The appendicular skeleton is formed by the pectoral girdle and upper limb, and the pelvic girdle and lower limb, which are described below.
The pectoral girdle refers to the bones that attach the upper limb to the thorax, and is made up of the scapula and clavicle.
The upper limb includes the shoulder, arm, forearm, wrist, hand and fingers and is attached to the axial skeleton via the pectoral girdle.
The pelvic girdle connects the lower limbs to the trunk and refers to the two hip bones as well as the sacrum. The hip bones articulate with each other in front at the symphysis pubis (pubic symphysis) and with the sacrum behind at the sacroiliac joints.
The pelvis refers to the articulated hip bones and sacrum. The pelvis is divided into greater and lesser parts by a plane through the pelvic brim. The pelvic brim is bounded by the arcuate lines anteriorly and laterally, and by the sacral promontory posteriorly. The greater, or false pelvis is above the pelvic brim and forms the lower part of the abdominal cavity. The lesser, or true, pelvis is below the pelvic brim.
In the female, the lesser pelvis forms the birth canal; and is described in terms of its inlet, cavity and outlet The pelvic brim forms the inlet.
The male and female pelvis differ slightly in size and shape. The male pelvis tends to be heavier, with the pelvic inlet being more heart-shaped. The female pelvis tends to be lighter, longer and thinner, with a circular pelvic inlet.
The lower limb includes the hip, thigh, leg, ankle and toes and is attached to the axial skeleton via the pelvic girdle.
In a patient with osteoporosis their bone mineral density (BMD) is lower than normal, which makes their bones weak and brittle, and much more susceptible to fractures.
In a normal person bone is continuously remodelled; old bone is absorbed and new bone is laid down. In young people bone is laid down at a quicker rate than it is absorbed and so our bone mass increases. This cumulates in people having a peak bone mass in the years between their mid 20s and 30s. After this age the rate at which bone is absorbed becomes slightly quicker than it is laid down. This cumulates in the gradual lose of bone density with age.
Factors such as low intake of dietary calcium and vitamin D, a sedentary life style, a drop in oestrogen levels due to the menopause, alcoholism and smoking, can all accelerate this process.
Preventing osteoporosis is the best way to treat it, this includes a diet rich in calcium and vitamin D and regular exercise.
A fracture is another name for a broken bone and usually occurs due to trauma. If the fracture does not penetrate the skin then it is referred to as a closed fracture. If the fractured bone penetrates through the skin then it is referred as an open or compound fracture and is more serious because the wound can allow infection into the area.
Fractures have many classifications; a few of them are listed below.
If a broken bone is moved, additional damage can be caused to the fracture as well as to the surrounding structures. The movement of the fracture must therefore be controlled 'immobilized'. This is often achieved with a splint or a cast, but more serious fractures may need surgical intervention to re-align the bones and internal or external fixation (plates, wire, screws and rods) to hold the bones in position until they have knitted together.