3-Lower limp MSQs Only (2)

Question 1

1- Which of the following is not contained within the deep posterior compartment of the lower leg?

Answer 1

Sural nerve

The deep posterior compartment lies anterior to soleus. The sural nerve is superficially sited and therefore not contained within it.

Question 2

4- At what level does the sciatic nerve usually bifurcate into the tibial and common peroneal nerves?

Answer 2

At the superior aspect of the popliteal fossa

The sciatic nerve passes vertically downwards over the posterior surface of the obturator internus and quadratus femoris to the hamstring compartment of the thigh, here it is crossed posteriorly by the long head of biceps femoris. In the buttock it lies under the cover of gluteus maximus. It separates into its tibial and common peroneal components at the upper aspect of the popliteal fossa.

Question 2

2- Which of the following structures are at risk of direct injury following a fracture dislocation of the femoral condyles?

Answer 2

Popliteal artery

The heads of gastrocnemius will contract to pull the fracture segment posteriorly. The popliteal artery lies against the bone and may be damaged or compressed.

Question 3

3- Which of the following structures does not pass anterior to the lateral malleolus?

Answer 3

Peroneus brevis

Peroneus brevis passes posterior to the lateral malleolus. Peroneus tertius is closely related to extensor digitorum and like that muscle, its tendon passes anterior to the lateral malleolus

Question 4

5- During an operation for varicose veins the surgeons are mobilising the long saphenous vein. Near its point of entry to the femoral vein an artery is injured and bleeding is encountered. From where is the bleeding most likely to originate?

Answer 4

Deep external pudendal artery

saphenous vein near its point of union with the femoral vein. The superficial external pudendal artery lies superior to the SFJ. Neither vessel is functionally important and if injured they are best ligated.

Question 5

6- A 23 year old man presents with delayed diagnosis of appendicitis. The appendix is retrocaecal and has perforated causing a psoas abscess. Into which structure does the psoas major muscle insert?

Answer 5

Lesser trochanter of the femur

The psoas major inserts into the lesser trochanter.

Question 6

10- Which of the following structures are not closely related to the adductor longus muscle?

Answer 6

Long saphenous vein
Tendon of iliacus ( Right)
The profunda branch of the femoral artery
Pectineus muscle
Femoral nerve

Femoral triangle:
Adductor longus medially
Inguinal ligament superiorly
Sartorius muscle laterally

Adductor longus forms the medial border of the femoral triangle. It is closely related to the long saphenous vein which overlies it and the profunda branch of the femoral artery. The femoral nerve is related to it inferiorly. However, the tendon of iliacus inserts proximally and is not in contact with adductor longus.

Question 6

8- Which of the following muscles is not within the posterior compartment of the lower leg?

Answer 6

Peroneus brevis

Peroneus brevis lies in the lateral compartment.

Question 6

9- Which of the nerves listed below is responsible for the innervation of gluteus medius?

Answer 6

Superior gluteal nerve

Question 7

7- The femoral nerve is transected by a rather careless surgeon during a botched femoro-popliteal bypass operation. Which of the following actions will be impaired?

Answer 7

Extension of the knee joint

The femoral nerve supplies the quadriceps muscle which is responsible for extension at the knee joint.

Question 8

11- A 73 year old lady presents with a femoral hernia. Which of the following structures forms the lateral wall of the femoral canal?

Answer 8

Femoral vein

The canal exists to allow for the physiological expansion of the femoral vein, which lies lateral to it.

Question 9

12- A 40-year-old man presents with pain in his lower back and ‘sciatica’ for the past three days. He describes bending down to pick up a washing machine when he felt ‘something go’. He now has severe pain radiating from his back down the right leg. On examination he describes paraesthesia over the anterior aspect of the right knee and the medial aspect of his calf. Power is intact and the right knee reflex is diminished. The femoral stretch test is positive on the right side. Which nerve or nerve root is most likely to be affected?

Answer 9

L3

Question 10

13- Which of the following statements relating to sartorius is untrue?

Answer 10

It inserts into the medial femoral condyle

It inserts into the medial aspect of the upper part of the tibia.

Question 10

14- A 70 year old man is due to undergo an arterial bypass procedure for claudication and foot ulceration. The anterior tibial artery will form the site of the distal arterial anastomosis. Which of the following structures is not closely related to it distally?

Answer 10

Tibialis posterior

As an artery of the anterior compartment, the anterior tibial artery is closely related to tibialis anterior. The tibialis posterior is related to it at its origin.

Question 11

15- A 66 year old man with peripheral vascular disease is undergoing a below knee amputation. In which of the lower leg compartments does peroneus brevis lie?

Answer 11

Lateral compartment

The interosseous membrane separates the anterior and posterior compartments. The deep and superficial compartments are separated by the deep transverse fascia. The peroneus brevis is part of the lateral compartment.

Question 12

17- Which of the muscles below does not cause lateral rotation of the hip?

Answer 12

Pectineus

lateral hip rotators: P-GO-GO-Q (top to bottom)
Piriformis
Gemellus superior
Obturator internus
Gemellus inferior
Obturator externus
Quadratus femoris

Pectineus adducts and medially rotates the femur.

Question 12

16- A 78 year old man is undergoing a femoro-popliteal bypass graft. The operation is not progressing well and the surgeon is complaining of poor access. Retraction of which of the following structures will improve access to the femoral artery in the groin?

Answer 12

Sartorius

At the lower border of the femoral triangle the femoral artery passes under the sartorius muscle. This can be retracted to improve access.

Question 13

18- A builder falls off a ladder whilst laying roof tiles. He sustains a burst fracture of L2. The MRI scan shows complete nerve transection at this level, as a result of the injury. Which clinical sign will not be present initially?

Answer 13

cid paralysis of the legs
Extensor plantar response ( Right)
Sensory loss in the legs
Incontinence
Areflexia

In lower motor neuron lesions everything is reduced

The main purpose of this question is to differentiate the features of an UMN lesion and a LMN
lesion. The features of a LMN lesion include:
· Flaccid paralysis of muscles supplied
· Atrophy of muscles supplied.
· Loss of reflexes of muscles supplied.
· Muscles fasciculation

For lesions below L1 LMN signs will occur. Hence in an L3 lesion, there will be loss of the patella reflex but there will be no extensor plantar reflex.

Question 14

19- An 80 year old lady with a caecal carcinoma is undergoing a right hemicolectomy performed
through a transverse incision. The procedure is difficult and the incision is extended medially by dividing the rectus sheath. Brisk arterial haemorrhage ensues. From which of the following does the damaged vessel originate?

Answer 14

External iliac artery

The vessel damaged is the epigastric artery. This originates from the external iliac artery (see below).

Question 15

20- Which of the following does not exit the pelvis through the greater sciatic foramen?

Answer 15

Obturator nerve

The obturator nerve exits through the obturator foramen.

Question 15

23- Which of the following statements relating to the knee joint is false?

Answer 15

The posterior aspect of the patella is extrasynovial

The posterior aspect is intrasynovial and the knee itself comprises the largest synovial joint in the body. It may swell considerably following trauma such as ACL injury. Which may be extremely painful owing to rich innervation from femoral, sciatic and ( a smaller) contribution from the obturator nerve. During full extension all ligaments are taut and the knee is locked.

Question 15

22- A 77 year old man with symptoms of intermittent claudication is due to have his ankle
brachial pressure indices measured. The dorsalis pedis artery is impalpable. Which of the following tendinous structures lies medial to it, that may facilitate its identification?

Answer 15

Extensor hallucis longus tendon

The extensor hallucis longus tendon lies medial to the dorsalis pedis artery.

Question 16

21- A 22 year man is shot in the groin. On examination, he has weak hip flexion, weak knee extension, and impaired quadriceps tendon reflex, as well as sensory deficit in the anteromedial aspect of the thigh. Which structure has been affected?

Answer 16

Femoral nerve

This is a classical description of a femoral nerve injury.

Question 17

24- Which of the following structures attaches periosteum to bone?

Answer 17

Sharpeys fibres

Periosteum is attached to bone by strong collagenous fibers called Sharpey’s fibres, which extend to the outer circumferential and interstitial lamellae. It also provides an attachment for muscles and tendons

Question 18

25- The integrity of which muscle is assessed by the Trendelenburg test?

Answer 18

Gluteus medius

Question 19

27- A 30 year old man presents with back pain and the surgeon tests the ankle reflex. Which of the following nerve roots are tested in this manoeuvre?

Answer 19

S1 and S2

Question 19

26- Which of the following structures is not closely related to the piriformis muscle?

Answer 19

Superior gluteal nerve
Sciatic nerve
Inferior gluteal artery
Inferior gluteal nerve
Medial femoral circumflex artery ( Right)

Nerve supply of lateral hip rotators
Piriformis: ventral rami S1, S2
Obturator internus: nerve to obturator internus
Superior gemellus: nerve to obturator internus
Inferior gemellus: nerve to quadratus femoris
Quadrator femoris: nerve to quadrator femoris

The piriformis muscle is an important anatomical landmark in the gluteal region. The following structures are closely related:
. Sciatic nerve
· Inferior gluteal artery and nerve
· Superior gluteal artery and nerve

The medial femoral circumflex artery runs deep to quadratus femoris.

Question 19

28- A 56 year old man suddenly develops severe back pain. His pain has a radicular pattern. On examination, he is unable to extend his great toe. Which of the spinal levels listed below is most likely to have been affected?

Answer 19

L5

Extensor hallucis longus is derived from L5 and loss of EHL function is a useful test to determine whether this level is involved.

Question 20

29- A 62 year old male complains of back pain. He has had a recent fall. Walking causes pain of the left lower leg. On examination, he is noted to have reduced sensation over the knee. Which of the spinal levels listed below is most likely to have been affected?

Answer 20

L3

Sensation over the knee is equivalent to the L3 dermatome. The four nerves involved include the infrapatellar branch of the saphenous nerve, the lateral cutaneous nerve of the thigh, anterior cutaneous nerve of the thigh (both lateral and medial branches).

Question 21

30- Which of the following structures is not closely related to the posterior tibial artery?

Answer 21

Soleus posteriorly
Tibial nerve laterally
Deep peroneal nerve laterally ( atrally)
Flexor hallucis longus postero-inferiorly
Popliteus

The deep peroneal nerve lies in the anterior compartment. The tibial nerve lies medially. At its termination it lies deep to the flexor retinaculum. The tibial nerve lies medial to the popliteal vessels but lateral to the posterior tibial artery.

Question 22

31- A 72 year old man with non reconstructible arterial disease is undergoing an above knee amputation. The posterior compartment muscles are divided. Which of the following muscles does not lie in the posterior compartment of the thigh?

Answer 22

Quadriceps femoris

The quadriceps femoris lies in the anterior compartment.

Question 23

32- A 40 year old lady presents with varicose veins, these are found to originate from the short saphenous vein. As the vein is mobilised which structure is at greatest risk of injury?

Answer 23

Sural nerve

The sural nerve is closely related and damage to this structure is a major cause of litigation. The other structures may all be injured but the risks are lower.

Question 23

33- A 34 year old lady presents with symptoms of faecal incontinence. Ten years previously she gave birth to a child by normal vaginal delivery. Injury to which of the following nerves is most likely to account for this process?

Answer 23

Pudendal

S2,3,4 keep the POO up off the floor. POOdendal nerve

Damage to the pudendal nerve is classically associated with faecal incontinence and it is for this reason that sacral neuromodulation is a popular treatment for the condition. Injury to the hypogastric autonomic nerves is an aetiological factor in the development of constipation.

Question 24

34- Which of the following nerves innervates the long head of the biceps femoris muscle?

Answer 24

Tibial division of sciatic nerve

The short head of biceps femoris, which may occasionally be absent, is innervated by the common peroneal component of the sciatic nerve. The long head is innervated by the tibial division of the sciatic nerve.

Question 24

35- A 25 year old man is stabbed in the groin and the area, which lies within the femoral triangle is explored. Which structure forms the lateral wall of the femoral triangle?

Answer 24

Sartorius

The sartorius forms the lateral wall of the femoral triangle

Question 25

36- Which of the following bones is related to the cuboid’s distal articular surface?

Answer 25

5th metatarsal

The cuboid is located at the lateral aspect of the foot between the calcaneus posteriorly and the 4th and 5th metatarsals distally.

Question 25

37- A 25 year old man undergoes an excision of a pelvic chondrosarcoma, during the operation the obturator nerve is sacrificed. Which of the following muscles is least likely to be affected as a result?

Answer 25

Sartorius

Sartorius is supplied by the femoral nerve. In approximately 20% of the population, pectineus is supplied by the accessory obturator nerve. Adductor magnus has a composite supply from the obturator and sciatic nerves.

Question 26

38- An 18 year old athlete attends orthopaedic clinic reporting pain and swelling over the medial aspect of the knee joint. The pain occurs when climbing the stairs, but is not present when walking on flat ground. Clinically there is pain over the medial, proximal tibia and the McMurray test is negative. What is the most likely cause of this patient’s symptoms?

Answer 26

Pes Anserinus Bursitis

Pes anserinus: GOOSE’S FOOT
Combination of sartorius, gracilis and semitendinous tendons inserting into the anteromedial proximal tibia.

Pes Anserinus Bursitis is common in sportsmen due to overuse injuries. The main sign is of pain in the medial proximal tibia. As the McMurray test is negative, medial meniscal injury is excluded.

Question 27

39- A 22 year old man suffers a compound fracture of the tibia. During attempted surgical repair the deep peroneal nerve is divided. Which of the following muscles will not be affected as a result?

Answer 27

Peroneus longus

Peroneus longus is innervated by the superficial peroneal nerve (L4, L5, S1).

Question 28

40- An elderly man falls and lands on his hip. On examination, his hip is tender to palpation and x-rays are taken. There are concerns that he may have an intertrochanteric fracture. What is the normal angle between the femoral neck and the femoral shaft?

Answer 28

130°

The normal angle in males between the femoral head and shaft is 130°. Changes to this angle may occur as a result of disease or pathology and should be investigated.
Females have an angle that is around 110-120°

Question 29

41- Which of the nerves listed below is at greatest risk of injury with a laceration to the upper lateral margin of the popliteal fossa?

Answer 29

Common peroneal nerve

The sural nerve exits at the lower infero-lateral aspect of the fossa and is more at risk in short saphenous vein surgery. The tibial nerve lies more medially and is even less likely to be injured in this location.

Question 30

42- A 56 year old lady with metastatic breast cancer develops an oestolytic deposit in the proximal femur. One morning whilst getting out of bed she notices severe groin pain. X-rays show that the lesser trochanter has been avulsed. Which muscle is the most likely culprit?

Answer 30

Psoas major

The psoas major inserts into the lesser trochanter and contracts when raising the trunk from the supine position. When osteolytic lesions are present in the femur the lesser trochanter may be avulsed.

Question 31

43- Which of the following is a content of the adductor canal?

Answer 31

Saphenous nerve

It contains the saphenous nerve and the superficial branch of the femoral artery.

Question 32

44- The following statements relating to the ankle joint are true except?

Answer 32

Three groups of ligaments provide mechanical stability
The sural nerve lies medial to the Achilles tendon at its point of insertion (Right)
Eversion of the foot occurs at the sub talar joint
The saphenous nerve crosses the ankle joint.

The sural nerve lies behind the distal fibula. Inversion and eversion are sub talar movements. The structures passing behind the medial malleolus from anterior to posterior include: tibialis posterior, flexor digitorum longus, posterior tibia vein, posterior tibial artery, nerve, flexor hallucis longus.

Question 33

45- At which of the following anatomical locations does the common peroneal nerve bifurcate into the superficial and deep peroneal nerves?

Answer 33

At the lateral aspect of the neck of the fibula

The common peroneal nerve bifurcates at the neck of the fibula (where it is most likely to be injured).

Question 34

46- A 72 year old lady with osteoporosis falls and sustains an intracapsular femoral neck fracture. The fracture is completely displaced. Which of the following vessels is the main contributor to the arterial supply of the femoral head?

Answer 34

Circumflex femoral arteries

The vessels which form the anastomoses around the femoral head are derived from the medial and lateral circumflex femoral arteries. These are usually derived from the profunda femoris artery.

Question 35

47- A 48 year old motor cyclist sustains a complex lower limb fracture in a motor accident. For a time the popliteal artery is occluded and eventually repaired. Subsequently he develops a compartment syndrome and the anterior and superficial posterior compartments of the lower leg are decompressed. Unfortunately, the operating surgeon neglects to decompress the deep posterior compartment. Which of the following muscles is least likely to be affected as a result?

Answer 35

Plantaris

Muscles of the deep posterior compartment:
· Tibialis posterior
· Flexor hallucis longus
· Flexor digitorum longus
· Popliteus

The plantaris muscle lies within the superficial posterior compartment of the lower leg.

Question 36

48- A 52 year female post hysterectomy attends clinic. She reports pain and reduced sensation over the medial aspect of her thigh. Clinically thigh adduction is weak. What is the most likely nerve injury?

Answer 36

Obturator nerve

The obturator nerve supplies sensation to the medial aspect of the thigh and causes adduction and internal rotation of the thigh.
Injury occurs during pelvic or abdominal surgery.
L3 cord compression is unlikely.

Question 37

49- A 23 year old lady is undergoing a trendelenberg procedure for varicose veins. During the dissection of the saphenofemoral junction, which of the structures listed below is most liable to injury?

Answer 37

Deep external pudendal artery

The deep external pudendal artery runs under the long saphenous vein close to its origin and may be injured. It is at greatest risk of injury during the flush ligation of the saphenofemoral junction. Provided an injury is identified and vessel ligated, injury is seldom associated with any serious adverse sequelae.

Question 38

50- A 22 year old man is involved in a fight and is stabbed in the posterior aspect of his right leg. The knife passes into the popliteal fossa. He sustains an injury to his tibial nerve. Which muscle is least likely to be compromised as a result?

Answer 38

Peroneus tertius

Peroneus tertius is innervated by the deep peroneal nerve.

Question 39

51- Which of the following structures does not pass close to the piriformis muscle in the greater sciatic foramen?

Answer 39

Sciatic nerve
Posterior cutaneous nerve of the thigh
Inferior gluteal artery
Obturator nerve ( Right)
None of the above

The obturator nerve does not pass through the greater sciatic foramen.

Question 40

52- A 78 year old lady falls over in her nursing home and sustains a displaced intracapsular fracture of the femoral neck. A decision is made to perform a hemi arthroplasty through a lateral approach. Which of these vessels will be divided to facilitate access?

Answer 40

Transverse branch of the lateral circumflex artery

During the Hardinge style lateral approach the transverse branch of the lateral circumflex artery is divided to gain access.

Question 41

53- A man with lung cancer and bone metastasis in the thoracic spinal vertebral bodies, sustains a pathological fracture at the level of T4. The fracture is unstable and the spinal cord is severely compressed at this level. Which of the findings below will not be present 6 weeks after injury?

Answer 41

Diminished patellar tendon reflex

A thoracic cord lesion causes spastic paraperesis, hyperrflexia and extensor plantar responses (UMN lesion), incontinence, sensory loss below the lesion and ‘sensory’ ataxia.These features typically manifest several weeks later, once spinal shock (in which areflexia predominates) has resolved.

Question 42

54- Which nerve supplies the 1st web space of the foot?

Answer 42

Deep peroneal nerve

The first web space is innervated by the deep peroneal nerve.

Question 42

55- How many compartments are there in the lower leg?

Answer 42

4

The posterior compartment of the lower leg has both superficial and deep posterior layers, together with the anterior and lateral compartments this allows for four compartments. Decompression of the deep posterior compartment during fasciotomy may be overlooked with significant sequelae.

Question 43

56- Which of the following structures separates the posterior cruciate ligament from the popliteal artery?

Answer 43

Oblique popliteal ligament

The posterior cruciate ligament is separated from the popliteal vessels at its origin by the oblique popliteal ligament.It is attached above to the upper margin of the intercondyloid fossa and posterior surface of the femur close to the articular margins of the condyles, and below to the posterior margin of the head of the tibia. The transverse ligament is located anteriorly.

Question 43

57- Which muscle is supplied by the superficial peroneal nerve?

Answer 43

Peroneus brevis

Question 43

58-Which of these nerves pass through the greater sciatic foramen and innervate the perineum?

Answer 43

Pudendal

3 divisions of the pudendal nerve:
. Rectal nerve
. Perineal nerve
· Dorsal nerve of penis/ clitoris
All these pass through the greater sciatic foramen.

The pudendal nerve innervates the perineum. It passes between piriformis and coccygeus medial to the sciatic nerve.

Question 44

59-Which of the following is true in relation to the sartorius muscle?

Answer 44

Forms the Pes anserinus with Gracilis and semitendinous muscle

It is innervated by the superficial branch of the femoral nerve. It is a component of the pes anserinus.

Question 45

60- A 23 year old man is stabbed in the groin, several structures are injured and the adductor longus muscle has been lacerated. Which of the following nerves is responsible for the innervation of adductor longus?

Answer 45

Obturator nerve

The adductors are innervated by the obturator nerve

Question 46

61- Which of the following muscles does not recieve any innervation from the sciatic nerve?

Answer 46

Quadriceps femoris

The sciatic nerve is traditionally viewed as being a nerve of the posterior compartment. It is known to contribute to the innervation of adductor magnus (although the main innervation to this muscle is from the obturator nerve). The quadriceps femoris is nearly always innervated by the femoral nerve.

Question 47

62- An 83 year old lady presents with a femoral hernia and undergoes a femoral hernia repair. Which of the following forms the posterior wall of the femoral canal?

Answer 47

Pectineal ligament

Question 48

63- A 78 year old man presents with symptoms consistent with intermittent claudication. To assess the severity of his disease you decide to measure his ankle brachial pressure index. To do this you will identify the dorsalis pedis artery. Which of the following statements relating to this vessel is false?

Answer 48

It originates from the peroneal artery (right)
It is crossed by the tendon of extensor hallucis brevis
Two veins are usually closely related to it
It passes under the inferior extensor retinaculum
The tendon of extensor digitorum longus lies lateral to it

The dorsalis pedis artery is a direct continuation of the anterior tibial artery.

Question 49

64- Which of the following structures does not pass behind the lateral malleolus?

Answer 49

Peroneus brevis tendon
Sural nerve
Short saphenous vein
Peroneus longus tendon
Tibialis anterior tendon (Right)

Tibialis anterior tendon passes anterior to the medial malleolus.

Question 50

65- Which of the following represents the root values of the sciatic nerve?

Answer 50

L4 to S3

The sciatic nerve most commonly arises from L4 to S3.

Question 51

68- A 42 year old lady is reviewed in the outpatient clinic following a routine surgical procedure. She complains of diminished sensation at the lateral aspect of her foot. Which of the following nerves is most likely to be affected?

Answer 51

Sural

The sural nerve supplies the lateral aspect of the foot. It runs alongside the short saphenous vein and may be injured in short saphenous vein surgery.

Question 51

69- A 24 year old motor cyclist is involved in a road traffic accident. He suffers a tibial fracture which is treated with an intra medullary nail. Post operatively he develops a compartment syndrome. Surgical decompression of the anterior compartment will relieve pressure on all of the following muscles except?

Answer 51

Peroneus brevis ( Right)
Peroneus tertius
Extensor digitorum longus
Tibialis anterior
None of the above

the anterior compartment contain:
Tibialis anterior
Extensor digitorum longus
Peroneus tertius
Extensor hallucis longus
Anterior tibial artery
All the muscles are innervated by the deep peroneal nerve.

Question 52

66- The sciatic nerve lies deep to the following structures except:

Answer 52

Gluteus maximus
The femoral cutaneous nerve
Long head of biceps femoris
Gluteus medius (Right)
Branch of the inferior gluteal artery

The gluteus medius does not extend around to the sciatic nerve.

Question 53

67- A sprinter attends A&E with severe leg pain. He had forgotten to warm up and ran a 100m sprint race. Towards the end of the race he experienced pain in the posterior aspect of his thigh. The pain worsens, localising to the lateral aspect of the knee. The sprinter is unable to flex the knee. What structure has been injured?

Answer 53

Biceps femoris tendon

The biceps femoris is commonly injured in sports that require explosive bending of the knee as seen in sprinting, especially if the athlete has not warmed up first. Avulsion most commonly occurs where the long head attaches to the ischial tuberosity. Injuries to biceps femoris are more common than to the other hamstrings.

Question 54

71- A 44 year old man has a malignant melanoma and is undergoing a block dissection of the groin. The femoral triangle is being explored for intra operative bleeding. Which of the following forms the medial border of the femoral triangle?

Answer 54

Adductor longus

Adductor longus forms the medial boundary of the femoral triangle .

Question 55

70- The foramen marking the termination of the adductor canal is located in which of the following?

Answer 55

Adductor magnus

The foramen marking the distal limit of the adductor canal is contained within adductor magnus. The vessel passes through this region to enter the popliteal fossa.

Question 56

72- Which of the following structures does not pass posteriorly to the medial malleolus?

Answer 56

Tibialis anterior tendon

Mnemonic for structures posterior to the medial malleolus:
Tom Dick And Nervous Harry

T ibialis posterior tendon
flexor Digitorum longus
A rtery
N erve
H allucis longus

Question 56

73- An intravenous drug user develops a false aneurysm and requires emergency surgery. The procedure is difficult and the femoral nerve is inadvertently transected. Which of the following muscles is least likely to be affected as a result?

Answer 56

Adductor magnus

Mnemonic for femoral nerve supply:

(don’t) M I S V Q Scan for PE
M edial cutaneous nerve of the thigh
I ntermediate cutaneous nerve of the thigh
S aphenous nerve

V astus
Q uadriceps femoris
S artorius

PE ectineus

Adductor magnus is innervated by the obturator and sciatic nerve. The pectineus muscle is sometimes supplied by the obturator nerve but this is variable. Since the question states least likely, the correct answer is adductor magnus.

Question 56

75- Which muscle does not insert on the medial or superomedial surface of the greater trochanter?

Answer 56

Quadratus femoris

Mnemonic for muscle attachment on greater trochanter is POGO:
· Piriformis
· Obturator internus
· Gemelli
· Obturator externus

The quadratus femoris fibres pass laterally to be inserted into the quadrate tubercle on the
intertrochanteric crest of the femur. The other muscles all insert on the trochanteric fossa lying medial to the greater trochanter.

Question 57

74- Which of the following structures lies deepest in the popliteal fossa?

Answer 57

Popliteal artery

From superficial to deep:
The common peroneal nerve exits the popliteal fossa along the medial border of the biceps tendon.
Then the tibial nerve lies lateral to the popliteal vessels to pass posteriorly and then medially to them.
The popliteal vein lies superficial to the popliteal artery, which is the deepest structure in the fossa.

Question 58

76- A 68 year old man with critical limb ischaemia is undergoing a femoro-distal bypass graft. During mobilisation of the proximal part of the posterior tibial artery which of the following is at greatest risk of injury?

Answer 58

Tibial nerve

The tibial nerve is closely related to the posterior tibial artery. The tibial nerve crosses the vessel posteriorly approximately 2.5cm distal to its origin. At its origin the nerve lies medial and then lateral after it crosses the vessel as described.

Question 59

77- Which of the following statements relating to quadratus lumborum is false?

Answer 59

Causes flexion of the thoracic spine

Quadratus lumborum
Origin: Medial aspect of iliac crest and iliolumbar ligament
Insertion: 12th rib
Action: Pulls the rib cage inferiorly. Lateral flexion.
Nerve supply: Anterior primary rami of T12 and L1-3

The rectus abdominis causes flexion of the thoracic spine and therefore the statement suggesting that quadratus lumborum does so is incorrect.

Question 60

78- A 42 year old woman complains of a burning pain of her anterolateral thigh which worsens on walking. There is a positive tinel sign over the inguinal ligament. Which nerve is affected?

Answer 60

Lateral cutaneous nerve of the thigh

The lateral cutaneous nerve supplies sensation to the anterior and lateral aspect of the thigh.
Entrapment is commonly due to intra and extra pelvic causes. Treatment involves local anaesthetic injections.

Question 61

79- Which of the following structures lies posterior to the femoral nerve in the femoral triangle?

Answer 61

lliacus

The iliacus lies posterior to the femoral nerve in the femoral triangle. The femoral sheath lies anterior to the iliacus and pectineus muscles.

Question 62

80- A 72 year old man has a fall. He is found to have a fractured neck of femur and goes on to have a left hip hemiarthroplasty. Two months post operatively he is found to have an odd gait. When standing on his left leg his pelvis dips on the right side. There is no foot drop. What is the cause?

Answer 62

Superior gluteal nerve damage

This patient has a trendelenburg gait caused by damage to the superior gluteal nerve causing weakness of the abductor muscles. Classically a patient is asked to stand on one leg and the pelvis dips on the opposite side. The absence of a foot drop excludes the possibility of polio or L5 radiculopathy.

Question 63

81- A 24 year old lady is stabbed in the buttock. Following the injury the wound is sutured in the emergency department. Eight weeks later she attends the clinic, as she walks into the clinic room she has a waddling gait and difficulty with thigh abduction. On examination she has buttock muscle wasting. Which nerve has been injured?

Answer 63

Superior gluteal nerve

Damage to the superior gluteal nerve will result in a Trendelenburg gait.

Question 63

82- A 34 year old man undergoes excision of a sarcoma from the right buttock. During the procedure the sciatic nerve is sacrificed. Which of the following will not occur as a result of this process?

Answer 63

Loss of extension at the knee joint

Extension of the knee joint is caused by the obturator and femoral nerves. Sensation to the posterior aspect of the thigh is via the posterior cutaneous nerve of the thigh and this is a direct branch from the plexus itself.

Question 63

84- A 65 year old man with long standing atrial fibrillation develops an embolus to the lower leg. The decision is made to perform an embolectomy, utilising a trans popliteal approach. After incising the deep fascia, which of the following structures will the surgeons encounter first on exploring the central region of the popliteal fossa?

Answer 63

Tibial nerve

The tibial nerve lies superior to the vessels in the inferior aspect of the popliteal fossa. In the upper part of the fossa the tibial nerve lies lateral to the vessels, it then passes superficial to them to lie medially. The popliteal artery is the deepest structure in the popliteal fossa.

Question 63

83- A 43 year old lady presents with varicose veins and undergoes a saphenofemoral disconnection, long saphenous vein stripping to the ankle and isolated hook phlebectomies. Post operatively she notices an area of numbness superior to her ankle. What is the most likely cause for this?

Answer 63

Saphenous nerve injury

The sural nerve is related to the short saphenous vein. The saphenous nerve is related to the long saphenous vein below the knee and for this reason full length stripping of the vein is no longer advocated.

Question 64

85- Which of the following is not found within the deep perineal pouch in an adult male?

Answer 64

Obturator nerve

Question 65

86- Which of these nerves passes through the greater and lesser sciatic foramina?

Answer 65

Pudendal nerve

Structures passing through the lesser and greater sciatic foramina (medial to lateral): PIN
· Pudendal nerve
· Internal pudendal artery
· Nerve to obturator internus

The pudendal nerve originates from the ventral rami of the second, third, and fourth sacral nerves (S2,S3, S4).

It passes between the piriformis and coccygeus muscles and exits the pelvis through the the greater sciatic foramen. It crosses the spine of the ischium and reenters the pelvis through the lesser sciatic foramen. It passes through the pudendal canal.

The pudendal nerve gives off the inferior rectal nerves. It terminates into 2 branches: perineal nerve, and the dorsal nerve of the penis or the dorsal nerve of the clitoris.

Question 66

87- A 67 year old man is due to undergo a revisional total hip replacement using a posterior approach. After dividing gluteus maximus in the line of its fibres there is brisk arterial bleeding. Which of the following vessels is likely to be responsible?

Answer 66

Inferior gluteal artery

The inferior gluteal artery runs on the deep surface of the gluteus maximus muscle. It is a branch of the internal iliac artery. It is commonly divided during the posterior approach to the hip joint.

Question 67

91- A 34 year old man is shot in the postero- inferior aspect of his thigh. Which of the following lies at the most lateral aspect of the popliteal fossa?

Answer 67

Common peroneal nerve

the content of the popliteal fossa from Medial to latral:
Popliteal artery
Popliteal vein
Tibial nerve
Common peroneal nerve

The sural nerve is a branch of the tibial nerve and usually arises at the inferior aspect of the popliteal fossa. However, its anatomy is variable.

Question 67

88- A 76 year old man complains of symptoms of claudication. The decision is made to measure his ankle brachial pressure index. The signal from the dorsalis pedis artery is auscultated with a hand held doppler device. This vessel is the continuation of which of the following?

Answer 67

Anterior tibial artery

The dorsalis pedis is a continuation of the anterior tibial artery.

Question 68

90- What is the origin of the superior gluteal artery?

Answer 68

Internal iliac artery

The inferior gluteal artery arises from the anterior trunk of the internal iliac artery
The superior gluteal artery arises from the posterior trunk of the internal iliac artery

Question 68

89- Which of the nerves listed below is responsible for the innervation of gluteus maximus?

Answer 68

Inferior gluteal nerve

Question 69

92- Which of the following forms the medial wall of the femoral canal?

Answer 69

Lacunar ligament

The femoral canal and the femoral triangle are distinct anatomical structures. Do not confuse them, especially in the time pressured exam situation.

Question 70

94- Which of the structures listed below inserts into the site labelled in the image.

Answer 70

Psoas major

Psoas major inserts into lasser trochanter

Question 70

93- A 56 year old man undergoes a low anterior resection with legs in the Lloyd-Davies position. Post operatively he complains of foot drop. Which nerve has been injured?

Answer 70

Common peroneal nerve

Positioning legs in Lloyd- Davies stirrups can carry the risk of peroneal nerve neuropraxia if not done carefully.

Question 71

95- During a block dissection of the groin, the sartorius muscle is identified. What is the nerve supply to this muscle?

Answer 71

Anterior division of the femoral nerve

Sartorius is supplied by the anterior (superficial) branch of the femoral nerve.

Most of the branches of the superficial femoral nerve are cutaneous. However, it does also supply sartorius.

Question 71

96- A 34 year old man is injured by farm machinery and sustains a laceration at the superolateral aspect of the popliteal fossa. The medial aspect of biceps femoris is lacerated. Which of the following underlying structures is at greatest risk of injury?

Answer 71

Common peroneal nerve

The common peroneal nerve lies under the medial aspect of biceps femoris and is therefore at greatest risk of injury. The tibial nerve may also be damaged in such an injury (but is not listed here). The sural nerve branches off more inferiorly.

Question 71

97- A 20 year old lady presents with pain on the medial aspect of her thigh. Investigations show a large ovarian cyst. Compression of which of the nerves listed below is the most likely underlying cause?

Answer 71

Obturator

The cutaneous branch of the obturator nerve is frequently absent. However, the obturator nerve is a recognised contributor to innervation of the medial thigh and large pelvic tumours may compress this nerve with resultant pain radiating distally.

Question 72

98- A 72 year old man develops a foot drop after a revision total hip replacement. Which nerve is likely to have been affected?

Answer 72

Sciatic

Whilst many of these nerves can be injured in hip surgery, for a foot drop to develop in this context (i.e. revision THR), the sciatic nerve is the most likely.

Question 73

99- A 45 year old motor cyclist sustains a tibial fracture and is noted to have anaesthesia of the web space between his first and second toes. Which of the nerves listed below is most likely to be compromised?

Answer 73

Deep peroneal nerve

The deep peroneal nerve lies in the anterior muscular compartment of the lower leg and can be compromised by compartment syndrome affecting this area. It provides cutaneous sensation to the first web space. The superficial peroneal nerve provides more lateral cutaneous innervation.