Lower Limb Pathology

Question 1

Describe pelvic sagging.

Answer 1

• Weak hip abductors (gluteus medius and minimus)
• Leads to the pelvis sagging towards the elevated leg (instead of the inverse) opposite of the affected abductors.

Question 2

What is the positive sign for pelvic sagging?

Answer 2

Trendenlenberg’s sign.

Question 3

Describe trochanteric bursitis.

Answer 3

• Trochanteric bursa between gluteus medius and minimus is inflamed.
• Leads to lateral hip pain, especially when lying on affected side / getting up from chair.
• Also leads to tenderness over trochanteric bursa, but no significant reduction in ROM

Question 4

Describe piriformis syndrome.

Answer 4

• Piriformis impinging on sciatic nerve

Question 5

Describe avascular necrosis of hip bone.

Answer 5

• Ischaemia to femoral head causes bone necrosis

Question 6

Describe femoral neck fractures.

Answer 6

• Commonly due to osteoporosis
• Leads to damage of medial Cx femoral a.’s retinacular arteries, which can cause avascular necrosis of femoral head

Question 7

Describe dislocation of femur head.

Answer 7

• Commonly due to head-on automobile accidents
• Can cause sciatic nerve impingement

Question 8

Describe meralgia paresthetica.

Answer 8

• Impingement of LCN (thigh)
• Leads to tingling, numbness, or burning sensation over lateral thigh

Question 9

Describe referred pain for hip OA.

Answer 9

• Referred to the knee

Question 10

Describe femoral pseudoaneurysm.

Answer 10

• Caused by femoral a. catheterisation
• Blood may escape and become collected in a sac outside the artery
• Pulsatile mass with bruit, swelling / pain, diminished foot pulses

Question 11

Describe patellar dislocation.

Answer 11

• Patella may become dislocated due to lateral and upward pull of quadriceps
• Prevented by (1) medial pull of vastus medius is greater than lateral pull of vastus lateralis, (2) medial pull of medial patellar retinaculum, (3) forward projection of lateral femoral condyle

Question 12

Describe ACL injury.

Answer 12

• ACL injury is usually caused by MCL injury, which causes medial joint instability and strain
• Leads to anterior drawer sign (tibia moves forward, as ACL no longer holds it in place)

Question 13

Describe PCL injury.

Answer 13

• PCL injury is caused by MCL / LCL injury + falling on lateral joint
• Leads to posterior drawer sign (tibia moves backward, as PCL no longer holds it in place)

Question 14

Describe knee meniscus injury.

Answer 14

• Medial meniscus is prone to tearing, due to its fixed position
• Causes bucket handle meniscal tear

Question 15

Describe pes anserine bursitis.

Answer 15

• Inflammation of pes anserine bursa
• Leads to medial knee inflammatory signs

Question 16

Describe anterior talofibular ligament strain.

Answer 16

• Occurs due to excessive inversion of plantarflexed foot

Question 17

Describe pes cavus / planus.

Answer 17

• High arch / flatfoot, due to calf muscle weakness
• Pes planus is caused by tibialis posterior weakness

Question 18

Describe equinovarus.

Answer 18

• Fibular damage causes common fibular nerve palsy
• Results in dorsiflexors and evertors of foot not functioning
• Plantarflexed and inverted foot

Question 19

Describe calcaneovagus.

Answer 19

• Tibial damage causes tibial nerve palsy
• Results in plantarflexors and invertors of foot not functioning
• Dorsiflexed and everted foot

Question 20

Describe hallux valgus.

Answer 20

• Bunion (bony prominence of big toe’s MTP joint) + lateral deviation of big toe
• Commonly due to footwear

Question 21

Describe poliomyelitis.

Answer 21

• Infection caused by poliovirus, which is faecal-orally transmitted > replicates in respiratory and GIT epithelium > travels in bloodstream to attack spinal cord and brainstem
• Causes asymmetric flaccid paralysis, but no sensory deficit (ventral horn affected)
• Typically affects bulbar muscles, causing difficulty in speaking, swallowing, and chewing
• Causes muscle atrophy

Question 22

Describe peripheral neuropathy.

Answer 22

• Commonly caused by diabetes / Vitamin B12 deficiency
• Sensory neurons degenerated, leading to symmetric stocking distribution of sensory loss (starts distally, progresses proximally)