Pseudoarthrosis. Bone plasty.

Question 1

what is the cause of nonunion ?

Answer 1

excessive mobilisation or distractive forced by muscles pulling on the fragment at fracture site 
not enough blood supply 
not enough compression 
not enough bone to bone contact 
Soft tissue interposition

smoking
diabetets
obesity
infection

Question 2

how can we say the fracture is non union

Answer 2

it is not before 6 months that a fracture can be declared as non-union. It is often difficult to say whether the fracture is in delayed union, or has gone into non- union

Question 3

what are the different types of nonunion ?

Answer 3

Atrophic, where there is minimal blood supply
the ends of the fracture become osteoporotic and atrophic
minimal or no callus formation

hypertrophic - vascular with abundant abundant callus but does not bridge the fracture site
result from mobility- there is a lot of callus

Question 4

which ar the common sites of non union ?

Answer 4

are neck of the femur, proximal scaphoid,
lower third of the tibia,
lower third of the ulna
lateral condyle of the humerus

Question 5

what are the treatment for nonunion ?

Answer 5

operative
open reduction and internal fixation with plate with bone graft which can be

autologous (bone harvested from the patient’s own body, often from the iliac crest)

allograft (cadaveric bone usually obtained from a bone bank)

Alloplastic grafts or bone graft substitutes may be made from hydroxylapatite in combination with Tricalcium phosphate which are the natural mineral found in the bone

A synthetic material may be used as a temporary antibiotic spacer

Question 6

why is the iliac crest used

Answer 6

The iliac crest has a large amount of red bone marrow having high regenerative capabilities