Foot and ankle problems Flashcards
Compartment syndrome
Trauma to fascial compartment = haemorrhage or oedema = increase in intra-compartmental pressure
Short term consequences of compartment syndrome
- Increased pressure = decreased muscle perfusion
- Ischaemic muscle releases mediators = further increase cap permeability and rise in intra-compartmental pressure
- Severe untreated = muscle necrosis resulting in acute kidney injury
Short term neurovascular signs of compartment syndrome
- Loss of peripheral pulses and increased cap refill time
- Nerves susceptible to ischaemia
- Thin cutaneous affected more quickly than motor fibres = distal paraesthesia then loss of motor function
Long term consequences of compartment syndrome
- Muscle necrosis can cause chronic kidney injury
- Volkmann’s isachaemic contracture = permanent and painful contracture of affected muscle groups
Rhabdomyolysis
Muscle necrosis
Causes of ankle fractures
- Inversion or eversion injury
- Co-morbities - diabetes, neuropathy, peripheral vascular disease, smoking make fracture healing longer
Fracture blisters
Blister in overlying soft tissue of ankle fracture
- Delay surgery until they have healed
- If skin has become necrotic take longer to heal
Open ankle fractures
Fracture direct communication w external environment
Surgery w extensive irrigation and debridement (removal of foreign bodies) to reduce risk of osteomyelitis (bone infection)
Single fracture effect on ring
Ankle joint and ligaments = ring
Single fracture = in association w ligament damage somewhere else in the ring
Talar shift
Disruption of any 2 of either medial, lateral or syndesmosis ligaments = unstable ankle mortise
Mortise widens = talus can shift in joint
Treatment of stable ankle fractures
Aircast boot or fibreglass case
Can weight bear and low rate of complications
Treatment of unstable ankle fractures
Surgical stabilisation
High risk if have diabetes or peripheral vascular disease
Ankle sprain
Partial or complete tear in one or ligaments of ankle joint due to excessive strain on them.
Most heal w rest and time or will have late ankle instability and may need surgery.
Risk factors of ankle sprain
- Weak muscles or tendons crossing ankle joint
- Weak or lax ankle ligaments
- Inadequate joint proprioception
- Slow neuromuscular response to an off-balance position
- Running on uneven surfaces
- Shoes w inadequate heel support or wearing high heels
Most common mechanism of injury in ankle sprain
Inversion injury - anterior talofibular ligament most at risk
Severe ankle sprain and fracture of 5th metatarsal tuberosity
Brevis tendon attached to base of 5th metatarsal - in inversion injury is under tension and can pull off a fragment of bone
Causes of Achilles tendon rupture
- Forceful push off w extended knee
- Fall w foot outstretch and ankle dorsiflexed
- Falling from heigh or abruptly stepping into hole or off curb
Symptoms and signs of Achilles rupture
- Sudden pain in back of ankle or calf
- Sound of pop/snap
- Palpable gap in tendon
- Initial pain and swelling then bruising
- Inability to stand on tip toe or push off when walking
Treatment of Achilles rupture
Surgical reconstruction difficult = two ends frayed
- Aircast boot w foot in correct position
- Surgery also high risk as skin thin and poorly vascularised
Hallux valgus
Common cause of bunion
- Varus deviation of first metatarsal
- Valgus deviation of hallux (big toe)
Cause of hallux valgus
- Trauma
- Arthritis - rheumatoid or psoriatic
- Gout
- Connective tissue disorders that cause lax ligaments eg. Ehlers Danlos syndrome
Treatment of hallux valgus
Metatarsal osteotomy = cut through bone and then realign the fragments
Never for cosmetic reasons
Hallux rigidus
OA of first MTPJ caused by gout and previous septic arthritis
Symptom of hallux rigidus
Pain on walking and dorsiflexion of toe - walk on outside of foot to compensate
May look like there is a bunion
