A total hip replacement swaps the worn parts of your hip for artificial ones called implants. A full set has four pieces: a cup that sits in your hip socket, a smooth plastic liner inside the cup, a ball, and a stem that anchors into your thigh bone.
Implants come in different materials and shapes, and your surgeon picks the combination that fits your body and how you live.
Parts of a hip implant
A healthy hip is a ball-and-socket joint. The ball is the top of your thigh bone (the femur) and the socket is part of your pelvis (the acetabulum). A hip implant rebuilds both sides of that joint.
- A cup, made of metal alloy or ceramic, is fixed into the socket with screws or a tight press-fit.
- A liner, made of a tough plastic called polyethylene, sits inside the cup so the joint glides smoothly.
- A ball (the head), made of metal alloy or ceramic, replaces the worn top of the thigh bone.
- A stem, made of metal alloy, sets into the thigh bone and holds the ball. It is held by a tight press-fit or by special bone cement.
Total Hip Replacement Components
Trial and Actual Implant (Head of femur and Acetabular Component)
What makes a good hip implant
A good implant should act as much like a natural hip as possible, so you can move freely and do the things you enjoy. The best implants share a few traits:
- They last a long time. Most hip implants last about 20-30 years or more.
- They cause little friction and shed very few wear particles as they move.
- They are safe in the body and do not trigger allergies.
- They have a long, proven track record.
Hard-on-soft hip implants
The two surfaces that rub together (the ball and the liner) are called the bearing surface. There are two main kinds: hard-on-soft and hard-on-hard.
In a hard-on-soft implant, the ball is hard and the liner is soft. The ball is metal (a cobalt-chromium alloy) or ceramic, and the liner is a plastic called polyethylene. The plastic is highly cross-linked, meaning its molecules are tightly bonded so it resists wear. A metal or ceramic ball on a polyethylene liner is the most common setup used today.
Ceramic is harder and smoother than metal alloy. It is ultra-smooth and scratch-resistant, so it sheds very few wear particles.
Hard-on-hard hip implants
In a hard-on-hard implant, both the ball and the cup are hard. They can be metal-on-metal or ceramic-on-ceramic. The surface is sometimes made slightly rough so your bone can grow onto the implant and grip it.
The main advantage is fewer dislocations. Hard-on-hard implants can use a larger ball, and a larger ball is less likely to slip out of the socket.
Metal-on-metal implants have a real downside: they release metal wear particles. This can raise cobalt-chromium levels in the blood, so these implants are avoided in people with kidney failure and in women of childbearing age.
The particles can also trigger an immune reaction called ALVAL, where immune cells build up around the implant, wear away bone, and inflame the tissue. In some cases this forms a lump called a pseudotumor, which is not cancer.
Ceramic-on-ceramic implants are usually made of alumina ceramic, which is very dense, smooth, and water-attracting, so a thin film of fluid lubricates the joint. Ceramic is scratch-resistant and inert, meaning it does not react in the body.
The trade-offs: ceramic has to be positioned very precisely or it can fail, the edges can chip against each other, and the joint can sometimes make a squeaking sound.
Hard bearing acetabular liner
Types of liners and shells
The liner and cup (the shell) also come in different shapes for different situations:
- Neutral liners are the standard choice for a first-time (primary) hip replacement.
- Lateralized liners and liners with a raised rim are used in revision surgery to help prevent the hip from dislocating.
- Constrained liners and dual-mobility heads are used when a hip replacement keeps dislocating.
Modular implants for revision surgery
When a hip implant has to be redone (revision surgery), surgeons often use modular implants that come in parts. A common one is a splined, tapered stem: the tapered end slides in easily, and the splined (ridged) design grips the thigh bone and stops it from rotating.
Modular implants are useful when there is bone loss, because they can be built up to reach healthy, stable bone.
How your surgeon chooses an implant
There is no single best implant for everyone. Your surgeon weighs your anatomy, your age and health, how active you are, and which implants they have the most experience with. Metal on polyethylene is a popular, well-proven choice, but the final decision is made with you after talking through the options.
Insurance & Cost
Total Hip Replacement Implants at Complete Orthopedics is covered by Medicare and most major insurance carriers (Aetna, Anthem BCBS, Cigna, Empire BCBS, UnitedHealthcare), as well as most workers’ compensation and no-fault insurance plans. Your out-of-pocket cost depends on your specific plan, deductible, and the medical necessity criteria that apply to your case.
Call our billing team at (631) 981-2663 before scheduling to verify your coverage and discuss expected out-of-pocket costs. For the full list of carriers we accept and patient billing protections, see our Insurance Information page.
Do you have more questions?
What are the potential complications associated with total hip replacement implants?
Potential complications of total hip replacement implants include implant loosening, wear of the implant components, dislocation, infection, nerve or blood vessel injury, and allergic reactions to implant materials. Other complications are more generally associated with the surgery.
Can total hip replacement implants be revised or replaced if they wear out or fail over time?
Yes, total hip replacement implants can be revised or replaced through a surgical procedure known as revision hip replacement if they wear out or fail over time. This involves removing the old implants and replacing them with new ones.
What are the differences between cemented and uncemented total hip replacement implants, and how do they affect the surgical procedure and recovery?
Cemented total hip replacement implants are fixed to the bone using bone cement, while uncemented implants rely on bone growing into the implant for stability. Your surgeons makes a decision what is most indicated in your particular circumstance.
Can total hip replacement implants be made of biocompatible materials to reduce the risk of adverse reactions or implant rejection?
Yes, total hip replacement implants are typically made of biocompatible materials such as titanium alloys, cobalt-chromium alloys, ceramic, or polyethylene to minimize the risk of adverse reactions.
How does the size and shape of total hip replacement implants impact their stability and performance in the hip joint?
The size and shape of total hip replacement implants are carefully selected to match the patient’s anatomy and optimize stability and performance in the hip joint, reducing the risk of implant-related complications.
What are the advantages and disadvantages of metal-on-metal, metal-on-polyethylene, ceramic-on-ceramic, and ceramic-on-polyethylene total hip replacement implants?
Each combination of materials for total hip replacement implants has its advantages and disadvantages in terms of wear resistance, durability, friction, and potential for adverse reactions or complications.
How does the cost of total hip replacement implants vary depending on the type of material and design chosen?
The cost of total hip replacement implants varies depending on factors such as the type of material, design complexity, manufacturer, and any additional features or customization options.
Can total hip replacement implants be MRI-compatible?
Modern day hip replacements do not limit you ability to have a MRI.
How do advancements in implant technology and materials influence the outcomes and longevity of total hip replacement surgery?
Advancements in implant technology and materials continue to improve the outcomes and longevity of total hip replacement surgery by enhancing implant durability, wear resistance, biocompatibility, and overall performance in the hip joint.
Can total hip replacement implants be used in patients with osteoporosis or compromised bone qualit?
Total hip replacement implants can be used in patients with osteoporosis or compromised bone quality, but special considerations may be necessary to ensure adequate implant fixation and stability.
How do total hip replacement implants affect joint biomechanics and function compared to the natural hip joint?
Total hip replacement implants aim to restore joint biomechanics and function as closely as possible to the natural hip joint, allowing for improved mobility, pain relief, and quality of life in patients with hip joint disease.
What are the potential risks and benefits of using modular total hip replacement implants compared to non-modular designs?
Modular total hip replacement implants offer advantages such as intraoperative flexibility and customization but may also pose risks such as component loosening or fretting corrosion. The choice between modular and non-modular designs depends on factors such as patient anatomy and surgeon preference.
Does the choice of bearing surface in total hip replacement implants impact wear rates and long-term implant survival?
The choice of bearing surface in total hip replacement implants, such as metal-on-metal, metal-on-polyethylene, ceramic-on-ceramic, or ceramic-on-polyethylene, can influence wear rates and long-term implant survival.
Are there different designs of total hip replacement implants available, and how do they vary in terms of stability and longevity?
Yes, there are various designs of total hip replacement implants, including cemented, uncemented, and hybrid designs, each with its advantages and considerations regarding stability and longevity.
The content on this page has been authored, edited, or approved by the doctors below, and was last reviewed for accuracy on July 2, 2026.
