O&T SC054: My Foot Hurts: Foot Problems Flashcards
Acute ischaemia of lower limb
Causes:
1. Embolism (usually cardiac source)
- Tend to lodge at bifurcations: Common femoral artery (giving SFA, PFA), Distal aorta (giving R + L common iliac —> Saddle emboli)
- ***Predisposing conditions: AF, Recent MI, Valvular heart disease
- Thrombosis
- ***Pre-existing LL arterial occlusive disease (i.e. atherosclerosis)
- Previous bypass (e.g. anastomotic stenosis of bypass —> suddenly occluded with thrombosis)
- Acute dissection (thrombosis in false lumen can compress on true lumen)
- Popliteal artery aneurysm (unlike AAA, PAA seldom rupture but can thrombosis) - Vascular trauma
S/S (6”P”s):
1. Pain
2. Pallor
3. Paresthesia
4. Paralysis
5. Pulseless
6. Perishing cold
Diagnosis: ***Clinical!!!
1. History
- Predisposing factors
—> Emboli: AF, Recent MI, Valvular heart disease
—> Thrombosis: Claudication, Previous bypass
- P/E
- Absent pulses
Investigations:
1. Angiography
- **Not used for diagnosis (∵ invasive)
- **Filling defect
—> Embolism: smooth contour of artery with sudden filling defect
—> Thrombosis: irregular contour of artery due to pre-existing atherosclerosis
- Duplex USG
Management:
- **Emergency —> revascularisation within **4-6 hours —> delay will cause irreversible damage to muscle + nerve —> loss of limb / loss of life
- Prompt diagnosis + treatment
- Anticoagulant
- Heparin (prevent further propagation of thrombus) - Surgery
- Embolectomy (Fogarty catheter) / Bypass - Endovascular intervention
- Thrombolysis / Thrombectomy
- +/- Angioplasty / Stent
Complications:
1. ***Compartment syndrome (∵ period of ischaemia —> damage to muscle —> increase vascular permeability —> reperfusion —> extravasation of fluid —> swelling)
- Prophylactic Fasciotomy
-
**Electrolytes imbalance (∵ **Rhabdomyolysis)
- HyperK -
**Renal failure (∵ **Rhabdomyolysis)
- Myoglobin deposit in renal tubules
- Adequate hydration + monitor urine output
Thrombolysis
- Catheter-directed intra-arterial local infusion
- Streptokinase, Urokinase, tPA
- +/- Adjunctive endovascular procedure (e.g. Angioplasty / Stent)
- Also useful in embolism
- Effective alternative treatment
- Takes time (need to monitor progress of thrombolysis)
- Require Interventional radiologist / facilities
- May need further procedure-bypass, angioplasty
- Risk of bleeding esp. Intracranial bleeding: 1%
Thrombectomy
Percutaneous mechanical thromboembolectomy:
4 functions:
1. Fragmentation of aspirated material
2. Detachment of occlusive material from vessel
3. Aspiration of detached material into catheter head
4. Transportation out of patient’s body
- +/- Adjunctive thrombolysis / Endovascular procedure (e.g. Angioplasty / Stent)
- vs Embolectomy with Fogarty catheter (Need to open up artery)
Arterial injury
Penetrating injury:
- Distal pulse may be normal
- In doubt: Angiography
Blunt injury:
- Adjacent to fractures (e.g. posterior dislocation of knee) —> Arteries compressed / contused —> Intimal tear —> Thrombosis
- Often delayed diagnosis (∵ only pay attention to MSS injury)
- Arterial spasm due to injury: should only be diagnosed at operation after exclusion of other causes (e.g. thrombosis)
- In doubt: Angiography
Chronic ischaemia of lower limb
Causes:
1. Atherosclerosis —> Stenosis
(2. Vasculitis)
S/S:
1. Intermittent claudication
2. Rest pain
3. Tissue loss (gangrene / ulcer)
History:
1. Other manifestations of Atherosclerosis
- IHD / Stroke / TIA
- Risk factors
- Smoking - Occupation
P/E:
Inspection:
1. Colour change
2. Trophies change
3. Tissue loss
Palpation:
1. Temperature
2. Weak / Absent Pulses (Femoral, Popliteal, Posterior tibial, Dorsalis pedis)
3. Vessel wall
Auscultation:
1. Bruit (Carotid + Femoral + Renal)
Investigations:
Non-invasive:
1. Doppler USG
- Ankle-brachial index
- Segmental BP
- Waveform analysis
- Duplex scan
Invasive:
3. Angiography
Others:
4. CT / MR angiogram
Management:
1. Conservative
- Stop smoking
- Weight reduction
- Exercise program (graded)
- Risk factor control
- Drugs:
—> Aspirin (survival improvement)
—> Cilostazol, Naftidrofuryl (symptom improvement)
- Surgery
- Balloon angioplasty / stenting
- Bypass
- Endarterectomy (local procedures)
***Clinical evaluation of Foot / Ankle disorders
- Presentation / HPI
- Traumatic —> Injury
- Non-traumatic —> Pain, Swelling / Lump, Deformity, Ulcer, Skin and nail changes
- Systemic / Bilateral involvement (suggest inflammatory nature)
- Mechanical vs Inflammatory pain
- Onset
- Associated symptom
- Function: Walking ability, ADL, Occupation, Shoewear, Foot care - Site
- Anatomy
- Function - P/E
- Sit
- Stand
- Walk (gait abnormality)
Anatomy of Foot / Ankle
Components:
1. Ankle
2. Foot
- Hindfoot (Talus, Calcaneus)
—> Midtarsal joint (Chopart’s joint)
- Midfoot (Navicular, Cuboid, Medial / Intermediate / Lateral Cuneiform)
—> Tarsometatarsal joint (Lisfranc joint —> Lisfranc fracture)
- Forefoot (Metatarsals, Phalanges)
Ankle:
- True ankle joint: Joint formed by Tibia (Medial malleolus), Fibula (Lateral malleolus), Talus
- Subtalar joint: Joint formed by Talus and Calcaneus
Surfaces:
1. Dorsal
2. Plantar
3. Medial
4. Lateral
Sitting P/E
Look:
1. Shape
2. Skin (e.g. ecchymosis)
3. Dorsal + Plantar (e.g. callosity, skin changes, ulcers)
Feel:
1. Tenderness
2. Pulse
3. Lump
4. Neuropathy
Move:
1. ROM (ankle + subtalar + MTP joint)
2. Stability
3. Power
Special tests:
1. **Anterior drawer test
2. **Talar tilt test
Standing P/E
Look:
1. Front
2. Back (e.g. Valgus / Varus deformity of hindfoot)
3. Shoewear inspection
Feel:
- Repeat if necessary
Move:
1. Heel raise (i.e. stand on toe)
2. Toe raise
Flat foot
Flexible: Valgus deformity of hindfoot but disappear when heel raise —> Common in children
Fixed: Fixed valgus deformity —> Indicate some pathology in foot and ankle region
Walking P/E
4 phases:
- Heel strike —> Mid-stance —> Push off —> Swing
- Pain
- Stiffness / Deformity
- Weakness
- Instability
- Lower limb malalignment
Classification of Foot / Ankle disorders
- Traumatic / Non-traumatic
- Traumatic: Fracture, Dislocation, Soft tissue injury - Urgent / Impending / Elective
- Urgent: Compartment syndrome, Dislocation, Fracture
- Impending: Infection (e.g. Cellulitis, Abscess), Ischaemia (e.g. PVD) - Systemic / Local
- Systemic: Neurovascular, Endocrine / Metabolic (e.g. Diabetic foot), Rheumatic (e.g. RA), Haematological
- Local: Arthritic, Degenerative, Post-traumatic, Overuse, Tumour - Adult / Paediatric
Inversion vs Eversion ankle sprain injury
Inversion ankle sprain injury:
Soft tissue injury:
1. Anterior talofibular Ligament (ATFL)
2. Posterior talofibular ligament (PTFL)
3. Calcaneofibular ligament (CFL)
—> Partial / Complete tear
Bone injury:
1. Lateral malleolus (Distal fibula) (avulsion)
2. Medial malleolus (Distal tibia) (push fracture)
3. 5th Metatarsal base fracture (3 zones: Stress, Jones, Avulsion)
Eversion ankle sprain injury:
1. Deltoid ligament (a collective group of ligaments)
***Orthopaedic emergency of Foot / Ankle
- Compartment syndrome of foot
- Clinical diagnosis
- High energy injury
- Associated with Calcaneal fracture, Midfoot fracture dislocation
- Pain out of proportion to bony injury
- Ecchymosis, tight skin, diminished sensation
- Emergency decompression - Dislocation
- ***All dislocation should be reduced immediately
- e.g. Peri-talar dislocation - Fracture
- Can cause Skin impingement + Skin breakdown —> become Open fracture —> infection + sepsis
- Some fracture need immediate reduction + fixation
- e.g. Fracture talus neck —> Avascular necrosis - Talar neck fracture —> AVN
Diabetic foot
- Neuropathy / Vasculopathy in 30% DM patients
- Reduced resistance to infection
- Neuropathic arthropathy in 1%: midfoot
- Osteoporosis
- May ultimately lead to amputation
