Independent, sourced patient educationInformedSurgery
Hip Replacement Explained
Reading as
Plain-language core. Switch lenses to reveal technical or purchasing detail.
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

Hip fracture

What is a hemiarthroplasty?

A hemiarthroplasty, sometimes called a partial hip replacement, replaces only the ball side of the hip: the broken ball at the top of the thighbone is removed and replaced with a metal ball on a stem. The natural socket in the pelvis is kept.26

It is mainly used for a particular kind of broken hip in older adults: a displaced femoral neck fracture, where the narrow "neck" just below the ball breaks and the pieces move apart. These fractures damage the blood supply to the ball, so fixing them with screws often fails and replacing the ball works better. Hemiarthroplasty is used in more than half of hip fracture operations in older adults.27

Side-by-side schematic. Left: a hemiarthroplasty, where only the ball and stem are replaced and the natural socket is kept. Right: a total hip replacement, where the socket is also lined with a cup. Hemiarthroplasty: ball and stem Total hip: cup, liner, ball, stem
Schematic only. A hemiarthroplasty keeps the natural socket; a total hip replacement resurfaces it too.

Cemented or uncemented?

The stem can be fixed with bone cement or pressed in so bone grows onto it. For older adults with this kind of fracture, the evidence favors cement. In a large UK trial of 1,225 people aged 60 and over, cemented hemiarthroplasty gave slightly better quality of life at four months and fewer fractures of the bone around the implant (0.5% vs 2.1%).25 A Cochrane review of 17 trials reached a similar conclusion and also found lower one-year mortality with cement.26 The AAOS guideline recommends cemented stems for these fractures.49

Unipolar or bipolar?

A unipolar head is a single solid ball. A bipolar head has a smaller inner ball inside an outer shell, so it can move at two surfaces. Trials have found no meaningful difference between them in mortality, and dislocation was uncommon with either (about 1.6%).26

How is it done?

As with a total hip, the surgeon can reach the hip from the front, side or back. A 2025 Cochrane review of 27 trials found no clear evidence that one approach is better for hemiarthroplasty, though early independent walking may be slightly better with the front approach (low-certainty evidence).27

Next: hemiarthroplasty vs total hip replacement.

Clinical detail
  • WHiTE 5 (n=1,225, age 60+): EQ-5D at 4 months 0.371 cemented vs 0.315 uncemented (adjusted difference 0.055); 12-month mortality 23.9% vs 27.8% (OR 0.80, 95% CI 0.62 to 1.05); periprosthetic fracture 0.5% vs 2.1%.25
  • Cochrane (cemented vs uncemented HA, 17 studies): 12-month mortality RR 0.86; fewer intraoperative (RR 0.20) and postoperative (RR 0.29) periprosthetic fractures, but higher pulmonary embolism risk (RR 3.56).26

Sources for this page

  1. Fernandez MA, et al. Cemented or uncemented hemiarthroplasty for intracapsular hip fracture (WHiTE 5). N Engl J Med. 2022;386(6):521-530. doi:10.1056/NEJMoa2108337
  2. Lewis SR, et al. Arthroplasties for hip fracture in adults. Cochrane Database Syst Rev. 2022;2(2):CD013410. doi:10.1002/14651858.CD013410.pub2
  3. Morrell AT, et al. Surgical approaches for inserting hemiarthroplasty of the hip in people with hip fractures. Cochrane Database Syst Rev. 2025;6(6):CD016031. doi:10.1002/14651858.CD016031
  4. American Academy of Orthopaedic Surgeons. Management of hip fractures in older adults: evidence-based clinical practice guideline (December 3, 2021). aaos.org/hipfxcpg

All references