Independent, sourced patient educationInformedSurgery
Hip Replacement Explained
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All topics
  1. What it is
  2. Who it helps
  3. Timing
  4. The procedure
  5. What a hemiarthroplasty is
  6. Hemi vs total hip
  7. Recovery after hip fracture
  8. Patient journey
  9. Recovery supplies
  10. Finding a surgeon
  11. Insurance and costs
  12. Questions to ask
  13. Implant designs
  14. Side-by-side
  15. Robotics and navigation
  16. US manufacturers
  17. What the evidence says
  18. Value analysis
  19. Resources
  20. Glossary
  21. References

Overview

What is total hip replacement?

Total hip replacement, also called total hip arthroplasty (THA), is surgery that replaces a worn or damaged hip joint. The hip is a ball-and-socket joint: the ball is the top of the thighbone (femur) and the socket is part of the pelvis (the acetabulum). In a total hip replacement, the surgeon replaces both.46

It is one of the most successful operations in medicine, sometimes called "the operation of the century."2 In Medicare alone there were 262,369 primary hip replacements in 2019.3

A hip replacement usually has four parts:

  • Cup (shell): a metal hemisphere fixed into the socket of the pelvis.
  • Liner: a smooth insert inside the cup, usually medical-grade polyethylene (plastic), sometimes ceramic.
  • Ball (femoral head): a polished ball made of metal or ceramic that moves inside the liner.
  • Stem: a metal stem fitted down the inside of the thighbone, which holds the ball.

The most common reason for a hip replacement is osteoarthritis that causes pain and limits daily life. Other reasons include rheumatoid arthritis, loss of blood supply to the ball (osteonecrosis), childhood hip conditions and arthritis after an injury.1,46

Some people, usually older adults with a broken hip, have a hemiarthroplasty instead. That replaces only the ball and stem and keeps the natural socket. See what a hemiarthroplasty is.

Front view of a hip joint with the four parts of a total hip replacement: a metal cup in the pelvis, a liner, a ball and a stem in the thighbone cup (shell) liner ball (head) stem pelvis thighbone
Schematic only. Implant shapes vary by design and manufacturer.
Clinical detail
  • Medicare primary THA volume rose about 177% between 2000 and 2019. One model projects about 719,000 Medicare THAs a year by 2040.3
  • Revision THA in Medicare is projected to rise from 30,541 in 2019 to about 43,500 by 2040, slower growth than revision knee surgery.4
Value analysis

Volume growth, the shift toward same-day surgery and episode-based payment programs all shape hip implant purchasing. See value analysis considerations.

Sources for this page

  1. Ferguson RJ, et al. Hip replacement. Lancet. 2018;392(10158):1662-1671. doi:10.1016/S0140-6736(18)31777-X
  2. Learmonth ID, Young C, Rorabeck C. The operation of the century: total hip replacement. Lancet. 2007;370(9597):1508-1519. doi:10.1016/S0140-6736(07)60457-7
  3. Shichman I, et al. Projections and epidemiology of primary hip and knee arthroplasty in Medicare patients to 2040-2060. JB JS Open Access. 2023;8(1):e22.00112. doi:10.2106/JBJS.OA.22.00112
  4. Shichman I, et al. Projections and epidemiology of revision hip and knee arthroplasty in the United States to 2040-2060. Arthroplast Today. 2023;21:101152. doi:10.1016/j.artd.2023.101152
  5. American Academy of Orthopaedic Surgeons, OrthoInfo. Total hip replacement. orthoinfo.org/bodypart/hip-thigh/total-hip-replacement

All references