Total Hip Arthroplasty (THA), commonly known as total hip replacement, is a highly successful orthopedic procedure performed worldwide. The surgery involves removing the damaged cartilage and bone of the hip joint and replacing it with prosthetic components made of metal, plastic, or ceramic. This intervention is the definitive treatment for end-stage hip disease, effectively alleviating pain and restoring mobility. Its success in significantly improving a person’s quality of life has made it one of the most transformative surgeries in modern medicine.
Current Annual Volume and Key Global Statistics
In the United States, the annual volume of hip replacement procedures is substantial, with over 450,000 total hip arthroplasties (THAs) carried out each year. This figure represents the replacement of both the ball and socket of the hip joint, making it the most frequent type of procedure performed. The high number of operations performed in the US makes North America a dominant region in the global hip replacement market.
THA must be distinguished from partial hip replacement, or hemiarthroplasty, which involves replacing only the ball of the joint, typically after a fracture. While hemiarthroplasty contributes to the overall count of hip surgeries, THA accounts for the majority of the surgical volume, representing approximately 73.5% of the market share.
Globally, the rate of primary THA varies across developed nations, generally falling within a range of 50 to 125 procedures per 100,000 inhabitants. This variation is partly due to differences in healthcare systems and the prevalence of underlying joint diseases. The high volume of procedures underscores the widespread acceptance of THA as the standard of care for severe hip dysfunction.
Trends in Hip Replacement Rates Over Time
The annual number of hip replacements has experienced a significant increase over the past two decades. Between 2000 and 2019, the estimated annual volume of primary THA in the US saw an increase of approximately 177% among Medicare patients alone. This growth is projected to continue, with models predicting the annual number of THA procedures will reach over 600,000 by 2030 and potentially 1.4 million by 2040.
This steep rise is driven by several demographic factors. The most significant driver is the overall aging of the population, as older individuals have a higher prevalence of degenerative joint disease. The expansion of surgical indications has also led to an increase in patients receiving the procedure at younger ages.
For example, between 2000 and 2010, the rate of THA more than doubled for patients in the 45-to-54 age group. This trend reflects both a greater willingness among surgeons to operate on younger, more active patients and the improved longevity of modern implant technology. The overall volume is also boosted by the need for revision surgeries to replace worn or failed implants.
Primary Medical Indications for the Procedure
The necessity for hip replacement surgery is linked to specific medical conditions that cause end-stage joint destruction. Osteoarthritis (OA) is the most common reason for primary THA, accounting for an estimated 80% or more of all procedures. This condition involves the progressive breakdown of cartilage, leading to bone-on-bone friction, severe pain, and loss of function.
Another significant indication is acute trauma, most commonly a displaced femoral neck fracture near the hip joint. For older patients, THA or partial replacement is often the preferred treatment for these fractures to ensure a faster return to mobility. Inflammatory arthritic conditions, such as Rheumatoid Arthritis, also necessitate THA by causing chronic inflammation and subsequent joint destruction.
A less common but notable indication is Avascular Necrosis (AVN), also known as osteonecrosis. AVN occurs when the blood supply to the head of the femur is interrupted, causing the bone tissue to die and collapse. While AVN is less frequent than osteoarthritis, it often affects a younger patient demographic.