All dead or devitalized bone must be identified by the preoperative injection of sulphan blue which stains all living tissue green, leaving dead material unstrained in
**Core Concept**
The preoperative injection of sulphan blue is a technique used to identify dead or devitalized bone in orthopedic surgery. This method relies on the principle of differential staining, where living tissue is stained green while dead or devitalized tissue remains unstained. Sulphan blue is a vital dye that selectively stains living bone, allowing surgeons to distinguish between viable and non-viable tissue.
**Why the Correct Answer is Right**
The selective staining of living tissue by sulphan blue is due to its ability to penetrate and bind to the osteoid matrix of healthy bone. This process is facilitated by the presence of enzymes such as alkaline phosphatase, which helps to break down the extracellular matrix and allow the dye to penetrate the bone tissue. As a result, living bone is stained green, while dead or devitalized bone remains unstained.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because sulphan blue is not typically used for this purpose in orthopedic surgery.
**Option B:** Incorrect because this option does not accurately describe the mechanism of action of sulphan blue.
**Option C:** Incorrect because this option is not relevant to the use of sulphan blue in preoperative bone identification.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that sulphan blue is a vital dye, which means it stains living tissue. This property makes it an excellent tool for identifying dead or devitalized bone in orthopedic surgery.
**Correct Answer: C.