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



Basic Science



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

Achilles Tendon Rupture

AnatomyAchilles tendon anatomy


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