Skeletal System
Diseases, Disorders and Fractures


Types of Skeletons
Skeletal Functions
Types of Bones
Structure of Long Bones
Microscopic Structure
Skeletal Development
Axial Skeleton
Appendicular Skeleton
Interactive Skeleton
Diseases, Disorders and Fractures

This section is devoted to al the things that go wrong with the skeletal system, from osteoporosis to bone cancer.

One of the most serious diseases affecting adults, especially caucasians, asians and females, is osteoporosis, or literally 'holes in the bone'.  Osteoporosis is a loss in bone mass leading to thin, fragile bones especially in the spine and the femur.  Estrogen loss, inactivity, vitamin D deficiency, lowered calcium and protein intake, and smoking are all factors leading to this disease.  With this disease, the number of bone fractures dramatically increases as pathological fractures, (spontaneous breaks without apparent injury) begin to occur.

Differences Between Normal and Osteoporotic Bone

Rickets is a disease that occurs in children and is marked by the inability of bones to calcify, or harden.  The bones then soften and the weight-bearing bones of the legs begin to bow.  Rickets is due to a lack of calcium or vitamin D, which aids in the absorbtion of calcium into the blood stream.  It is not seen in the USA very often due to a wide avalability of vitamin D fortified foods and dairy products, but remains a problem in third world countries. 

X-Ray of Child with Rickets

Joint Disorders:
Osteoarthritis: degeneration of the joints, usually weight-bearing ones; common in elderly people
Bursitis: inflamation of bursa sacs within the joints, usually caused by excessive stess; creates pain, redness, swelling, and stiffness around the affected joint
Rheumatoid Arthritis: most serious form arthritis, extremely painfull, recurring inflammation can lead to deformaties; is an autoimmune disorder affecting the synovial membranes.

Tuberculosis and Syphilis can also create an infection within bones (osteomyelitis) which are difficult to treat and may cause skeletal difformaties.

Affects of Rheumatoid Arthritis on a Joint

Osteosarcoma - Bone Cancer:
Osteosarcoma usually occurs in the femur or around the knee and the tibia, or around the shoulder.  The typical patient is between 20-25 and the symptoms include deep, ill-defined pain and swelling in the area of the tumor.  Sometimes the patient will have a pathologic fracture (see osteoporosis).  An x-ray typically shows the tumor and a CAT scan is used to look for metastases, or to see if the cancer is spreading.  A biopsy is then performed and the treatment plan is created.  Chemotherapy is common and surgery to remove the tumorous materials is regular.  Statistics shows that  60-70% of patients with non-metastatic osteosarcomas live without a recurrence of the disease.  If the patient lives more than 5 years after diagnosis they have a very high chance of never relapsing.

X-Ray of Femur & Skull with Bone Tumors

Femur with Osteosarcoma

Classification of Bone Fractures:


Transverse: horizonal break through the bone
Simple: bone breaks completely, but does not  pentrate the skin   AKA: Closed Fracture
Greenstick: bone breaks incompletely, like a green twig,  common in children b/c their bones have not completely ossified
Compound: bone breaks completely and damages soft tissues around it, usually penetrates the skin may result in an infection - osteomyelitis           AKA: Open Frature
Comminuted: bone breaks into more than two pieces usually has soft tissue damage
Spiral: ragged break occurs when excessive forces are applied to the bone, may become displaced
Oblique: bone breaks completely but diagonally


More Types Of Fractures:
Compression: bone is crushed or squezzed together at one side,  common in osteoporotic bones
Depressed: portion of the bone is pressed inward, common is skull fractures
Impacted: ends of the broken bone are forced into each other, common in hip fractures
Displaced: fracture with one or many fragments out of normal alignment, occurs with extreme sideways force
Intraaarticular: fracture involving bones within a joint
Pathologic or Neoplastic: fracture due to a weakened bone with no apparent injury, common in osteoporotic bones or because of tumor pressure
Occult: fracture that is hidden or not easily discernible
Stellate: contains a central fracture point with radiating fissures
Stress: fracture that goes through less than half of the bone width, caused by repetitive direct force, like in running