The foot and ankle Flashcards
How is the ankle joint formed?
articulation between the distal tibia and fibula with the talus
What 2 movements does the synovial hinge joint allow?
dorsiflexion
plantarflexion
What is the osteoology of the ankle?
- tibia
- fibula
- medial malleolus - distal tibia
- talus
- lateral malleolus - distal fibula
- calcaneus - heal bone
- fibular trochlear
- cuboid
- groove
- navicular
- cuneiforms
What is the stability of the ankle joint like?
it is stable
What makes the ankle joint stable?
- good congruity between malleolar mortice and trochlea - the malleoli grip the talus
- involves strong ligaments
What ligaments make the ankle joint stable?
- distal part - interosseous membrane
2. anterior and posterior tibiofibular ligaments
Where is the trochlea wider?
wider anteriorly than posteriorly
What is the movement of the trochlea during dorsiflexion and what does this movement do to the tibia and fibula?
the anterior part of the trochlea moves between the malleoli
spreads the tibia and fibula slightly increasing their grip on the talus
What is the most stable position of the ankle?
dorsiflexion
What are the lateral ligaments of the ankle joint that contribute to stability?
- posterior talofibular ligament
- anterior talofibular ligament
- calcaneofibular ligament
What is the weakest ligament of the ankle joint?
Calcaneofibular ligament
What is the medial ligament attached to and where does it fan out to?
- attaches to the medial malleolus
- fans out to attach to talus, navicular and calcaneus
What is the medial ligament also called?
deltoid ligament due to it’s resemblance to the greek letter delta
What are the movements of the ankle joint? (4)
- dorsiflexion
- plantarflexion
- inversion
- eversion
What muscles does dorsiflexion involve and what nerve and artery are these muscles supplied by?
muscles of the anterior compartment of the leg
deep fibular (perineal) nerve
anterior tibial artery
What muscles does plantar flexion involve and what nerve and artery are these muscles supplied by?
muscles of the posterior compartment of the leg - except popliteus
supplied by the tibial nerve
posterior tibial artery
Where does inversion and eversion usually occur?
- at subtler joint - with some movement in the transverse tarsal joint
Where does the subtler joint lie?
between the talus and underlying calcaneus
What type of injuries are most ankle sprains? (inversion or eversion?)
inversion injuries
with twisting of the plantar-flexed foot
What ligament is usually injured in an ankle sprain?
lateral ligament
How quickly do ligaments heal in ankle sprains and why?
they heal slowly
as ligaments are relatively avascular
What happens to the growth and strength of a ligament when it is detached from bone?
fibres don’t grow back into the bone as extensively
healed ligament is usually weaker
What do torn ligaments predispose the ankle joint to and why?
They predispose the ankle joint to dislocation
As the ankle joint is less stable
Which ligament is weaker - the lateral or medial ligament and which part in particularly?
the lateral ligament
particularly the anterior talofibular part
What do you look for in a normal ankle joint x ray?
- even joint space all the way
What can been seen on a x ray of a patient with osteoarthritis?
loss of joint space
loss of cartilage space
contour of talus is gone
What types of fractures can you have at the ankle joint?
- fracture at distal fibula - lateral malleolar fracture
- left ankle bimalleolar fracture
- open fracture of lateral side of leg
- fracture of fibula
What type of dislocation can you have at the ankle joint?
- anterior dislocation of the distal talus of the tibia
What ligament can an eversion injury pull on and avulse and how can this fracture the fibula?
pull on strong medial ligament
causes avulsion of medial malleolus
fracture of fibula - lateral rotation of the talus
How common are eversion injuries?
not very common
Where does the force come from in an eversion injury?
on medial aspect of the ankle
What is the role of the foot? (3)
- support and transmit body weight
- act as a lever to propel body weight
- act as a resilient spring to absorb shock
What would happen to the about of force generated with impact on ground if the foot was rigid?
the force generated would be large
What makes the foot able to deform to absorb shock and adapt to uneven surfaces?
the fact that it is a series of small bones and ligaments
What is the osteology of the foot?
- calcaneus
- talus
- navicular
- cuneiforms
- metacarpals
- phalanges
What are the joints of the foot?
- naviculo-cuneiform joints
- tarsometatarsal joints
- metatarsophalangeal joints
- interphalangeal joints
On an x ray what would you see on a patient with gout?
build up of uric acid on the first big toe
1st metatarsal phalangeal joint
What would you see on an x ray of the foot on a patient with gout?
Reduce space in interphalangeal joint
What would you see in a patient with rheumatoid arthritis on an X ray?
metarsophalangeal joints and interphalangeal joints affected
What is the medical term for a bunion?
Halux valgus
How the arches of the foot contribute to stability/what is their role?
- help distribute weight acting as shock absorbers
- increase flexibility of the foot
- act as springboards for propulsion during walking, running and jumping
What are the 3 arches of the foot?
- medial longitudinal - MLA
- lateral longitudinal - LLA
- transverse - TA
What bones does the medial longitudinal arch compromise of? (5)
- calcaneus
- talus
- navicular
- 3 cuneiforms
- 3 medial metatarsals
In the medial longitudinal arch where is weight transmitted?
Through the talus to the calcaneus and metatarsal heads
Which arch is higher and more important the lateral longitudinal arch or medial longitudinal arch?
medial longitudinal arch
What bones make up the lateral longitudinal arch?
- calcaneous
- cuboid
- lateral 2 metatarsals
What bones make up the transverse arch?
- cuboid
- 3 cuneiforms
- bases of the 5 metatarsals
What would the weight of the body do to the arches if they were not supported?
would flatten the arches
How is the stability of the arches maintained? (2)
- passive - includes ligaments and shape of the bones
2. dynamic- intrinsic and extrinsic muscles of the foot
What is pes planus?
Flat foot
can be asymptomatic
What age groups is pes planus seen in?
adults and adolescents
What are the 2 types of pes planus?
- flexible
2. rigid - fusion of tarsal bones
What is flexible pes planus?
- more common
2. arch is present when not weight bearing and absent when standing
What is pes planus caused by?
loose or degenerating ligaments
What can exacerbate pes planus?
gaining weight
spending a long time standing
What is the treatment for pes planus?
orthotics - specilaised insoles
What problems can pes planus cause?
- displacement of the talus infer-medially
- misalignment of ankle and knees causing pain in these areas
- can decrease shock absorption by the foot leading to lower back pain
What are the movements of the toes of the foot and what joints do they occur at?
- flexion - metatarsophalangeal joints and proximal and distal interphalangeal joints
- extension - metatarsophalangeal joints and proximal and distal interphalangeal joints
- abduction - limited - at metatarsophalangeal joints
- adduction - relaxed position - limited - metattarsopahlangeal joints
What injuries can occur to the foot?
- dislocated toes
- communitive fracture
- oblique fractures
- stress fractures - running
- fracture at bases of metatarsophalangeal joints
- lisfranc injury - disruption of mid foot when foot is thrown forwards like in horse riding and is easy to miss on x rays
- fracture of calcaneus - jumping or falling from a height
