Case Study 1. What is meant by a "complete, comminuted, intertrochanteric fracture of the right hip"? A. Complete - refers to a fracture completely through the bone: B. Comminuted - refers to a fracture in which the broken bone has shattered into several smaller pieces: C. Intertrochanteric - refers to a fracture located between the greater trochanter and lesser trochanter of the femur: 2. Draw a picture of what you think Margaret's fracture looks like. 3. The radiologist reported signs of osteoporosis. Describe the characteristics of an osteoporotic femur as seen on an X-ray. (How does it differ in appearance from a normal femur?) Osteoporosis is marked by a decreased bone volume. Loss of spongy ("cancellous") bone is greater than …show more content…
cartilage-forming cells) and lay down a fibrocartilage splint (i.e. soft tissue callus) | C. bony callus(starting 3 to 4 weeksafter the injury) | - osteoblasts begin to replace the fibrocartilage splint with spongy and compact bone, forming a bulge that is initially wider than the original bony shaft | D. bone remodeling | - as the patient starts to use (or bear weight on) the bone, the bone starts to remodel along lines of maximal stress (this remodeling process requires the activity of both osteoblasts and osteoclasts | 7. During her long recovery, Margaret is advised by her physician to begin weight-bearing as soon as she can. How does weight-bearing influence the process you described in question #6? (Be specific in your answer and describe what weight-bearing does to bone at the microscopic level.) The most popular hypothesis regarding the effect of weight-bearing on bone remodeling is called Wolff's law . Wolff's law states that bone grows and remodels in response to the mechanical stresses placed upon it (e.g. from muscle pull or gravitational pull). Thus, bone is laid down along lines of maximal stress. This is presumably why: A. long bones are the thickest midway down the diaphysis, where the stresses are the greatest. B. curved bones are the thickest where they are most likely to buckle (e.g. note the thick greater
The bone mass and bone strength is decreased, due to loss of tissue. Due to the loss of bone strength and bone mass the bones are easier to break and fracture. The bone is formed on a protein base by the deposition of minerals that is particularly calcium. Out of
The bone remodeling process consists of continually removing older bone and replacing it with new bone and plays and important role in maintaining a healthy skeleton. A decrease in bone density occurs when this balance is altered, resulting in greater bone removal than replacement. This imbalance is seen greatly with advancing age and menopause. With the onset of menopause, the rate of remodeling increases and it increases the risk of fractures.
Bone is a living organism that is continuously regenerating its self through two stages (formation and resorption). In the resorption stage old bone is broken down then removed by cells. Then in the formation stage, new bone is built to replace the old by cells called osteoclasts. When the human body is younger more bone is produced than removed and as the body grows in age it’s the opposite also known as primary osteoporosis since it isn’t caused by other condition or long time medication.
Osteoporosis is the most frequent skeletal alteration. It is categorized as an atrophy of the bone tissue (Beskow 1997). It is a generalized, progressive diminution of bone tissue mass per unit volume, causing skeletal weakness, even though the ratio of mineral to organic elements is unchanged in the remaining morphologically normal bone. Histologically there is a reduction in cortical thickness and in the number and size of the trabeculae of cancellous bone, normal width of the osteoid seams. Bone reabsorption is increased; bone formation appears to be normal but defective (Bullock, 1984).
As the remodeling process that conducts by both of the cells is unstable, the bone tissues are affected too. Bones consists of two types of bones tissue which is compact bone and spongy bone. Compact bone also known as cortical bone is the hard outer layer of the bone and it is found beneath the periosteum. It provides support and protection and withstands the stress produce by weight and movement. Meanwhile, spongy bone also called as trabecular or cancellous bone is usually found at the end of the long bones. The spongy bone tissues have a honey-comb like structure. In osteoporosis, the bones tissue start to break down faster than it can regenerate. Hence, the bones tissue slowly lose their density and becomes thinner. Plus,the holes structure
Mature long bones consist of 3 distinct parts which are epiphysis, metaphysis and diaphysis. The epiphysis located at the both ends of long bone and composed of thin compact bone shell with a large amount of bony struts (trabecular bone) for supporting the cortical shell. In fact, the bony struts which located below the compact bone also aid as shock absorber. The thicker shell of compact bone which located just below a joint is known as the subchondral bone. It helps to support the hyaline articular cartilage of the joint just above it and have some lacks in organization of cortical bone as it is not true cortical bone. The epiphysis also serves as an attachment region in many bones includings joint capsular, ligaments, and some tendons.
Unlike engineering material, healthy bone can maintain its reliability by restoring the micro damage and remodeling itself. Bone remodeling follows two steps handled by the cells named osteoclast and osteoblast. Osteoclasts which digests the bone at a molecular level are responsible for the bone resorption. On the other hand, new bone is formed by a group of osteoblasts cell by cell. This process results bone to preserve itself and adjust to the person’s daily activity. Although bone maintains itself, the material property is changing with the remodeling process resulting bone to gain its unique heterogeneous material distribution. Furthermore, the remodeling process, not only involve with material properties, but architecture, besides. This transformation of bone occurs as a response to altered loading conditions. The transformation can be seen in osteon density, porosity, average osteonal area etc.
depends on the thickness of the bones early in life, as well as health, diet, and physical activity later in life.
Bone is a dynamic tissue which adapts its mass and architecture to the external loads constantly. Bone’s adaptation is finished through a coupled process of bone resorption by osteoclasts, and subsequent bone formation by osteoblasts, the so-called bone remodeling process [1, 2]. Optimal remodeling is responsible for bone health and strength throughout
Spongy or cancellous bone tissue consists of trabeculae that are arranged as rods or plates with red bone marrow in between. (40)
body approaches full maturity at 20 years of age. In the process of ossification, osteoblasts absorb
The word Osteoporosis literally means “porous bone” (Martini, Nath, & Bartholomew, 2014). When looked at closely with the use of a microscope, a bone that has not lost an adequate amount of bone mass as it does in Osteoporosis, resembles a honey comb (What is Osteoporosis and What Causes it?, 2016). Once osteoporosis takes place and the bone loses mass or density, the holes and spaces in the honeycomb become much larger than they would be in healthy bone (What is Osteoporosis and What Causes it?, 2016). In the femur, osteoporotic changes would appear as a diminishing of the outer layer of compact bone around the epiphyses and diminishing of the bony collar around the diaphysis (Osteoporosis, 2014). There would likewise be loss of cancellous
As a person ages, their bones may weaken because of the lack of natural bone tissue.
To study the longitudinal growth of a long bone, Duhamel inserted needles at equal intervals into the femur of a newly-hatched chick. Dissection of the femur of the chick, fifteen days later, revealed the impressions made by the needles to be separated by various intervals, smallest nearest the trabecular region and largest nearest the cortical bone because hardening begins in the trabecular of the bone and gradually proceeds towards the cortical bone. This proved that the different portions of the bone do not all grow equally but the trabecular bone grow more than the cortical bone. This phenomenon is now known as longitudinal bone growth.
It is composed of living cells some of them among those control the re-modeling of bone where as few of them nourish the bone tissue. Like all other living processes, regeneration of bone also takes place till the individual has life, in this process of remodeling or regeneration of bone old cells of bone are replaced by new cells of bone. Age factor plays an important role in deciding the speed of reformation process. Age factor plays inverse proportionality with bone remodeling. Bone resorption and bone formation takes place. If there is less calcium intake and the body is in need of calcium for other process, bone calcium is absorbed into blood. Also if the formation process does not equal the absorption process of bone, bone mass density gets less, further leading to fractures, deformations, Osteopenia and Osteoporosis of bone. Bone resorption and bone formation takes place by Osteoclasts, and Osteoblasts respectively.