Hi there There can be many factors responsible for non union of fracture like too large space for bony remodelling to bridge, Interposition of periosteum, muscle or cartilage, Bony site with limited or less blood supply and more. If fracture won't unite after 6 months it my be considered in as delayed or non union of fracture.
These approaches can be effective after non union: Non-surgical approaches
Early weight bearing and casting may be helpful for delayed union and non-union. Bone stimulation can sometimes be used. This delivers pulsed ultrasonic or electromagnetic waves to stimulate new bone formation. It needs to be used for up to an hour every day, and may take several weeks to be effective.
Medical treatments such as teriparatide
have also been used to promote fracture healing, particularly in patients with osteoporosis.
Debridement to establish a healthy infection-free vascularity at the fracture site.
Bone grafting to stimulate new callus formation. Bone may be taken from the patient or may be cadaveric.
substitutes/osteobiologics. Internal fixation to reduce and stabilise the fracture.
Depending on the type of non-union, any combination of the above procedures.