches, an acetabular branch to the hip joint, an ascending branch to anastomose with branches of the gluteal arteries, and a transverse branch that joins the cruciate anastomosis.
The lateral femoral circumflex artery gives off an ascending branch, which forms a vascular circle with branches of the medial femoral circumflex artery around the femoral neck; a transverse branch, which joins the cruciate anastomosis; and a descending branch, which
anastomoses with genicular arteries. The cruciate anastomosis bypasses obstruction of external iliac or femoral artery.
Arteries
• Popliteal artery—continuation of the femoral artery; gives rise to five genicular arteries and divides into the anterior and posterior tibial arteries.
• Posterior tibial artery gives off the peroneal artery, which gives off the posterior lateral malleolar branches. The posterior tibial also gives off the posterior medial malleolar branch and then divides into the medial and lateral plantar arteries.
• Anterior tibial artery gives off the anterior tibial recurrent artery and anterior medial and lateral malleolar arteries and ends at the ankle, where it becomes the dorsalis pedis artery.
• Dorsalis pedis artery gives off the medial and lateral tarsal, arcuate, and the first dorsal metatarsal arteries and ends as the deep plantar artery.
• A pulse from the femoral artery can be felt behind the inguinal ligament at a point midway between the anterior superior iliac spine and the symphysis pubis; the popliteal artery pulsation can be felt in the depths of the popliteal fossa; the pulsations of the posterior tibial artery can be felt behind the medial malleolus and between the flexor digitorum longus and flexor hallucis longus tendons; and the pulsations of the dorsalis pedis artery can be felt between the extensor hallucis longus and extensor digitorum longus tendons midway between the medial and lateral malleoli on the ankle.
Femoral hernia—passes through the femoral canal and lies lateral and inferior to the pubic tubercle and deep to the inguinal ligament.
Femoral artery—vulnerable to injury because of its superficial position in the femoral triangle.
Aberrant obturator artery—vulnerable during surgical repair of a femoral hernia.
Saphenous nerve—vulnerable to injury when the greater saphenous vein is harvested for a coronary artery bypass surgery.
Gluteal gait—waddling gait, characterized by the pelvis falling (drooping) toward the unaffected side at each step resulting from paralysis of the gluteus medius muscle. The gluteal region is a common site for intramuscular injection, which should be given on the superior lateral quadrant.
Fracture of the femoral neck—results in ischemic necrosis of the neck and the distal part of the head, except for its small proximal fragment, because of an interruption of blood supply from the medial femoral circumflex artery. It causes a pull of the distal fragment upward by the quadriceps femoris, adductor, and hamstring muscles so that the lower limb is shortened with lateral rotation. A dislocated knee or fractured distal femur may injure the popliteal artery because of its deep position adjacent to the femur and the knee joint capsule.
Fracture of the fibular neck—causes damage to the common peroneal nerve, which winds around the fibular neck.
Bumper fracture—fracture of the leg bone below the knee caused by an automobile bumper and it is usually associated with a common peroneal nerve injury.
Pott's fracture (Dupuytren's fracture)—fracture of the lower end of the fibula, often accompanied by fracture of the medial malleolus or rupture of the deltoid ligament. It is caused by forced eversion of the foot.
3 Pulled groin (groin injury)—a strain, stretching, and tearing of the origin of the flexors and adductors of the thigh that occurs in sports players.
3 Intermittent claudication—a condition of limping caused by ischemia of the muscles in the
lower limbs chiefly the calf muscles, and is seen in occlusive peripheral arterial diseases particularly
in the popliteal artery and its branches.
Reflexes
Knee-jerk (patellar) reflex—occurs when the patellar ligament is tapped, resulting in a sudden contraction of the quadriceps femoris. Both afferent and efferent limbs of the reflex arc are in the femoral nerve (L2-L4).
Ankle-jerk (Achilles) reflex—reflex twitch of the triceps surae. Its reflex center is in the L5 and S1 spinal nerve segments. It is induced by tapping the tendocalcaneus to elicit plantar flexion of the foot. Rupture of the Achilles tendon disables the gastrocnemius and soleus muscles, causing an impaired plantar flexion of the foot.
Unhi triad of the knee joint—may occur when a football player's cleated shoe is planted firmly in turf and the knee is struck from the lateral side. It is characterized by rupture of the
tibial coll. 2ral ligament, injury to the medial meniscus, and tearing of the anterior cruciate ligament. '1 he medial meniscus is more frequently torn in injuries than the lateral because it is firmly attached to the joint capsule and the tibial collateral ligament.
Housemaid's knee (prepatellar bursitis)—inflammation and swelling of the prepatellar bursa.
Popliteal (Baker's) cyst—collection of synovial fluid in a synovial-lined sac herniated from the knee joint into the popliteal fossa, impairing flexion and extension of the knee joint.
Knock-knee (genu valgum)—deformity in which the tibia is bent laterally and may occur as a result of rupture of the medial collateral ligament.
Bowler' (genu varum)—deformity in which the tibia is bent medially and may occur as a result of ri ,cure of the lateral collateral ligament.
Anterior tibial compartment syndrome—characterized by ischemic necrosis of the muscles of the anterior compartment of the leg and occurs as a result of compression of arteries by swollen muscles, following excessive exertion.
Tarsal tunnel—osseofibrous passage for the tibial nerve, posterior tibial vessels, and flexor tendons, formed by the flexor retinaculum and tarsal bones.
Tarsal tunnel syndrome—complex symptom resulting from compression of the tibial nerve
or of the medial and lateral plantar nerves in the tarsal tunnel, with pain, numbness, and tingling
(paresthesia) of the sole of the foot.
Damage to the femoral nerve causes impaired flexion of the hip and extension of the leg resulting from paralysis of the quadriceps femoris.
Damage to the common peroneal nerve by fracture of the fibular neck results in foot drop and paralysis of all of the dorsiflexor and evertor muscles of the foot.
Damage to the tibial nerve causes loss of plantar flexion of the foot, impaired inversion because of paralysis of the tibialis posterior, and clawing of the toes.
Damage to the deep peroneal nerve results in foot drop. Damage to the superficial peroneal nerve causes loss of eversion of the foot.
CUTANEOUS NERVES
Lateral femoral cutaneous nerve
• Arises from the lumbar plexus (L2-L3), emerges from the lateral border of the psoas major, crosses the iliacus, and passes under the inguinal ligament near the anterior-superior iliac spine.
• Innervates the skin on the anterior and lateral aspects of the thigh as far as the knee.
Clunial (buttock) nerves
• Innervate the skin of the gluteal region.
• Consist of superior (lateral branches of the dorsal rami of the upper three lumbar nerves), middle (lateral branches of the dorsal rami of the upper three sacral nerves), and inferior
(gluteal branches of the posterior femoral cutaneous nerve) nerves.
Posterior femoral cutaneous nerve
• Arises from the sacral plexus (S1-S3), passes through the greater sciatic foramen below the
piriformis muscle, runs deep to the gluteus maximus muscle, and emerges from the inferior border of this muscle.
• Descends in the posterior midline of the thigh deep to the fascia lata and pierces the fascia
lata near the popliteal fossa.
• Innervates the skin of the buttock, thigh, and calf.
Saphenous nerve
• Arises from the femoral nerve in the femoral triangle and descends with the femoral vessels through the femoral triangle and the adductor canal.
• Pierces the fascial covering of the adductor canal at its distal end in company with the
saphenous branch of the descending genicular artery.
• Becomes cutaneous between the sartorius and the gracilis and descends behind the condyles of the femur and tibia and medial aspect of the leg in company with the great saphenous vein.
• Innervates the skin on the medial side of the leg and foot.
• Is vulnerable to injury (proximal portion) during surgery to repair varicose veins.
Lateral sural cutaneous nerve
• Arises from the common peroneal nerve in the popliteal fossa and may have a communicating branch that joins the medial sural cutaneous nerve.
• Innervates the skin on the posterolateral side of the leg.
Medial sural cutaneous nerve
• Arises from the tibia/ nerve in the popliteal fossa and may join the lateral sural nerve or its communicating branch to form the sural nerve.
• Innervates the skin on the back of the leg and the lateral side of the ankle, heel, and foot.
Surat nerve
• Is formed by the union of the medial sural and lateral sural nerves (or the communicating branch of the lateral sural nerve).
• Innervates the skin on the back of the leg and the lateral side of the ankle, heel, and foot.
Superficial peroneal nerve
• Passes distally between the peroneus muscles and the extensor digitorum longus and pierces the deep fascia in the lower third of the leg to innervate the skin on the lateral side of the lower leg and the dorsum of the foot.
• Divides into a medial dorsal cutaneous nerve, which supplies the medial sides of the foot and ankle, the medial side of the great toe, and the adjacent sides of the second and third toes, and an intermediate dorsal cutaneous nerve, which supplies the skin of the lateral sides of the foot and ankle and the adjacent sides of the third, fourth, and little toes.
Deep peroneal nerve
• Supplies anterior muscles of the leg and foot and the skin of the contiguous sides of the first and second toes.
Superficial Veins
Great saphenous vein
• Begins at the medial end of the dorsal venous arch of the foot.
• Ascends in front of the medial malleolus and along the medial aspect of the tibia along with the saphenous nerve, passes behind the medial condyles of the tibia and femur, and then ascends along the medial side of the femur.
• Passes through the saphenous opening (fossa ovalis) in the fascia lata and pierces the femoral sheath to join the femoral vein.
• Receives the external pudendal, superficial epigastric, superficial circumflex ilia, lateral femoral cutaneous, and accessory saphenous veins.
• Is a suitable vessel for use in coronary artery bypass surgery and for venipuncture.
C.A The greater saphenous vein: accompanies the saphenous nerve, which is vulnerable to injury when it is harvested surgically. It is commonly used for coronary artery bypass surgery, and the vein should be reversed so its valves do not obstruct blood flow in the graft. This vein and its tributaries become dilated and varicosed and varicose veins are common in the posteromedial parts of the lower limb.
Small (short) saphenous vein
• Begins at the lateral end of the dorsal venous arch and passes upward along the lateral side of the foot with the sural nerve, behind the lateral malleolus.
• Ascends in company with the sural nerve and passes to the popliteal fossa, where it perforates the deep fascia and terminates in the popliteal vein.
C.A Thrombophlebitis: is a venous inflammation with thrombus formation, which occurs in the superficial veins in the lower limb, leading to pulmonary embolism. However, most pulmonary emboli originate in deep veins, and the risk of embolism can be reduced by anticoagulant treatment.
Varicose veins: develop in the superficial veins of the lower limb because of a reduced elasticity and incompetent valves in the veins or thrombophlebitis of the deep veins.
Lymphatics
Vessels
. Superficial lymph vessels
• Are formed by vessels from the gluteal region, the abdominal wall and the external genitalia.
• Are divided into a medial group, which follows the great saphenous vein to end in the inguinal nodes, and a lateral group, which follows the small saphenous vein to end in the popliteal nodes and their efferents accompany the femoral vessels to end in the inguinal nodes.
Deep lymph vessels
• Consist of the anterior tibial, posterior tibial, and peroneal vessels, which follow the course of the corresponding blood vessels and enter the popliteal lymph nodes. The lymph vessels from the popliteal nodes accompany the femoral vessels to the inguinal nodes, which enter the external iliac nodes and ultimately drain into the lumbar (aortic) nodes and vessels.
Lymph nodes
Superficial inguinal group of lymph nodes
• Is located subcutaneously near the saphenofemoral junction and drains the superficial thigh region.
• Receives lymph from the anterolateral abdominal wall below the umbilicus, gluteal region, lower parts of the vagina and anus, and external genitalia except the glans, and drains into the external iliac nodes.
Deep inguinal group of lymph nodes
• Lies deep to the fascia lata on the medial side of the femoral vein.
• Receives lymph from deep lymph vessels (i.e., efferents of the popliteal nodes) that accompany the femoral vessels and from the glans penis or glans clitoris, and drains into the external iliac nodes through the femoral canal.
Fibrous Structures
Iliotibial tract
• Is a thick lateral portion of the fascia lata.
• Provides insertion for the gluteus maximus and tensor fasciae latae muscles.
• Helps form the fibrous capsule of the knee joint and is important in maintaining posture and locomotion.
Fascia lata
• Is a membranous, deep fascia covering muscles of the thigh and forms the lateral and medial intermuscular septa by its inward extension to the femur.
• Is attached to the pubic symphysis, pubic crest, pubic rami, ischial tuberosity, inguinal and
sacrotuberous ligaments, and the sacrum and coccyx.
C.A Gluteal gait (gluteus medius limp): is a waddling gait, characterized by the pelvis falling (or drooping) toward the unaffected side when the opposite leg is raised at each step. It results from paralysis of the gluteus medius muscle, which normally functions to stabilize the pelvis when the opposite foot is off the ground.
The gluteal region is a common site for intramuscular injection of drugs. Injection should always be made in the superior lateral quadrant of the gluteal region.
Piriformis syndrome: is a condition in which the piriformis muscle irritates and places pressure on the sciatic nerve, causing pain in the buttocks and referring pain along the course of the sciatic nerve. This referred pain, called "sciatica," in the lower back and hip radiates down the back of the thigh and into the lower back. (The pain initially was attributed to sciatic nerve dysfunction but now is known to be due to herniation of lower lumbar intervertebral disk compromising nerve roots.) It can be treated with progressive piriformis stretching. If this fails, then a corticosteroid may be injected into the piriformis muscle. Finally, surgical exploration may be undertaken as a last resort.
Positive Trendelenburg's sign: is seen in a fracture of the femoral neck, dislocated hip joint (head of femur), or weakness and paralysis of the gluteus medius and minimus muscle, causing inability to abduct the hip. If the right gluteus medius and minimus muscles are paralyzed, the unsupported left side (sound side) of the pelvis falls (sags) instead of rising; normally the pelvis rises.
Hamstring injury or strains (pulled or torn hamstring): are common in person who are involved in running, jumping, and in quick-start sport the origin of hamstring from the ischial tuberosity may be avulsed, resulting in rupture of blood vessels. Avulsion of the ischial tuberosity may result from forcible flexion of the hip with the knee extended, and tearing of hamstring fibers is very painful.
Congenital dislocation isubluxation) of the hip joint: is characterized by movement of the head of the femur out of the acetabulum through the ruptured capsule onto the gluteal surface of the ilium. It occurs because of faulty development of the upper lip of the acetabulum and results in shortening, adduction, and medial rotation of the affected limb.
Traumatic dislocation of the hip joint: is usually produced by trauma (severe enough to fracture the acetabulum), when the thigh is in the flexed position because the hip joint is less stable.
FIBROUS STRUCTURES OF THE ANTERIOR THIGH
Femoral triangle
• Is bounded by the inguinal ligament superiorly, the sartorius muscle laterally, and the adductor longus muscle medially.
• Has the floor, which is formed by the iliopsoas, pectineus, and adductor long muscles. Its roof is formed by the fascia lata and the cribriform fascia.
• Contains the femoral nerve, artery, vein, and canal from the lateral to medial. The pulsation of the femoral artery may be felt just inferior to the midpoint of the inguinal ligament.
Femoral ring
• Is the abdominal opening of the femoral canal.
• Is bounded by the inguinal ligament anteriorly, the femoral vein laterally, the lacunar ligament medially, and the pectineal ligament posteriorly.
Femoral canal
• Lies medial to the femoral vein in the femoral sheath.
• Contains fat, areolar connective tissue, and lymph nodes.
• Transmits lymphatics from the lower limb and perineum to the peritoneal cavity.
• Is a potential weak area and a site of femoral herniation, which occurs most frequently in women because of the greater width of the superior pubic ramus of the female pelvis.
Femoral hernia: is more common in women than in men, passes through the femoral ring and canal, and lies lateral and inferior to the pubic tubercle and deep and inferior to the inguinal ligament; its sac is formed by the parietal peritoneum. Strangulation of a femoral hernia may occur because of the sharp, stiff boundaries of the femoral ring, and the strangulation interferes with the blood supply to the herniated intestine, resulting in death of the tissues.
Femoral sheath
• Is formed by a prolongation of the transversalis and iliac fasciae in the thigh.
• Contains the femoral artery and vein, the femoral branch of the genitofemoral nerve, and the femoral canal. (The femoral nerve lies outside the femoral sheath, lateral to the femoral artery.)
• Reaches the level of the proximal end of the saphenous opening with its distal end.
Adductor canal
• Begins at the apex of the femoral triangle and ends at the adductor hiatus (hiatus
tendineus).
• Lies between the adductor magnus and longus muscles and the vastus medialis muscle and is covered by the sartorius muscle and fascia.
• Contains the femoral vessels, the saphenous nerve, the nerve to the vastus medialis, and the descending genicular artery.
Adductor hiatus (hiatus tendineus)
• Is the aperture in the tendon of insertion of the adductor magnus.
• Allows the passage of the femoral vessels into the popliteal fossa.
Saphenous opening (saphenous hiatus) or fossa ovalis
• Is an oval gap in the fascia lata below the inguinal ligament that is covered by the cribriform fascia, which is a part of the superficial fascia of the thigh.
• Provides a pathway for the greater saphenous vein.
Innervation of the lower limb.
LEG AND POPLITEAL FOSSA
Popliteal fossa
• Is bounded superomedially by the semitendinosus and semimembranosus muscles and
superolaterally by the biceps muscle.
• Is bounded inferolaterally by the lateral head of the gastrocnemius muscle and inferomedially by the medial head of the gastrocnemius muscle.
• Has a floor that is composed of the femur, the oblique popliteal ligament, and the popliteus muscle.
• Contains the popliteal vessels, the common peroneal and tibial nerves, and the small
saphenous vein.
Pes anserinus
• Is the combined tendinous expansions of the sartorius, gracilis, and semitendinosus muscles at the medial border of the tuberosity of the tibia. It may be used for surgical repair of the anterior cruciate ligament of the knee joint.
Anterior tibial compartment syndrome: is characterized by ischemic necrosis of the muscles of the anterior compartment of the leg. It occurs, presumably, as a result of compression of arteries (anterior tibial artery and its branches) by swollen muscles, following excessive exertion. It is accompanied by extreme tenderness and pain on the anterolateral aspect of the leg.
Intermittent claudication is a condition of limping caused by ischemia of the muscles in the lower limbs chiefly the calf muscles, and is seen in occlusive peripheral arterial diseases particularly in the popliteal artery and its branches. Symptom is the leg pain that occurs during walking and intensifies until walking is impossible, but it is relieved by rest.
Ankle-jerk (Achilles) reflex: is a reflex twitch of the triceps surae (i.e., the medial and lateral heads of the gastrocnemius and the soleus muscles) induced by tapping the tendo calcaneus. It causes plantar flexion of the foot and tests its reflex center in the L5-S1 or
S1-S2 segments of the spinal cord. Both afferent and efferent limbs of the reflex arc are carried in the tibial nerve.
Popliteal (Baker's) cyst: is a firm swelling behind the knee, caused by herniation of synovial membrane of the knee joint with synovial fluid posteriorly through the joint capsule into the popliteal fossa. It impairs flexion and extension of the knee joint, limits the joint mobility, and may be painful.
Shin splint: is a painful condition of the anterior compartment of the leg along the shin bone (tibia) caused by swollen muscles in the anterior compartment, particularly the tibialis anterior muscle following athletic overexertion. It may be a mild form of the anterior compartment syndrome.
ANKLE AND FOOT
Superior extensor retinaculum
• Is a broad band of deep fascia extending between the tibia arid fibula, above the ankle.
Inferior extensor retinaculum
• Is a Y-shaped band of deep fascia that forms a loop for the tendons of the extensor digitorum
longus and the peroneus tertius and then divides into an upper band, which attaches to the medial malleolus, and a lower band, which attaches to the deep fascia of the foot and the plantar aponeurosis.
Flexor retinaculum
• Is a deep fascial band that passes between the medial malleolus and the medial surface of the calcaneus and forms the tarsal tunnel with tarsal bones for the tibial nerve, posterior
tibial vessels, and flexor tendons.
• Holds three tendons and blood vessels and nerve in place deep to it: (from anterior to posterior) the tibialis posterior, flexor digitorum longus, posterior tibial artery and vein, tibial nerve, and flexor hallucis longus (mnemonic device: Tom, Dick ANd Harry or Tom Drives A Very Nervous Horse).
• Provides a pathway for the tibial nerve and posterior tibial artery beneath it.
Tendo calcaneus (Achilles tendon)
• Is the tendon of insertion of the triceps surae (gastrocnemius and soleus) into the tuberosity of the calcaneus.
Plantar aponeurosis
• Is a thick fascia investing the plantar muscles.
• Radiates from the calcaneal tuberosity (tuber calcanei) toward the toes and provides attachment to the short flexor muscles of the toes.
C.A Tarsal tunnel syndrome: is a complex symptom resulting from compression of the tibial nerve or its medial and lateral plantar branches in the tarsal tunnel, with pain, numbless, and tingling sensations on the ankle, heel, and sole of the foot. It may be caused by repetitive stress with activities, flat feet, and excess weight.
Arches
• Consist of medial and lateral longitudinal arches and proximal and distal transverse arches.
• Support the body in the erect position and act as a spring in locomotion.
Medial longitudinal arch
• Is formed and maintained by the interlocking of the talus, calcaneus, navicular, cuneiform
bones, and three medial metatarsal bones.
• Has, as its keystone, the head of the talus, which is located at the summit between the
sustentaculum tali and the navicular hone.
• Is supported by the spring ligament and the tendon of the flexor hallucis longus.
C.A Flat foot (pes planus or talipes planus): is a condition of disappearance or collapse of the medial longitudinal arch with eversion and abduction of the forefoot and causes greater wear on the inner border of the soles and heels of shoes than on the outer border. It causes pain as a result of stretching of the plantar muscles and straining of the spring ligament and the long and short plantar ligaments. Pes cavus exhibits an exaggerated height of the medial longitudinal arch of the foot.
Lateral longitudinal arch
• Is formed by the calcaneus, the cuhoid bone, and the lateral two metatarsal bones. The keystone is the cuboid bone.
• Is supported by the peroneus longus tendon and the long and short plantar ligaments.
• Supports the body in the erect position and acts as a spring in locomotion.
Transverse arch
Proximal (metatarsal) arch
• Is formed by the navicular bone, the three cuneiform bones, the cuhoid bone, and the bases of the five metatarsal bones of the foot.
• Is supported by the tendon of the peroneus longus.
Distal arch
• Is formed by the heads of five metatarsal bones.
• Is maintained by the transverse head of the adductor hallucis.
Superficial Vein
• The greater saphenous vein begins at the medial end of the dorsal venous arch of the foot, passes anterior to the medial malleolus, runs on the medial side of the lower limb, and empties into the femoral vein. The small saphenous vein begins at the lateral end of the dorsal venous arch, passes posterior to the lateral malleolus, ascends on the posterior side of the leg along with the sural nerve and empties into the popliteal vein. Emergency blood transfusion can be performed on the greater saphenous vein anterior to the medial malleolus and a graft of a portion of the greater saphenous vein can be used for coronary bypass operations and also for bypass obstructions of the brachial or femoral arteries.
Arterial Supply
The obturator artery arises from the internal iliac artery and supplies the adductor compartment of the thigh. This artery may arise from the inferior epigastric artery and is at risk in surgical repair of a femoral hernia as it courses over the pelvic brim to reach the obturator foramen.
The femoral artery begins as the continuation of the external iliac artery, descends through the femoral triangle where it is vulnerable to injury, and enters the adductor canal. This artery gives off the superficial epigastric, superficial circumflex iliac, superficial and deep external pudendal, deep femoral, medial and lateral femoral circumflex, and descending genicular arteries. The medial femoral circumflex artery is the most important source of blood to the femoral head and proximal neck and gives off muscular branches, an acetabular branch to the hip joint, an ascending branch to anastomose with branches of the gluteal arteries, and a transverse branch that joins the cruciate anastomosis.
The lateral femoral circumflex artery gives off an ascending branch, which forms a vascular circle with branches of the medial femoral circumflex artery around the femoral neck; a transverse branch, which joins the cruciate anastomosis; and a descending branch, which
anastomoses with genicular arteries. The cruciate anastomosis bypasses obstruction of external iliac or femoral artery.
Arteries
• Popliteal artery—continuation of the femoral artery; gives rise to five genicular arteries and divides into the anterior and posterior tibial arteries.
• Posterior tibial artery gives off the peroneal artery, which gives off the posterior lateral malleolar branches. The posterior tibial also gives off the posterior medial malleolar branch and then divides into the medial and lateral plantar arteries.
• Anterior tibial artery gives off the anterior tibial recurrent artery and anterior medial and lateral malleolar arteries and ends at the ankle, where it becomes the dorsalis pedis artery.
• Dorsalis pedis artery gives off the medial and lateral tarsal, arcuate, and the first dorsal metatarsal arteries and ends as the deep plantar artery.
• A pulse from the femoral artery can be felt behind the inguinal ligament at a point midway between the anterior superior iliac spine and the symphysis pubis; the popliteal artery pulsation can be felt in the depths of the popliteal fossa; the pulsations of the posterior tibial artery can be felt behind the medial malleolus and between the flexor digitorum longus and flexor hallucis longus tendons; and the pulsations of the dorsalis pedis artery can be felt between the extensor hallucis longus and extensor digitorum longus tendons midway between the medial and lateral malleoli on the ankle.
Femoral hernia—passes through the femoral canal and lies lateral and inferior to the pubic tubercle and deep to the inguinal ligament.
Femoral artery—vulnerable to injury because of its superficial position in the femoral triangle.
Aberrant obturator artery—vulnerable during surgical repair of a femoral hernia.
Saphenous nerve—vulnerable to injury when the greater saphenous vein is harvested for a coronary artery bypass surgery.
Gluteal gait—waddling gait, characterized by the pelvis falling (drooping) toward the unaffected side at each step resulting from paralysis of the gluteus medius muscle. The gluteal region is a common site for intramuscular injection, which should be given on the superior lateral quadrant.
Fracture of the femoral neck—results in ischemic necrosis of the neck and the distal part of the head, except for its small proximal fragment, because of an interruption of blood supply from the medial femoral circumflex artery. It causes a pull of the distal fragment upward by the quadriceps femoris, adductor, and hamstring muscles so that the lower limb is shortened with lateral rotation. A dislocated knee or fractured distal femur may injure the popliteal artery because of its deep position adjacent to the femur and the knee joint capsule.
Fracture of the fibular neck—causes damage to the common peroneal nerve, which winds around the fibular neck.
Bumper fracture—fracture of the leg bone below the knee caused by an automobile bumper and it is usually associated with a common peroneal nerve injury.
Pott's fracture (Dupuytren's fracture)—fracture of the lower end of the fibula, often accompanied by fracture of the medial malleolus or rupture of the deltoid ligament. It is caused by forced eversion of the foot.
3 Pulled groin (groin injury)—a strain, stretching, and tearing of the origin of the flexors and adductors of the thigh that occurs in sports players.
3 Intermittent claudication—a condition of limping caused by ischemia of the muscles in the
lower limbs chiefly the calf muscles, and is seen in occlusive peripheral arterial diseases particularly
in the popliteal artery and its branches.
Reflexes
Knee-jerk (patellar) reflex—occurs when the patellar ligament is tapped, resulting in a sudden contraction of the quadriceps femoris. Both afferent and efferent limbs of the reflex arc are in the femoral nerve (L2-L4).
Ankle-jerk (Achilles) reflex—reflex twitch of the triceps surae. Its reflex center is in the L5 and S1 spinal nerve segments. It is induced by tapping the tendocalcaneus to elicit plantar flexion of the foot. Rupture of the Achilles tendon disables the gastrocnemius and soleus muscles, causing an impaired plantar flexion of the foot.
Unhi triad of the knee joint—may occur when a football player's cleated shoe is planted firmly in turf and the knee is struck from the lateral side. It is characterized by rupture of the
tibial coll. 2ral ligament, injury to the medial meniscus, and tearing of the anterior cruciate ligament. '1 he medial meniscus is more frequently torn in injuries than the lateral because it is firmly attached to the joint capsule and the tibial collateral ligament.
Housemaid's knee (prepatellar bursitis)—inflammation and swelling of the prepatellar bursa.
Popliteal (Baker's) cyst—collection of synovial fluid in a synovial-lined sac herniated from the knee joint into the popliteal fossa, impairing flexion and extension of the knee joint.
Knock-knee (genu valgum)—deformity in which the tibia is bent laterally and may occur as a result of rupture of the medial collateral ligament.
Bowler' (genu varum)—deformity in which the tibia is bent medially and may occur as a result of ri ,cure of the lateral collateral ligament.
Anterior tibial compartment syndrome—characterized by ischemic necrosis of the muscles of the anterior compartment of the leg and occurs as a result of compression of arteries by swollen muscles, following excessive exertion.
Tarsal tunnel—osseofibrous passage for the tibial nerve, posterior tibial vessels, and flexor tendons, formed by the flexor retinaculum and tarsal bones.
Tarsal tunnel syndrome—complex symptom resulting from compression of the tibial nerve
or of the medial and lateral plantar nerves in the tarsal tunnel, with pain, numbness, and tingling
(paresthesia) of the sole of the foot.
Damage to the femoral nerve causes impaired flexion of the hip and extension of the leg resulting from paralysis of the quadriceps femoris.
Damage to the common peroneal nerve by fracture of the fibular neck results in foot drop and paralysis of all of the dorsiflexor and evertor muscles of the foot.
Damage to the tibial nerve causes loss of plantar flexion of the foot, impaired inversion because of paralysis of the tibialis posterior, and clawing of the toes.
Damage to the deep peroneal nerve results in foot drop. Damage to the superficial peroneal nerve causes loss of eversion of the foot.
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