Osseous canal between talus and calcaneum
- interosseous talo-calcaneal ligament
- cervical ligament
- joint capsule
- nerve endings / arterial anastomoses
Flat foot / overpronation
Inversion / sprain
Bunion
- medial prominence of head of 1st MT
Hallux Valgus
- medial deviation 1st MT
- lateral deviation of great toe
Metatarsal head
- has 2 grooves separating ridge (cristae)
10%
70o swing phase
80o climb up stairs
90o climb down stairs + sit down in chair
100o low chair
Stiffness usually subsides at 6-8/52
- generally improves out to 3/12
- slow improvement for up to next 9/12
Knee > Hip
- superficial position
- limited cover of well vascularised muscle
- watershed area of skin blood supply anterior to the skin incision
- much increased in fully constrained prosthesis
Ideal < 1%
Increased with
- revision
- prior infection
- RA / Psoriatic arthropathy
- DM
Repeated dislocation of patella with minimal trauma
- 15-20% of paediatric acute patella dislocations
- more common girls
- often bilateral
Dislocation occurs unexpectedly when quadriceps contracted with knee in flexion
1. Loosening
2. Infection
3. Instability
4. Periprosthetic fracture
Biological response to particulate matter
- characterised by periprosthetic osteolysis
- stimulated by wear debris
- debris gains access to any area accessible by fluid
1. Wear
Mechanisms of wear
Adolescent apophyseal avulsion
- treat non operatively
- unless displaced > 2 cm
Adult
- soft tissue avulsion
Usually associated with sporting activities
- skiing
- water skiing
Violent contraction
- knee extended
- hip flexing
Usually young patients
- 15 - 40
15% compound
High velocity injury
- MBA
- MVA
- pedestrian v car
- fall from height
EMST principles
- need for transfusion not uncommon
Young men
Posterior / Anterior 9:1
High velocity injury
- head direction at impact decides direction of dislocation
Anterior Dislocation
Externally rotated & abducted leg
- flexion = inferior dislocation