The Hip, Thigh, And Knee

Front 1

Describe the articulation at the hip joint and how it differs from the glenohumeral joint.

Back 1

The hip joint is of the ball-and-socket variety, with articulation involving the head of the femur (ball) and the acetabulum (socket). The weight-bearing surface of the acetabulum is C-shaped and the transverse acetabular ligament spans the acetabular notch inferiorly. The acetabulum is deepened by a fibrocartilaginous acetabular labrum. Motions at the hip joint are flexion, extension, adduction, abduction, internal rotation and external rotation.

The glenohumeral joint of the shoulder articulates identically; however, the glenoid cavity of the joint (the socket) is fairly shallow, even with augmentation by the glenoid labrum. This is necessarily to enable the incredible range of movement of the shoulder and arm. Ligamentous support completes the socket but can be comprised, as is the case in dislocations.

The hip joint sacrifices in range of motion for gains in strength. The acetabulum is a larger articulating surface compared to the glenoid cavity, and is even reinforced for weight-bearing capacity. Moreover, the hip joint contains vasculature (small artery of the femur head), whereas the glenohumeral joint contains a tendon (tendon of the long head of the biceps brachii muscle).

Front 2

Explain why fractures of the femoral neck are treated with surgical arthroplastic replacement of the femoral head and neck.

Back 2

Fractures through the neck of the femur may damage the medial and lateral circumflex femoral arteries, which supply the femoral head, placing the femoral head at risk for avascular necrosis. To prevent this, femoral neck fractures are often treated with arthroplastic surgical replacement of the femoral head and neck.

Front 3

Describe or draw the knee joint, including the synovial lining, joint capsule, bursae, and supportive ligaments.

Back 3

The articulating surfaces of the bones are covered with hyaline and articular cartilage, while the entire articulating mechanism is encased within the joint capsule. A synovial membrane lines the fibrous joint capsule and produces synovial fluid to lubricate the joint surfaces. Various bursae exist to reduce friction over tendon and bones. The suprapatellar bursa lies between the anterior surface of the distal femur and the quadriceps femoris muscle. The prepatellar bursa separates the anterior patella from the skin. The deep infrapatellar bursa is situated between the proximal tibia and the patellar ligament.

The following diagram depicts the supportive ligaments lateral/medial collateral ligaments, ACL, PCL, patellar ligament). It does not illustrate the synovial lining, joint capsule or the bursae.

Front 4

Explain the fetal origin of the difference between the orientation of the knee and elbow joints.

Back 4

While the fetus is developing, the palms of the hands and the soles of the feet are both oriented medially. Eventually, the upper limbs rotate 90° laterally, while the lower limbs rotate 90° medially. Consequently, the extensor muscles of the elbow joint are posterior in the upper limb, and the extensors of the knee joint are anterior in the lower limb.

Front 5

List the structural injuries that may occur to the knee joint if a blow is received from the lateral side of the knee when the foot is planted on the ground.

Back 5

A blow to the lateral aspect of the knee when the foot is planted on the ground may result in injury to the tibial/medial collateral ligament, the medial meniscus and the ACL

Front 6

Describe how the gluteus medius muscle acts to stabilize the pelvis in a horizontal plane when the body is supported on one lower limb.

Back 6

The gluteus medius muscle attaches to the greater trochanter of the femur, and abducts the thigh at the hip. When standing on one foot, the gluteus medius of the non-weight bearing lower limb acts to keep the pelvis in a horizontal plane. Weakness in the gluteus medius results in “Trendelenberg” sign, in which the pelvis drops on the non-weight bearing side.

Weak right gluteus medius means that the pelvis will drop on the left side!

Front 7

List their muscles, actions, innervations and blood supply:
Gluteal Region

Back 7

1) Gluteus maximus: Thigh extension (major) + stabilizes knee in extension + abduction + rotation of femur
2) Gluteus medius and minimus: Thigh abduction
3) Tensor fasciae latae: thigh flexion; abduction
4) Lateral Rotators - piriformis (also abduction), gemellus superior/inferior, obturator superior/inferior, quadratus femoris: Laterally rotate thigh at the hip joint

Hint 7

Superior and inferior gluteal arteries are branches of the internal iliac artery in the pelvis and pass through the greater sciatic foramen to reach the gluteal region.

Gluteus medius/minimus, tensor fasciae latae muscles: Superior gluteal nerve

Gluteus maximus: inferior gluteal nerve

Front 8

Describe the femoral triangle and its contents, and name the muscles that would be weakened by damage to the femoral nerve during a procedure involving the femoral triangle.

Back 8

The femoral triangle is located in the anterior aspect of the thigh, and is bound by the sartorius, adductor longus and the inguinal ligament (mnemonic = SAIL). The iliopsoas and pectineus muscles form the floor of the triangle. The femoral triangle contains the
femoral nerve, femoral artery, femoral vein and lymphatic vessels. Damage to the femoral nerve during a procedure involving the femoral triangle threatens the muscles and skin it innervates: the muscles of the anterior thigh (iliopsoas,
quadriceps and sartorius), as well as the skin of the medial leg (via saphenous nerve) and anterior thigh.

Front 9

Describe the route and major branches of the femoral artery.

Back 9

The external iliac becomes the femoral artery as it passes posterior and inferior to the inguinal ligament. From the femoral triangle, the femoral artery passes through the adductor canal to vascularize the anterior thigh. From there, it transits the adductor hiatus to become the popliteal artery.

Alternately, from the femoral triangle, the femoral artery branches to form the deep femoral artery, which services the medial and posterior thigh. Still another branch of the deep femoral gives off the medial/lateral circumflex femoral arteries.

Front 10

Describe the pulse points of the femoral and popliteal arteries.

Back 10

Syllabus page 847
“The pulse of the femoral artery is palpable in the femoral triangle. The pulse of the popliteal artery is palpable in the superior region of the popliteal fossa.”

Front 11

List their muscles, actions, innervations and blood supply:
Anterior Thigh Region

Back 11

1) Iliopsoas: Thigh Flexion
2) Quadriceps- rectus femoris, vastus lateralis/intermedius/medialis: all involved with leg extension. Rectus femoris also does Thigh flexion.
3) Sartorius: Thigh flexion (major) and Leg flexion + lateral rotation and abduction

Hint 11

Muscular branches of the femoral artery

Femoral Nerve which passes deep to the inguinal ligament (also innervates skin of anterior aspect of thigh and medial aspect of leg)

Front 12

List their muscles, actions, innervations and blood supply:
Medial Thigh Region

Back 12

All of the muscles attach proximally to the pelvic bone. All participate in thigh adduction

adductor brevis/longus/magnus, gracilis

Pectineus can be classified as medial or anterior compartment (major action is thigh flexion)

remember that when finding pectineus, it is superficial to adductor brevis --> "superficial people have pecs"

Hint 12

Deep femoral artery

Obturator nerve which passes through obturator foramen of the pelvic bone. also innervates skin on the medial aspect of the thigh

Front 13

List their muscles, actions, innervations and blood supply:
Posterior Thigh Region

Back 13

biceps femoris, semitendinosus, semimembranosus

Muscles attach proximally to the ischial tuberosity. Participate in Thigh extension and Leg Flexion

Biceps femoris: also externally rotates
Semimembranosus/tendinosus: also internally rotates

Hint 13

Deep femoral artery

Sciatic nerve passes through the greater sciatic foramen

Front 14

Extra Information

Back 14

1) to reach full leg extension, the tibia rotates laterally
2) patella acts as a pulley system to help give the quadriceps leverage
3) fascia lata in thigh becomes continuous with the crural fascia in the leg
4) lateral rotators: piriformis, gemellus inferior/superior, obturator internus/externus, quadratus femoris
5) great saphenous vein: superficial vein on the medial side of the lower limb, which empties into the femoral vein in the femoral triangle inferior to the inguinal ligament
6) superior gluteal nerve: L4-S1; inferior gluteal nerve: L5-S2; obturator nerve: L2-L4; femoral nerve: L2-L4; Sciatic nerve: L4-S3