Arthroplasty may be used to treat affected joints in a number of conditions, including:

• Osteoarthritis. A degenerative bone arthritis typically affecting older individuals. Individuals with advanced forms of this condition that do not respond to other treatments are good candidates for arthroplasty. The procedure is often performed primarily to reduce the pain in the joint and improve quality of life. Knee replacements have become a common treatment for severe osteoarthritis in the knees.
  
  
• Rheumatoid arthritis (RA). A chronic inflammatory form of arthritis that may affect individuals of any age. Adult and juvenile rheumatoid arthritis may lead to the need for arthroplasty. Individuals with RA often require knuckle arthroplasty.
  
  
• Fractures. Falls and osteoporosis often cause hip fractures in elders that may require a partial or total hip replacement.

• Osteonecrosis. Death of bone tissue caused by obstructed blood flow. Arthroplasty may be useful in the treatment of this condition, particularly when it occurs in parts of the bones close to the joint, such as the head of the femur in the hip.
  
  
• Post-traumatic arthritis. Arthritis caused by injury. Arthritis that follows a dislocation or fracture may call for the use of arthroplasty.
  
  
• Hip dysplasia. Abnormal growth of the hip. When the acetabulum (the cavity in the pelvic bone into which the head of the femur fits) is shallow and the femoral head is exposed, early osteoarthritis often results. In these cases, a total hip arthroplasty may be required.
  
  
• Primary bone cancer or metastasis (spread of cancer cells from other tumors to bone tissue). When this occurs at a joint, arthroplasty may be needed to restore the joint.
  
  
• Joint deformity. Some joints, such as the knees, bow in or out, causing pain and limiting range of motion. Other deformities that may in severe causes require arthroplasty include hammer toes and mallet toes, common sources of foot pain.
  
  
• TMJ disorder. Used to repair, reposition, replace or remove the articular disc that cushions the temporomandibular joint in the jaw.
  
  
• Psoriatic arthritis. A form of arthritis that occasionally affects patients with psoriasis and can cause painful inflammation in the joints of the hands.
  
  
• Sports injuries. Acute or cumulative trauma sustained during athletics can often be treated with noninvasive methods or arthroscopy, but sometimes arthroplasty is needed.

Some sources of back pain and neck pain can be treated with vertebral arthroplasty, but spine surgery is often considered separately.