Osteoporosis Synthesis

Osteoporosis is most commonly diagnosed using bone densitometry. Various techniques are available to quantify bone mass but the most accurate and precise is the central dual-energy x-ray absorptiometry (DXA) scan. This test capable of measuring mineral content at any site in the body. The basic principles of the DXA scan is that beam of x-ray is generated and is allowed to pass through the area of interest which is usually spine or the hip. The density of the bone which usually determined by its calcium content, causes varying degrees of attenuation of the x-ray beam. As the beam passed through bone and soft tissue, two photoelectric peaks are quantified and the device is able to subtract the contribution of soft tissues to the measured density.

There are four distinct stages of bone remodeling, specifically, activation, resorption, reversal and formation. Activation is initiated by the recruitment of osteoclast precursors into the areas that need be absorbed. The precursor cells fuse to become preosteoclast cells and mature further into osteoclasts. Once activated, osteoclasts acidify and release resorptive enzymes leading to the formation of resorption cavities. After their job is accomplished, the osteoclast undergo apoptosis. This process proceed to the reversal stage, during which coupling signals are sent to attract osteoblast into resorptive sites. Resorption is then turned off and the formation stage follows. The osteoclasts synthesize bone matrix and facilitate its mineralization. Calcium and phosphate ion are deposited into the matrix, leading to hardening of the bone. Osteoblast undergo apoptosis, become encased within the mineralized matrix to become osteocytes or evolve into bone-lining cells. The osteocytes maintain communication with each other and likely played the role in sensing the areas that need to be remodelled, transmitting information to other cells, and initiating the bone-remodelling process. However, as we age daily remodelling

Osteoclasts are endowed with highly active ion channels in the cell membrane that pump protons into the extracellular space, thus lowering the pH in their