SCID 242 - Quiz 5 - Gluteal And Thigh

1. During recovery from a gunshot wound of the right pelvis, the patient notices a sway in his gait. When he lifts his left foot off of the ground, his pelvis dips down on the left side. The nerve that appears to have been injured is the: _________

Nerve to piriformis

Nerve to obturator internus

Sciatic nerve

Femoral nerve

Superior gluteal nerve

he superior gluteal nerve supplies gluteus minimus and medius--two muscles that are important abductors of the hip--as well as tensor fasciae latae. These muscles stabilize the pelvis when walking. The gluteus medius and minimus work in such a way that when you are standing on your right leg only, the muscles on the right side are supporting the left side of the pelvis. When you are standing on your left leg only, the muscles of the left side are supporting the right side of the pelvis. If a patient exhibits a characteristic hip drop on the uninjured side (in this case, the left side) while standing on the injured side (right), this is called Trendelenburg's sign. It occurs when the superior gluteal nerve--the nerve supply to the abductors of the thigh--is disrupted due to injury or disease.

Explanation

he superior gluteal nerve supplies gluteus minimus and medius--two muscles that are important abductors of the hip--as well as tensor fasciae latae. These muscles stabilize the pelvis when walking. The gluteus medius and minimus work in such a way that when you are standing on your right leg only, the muscles on the right side are supporting the left side of the pelvis. When you are standing on your left leg only, the muscles of the left side are supporting the right side of the pelvis. If a patient exhibits a characteristic hip drop on the uninjured side (in this case, the left side) while standing on the injured side (right), this is called Trendelenburg's sign. It occurs when the superior gluteal nerve--the nerve supply to the abductors of the thigh--is disrupted due to injury or disease.

2. During a surgical procedure in which the lower abdominal wall has been opened, the retractor blades damaged a nerve lying between the iliacus and psoas major muscles. The patient has weakened hip flexion and an inability to extend the knee. What nerve has been compressed?

Obturator

Femoral

Sciatic

Tibial

Common fibular

The femoral nerve lies between the iliacus and psoas major muscles. So, if a surgeon pulls these muscles apart with a retractor, the femoral nerve can be easily injured.

Explanation

The femoral nerve lies between the iliacus and psoas major muscles. So, if a surgeon pulls these muscles apart with a retractor, the femoral nerve can be easily injured.

3. An elderly patient complains of difficulty in walking up stairs. Tests by her doctor reveal weakness in extension at her hip, but no change in hip flexion, or flexion or extension of the knee. Based upon these results, what muscle is most likely not functioning properly.

Adductor magnus

Gluteus maximus

Gluteus medius

Iliopsoas

Semitendinosus

Gluteus maximus is the most important muscle for powerfully extending the thigh. This is the muscle that is used for forceful extension at the hip joint, which is what you need to go up the stairs or to jump powerfully.

Explanation

Gluteus maximus is the most important muscle for powerfully extending the thigh. This is the muscle that is used for forceful extension at the hip joint, which is what you need to go up the stairs or to jump powerfully.

4. A serious complication of fractures of the femoral neck is avascular necrosis of the femoral head. This usually results from rupture of which artery?

Acetabular branch of obturator

Deep circumflex iliac

Medial circumflex femoral

Descending branch of lateral circumflex femoral

Second perforating branch of lateral circumflex

It is important to remember that the medial circumflex femoral artery supplies blood to the femoral neck. During fractures of the femoral neck, this artery may be ruptured, and the femoral neck will be deprived of blood.

Explanation

It is important to remember that the medial circumflex femoral artery supplies blood to the femoral neck. During fractures of the femoral neck, this artery may be ruptured, and the femoral neck will be deprived of blood.

5. A patient with a tuberculous abscess (localized collection of pus) on the iliopsoas muscle in the femoral triangle presented impaired flexion of the thigh and extension of the leg. Which of the following nerves was likely involved?

Femoral

Inferior gluteal

Obturator

Sciatic

Superior gluteal

The quadriceps muscles, innervated by the femoral nerve, are the most important leg extensors. Rectus femoris, a component of the quads, is also a hip flexor. So, the patient's deficits, as well as the clinical history of an abscess in the femoral triangle, are consistent with an injury to the femoral nerve.

Explanation

The quadriceps muscles, innervated by the femoral nerve, are the most important leg extensors. Rectus femoris, a component of the quads, is also a hip flexor. So, the patient's deficits, as well as the clinical history of an abscess in the femoral triangle, are consistent with an injury to the femoral nerve.

6. Weakness in climbing stairs or jumping would indicate a lesion of which nerve?

Superior gluteal

Inferior gluteal

Obturator

Femoral

Tibial

The first thing that you want to do with this question is determine which muscle was impaired. Since the question specifies that there is a weakness when climbing steps or jumping, you should know that there is a problem with powerfully extending the hip. And that's what gluteus maximus does. The nerve to gluteus maximus, the inferior gluteal nerve, must be the nerve that was injured.

Explanation

The first thing that you want to do with this question is determine which muscle was impaired. Since the question specifies that there is a weakness when climbing steps or jumping, you should know that there is a problem with powerfully extending the hip. And that's what gluteus maximus does. The nerve to gluteus maximus, the inferior gluteal nerve, must be the nerve that was injured.

7. If the head of the femur is dislocated postero-medially, compression of which nerve is likely to result?

Sciatic

Femoral

Obturator

Superior gluteal

Lumbosacral trunk

The sciatic nerve is closely related to the posterior hip joint, which makes this nerve very vulnerable in cases where the femur is dislocated postero-medially.

Explanation

The sciatic nerve is closely related to the posterior hip joint, which makes this nerve very vulnerable in cases where the femur is dislocated postero-medially.

8. An elderly woman was found to have a hernial sac in the right femoral triangle and a marked weakness in adduction at the right hip joint. Which nerve was likely compressed by this herniation?

Femoral

Inferior gluteal

Obturator

Pudendal

Sciatic

an injury to the femoral nerve would not cause problems with adduction. Instead, the patient would have problems extending her knee. The nerve which supplies the adductor compartment is the obturator nerve, so that must be the structure that was injured. Although the obturator nerve is not in the femoral triangle, it enters the thigh by passing through the obturator canal and under pectineus, part of the floor of the femoral triangle. So, it could be injured by an obturator hernia passing through the obturator canal.

Explanation

an injury to the femoral nerve would not cause problems with adduction. Instead, the patient would have problems extending her knee. The nerve which supplies the adductor compartment is the obturator nerve, so that must be the structure that was injured. Although the obturator nerve is not in the femoral triangle, it enters the thigh by passing through the obturator canal and under pectineus, part of the floor of the femoral triangle. So, it could be injured by an obturator hernia passing through the obturator canal.

9. Following surgical opening of the adductor canal, a patient experienced a loss of cutaneous sensation of the medial side of the leg. Which nerve was cut?

Ilioinguinal

Femoral

Obturator

Medial sural cutaneous

Saphenous

The saphenous nerve is a branch of the femoral nerve. This nerve, and the nerve to vastus medialis, are the only nerves found in the adductor canal. So, it makes sense that one of these structures was injured. The saphenous nerve is a sensory nerve only; it supplies the skin on the medial side of the leg.

Explanation

The saphenous nerve is a branch of the femoral nerve. This nerve, and the nerve to vastus medialis, are the only nerves found in the adductor canal. So, it makes sense that one of these structures was injured. The saphenous nerve is a sensory nerve only; it supplies the skin on the medial side of the leg.

10. Childhood immunizations are sometimes given via intramuscular injections into the quadriceps muscles of the anterior thigh. At the mid-thigh level, a needle passing into the space deep to the sartorius muscle might pierce the femoral vessels as they lie in the: _________

Adductor canal

Adductor hiatus

Adductor triangle

Femoral canal

Femoral ring

Sartorius is the roof of the adductor canal. The femoral artery, femoral vein, saphenous nerve, and nerve to vastus medialis are all found in the adductor canal, deep to sartorius. So, if a needle pierced sartorius to enter the femoral vessels, the needle would be entering the adductor canal.

Explanation

Sartorius is the roof of the adductor canal. The femoral artery, femoral vein, saphenous nerve, and nerve to vastus medialis are all found in the adductor canal, deep to sartorius. So, if a needle pierced sartorius to enter the femoral vessels, the needle would be entering the adductor canal.

11. When the femur is fractured, the broken distal end often turns posteriorly to enter the popliteal fossa due to muscle traction. Because of its position deepest in the fossa, which structure is most vulnerable to laceration?

Common fibular n.

Lesser saphenous v.

Popliteal a.

Popliteal v.

Tibial n.

The popliteal fossa contains the popliteal artery, popliteal vein, common fibular nerve, and tibial nerve. The popliteal artery is the deepest structure in the fossa--it lies on the posterior side of the knee joint. So, it is the structure that would be most likely to be lacerated by the broken distal end of the femur.

Explanation

The popliteal fossa contains the popliteal artery, popliteal vein, common fibular nerve, and tibial nerve. The popliteal artery is the deepest structure in the fossa--it lies on the posterior side of the knee joint. So, it is the structure that would be most likely to be lacerated by the broken distal end of the femur.

12. If the femoral artery is occluded at the beginning of the adductor canal, which artery could help provide viability to the leg through collateral circulation?

Descending branch of the lateral circumflex femoral

Descending genicular

First perforating branch of the deep femoral

Medial circumflex femoral

Obturator

The descending branch of the lateral circumflex femoral artery anastamoses with both the descending genicular branch of the femoral artery as well as the lateral superior genicular branch of the popliteal artery. These connections provide collateral circulation to the knee and leg.

Explanation

The descending branch of the lateral circumflex femoral artery anastamoses with both the descending genicular branch of the femoral artery as well as the lateral superior genicular branch of the popliteal artery. These connections provide collateral circulation to the knee and leg.

13. A fracture of the ischial tuberosity might be expected to most directly affect the muscles that produce which lower limb movement?

Abduction at the hip

Adduction at the hip

Extension at the knee

Flexion at the hip

Flexion at the knee

The ischial tuberosity is the origin for the hamstrings muscles which are the muscles that allow for extension at the hip and flexion at the knee.

Explanation

The ischial tuberosity is the origin for the hamstrings muscles which are the muscles that allow for extension at the hip and flexion at the knee.