Joint Immobilization Lab

Long Bone Immobilization Lab 

(A review of Bones and Joints)

Yes we have already completed these chapters, but we ran out of time to complete the lab.  We are now going back and practicing how to immobilize a long bone and joint because it is fun and a good thing to know.  

Fractures

Bone fractures are most common in the diaphysis of long bones.  More than 6.8 million people must seek medical assistance for fractures in the United States per year.  On average, an individual can expect to suffer from at least two fractures in his or her lifetime. Wrist fractures are the most common location for those under the age of 75, while hip fractures are the most common over the age of 75.

A fracture occurs when the force on a bone is greater than it is able to withstand.  This force is most commonly stretching, compression, or torsion (twisting).  Low bone density or pathological causes, such as cancer, can also cause a bone to fracture.  Bone fractures are commonly caused by sport injuries, overuse, falls, and accidents.  Bones can fracture differently depending on the cause.  Diagram A shows a few examples of different types of bone fractures. 

Symptoms of a fracture can include:

• Limitation of movement in fractured extremity
• Pain at the fracture site
• Swelling and bruising
• Misshapen joint or limb
• Tingling and numbness

Immediate treatment of a fracture is immobilization and splinting to control pain and prevent further injury.  It is important that the joint above and below the break is prevented from moving, since movement of the limb causes further pain and displacement of the bone.  Once a fracture has been diagnosed a simple fracture that does not break the skin, and without bone displacement, can easily be treated with a cast to hold the bone in position while healing.  If the fracture is compound, the bone has been shattered, or the fracture is displaced, the fracture will require reduction (placement of the bone back in alignment), and surgical intervention with pins, plates, or screws to hold the bone in place as it heals.

 Bone Healing

Bone is an amazing organ capable of repairing and remodeling itself.  The length of time necessary for bone to repair itself can range from a few weeks to a few months, depending on the location and extent of the fracture.  The healing process is initiated by cells in the periosteum that respond to the stress, and a hematoma that develop within the fracture site of the bone.  The periosteum produces cells that develop into chondroblasts and osteoblasts that will fill in the fracture site first with cartilage and then bone.  Diagram B provided is a detailed explanation of the bone healing process.