**Question:** Which of the following is commonest material used to make orthopedic implant?

A. Titanium
B. Polyethylene
C. Ceramic
D. Stainless Steel

**Core Concept:** Orthopedic implants are medical devices that are surgically inserted into the human body to support, replace, or stabilize a damaged or diseased bone, joint, or soft tissue. These implants are primarily made of materials that are biocompatible, strong, and have low friction for smooth joint movement.

**Why the Correct Answer is Right:** Among the options provided, Titanium (A) is the most common material used for orthopedic implants. Titanium exhibits excellent biocompatibility, corrosion resistance, and strength. It is lightweight, which reduces stress on surrounding tissues and allows for better patient mobility. Titanium's ability to form a stable bond with bone through a process called osseointegration enhances implant stability and reduces the risk of infection and rejection.

**Why Each Wrong Option is Incorrect:**

- Polyethylene (B) is frequently used for artificial joint linings, such as in total hip and knee replacements. However, it is not as common as Titanium for structural implants due to its lower strength and increased friction compared to Titanium.

- Ceramic (C) materials, like Alumina or Zirconia, are used for joint surfaces, particularly in total hip replacements. However, they are less common for structural implants due to potential brittleness, wear, and the need for a stronger joint surface material.

- Stainless Steel (D) is commonly used for fixation devices, such as screws and plates, due to its strength and resistance to corrosion. However, it is not as common for structural implants as Titanium, as it is heavier and may cause more stress on surrounding tissues, leading to potential complications.

**Clinical Pearl:** Titanium's superior properties make it a preferred choice for orthopedic implants, ensuring better osseointegration, reduced complications, and improved patient outcomes.