Non-union
- arrest of progression to union at fracture site
- > 6-9 /12
- no visible progressive signs of healing for at least three consecutive months
- individualise for each fracture
- when the surgeon believes the fracture has little or no chance to heal
Delayed union
- failure of fracture to unite within expected time
- still may spontaneously unite
Very high frequency sound waves
- 3 - 15 MHz
Piezoelectric effect
- run electric current through a crystal
- produces ultrasound waves
Density of substance determines velocity of the US
- reflected back to the probe at different velocities
- converted into 2D image on monitor
Virchow's Triad
1. Venous stasis
2. Hypercoagulability
3. Endothelial damage
Starts as platelet nidus at valves
- thrombogenic materials elaborated by platelets
- leads to development of fibrin thrombus
- thrombus grows
Thrombus may
- detach as embolus
- be completely dissolved / recanalise
- organise with valve incompetence
Mid-substance calcification of the rotator cuff
- part of a metaplasia secondary to hypoxia
2 groups of patients
Increased pressure within a closed fibro-osseous space
Seen in athletes, associated with repetitive exertion
Leg
1. Anterior compartment
- anterior tibial artery
- deep peroneal nerve
Gastrocnemius tendon 10-25 cm long
- soleus 3-10 cm
- inserts superior calcaneal tuberosity
- fibres spiral 90°
- fibres that lie medially in proximal portion become posterior distally
- allows elastic recoil & energy storage
Plantaris present in 90% population
- medial to T Achilles
Poor blood supply midportion
- mesotenal vessels