Non – union is a complication of:
**Core Concept**
Non-union is a complication of bone fracture healing where the bone fails to properly unite with the surrounding tissue, resulting in a persistent fracture gap. This condition is often caused by inadequate blood supply, infection, or improper immobilization of the affected bone.
**Why the Correct Answer is Right**
Non-union is commonly seen in fractures with significant comminution or segmental bone loss. This is because the bone fragments are unable to maintain contact, leading to a lack of stability and a failure in the fracture healing process. In such cases, the body's ability to form a callus and eventually a bony union is compromised. The lack of blood supply and the presence of a fracture gap further exacerbate the problem, making it challenging for the bone to heal properly.
**Why Each Wrong Option is Incorrect**
* **Option A:** While osteoporosis can increase the risk of fractures, it is not a direct cause of non-union.
* **Option B:** Malunion refers to a bone fracture that heals in an abnormal position, but it is not the same as non-union.
* **Option C:** Delayed union is a condition where bone healing is slower than expected, but it is still a potential for bony union to occur.
**Clinical Pearl / High-Yield Fact**
In cases of non-union, the management often involves surgical intervention, such as bone grafting or the use of internal fixation devices to stabilize the bone fragments and promote healing.
**Correct Answer:** D.