T&O - Lower Limb Neurovasculature Flashcards
1
Q
Avascular Necrosis of Hip: Dx and Presentation
A
- Defined as death of bone tissue secondary to loss of the blood supply.
- Leads to bone destruction and loss of joint function.
- Most commonly affects the epiphysis of long bones such as the femur.
- Features
- Initially asymptomatic
- Pain in the affected joint
- Features
2
Q
Causes of AVN of Hip
A
- Long-term steroid use
- Chemotherapy
- Alcohol excess
- Trauma
3
Q
AVN: Ix and MX
A
- MRI is the investigation of choice
- X-Ray normal initially.
- Osteopenia and microfractures may be seen early on.
- Collapse of the articular surface may result in the crescent sign
- Management: Joint replacement may be necessary
4
Q
Leriche Syndrome: Dx, Ix, Mx
A
- Definition: Atheromatous disease involving iliac vessel so blood flow to pelvic viscera is compromised
- Diagnostic test: Angiography where feasible
- Managment: Endovascular angioplasty and stent insertion
5
Q
Leriche Syndrome presentation
A
- Claudication of the buttocks and thighs
- Atrophy of the musculature of the legs
- Impotence (due to paralysis of the L1 nerve)
6
Q
Iliopsoas Abscess: Dx
A
- Psoas abscess is a collection within the psoas muscle
- Psoas muscle extends from T12 - L5 caudally, inserting on the lesser trochanter of the femur.
- Left untreated it can lead to septicaemia and multi organ failure.
7
Q
Iliopsoas Abscess: Risk Factors
A
- HIV
- Cancer
- Diabetes
- IV drug user
- Previous surgery
- Tuberculosis
8
Q
Causes of Iliopsoas Abscess
A
- Primary
- Haematogenous spread of bacteria
- Staphylococcus aureus: most common
- Haematogenous spread of bacteria
- Secondary
- Crohn’s (commonest cause in this category)
- Diverticulitis
- Colorectal cancer
- UTI, GU cancers
- Vertebral osteomyelitis
- Femoral catheter, lithotripsy
- Endocarditis
9
Q
Iliopsoas abscess: presentation
A
- Fever
- Back/flank pain
- Limp
- Weight loss
10
Q
Iliopsoas abscess: examination findings
A
- Patient in the supine position with the knee flexed and the hip mildly externally rotated
- Specific tests to diagnose iliopsoas inflammation:
- Place hand proximal to the patient’s ipsilateral knee and ask patient to lift thigh against your hand. This will cause pain due to contraction of the psoas muscle.
- Lie the patient on the normal side and hyperextend the affected hip. In inflammation this should elicit pain as the psoas muscle is stretched.
11
Q
Iliopsoas abscess: Ix
A
- CT is the gold standard (MRI sometimes)
- X-Ray: useful for ruling out differentials.
- Bloods to evidence infection and a complete septic screen if systemic inflammatory response syndrome criteria are met.
12
Q
Iliopsoas abscess: Mx
A
- Antibiotics
- Percutaneous drainage
- Surgery is indicated if:
- Failure of percutaneous drainage
- Presence of another intra-abdominal pathology which requires surgery
13
Q
Meralgia paraesthetica: Dx
A
Syndrome of paraesthesia or anaesthesia in the distribution of the lateral femoral cutaneous nerve (LFCN) due to entrapment mononeuropathy of the LFCN, but can also be iatrogenic after a surgical procedure, or result from a neuroma.
14
Q
LFCN anatomical relations
A
- Originates from the L2/3 segments.
- Passes behind the psoas muscle
- Runs beneath the iliac fascia as it crosses the surface of the iliac muscle and eventually exits through or under the lateral aspect of the inguinal ligament.
- Nerve curves medially and inferiorly around the anterior superior iliac spine (ASIS), it may be subject to repetitive trauma or pressure as it passes
- Compression of this nerve can lead to the development of meralgia paraesthetica.
15
Q
Meralgia paraesthetica: Epidemiology
A
- Majority of cases occur in people aged between 30 and 40.
- Both legs may be affected
- More common in men than women. Occurs more commonly in those with diabetes than in the general population.
