THE LOWER LIMB

THE LIST OF TOPICS:

Gluteal region

Thigh and popliteal fossa

Leg and dorsum of foot

Sole of foot

Joints of the lower limb

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Gluteal region

The hip bone (os coxae) is formed by 3 bones fusing at the acetabulum (the articular depression for the head of the femur) by a y-shaped cartilage around the 16th - 23rd year (Clemente 265-266; Grant p. 397; Netter 3e 468; 4e 486).

The 3 bones are the:

• Ilium
• Ischium
• Pubis

The ilium (located superior to the acetabulum) has the following landmarks:

• the dorsum ilii with the anterior, posterior and inferior gluteal lines (origins of gluteus minimus, medius and maximus; Clemente 265; Grant p. 397; Netter 3e 468; 4e 486)
• the iliac crest
  • a line joining the most superior point of the bilateral iliac crests will cross the 4th lumbar spine (L4; Clinically Oriented Anatomy, 5th ed., p. 533). This is a guide to lumbar spinal tap because the spinal cord ends around L1-L2 (Clemente 356; Grant p. 344; Clinically Oriented Anatomy, 5th ed., p. 527; Netter 3e 153, 154; 4e 161).
• the anterior superior iliac spine (Clemente 265; Grant p. 396-397; Netter 3e 468-469; 4e 486).
• the anterior inferior iliac spine which serves as attachment point for the straight head of the rectus femoris (Clemente plate 320, 375; Grant p. 394; Netter 474)
• the posterior superior iliac spine (Clemente plate 250 fig. 378; Grant p. 397; Netter 3e 468; 4e 486, 492)
  • a line joining the 2 spines bilaterally will cross the 2nd sacral spine: this is the level of the bottom of subarachnoid space which contains cerebrospinal fluid (Clinically Oriented Anatomy, 5th ed., p. 527). This line will also cross the sacroiliac articulation (Clinically Oriented Anatomy, 5th ed., p. 533).
• the posterior inferior iliac spine
• the greater sciatic notch (Clemente 265-266; Grant p. 397; Netter 3e 468; 4e 486)

ISCHIUM, located posteroinferior to the acetabulum, has the following landmarks (Clemente 265-266; Grant p. 397; Netter 3e 468; 4e 486):

• the ischial spine
• the lesser sciatic notch
• the body of the ischium
• the ischial tuberosity
• the ramus of the ischium fuses with the inferior ramus of pubis in the 8th year.
  • The pubic arch or subpubic angle (Clemente 270-271; Grant p. 196; Netter 3e 342; 4e 354) is formed by joined rami of ischium and pubis, bilaterally.

PUBIS, located anteroinferior to the acetabulum, has the following landmarks (Clemente 265-266, 270-273; Grant p. 196-199; Netter 3e 340-341, 468-469; 4e 352-355, 486)

• The body has a symphyseal surface for articulation with the contralateral pubis.
• The pubic crest (medial) ends at the pubic tubercle (lateral).
• The superior ramus has a ridge called the pecten pubis or pectineal line.
  • the pectineal line serves as attachment point for the pectineus muscle (Clemente 374-375; Grant p. 376; Netter 3e 474; 4e 492-493)
• the spiral margin of the obturator foramen
  • obturator vessels and nerves running through the obturator foramen will lie in contact with the inferior surface of the superior ramus (Clemente 379; Grant p. 394, 396; Netter 3e 480, 494; 4e 487, 497, 501).
• the inferior ramus

The proximal end of femur (Clemente 430-431; Grant p. 380-381; Netter 3e 470-471; 4e 488-489) has the following landmarks:

• the head
• the neck
• the greater trochanter
• the lesser trochanter
• the gluteal tuberosity
• the linea aspera

Gluteus maximus (Clemente 383-385; Grant p. 383-384; Netter 3e 476-477; 4e 494-495):

• Arising from a strip of bones and ligaments between the posterior superior iliac spine and the tip of the coccyx, the muscle fibers run across the ischial tuberosity to the shaft of femur.
  • The ischial tuberosity is uncovered in the sitting position.
  • A bursa exists between these fibers and the greater trochanter (Clemente 385; Grant p. 385).
• 1/4 of the muscle fibers attaches to the gluteal tuberosity, between the greater trochanter and the linea aspera.
• the rest joins with the tensor fasciae latae to form the iliotibial tract (Clemente 383-384; Grant p. 384-385; Netter 3e 476; 4e 494).
  • The iliotibial tract attaches inferiorly to the lateral condyle of the tibia. It assists in keeping the extended knee joint extended.
• The muscle fibers also attach to the linea aspera.
• The gluteus maximus is innervated by the inferior gluteal nerve (L5, S1 & 2) and vascularized by inferior gluteal vessels along with neighboring vessels such as the superficial branch of the superior gluteal artery (Clemente 387; Grant p. 388; Netter 3e 484-485; 4e 502-503).
• The gluteus maximus extends the hip joint and lateral rotates the femur. It also supports the extended knee via the iliotibial tract (anti-gravity function).

STRUCTURES DEEP TO THE GLUTEUS MAXIMUS

• Communication between the pelvis and the gluteal region is done via the greater sciatic foramen (Clemente 270-273; Grant p. 201; Netter 4e 352).
• The piriformis muscle is the key to this region.

Superior gluteal vessels and nerve emerge above the piriformis (Clemente 387; Grant p. 389; Netter 3e 484-485; 4e 502-503).

2 groups of nerve and vessels emerge inferior to piriformis

A group of 5 structures (Grant 385, 388-389; Netter 3e 484, 527; 4e 502-503, 540):

1) Sciatic nerve (L4, 5, S1, 2, 3) lies between the ischial tuberosity and the greater trochanter. Its "safe" side for gluteal injection is the lateral side where it has no branches. It may divide in this region into the common peroneal (L4, 5, S1, 2) and the tibial (L4, 5, S1, 2, 3) nerves.

2) Inferior gluteal nerve.

3) Inferior gluteal artery and 4) vein supply the piriformis, obturator internus and gluteus maximus.

5) Posterior femoral cutaneous nerve.

A group of 3 structures (Clemente 386-387, 393; Grant p. 388-389; Netter 3e 484-485; 4e 502-503):

1) Nerve to obturator internus (L5, S1, 2)

2) Internal pudendal vessels

3) Pudendal nerve (S2, 3, 4)

• The group of 3 emerges from the greater sciatic foramen and runs through the lesser sciatic foramen into the ischiorectal fossa.
• The internal pudendal vessels cross the ischial spine but the pudendal nerve lies on the sacrospinous ligament. Vessels are thus protected during a transvaginal perineal block.

The obturator internus is the only structure entering the gluteal region via the lesser sciatic foramen (Clemente 391-392; Grant p. 387, 391; Netter 3e 477, 484-485; 4e 503).

The greater trochanter serves as attachment point for 5 muscles. The:

1) Gluteus medius attaching from the gluteal surface of the ilium to the lateral greater trochanter (Clemente 391; Grant p. 386; Netter 503).

2) Gluteus minimus attaching from the gluteal surface of the ilium to the anterior aspect of the greater trochanter.

*Glutei medius and minimus abduct the hip joint and prevent adduction of the thigh when the body weight is on the same leg.

3) Piriformis attaching from the sacrum through the greater sciatic notch to the apex of the greater trochanter (Clemente 503; Grant p. 390; Netter 3e 484-485; 4e 391-392).

4) Obturator internus and gemelli

5) Obturator externus

The superior gluteal nerve (L4, 5, S1; Clemente 387; Grant p. 389; Netter 3e 484-485; 4e 502-503)

• runs along with the superior gluteal vessels, through the greater sciatic foramen (superior to the piriformis),
• across the lateral surface of the ilium between the gluteus medius and minimus, along with the deep branch of the superior gluteal artery.
• innervates the gluteus medius, minimus and tensor fasciae latae (all abductors of the hip joint).

Tensor fasciae latae (Clemente 383; Grant p. 383; Netter 3e 476; 4e 494)

• arises from the anterior superior iliac spine and the outer lip of the iliac crest;
• inserts into the iliotibial tract and pulls on it.

Small lateral rotator muscles stabilize the hip joint:

1) The quadratus femoris ( the "carpet" of the sciatic nerve; Clemente 386; Grant p. 385; Netter 3e 477, 484-485; 4e 502-503) is innervated by a sciatic nerve branch called the nerve to quadratus femoris (L4, 5, S1). The obturator internus and the gemelli lie above the quadratus femoris.

2) The obturator internus (Clemente 371, 385-387; Grant p. 391, 395; Netter 3e 484-485; 4e 490-491, 502-503) arises from the pelvic surface of the obturator membrane, makes a sharp turn, through the lesser sciatic foramen (a bursa exists underneath), inserts into the upper border of the greater trochanter. It is innervated by the nerve to obturator internus (L5, S1, 2).

3) The superior gemellus arises from the upper margin of the lesser sciatic foramen by the ischial spine. It is innervated by the nerve to obturator internus (L5, S1, 2).

4) The inferior gemellus arises from the lower margin of the lesser sciatic foramen by the ischial tuberosity. It is innervated by the nerve to quadratus femoris (L4, 5, S1).

Both distal tendons of the gemelli join with that of the obturator internus.

5) Piriformis.

6) Obturator externus arises from the lateral surface of the obturator membrane and attaches to the back of the femoral neck (Clemente 386-387; Grant p. 394; Netter 3e 483; 4e 490-491, 493, 539).

Gluteal arteries:

• The superior and inferior gluteal arteries are branches of the internal iliac artery (Clemente 282; Grant p. 224-225; Netter 3e 382-383; 4e 402-403).
• They supply the entire gluteal region, with the largest branches being muscular (Clemente 387; Grant p. 388-389; Netter 3e 484; 4e 502).

The posterior femoral cutaneous nerve (Clemente 373; Grant p. 359; Netter 3e 527; 4e 540) duplicates subcutaneously the line of the sciatic nerve. It has 2 large branches: gluteal and cluneal.

updated 9/3/2009

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Thigh and popliteal fossa

ANTERIOR ASPECT OF THE THIGH

The deep fascia is called the fascia lata (Clemente 370, Grant p. 368; Netter 3e 482; 4e 500).

It is reinforced laterally by the iliotibial tract, which is a joint attachment point of tensor fasciae latae and gluteus maximus (Clemente 383; Grant p. 368; Netter 3e 476; 4e 494).

Medially, the great saphenous vein ascends subcutaneously (Clemente 368-370; Grant p. 342-345; Netter 3e 526-528; 4e 544).

The course of the great saphenous vein

• It arises from the dorsal venous arch on the dorsum of the foot (Clemente 406; Grant p. 364; Netter 3e 526, 4e 544),
• runs anterior to the medial malleolus, crosses the lower 1/3 of the medial surface of tibia,
• runs 1 cm posterior to the medial border of the tibia,
• lies a handwidth posterior to the patella at the knee (Clemente 398; Grant p. 364-365; Netter 3e 528, 4e 546),
• runs up and passes through the fascia lata (saphenous opening) and joins with the femoral vein, 4 cm inferolateral to the pubic tubercle (Clemente 368-370; Grant p. 370-371; Netter 3e 526; 4e 546).

The great saphenous vein:

• Anastomoses with the small saphenous vein, below the knee and communicates along intermuscular septa with the deep veins (Clemente 412; Grant p. 364; Netter 3e 527; 4e 545).
• Receives many venous tributaries, including from 3 superficial veins near the inguinal ligament. These 3 superficial veins have the same names as the superficial arteries of the femoral artery at this level (Clemente 370; Grant p. 370; Netter 3e 526; 4e 544).

Superficial branches of the femoral artery (Clemente 368; Grant p. 370; Netter 3e 482; 4e 512).

1) Superficial external pudendal artery crosses anterior to the spermatic cord to supply scrotum and labium majus.

2) Superficial epigastric artery passes towards the umbilicus.

3) Superficial circumflex iliac artery, passes laterally, just inferior to the inguinal ligament.

Inguinal lymph nodes are palpable and are divided into superficial and deep groups.

Superficial nodes are divided into (Clemente 369; Grant p. 367; Netter 3e 528; 4e 546):

• a superior horizontal (superolateral and superomedial) group, draining the subcutaneous tissues of the anterior abdominal wall inferior to the umbilicus, of the penis and scrotum, or the vulva and distal part of the vagina, the gluteal region, the perineum and distal part of the anal canal.
• and an inferior vertical group, which lies along the great saphenous vein and receives most lymph vessels of the lower limb.

 Cutaneous nerves arise from the ventral rami of L1, 2, 3, 4.  They pierce the deep fascia along the upper border of the sartorius. 

• Those arising from the femoral nerve form the anterior femoral cutaneous nerve (used to be named the intermediate and medial cutaneous nerves of the thigh).
• Others arise from the saphenous nerve (Clemente 368; Grant p. 359; Netter 3e 526; 4e 545).

The femoral sheath is a prolongation of extraperitoneal areolar tissue which envelops the external iliac vessels in the abdomen (Clemente 257; Grant p. 106, 350, 352-353; Netter 3e 242, 528; 4e 262, 546).

The femoral sheath has 3 compartments (Clemente 369; Grant p. 371; Netter 3e 528; 4e 262, 546):

• a lateral for the femoral artery,
• a middle for the femoral vein
• and a medial for the femoral canal (lymph vessels and deep lymph nodes - this is the site of femoral hernia (Grant p. 372-373).

The mouth of the femoral canal is the femoral ring.

The femoral ring is bounded:

• laterally by the femoral vein (Clemente 369; Grant p. 372; Netter 3e 528; 4e 546),
• posteriorly by the superior ramus of the pubic bone (which is covered by the pectineus),
• medially by the lacunar ligament (Clemente 369; Grant p. 372; Netter 3e 528; 4e 546) and conjoint tendon, which is attached to the pecten pubis (Clemente 374-375),
• and anteriorly by the inguinal ligament and round ligament of the uterus or the spermatic cord (Clemente 188, 190; Grant p. 372; Netter 3e 528; 4e 250).

Bony landmarks on the femur (Clemente 430; Grant p. 355; Netter 3e 471; 4e 489)

• Head.
• Neck.
• Intertrochanteric line (anterior) for attachment of the iliofemoral ligament.
• Intertrochanteric crest (posterior).
• Lesser trochanter (attachment of iliopsoas muscle) points medially.
• Greater trochanter (attachment of gluteal muscles).
• Shaft with the linea aspera (located posteriorly).
• Medial and lateral condyles (distally).
• Intercondylar notch.
• Medial and lateral epicondyles.
• Patellar surface for articulation with the patella (Clemente plate 374; Grant p. 393; Netter 471).

The femoral triangle (Clemente 371-372, 374; Grant p. 372-373; Netter 3e 482; 4e 492).

• the base is formed by the inguinal ligament
• the apex lies 10 cm inferior to the crossing of the sartorius over the lateral edge of the adductor longus.
• the femoral triangle contains the femoral artery which begins at the midinguinal point, anterior to the femoral head (Clemente 372; Grant p. 372; Netter 3e 482-483; 4e 500). The femoral artery leaves the triangle at its apex and enters the adductor canal.

Contents of the femoral triangle:

• the femoral vein, artery and nerve, and their respective branches (Clemente 372; Grant p. 372-373; Netter 3e 482; 4e 500),
• deep inguinal lymph nodes
• the profunda femoris artery (Clemente 377, 379; Grant p. 373; Netter 3e 483; 4e 500-501) and vein and their circumflex branches.

The profunda femoris artery:

• begins below the inguinal ligament
• is a branch of the femoral artery and supplies many muscles of the thigh.
• the medial femoral circumflex branch of the profunda femoris artery leaves the triangle between the pectineus and iliopsoas (Clemente 377-379; Grant p. 393; Netter 3e 483, 4e 501).
• The lateral femoral circumflex branch passes laterally through or posterior to the branches of the femoral nerve (Clemente 377; Grant p. 373; Netter 3e 486, 4e 501), disappears below the sartorius and rectus femoris muscle and terminates in 3 (ascending, transverse and descending) branches (Clemente 376; Grant p. 400; Netter 3e 486; 4e 504) .

The femoral vein

• lies medial to the femoral artery in the femoral sheath (Clemente 369; Grant p. 371; Netter 3e 528; 4e 546).
• slips posterior to the artery at the apex (Clemente 377; Grant p. 372-373; Netter 3e 483, 4e 500).

*At the apex of the femoral triangle, a stab or bullet may penetrate all 4 vessels of the thigh (Clemente 377, 379; Grant p. 373; Netter 3e 482; 4e 500-501).

Venous valves are found in the saphenous and femoral veins (not in the inferior vena cava or in the common iliac vein; Grant p. 370).

The femoral nerve (Clemente 372, 377, 379; Grant p. 372; Netter 3e 482-483; 4e 500-501):

• lies in front of the iliacus
• crosses deep to the inguinal ligament.
• lies lateral to the artery, deep to the fascia lata.
• breaks up into motor and sensory branches.
• 2 of the branches follow the artery on its lateral side, into the adductor canal (Clemente 377, 379; Grant p. 373; Netter 3e 482; 4e 500):
  • the nerve to vastus medialis (motor)
  • and the saphenous nerve (sensory).

Relationships:

• The femoral artery lies in front of the psoas tendon.
• The femoral vein and most lymph vessels lie in front of the pectineus.

Adductor canal (of Hunter; Clemente 377; Grant p. 373; Netter 3e 482; 4e 500-501)

• forms the outlet of the femoral triangle.
• is enclosed by the sartorius.
• ends 10cm above the adductor tubercle.

The walls of the adductor canal are:

• the sartorius anteriorly
• the iliopsoas and vastus medialis laterally
• the adductor muscles posteromedially

Overview of the adductor muscles

Adductor muscles attach (Clemente 371, 374, 375, 378; Grant p. 378-379; Netter 3e 482-483; 4e 492-493) from the pubis and ischium to the linea aspera.

• The adductor brevis lies posteriorly between the pectineus and adductor longus.
• The adductor magnus lies between the adductor longus and gracilis. The adductor magnus descends as far as the adductor tubercle (Clemente 430-431; Grant p. 378; Netter 3e 483; 4e 490-491).
• The gracilis inserts into the medial tibia, posterior and deep to the sartorius.

Contents of the adductor canal:

• the femoral artery becomes the popliteal artery.
• The saphenous nerve becomes cutaneous. The saphenous nerve accompanies the femoral artery then joins with the saphenous vein ending 1/2 way along the medial border of the foot (Clemente 367; Grant p. 359; Netter 3e 520; 4e 538).
• The nerve to vastus medialis accompanying its muscle.

The sartorius (Clemente 371; Grant p. 375; Netter 3e 474; 4e 492)

• attaches from the anterior superior iliac spine
• to the medial surface of the tibia (inferior to the tuberosity)
• is innervated by the femoral nerve
• puts the lower limb in the "tailor's position" when contracted.

The quadriceps femoris (Clemente 492; Grant p. 375; Netter 3e 474, 4e 374-375)

• The rectus femoris attaches from the anterior inferior iliac spine (by its straight head; Clemente 430; Grant p. 376; Netter 3e 472, 474; 4e 490) and the acetabular margin (by its reflected head; Clemente 431; Grant p. 395). Thus, it can also flex the hip joint.
• The vastus lateralis attaches from the aponeurosis from the lateral lip of the linea aspera.
• The vastus intermedius attaches from the anterior and lateral aspects of the femur. Its most distal fibers attach to the synovial capsule at the knee and retracts the capsule during extension of knee. This portion is called the articularis genu.
• The vastus medialis attaches from the aponeurosis from the medial lip of the linea aspera.
• All insert into the tibial tuberosity by a common distal tendon
• The distal tendon contains a sesamoid bone: the patella. The portion of the tendon distal to the patella is named the ligamentum patellae.

An internervous line exists between the motor territories of the gluteal and femoral nerve: It runs down in a vertical line from the anterior superior iliac spine.

Posteromedial region of the thigh.

The anterior wall is formed by the adductor magnus and vastus lateralis muscles.

• Hamstring muscles (Clemente 384-385; Grant p. 366-367, 369; Netter 3e 477, 4e 495):
  • The long head of the biceps femoris
  • The short head of the biceps femoris
  • The semitendinosus
  • The semimembranosus
• The sciatic nerve (Clemente 390; Grant p. 367; Netter 3e 484, 4e 502)
• The posterior femoral cutaneous nerve (Clemente 367, 382, 390; Grant p. 340; Netter 3e 527, 4e 503, 540)
• Vessels

HAMSTRING MUSCLES

• arise from the ischial tuberosity
• insert into the tibia or fibula
• are innervated by the tibial division of the sciatic nerve
• extend hip and flex knee joint

The biceps femoris (Clemente 391; Grant p. 384-385; Netter 3e 484, 488; 4e 495)

• The long head of the biceps femoris attaches from the ischial tuberosity.
• The short head of the biceps femoris attaches from the linea aspera, from the lateral supracondylar line and from the lateral intermuscular septum (innervated by peroneal division of sciatic nerve).
• The biceps femoris attaches distally to the fibula and also rotates the leg laterally.

The semimembranosus and semitendinosus also rotate the leg medially, being attached to the medial head of the tibia (Clemente 391; Grant p. 366-367, 369; Netter 3e 484, 488, 4e 495).

The sciatic nerve is accessible between the gluteus maximus and the long head of the biceps.

• It divides into the tibial and the common peroneal (fibular) nerves deep to the biceps femoris (Clemente 393; Grant p. 402-403; Netter 3e 484, 522, 4e 502).
• The nerve to the short head of the biceps femoris comes from the lateral (peroneal) division whereas branches to other hamstrings arise from the medial (tibial) division (Clemente 393; Grant p. 388-389; Netter 3e 484; 4e 502).

Medial region of the thigh

The muscles in this region (Clemente 371-381; Grant p. 378; Netter 3e 482-483, 4e 492-493):

• attach proximally from the anterior aspect of the hip bone and the obturator membrane;
• attach distally into the length of the femur and the tibia;
• adduct and medially rotate the lower limb.
• are innervated by the obturator nerve (Clemente 377, 379; Grant p. 382, 394; Netter 3e 483; 4e 500-501);
• are vascularized by the profunda femoris and obturator arteries (Clemente 379; Grant p. 382, 396; Netter 3e 483, 494; 4e 500-501).

Prevalent hernias in this region are (Grant p. 372):

• femoral
• inguinal
• and obturator

The obturator nerve (L2,3,4; Clemente 379; Grant p. 356; Netter 3e 521, 4e 501, 539)

• divides into anterior and posterior divisions past the obturator foramen and supplies 6 adductors.
  • The nerve to gracilis becomes the only cutaneous branch (Clemente 368, 379; Grant p. 359; Netter 3e 521, 4e 539).
• has articular branches for both the hip and knee joint.

The obturatory artery supplies the adductors (Clemente 379; Grant p. 362; Netter 3e 494, 4e 512).

The course of the profunda femoris artery (Clemente 362; Netter 4e 512)

• arises from the lateral side of the femoral artery below the inguinal ligament,
• lies posterior to the femoral vessels at the apex of femoral triangle,
• descends with the adductors.
• has branches to muscles, hip and knee joints. Muscular branches are unnamed.
  • the lateral femoral circumflex branch (has terminal branches named ascending, transverse and descending).
  • the medial femoral circumflex branch has transverse and ascending branches
  • The first, second, third and fourth perforating branches hug the shaft of the femur. They supply muscles and a nutrient artery to the femur.

The anastomosis at the hip joint is formed by the medial and lateral circumflex arteries with the inferior gluteal artery and the first perforating artery (Clemente 363, 376, 393; Grant p. 393; Netter 3e 486-494, 4e 504, 512).

The popliteal fossa:

The floor of the popliteal fossa is formed by (Clemente 418; Grant p. 404-405; Netter 3e 493, 4e 511):

• the popliteal surface of the femur
• the capsule of the knee joint
• the fascia over the popliteus muscle

Contents of the popliteal fossa (Clemente 412-413, 415-419; Grant p. 402-404; Netter 3e 498-499, 4e 502):

• The popliteal vessels (artery, vein and lymphatics)
• The tibial and common peroneal (fibular) nerves
• The small saphenous vein

The tibial nerve (L4, 5, S1, 2, 3; Clemente 417; Grant p. 403; Netter 3e 523, 4e 541)

• has motor branches to the plantaris, to the medial and lateral heads of the gastrocnemius, to the soleus and the popliteus.
• has articular and cutaneous branches.

The arrangement in the inferior portion of the fossa is tibial nerve, popliteal vein and artery from superficial to deep, from a posterior view (Clemente 417; Grant p. 404; Netter 3e 498-499, 4e 516-517). They are bounded by a femoral condyle and a head of the gastrocnemius on each side (Clemente 413, 421; Grant p. 404; Netter 3e 498, 4e 511).

The popliteal artery (Clemente 419, 443; Grant p. 404, 416; Netter 3e 500, 4e 512):

• has cutaneous, articular and muscular branches
• has arteriovenous anastomoses with the popliteal vein
• divides into anterior and posterior tibial arteries behind the tibia.
  • The posterior tibial artery gives off the peroneal artery (Clemente 419; Grant p. 437; Netter 3e 500, 4e 512).

The popliteal vein begins as an assembly of venae comitantes below the knee.

The common peroneal (fibular) nerve (L4, 5, S1, 2; Clemente 402; Grant p. 424; Netter 3e 498, 502, 4e 520)

• separates from the tibial nerve halfway down the thigh
• divides into deep peroneal and superficial peroneal (fibular) nerves lateral to the head of the fibula.
• has articular and cutaneous branches.

The sural nerve (Clemente 412; Grant p. 359; Netter 3e 498, 4e 516, 540) arises from the tibial nerve, runs with the small saphenous vein and is joined by a branch of the common peroneal nerve (the communicating peroneal nerve).

The small saphenous vein

• is the lateral continuation of the dorsal venous arch on the foot (Clemente 412; Grant p. 364; Netter 3e 527, 4e 544).
• passes below and behind the lateral malleolus.
• ends in the popliteal and profunda femoris vein (Clemente 412, 416; Grant p. 402; Netter 3e 498, 4e 516, 545).
• is connected to the great saphenous vein.

updated 9/03/2009

The leg and the dorsum of the foot

The leg or crus is the portion of the lower limb between the knee and the ankle. It is divided into (Clemente 400; Grant p. 472; Netter 3e 504, 4e 522):

• an anterior crural compartment,
• a posterior crural compartment,
• and a lateral (or fibular or peroneal) compartment.

The bones of the leg are the tibia and the fibula (Clemente 446-447; Grant p. 423; Netter 3e 495, 4e 513-514)

Osteology of the foot (Clemente 450-451; Grant p. 427; Netter 3e 505, 4e 523-524):

• Talus
• Calcaneus
• Navicular
• Cuboid
• Medial, intermediate and lateral cuneiforms
• 5 metatarsals
• 14 phalanges

The anterior tibial artery (Clemente 402, 411; Grant p. 424-425; Netter 3e 502, 4e 520, 530, 531)

• is the artery of the anterior compartment, lying medial to the head of the fibula.
• becomes the dorsalis pedis artery.
• divides and end as branches supplying big toe and digit 2.

The branches of the anterior tibial artery are the:

• anterior tibial recurrent artery for the knee anastomosis.
• branch runnning with the superficial peroneal nerve.
• medial and lateral malleolar arteries which join with the perforating branch of the peroneal artery at the ankle anastomosis.
• medial and lateral tarsal arteries.
• arcuate artery which gives rise to the dorsal metatarsal arteries in the 2nd, 3rd, and 4th interdigital spaces. These are joined by perforating branches of the deep plantar arch and in turn divide into 2 dorsal digital arteries.

*Dorsal metatarsal arteries to the medial side of the 1st toe and lateral side of the 5th toe receive digital branches from the 1st and 4th metatarsal arteries, respectively (Clemente 411; Grant p. 427; Netter 3e 512-513, 4e 530-531) .

*Dorsal digital arteries may also originate from the perforating branch of the peroneal artery.

Muscles of the anterior crural region

1. The tibialis anterior (Clemente 399; Grant p. 422; Netter 3e 502-503, 4e 519)

• attaches from the antero-lateral (upper 2/3) surface of tibia, from the adjacent interosseous membrane and from the deep fascia
• to the medial surface of metatarsal 1 and cuneiform 1 (Clemente 455; Grant p. 439; Netter 3e 502, 4e 528) .
• dorsiflexes and inverts the foot

2. The extensor digitorum longus (Clemente 402; Grant p. 422; Netter 3e 501, 4e 519-520)

• attaches from the anterior surface of the fibula, the interosseous membrane, and the deep fascia
• to the dorsal expansions on the distal phalanges of the lateral 4 toes (Clemente 407; Grant p. 426; Netter 3e 512, 4e 530).
• dorsiflexes and everts the foot; extend the toes

3. The peroneus tertius (Clemente 399; Grant p. 426; Netter 3e 501, 4e 519)

• is the distal 1/4 of the extensor digitorum longus
• attaches into the dorsum of the 4th or 5th metatarsal bone.
• dorsiflexes and everts the foot

4. The extensor hallucis longus (Clemente 407-411; Grant p. 424; Netter 3e 502, 4e 519-520):

• attaches from 1/2 of the anterior surface of fibula and from the interosseous membrane
• into the base of the distal phalanx of the big toe (Clemente 399; Grant p. 426; Netter 3e 512, 4e 530-531).
• dorsiflexes and inverts the foot; extends toe 1

The extensor digitorum brevis

• from the dorsum of the foot (the anterior part of the calcaneus and the extensor retinaculum; Clemente 407; Grant p. 425-426, 428, 431; Netter 3e 512, 513, 4e 530)
• gives rise to 4 tendons attaching to the medial 4 toes.
  • The muscle belly and its tendon attaching to the base of the proximal phalanx of the big toe is named the extensor hallucis brevis.
  • The other tendons join with dorsal expansions of the extensor digitorum.
• Extends toes 1-4

In the anterior compartment syndrome, there is edema in the anterior compartment. Since the extensor retinaculum over the deep fascia is tight, the swelling shuts off the circulation and results in worsening of the condition. Shin splints are a mild form of the anterior compartment syndrome.

The common peroneal nerve divides into a superficial peroneal nerve and a deep peroneal nerve (Clemente 402; Grant p. 424; Netter 3e 523, 4e 520).

The deep peroneal nerve

• accompanies the anterior tibial artery and then the dorsalis pedis artery, supplying all crossed joints
• It then becomes cutaneous and divides into 2 dorsal digital nerves innervating the lateral surface of the big toe and the medial surface of digit 2 (Clemente 411; Grant p. 424-425; Netter 3e 524, 4e 530).

The superficial peroneal nerve (Clemente 402; Grant p. 425; Netter 3e 524, 4e 520, 542)

• runs inferior and anterior to the shaft of the fibula.
• is covered by and provides the motor innervation to peronei (fibular) muscles
• provides dorsal digital branches to all toes (Grant 359; Netter 3e 524, 4e 542).

The extensor retinaculum (Clemente 399; Grant p. 422, 426; Netter 3e 501, 4e 530)

• has superior and inferior portions.
• prevents the tendons of peroneus tertius, extensor hallucis longus and extensor digitorum longus from bowstringing during contraction.

There is also a superior and an inferior peroneal (fibular) retinaculum for the the tendons of the peroneus brevis and longus (Clemente 404; Grant p. 425, 430; Netter 3e 503, 4e 529)

The peroneal (fibular) region

The peroneus longus and brevis muscles

• are bound down by superior and inferior peroneal retinaculata (Clemente 404; Grant p. 430; Netter 3e 503, 4e 529)
• attach from the lateral aspect of the fibula (Clemente 405; Grant p. 429; Netter 3e 503, 4e 515)
• The peroneus brevis attaches to the base of the 5th metatarsal (Clemente 452; Grant p. 430; Netter 3e 509, 4e 528).
• The peroneus longus has a tendon lying in a groove crossing the sole of the foot under the cuboid. This tendon inserts onto the medial cuneiform and metatarsal 1 (Clemente 455; Grant p. 429, 447; Netter 3e 510, 4e 528).
• Both of these muscles evert and plantar flex the foot.

The tibialis anterior also inserts into the medial cuneiform and metatarsal 1, but from the medial aspect of the foot: the peroneus longus and the tibialis anterior are thus antagonists.

OSTEOLOGY OF THE FIBULA (Clemente 447; Grant p. 354, 423, 433, 442; Netter 3e 495-497, 4e 513-514)

• Peroneal surface
• Anterior and posterior borders
• Flexor or posterior surface
• Anterior line
• Posterior crest
• Interosseous border
• Malleolar fossa
• Extensor or anterior surface

Ossification of the fibula

• The shaft begins to ossify around the 8th prenatal week.
• The upper epiphysis ossifies around the 5th year and is complete by the 22nd year.
• The lower epiphysis ossifies around the 2nd year and is complete by the 20th year.

The posterior crural region

Bony landmarks (Clemente 447-449; Grant p. 433; Netter 3e 495, 4e 513, 515):

• Tibial condyles
• Soleal line
• Tibial (medial) malleolus
• Head of the fibula
• Fibular (lateral) malleolus
• Posterior talus
• Posterior third of the calcaneus

The superficial group has 3 muscles:

• Gastrocnemius
• Soleus
• Plantaris

All 3 muscles plantar flex the foot.

The gastrocnemius

• has 2 attachments just superior to the lateral and medial epicondyles of the femur (Clemente 413; Grant p.432, 434; Netter 3e 498, 4e 515-517)
• ends in the tendo calcaneus (Achilles' tendon) which it shares with the soleus and plantaris. These 3 muscles form the triceps surae.
• The tendo calcaneus inserts into the middle of the posterior surface of the calcaneus

• The gastrocnemius flexes the leg and plantar flexes the foot

The soleus (Clemente 415-416; Grant p. 432, 435; Netter 3e 499, 4e 517)

• attaches:
  • from the proximal part of the posterior surface of the fibula and the soleal line of the tibia
  • into the tendo calcaneus.
• plantar flexes the foot

The plantaris (Clemente ; Grant 432; Netter 3e 498-499, 4e 517)

• lies between the gastrocnemius and the soleus
• arises near the lateral head of the gastrocnemius
• inserts into the tendo calcaneus.
• flexes the leg and plantar flexes the foot

The deep group of muscles contains (Clemente 418; Grant p. 432, 436-437; Netter 3e 500, 4e 518):

1. the popliteus
2. the flexor hallucis longus
3. the flexor digitorum longus (to terminal phalanges of the toes)
4. the tibialis posterior (to every small tarsal and most metatarsals)

Muscles 2-4 plantar flex the foot.

The popliteus (Clemente 396, 418; Grant p. 415; Netter 3e 500 4e 511,)

• attaches just inferior to the lateral epicondyle of the femur
• attaches distally to the posterior surface of the tibia.
• Flexes the knee and rotates the leg medially

The tibialis posterior (Clemente 418; Grant p. 432, 437; Netter 3e 500, 4e 518)

• attaches from the interosseous membrane and the adjacent bones
• 2/3 attaches distally to the tuberosity of navicular and 1/3 by bands into the cuboid, the cuneiforms, and the metatarsals 2, 3 and 4 (Clemente 453; Grant p. 437, 439; Netter 3e 492, 4e 528).
• Plantar flexes and inverts the foot

The flexor digitorum longus (Clemente 421; Grant p. 432, 437; Netter 3e 500, 510, 4e 518)

• attaches from the posterior surface of the tibia and the fascia covering the tibialis posterior
• into the bases of distal phalanges (Clemente 424, 451; Grant p. 439; Netter 3e 500, 4e 528)
• Plantar flexes the foot and flexe toes 2-5

The flexor hallucis longus (Clemente 421; Grant p. 432, 436-437; Netter 3e 500, 4e 518)

• attaches from the fibula distal to the soleus, the posterior crural septum, the fascia of the tibialis posterior, the interosseous membrane and the tibia
• inserts into distal phalanx of hallux (Clemente 424; Grant p. 439; Netter 3e 498, 510, 515-516, 4e 528)
• PPlantar flexes the foot and flexes the distal phalanx of toe 1

Tendons posterior to the ankle

• The tendons of the peronei brevis and longus lie against the posterior surface of the fibular malleolus (Clemente 408; Grant p. 429; Netter 3e 511, 4e 529)
• The tendon of the flexor hallucis longus grooves the distal end of the tibia midway between the malleoli (Clemente 408; Grant p. 439; Netter 3e 511, 4e 529)
• The tendons of the tibialis posterior and flexor digitorum longus groove the posterior surface of the tibial malleolus (Clemente 408; Grant p. 439; Netter 3e 511, 4e 529).

The tibial nerve

• lie on the posterior surface of the tibialis posterior fascia and then on the tibia (Clemente 416-419; Grant p. 436-437; Netter 3e 523, 4e 518).
• accompanies the posterior tibial artery.
• runs deep to the flexor retinaculum.
• divides into the medial and lateral plantar nerves (Clemente 422; Grant p. 438; Netter 3e 523, 4e 535).

The branches of the tibial nerve are:

• muscular branches to muscles of the posterior compartment of the leg.
• cutaneous branches to the heel (medial calcaneal nerves; Clemente 422; Grant p. 437-438; Netter 3e 523, 4e 534)
• articular branches to the ankle joint.

The posterior tibial artery:

• begins at the superior border of the soleus (Clemente 419; Grant p. 436; Netter 3e 500, 4e 518)
• ends deep to the flexor retinaculum by dividing into medial and lateral plantar arteries (Clemente 428; Grant p. 438; Netter 3e 500, 4e 535).

The peroneal (fibular) artery:

• arises from the posterior tibial artery (Clemente 419; Grant p. 437; Netter 3e 500, 4e 518);
• runs posterior to the fibula, the distal tibiofibular joint and the ankle joint;
• ends as the lateral calcanean artery on the lateral surface of the calcaneus.

updated 09/03/2009

Osteology of the foot (Clemente 451; Grant p. 444; Netter 3e 505-508, 4e 523-524)

• Talus
• Calcaneus
• Navicular
• Cuboid
• Medial, intermediate and lateral cuneiforms
• 5 metatarsals
• 14 phalanges

The medial longitudinal arch (Clemente 451; Grant p. 452, 466; Netter 3e 489, 4e 524) is formed by:

• the 3 medial digits and their metatarsals
• the 3 cuneiforms
• the navicular
• the talus
• The medial longitudinal arch is supported by the calcaneus.
• The medial longitudinal arch is held by ligaments, the plantar aponeurosis and the first layer of plantar muscles

The lateral longitudinal arch (Clemente 451; Grant p. 431, 466; Netter 3e 489, 4e 524) is formed by:

• The 2 lateral digits and their metatarsals
• the cuboid
• and the calcaneus

Ossification sequence of the foot

• Calcaneus
• Talus
• Cuboid
• Medial, intermediate, and lateral cuneiforms
• Navicular

The plantar fascia (Clemente 422; Grant p.443; Netter 3e 514, 4e 532)

• is attached posteriorly to the medial process of the calcaneus (Clemente 451; Grant p. 444; Netter 3e 507, 4e 528)
• is attached anteriorly to the heads of the metatarsals by 5 bands
• is thin in the medial and lateral portions
• is thick centrally as the plantar aponeurosis, which becomes taut when the toes are dorsiflexed (when the arches are increased).

Cutaneous nerves

• The medial plantar nerve supplies 3.5 digits on the hallux (big toe) side (Clemente 425; Grant p. 444; Netter 3e 515-516, 4e 534).
• The lateral plantar nerve supplies the lateral 1.5 digit.

There are 4 layers of plantar muscles, organized as follows:

1. 3 muscles
2. 2 muscles and 2 tendons
3. 3 muscles
4. 2 muscles and 2 tendons

The most superficial layer (layer 1) is formed by 3 muscles (Clemente 423; Grant p. 444; Netter 3e 515, 4e 533)

• which arise from the calcaneus;
• and consists of a flexor between 2 abductors

Abductor hallucis

• inserts into the proximal phalanx of hallux
• is innervated by the medial plantar nerve
• Abducts toe 1

Abductor digiti minimi

• inserts into the proximal phalanx of toe 5
• is innervated by the lateral plantar nerve
• Abducts toe 5

Flexor digitorum brevis

• inserts into the middle phalanges of toes 2-5 by splitting into 2 bands.
• is innervated by the medial plantar nerve
• Flexes middle phalanges of toes 2-5

Layer 2 is formed by 2 muscles and 2 tendons (Clemente 424; Grant p. 445; Netter 3e 516, 4e 534):

The flexor digitorum longus tendon

• inserts into the bases of distal phalanges.
• Plantar flexes the foot and flexes toes 2-5

The quadratus plantae (flexor digitorum accessorius)

• arises from the medial side of the calcaneus.
• inserts into the tendon of the flexor digitorum longus.
• is innervated by the lateral plantar nerve.
• overlies the long plantar ligament (Clemente 455; Grant p. 464; Netter 3e 500, 4e 528).
• Assists in flexing the toes

The lumbricals

• arise from the tendons of the flexor digitorum longus.
• insert into dorsal digital expansions.
• lumbrical 1 is innervated by the medial plantar nerve; lumbricals 2, 3 and 4 are innervated by the lateral plantar nerve.
• Flex metatarsophalangeal joints and extend interphalangeal joints

Flexor hallucis longus tendon

• inserts into the distal phalanx of the hallux
• Plantar flexes the foot and flexes the distal phalanx of toe 1

Layer 3 is formed by 3 muscles: An adductor lying between 2 flexors (Clemente 427; Grant p. 446; Netter 3e 517, 4e 535).

Adductor hallucis

• has an oblique head from the tarsal bones;
• has a transverse head from the metatarsal heads;
• attaches to the lateral base of phalanx 1 of the hallux.
• is innervated by the lateral plantar nerve.
• adducts toe 1

Flexor hallucis brevis

• attaches from the tarsal bones to both sides of the proximal phalanx of the hallux.
• is innervated by the medial plantar nerve.
• flexes toe 1

Flexor digiti minimi

• attaches from the base of the 5th metatarsal to the lateral side of the proximal phalanx of toe 5.
• is innervated by the lateral plantar nerve.
• flexes toe 5

Layer 4 is formed by 2 muscles and 2 tendons (Clemente 428, 455; Grant p. 447, ; Netter 3e 517-519, 4e 536-537):

The 7 interossei (4 dorsal and 3 plantar) keep the foot from spreading by holding the heads of the metatarsals together.

• also flex the metatarsophalangeal joints and extend the interphalangeal joints
• Dorsal interossei abduct and plantar interossei adduct the toes (DAb and PAd). Abduction and adduction are in reference to toe #2.
• are innervated by the lateral plantar nerve. 

The tibialis posterior tendon (Clemente 455; Grant p. 447; Netter 3e 509-511, 4e 536).

• 2/3 attaches to the tuberosity of the navicular and 1/3 to bands attaching to cuboid, cuneiforms and metatarsals 2, 3 and 4.
• Plantar flexes and inverts the foot.

The peroneus (fibularis) longus tendon.

• attaches to the lateral side of metatarsal 1 and adjacent part of cuneiform 1 on the medial aspect of the foot.
• Everts and plantar flexes the foot.

Blood supply of the sole of the foot

The medial plantar artery (Clemente 425, 426, 428; Grant p. 444, 446; Netter 3e 516-517, 4e 533-535)

• is the smaller terminal branch of the posterior tibial artery (Clemente 428; Grant p. 441; Netter 3e 516, 4e 535).
• arises deep to the flexor retinaculum.
• runs on the medial side of the foot between the abductor hallucis and flexor digitorum brevis.
• supplies the medial side of the hallux and gives muscular, cutaneous and articular branches.

Lateral plantar artery (Clemente 425-426; Grant p. 441, 446; Netter 3e 516-517, 534-535)

• is the larger terminal branch of the posterior tibial artery (Clemente 428; Grant p.441; Netter 3e 516, 4e 535).
• runs between layers 1 and 2 (Clemente 423-425; Grant p. 444; Netter 3e 516, 4e 533-534) and then between layers 3 and 4 (Clemente 426; Grant p. 446; Netter 3e 517, 4e 535).
• gives off calcaneal, cutaneous, muscular and articular branches.
• forms the deep plantar arch by joining with the deep plantar branch of the dorsalis pedis artery (Clemente 411; Grant p. 446; Netter 3e 518, 4e 536).

Anastomoses in the foot are important due to its vulnerability to arteriosclerosis.

The plantar arterial arch

• 3 perforating arteries from the deep plantar arch join with the dorsal metatarsal arteries (Clemente 411; Grant p. 446; Netter 3e 518, 4e 536).
• 4 plantar metatarsal arteries bifurcate into plantar digital arteries (Clemente 428; Grant p. 446; Netter 3e 518, 4e 535).
• supplies a branch to the medial side of the hallux and to the lateral side of toe 5.

The lateral plantar nerve has (Clemente 426; Grant p. 444, 446; Netter 3e 523, 4e 541):

• cutaneous branches to the lateral 1.5 digit.
• motor branches to the:
  • quadratus plantae.
  • abductor digiti minimi.
  • flexor digiti minimi.
  • 3 lateral lumbricals.
  • 7 interossei.
  • adductor hallucis.

The medial plantar nerve has (Clemente 425; Grant p. 444, 446; Netter 3e 523, 4e 541):

• cutaneous branches to the medial 3.5 digits
• motor branches to the :
  • abductor hallucis
  • flexor digitorum brevis
  • flexor hallucis brevis
  • lumbrical 1

updated 09/03/2009

Joints of the lower limb

The hip joint

The ossification of the head of the femur begins during year 1 and is done by year 20 (Grant p. 468).

The pelvic acetabulum

• The epiphyseal line of synostosis (Clemente 265; Grant p. 397; Netter 3e 468, 4e 486) is ossified by year 17 to 23
• The acetabular notch is converted into a foramen by the transverse acetabular ligament (Clemente 433; Grant p. 396; Netter 3e 469, 4e 487)
• The acetabular fossa has a non-articular surface.
• The acetabular labrum deepens the acetabulum.

The hip joint

• The fibrous capsule is attached to the rim of the acetabulum, to the labrum and transverse ligament (Clemente 432-433; Grant p. 398; Netter 3e 469, 4e 487).
• The synovial membrane droops posteroinferiorly to the obturator externus (Clemente 432; Grant p. 395, 398; Netter 3e 469, 4e 487). It is attached to all nonarticular surfaces of the joint.

Ligaments of the hip joint consist of:

• The ligament of the head of the femur (Clemente 433; Grant p. 400-401; Netter 3e 469, 4e 487)
• The iliofemoral ligament (Clemente 432; Grant p. 394-395; Netter 3e 469, 4e 487)
• The pubofemoral and ischiofemoral ligaments (Clemente plate 395; Grant p.377; Netter 469)

The ligament of the head of the femur:

• is a hollow cone of synovial membrane transmitting blood vessels to the head of the femur (Clemente 433; Grant p. 401; Netter 3e 469, 4e 487).
• lies between the fovea (pit for ligament) in the head and the acetabular fossa.

The iliofemoral ligament (Clemente 432; Grant p. 394-395; Netter 3e 469, 4e 487):

• is attached superiorly to the anterior inferior iliac spine and to the acetabular margin.
• is attached inferiorly to the intertrochanteric line of the femur.
• checks the posterior rotation of the trunk

The pubofemoral and ischiofemoral ligaments (Clemente 432; Grant p. 395; Netter 3e 469, 4e 487):

• are attached to the pubic and ischial parts of the acetabular margin, respectively.
• insert into the superior end of the intertrochanteric line.

*The tendon of the psoas major muscle lies between the iliofemoral and pubofemoral ligaments.

Blood supply of the hip joint (Clemente plate 376; Grant p. 362, 400; Netter  3e 486, 4e 504)

• Medial femoral circumflex artery
• Lateral femoral circumflex artery
• Obturator artery
• Anastomosis between arterial branches of the shaft and artery of the head of the femur.
• Inferior gluteal artery

Nerve supply of the hip joint

• Femoral nerve (by the branch to rectus femoris)
• Obturator nerve
• Sciatic nerve
• (Superior gluteal nerve)

Movements of the hip joint (Clemente 380; Grant p.357)

• Flexion
• Extension
• Abduction
• Adduction
• Circumduction
• Medial and lateral rotation

The knee joint

• is a hinge joint for flexion and extension (Clemente 442; Grant p.357).
• has a prepatellar bursa between the patella and skin (Clemente 441; Grant p. 414; Netter 3e 493, 4e 511).
• has a superficial infrapatellar bursa lying anterior to the patellar ligament.
• is formed by the involvement of the femur, tibia and patella (Clemente plate 385 fig. 582; Grant p. 408; Netter 3e 492, 4e 510, 442).

Knee articulations

• The medial and lateral articulations are divided into upper and lower parts by the medial and lateral menisci (Clemente 443; Grant p. 411; Netter 3e 490-491, 4e 443).
• Vulnerability of the patellar articulation:
  • The patella tends to dislocate laterally due to the obliquity of the femur.
  • This is prevented by the anterior projection of the lateral femoral condyle (Clemente 436; Grant p. 410-411; Netter 3e 490, 4e 509) and the inferior fibers of the vastus medialis (Clemente 371; Grant p. 375; Netter 3e 489, 4e 506).

Tibiofemoral (condylar) articulations

The fibrous capsule includes (Clemente 435-443; Grant p. 410-411; Netter 3e 490-491, 4e 506-511):

• the ligamentum patellae,
• the coronary ligaments,
• and the tibial (medial) collateral ligament.
• but NOT the fibular (lateral) collateral ligament

The fibrous capsule:

• is reinforced anteriorly and on the sides by the aponeurosis from the vasti, sartorius, semimembranosus (Clemente 395, Grant p. 375, 379; Netter 3e 472, 4e 506), biceps femoris and iliotibial tract (Clemente 404; Grant p. 383; Netter 488).
• has posterior fibers, named the oblique popliteal ligament, running parallel to the popliteus and attaching to the semimembranosus tendon (Clemente plate 382; Grant p. 415; Netter 3e 493).

Ligaments of the knee

Collateral ligaments are lax when the knee is flexed and allow for some degree of medial and lateral rotation. They are taut when the knee is extended.

Collateral ligaments (Clemente 437-442; Grant p. 408-415; Netter 3e 473-475, 491, 4e 506-511)

Tibial (medial) collateral ligament:

• has a superficial portion underlying the bursae and a deep, deltoid-shaped portion attached to the medial meniscus.
• is crossed by the pes anserinus (distal tendon of sartorius, gracilis and semitendinosus; Clemente 395; Grant p. 379; Netter 3e 488, 4e 506).

Fibular (lateral) collateral ligament runs from the lateral epicondyle of the humerus to the head of the fibula .

Cruciate ligament (Clemente 436, 438-440, 443; Grant p. 411-413; Netter 3e 490-491, 4e 508-509

The anterior cruciate ligament:

• runs from the tibia anteroinferiorly to the intercondylar notch of the femur posterosuperiorly.
• prevents posterior displacement of the femur and hyperextension (Grant p. 412).

The posterior cruciate ligament:

• runs from tibia posteroinferiorly to intercondylar notch of the femur anterosuperiorly.
• prevents anterior displacement of the femur (posterior displacement of the tibia; Grant p. 412).

Intercondylar septum

• separates the medial and lateral condylar joints in intrauterine life.
• is attached to the intercondylar notch at the posterosuperior border.
• is attached from the intercondylar notch to the patella at the anterosuperior border.
• has perforations extending posteriorly to the anterior cruciate ligament, dividing septum into anterior and posterior portions. The cruciate ligaments develop in these portions.

3 bursae of the knee

• The suprapatellar bursa is deep to the tendons of quadriceps femoris and opens into the patellar cavity (Clemente 435; Grant p. 414; Netter 3e 493, 507). It is retracted by the articularis genu during extension. A vertical incision on the femur should stop 2 fingerbreadths above the patella to avoid the suprapatellar bursa.
• The popliteus bursa opens into the lateral condylar cavity below the meniscus (Clemente 441; Grant p. 415).
• The gastrocnemius bursa.

Ossification of the knee

• The distal head of the femur ossifies around the 9th month of intrauterine life and fuses with the shaft around the 19th year.
• The proximal head of the tibia ossifies around birth and fuses with the shaft around the 19th year.
• The patella ossifies around the 3rd year.

Blood supply of the knee joint

• The middle genicular artery arises from the popliteal artery.
• The 2 medial and 2 lateral (superior and inferior) genicular arteries from the popliteal artery embrace the femur and the tibia (Clemente  396-397,443; Grant p. 416; Netter 3e 494, 4e 512)
• Anastomoses exist with the descending branch of the lateral circumflex femoral artery, the descending genicular artery (from the femoral artery) and the anterior tibial recurrent artery (Clemente 363; Grant p. 416; Netter 3e 494, 4e 512).

The nerve supply of the knee joint is supplied:

• from the femoral nerve by branches to the vasti (Clemente 373; Grant p. 372; Netter 3e 520, 4e 538) and the saphenous nerve.
• from the obturator nerve by the branch to the adductor magnus ((Clemente 379; Grant p. 382; Netter 3e 521, 4e 539).
• from the sciatic nerve (6 genicular branches).

The ankle (talocrural) joint

• The weight of the body is transmitted to the talus by the tibia (Clemente 448; Grant p. 456; Netter 3e 497, 508, 4e 526).
• The socket for the the talus is formed by the malleoli, the inferior articular surface of the tibia (Clemente 448; Grant p.455-456; Netter 3e 496, 4e 526) and the transverse tibiofibular ligament.
• In flexion and extension, the talus acts as part of the foot whereas in inversion and eversion, the talus acts as part of the leg.

Collateral ligaments of the ankle

• Medial or deltoid ligament has a superficial portion attaching to the sustentaculum tali and a deep portion attaching to the nonarticular medial part of the talus and as far as the navicular (Clemente 453; Grant p. 452; Netter 3e 509, 4e 527).
• Lateral ligament:
  • Calcaneofibular ligament (Clemente 452; Grant p. 454; Netter 3e 509, 4e 527).
  • Anterior talofibular ligament.
  • Posterior talofibular ligament (Clemente 449; Grant p. 450-451; Netter 3e 490, 4e 525)

The blood supply of the ankle joint is supplied by all blood vessels around the joint.

The nerve supply is derived from the deep peroneal and tibial nerves.

Joints of the foot are joints of inversion and eversion

The plantar calcaneonavicular joint is joined by the plantar calcaneonavicular (spring) ligament (Clemente 455; Grant p.464-465; Netter 3e 510, 4e 528) which contributes to the longitudinal arch of the foot.

The inferior surface of the talus has an anterior, middle (both concave) and posterior (convex) talar facets (Clemente 454; Grant p.459;  Netter 4e 525) which fit into corresponding surfaces on the calcaneus.

The tarsal sinus (sulcus tali) is found between the posterior and middle tarsal facets and contains the interosseous talocalcanean ligament.

Ligaments of the foot

• The interosseous talocalcanean (Clemente 452-454; Grant p. 456; Netter 3e 509, 4e 527) and the lateral talocalcanean ligaments are found between the talus and calcaneus.
• The calcaneofibular portion of the lateral ligament of the ankle and the calcaneotibial portion of the medial (deltoid) ligament are found between the calcaneus and the bones of the leg (Clemente 452-453; Grant p.452-454; Netter 3e 509, 4e 527).

Joints of the foot

• Subtalar joint (posterior talocalcanean joint; Clemente 453; Grant p.459; Netter 3e 506, 4e 525)
• Anterior talocalcanean joints.
• The talonavicular joint (Clemente 453-457; Grant p. 461; Netter 3e 506, 4e 523-525).
• The calcaneocuboid joint.

The bifurcate ligament is the collateral ligament for the talonavicular and calcaneocuboid joints (Clemente 452-454; Grant p. 458; Netter 3e 509, 4e 527).

The plantar calcaneocuboid ("short plantar") ligament runs from the inferior surface of the calcaneus to the large area inferior to the ridge on the cuboid (Clemente 455; Grant p. 465; Netter 3e 510, 4e 528).

The long plantar ligament converts the groove on the cuboid into a tunnel for the peroneus (fibularis) longus tendon (Clemente 455; Grant p.464; Netter 3e 510, 4e 528).

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