All the following are causes of nonunion except
|A||Distraction and separation of fragments|
|B||Interposition of soft tissues|
|C||Excessive movement at the fracture site|
|D||Immobilization` of one joint above and one below|
Immobilization` of one joint above and one below
a. Immobilization of one joint above and one below is of course one of the basic principles of orthopaedics.
b. Other causes of nonunion are poor blood supply, infection, bone loss, soft tissue loss and some times in tact other bone as in the leg, intact fibula is supposed to cause a tibial non-union.