Total hip replacement is a surgery that removes the damaged parts of the hip joint and replaces them with artificial components. The goal is to relieve pain, restore movement, and help people return to daily activities that hip problems had made difficult. It is one of the most common joint surgeries performed in the United States today.
You may hear doctors use the term total hip arthroplasty, or THA for short. Both terms describe the same surgery. This guide walks through the basics of what the procedure involves, the different types available, and why someone might need one. Later articles in this cluster cover causes and diagnosis, the procedure and recovery, and answers to common patient questions.
What Is Total Hip Replacement?
A total hip replacement is a surgery in which a surgeon removes damaged bone and cartilage from the hip joint and replaces them with artificial parts, called a prosthesis or implant. The goal is to reduce pain and restore the joint’s natural movement so patients can walk, stand, and move with less difficulty.
According to the American Academy of Orthopaedic Surgeons, hip replacement is one of the most successful operations in modern medicine. It is typically considered when daily pain or stiffness limits activity and other treatments no longer help.
How the Hip Joint Works (Simple Anatomy)
To understand what gets replaced, it helps to picture how a healthy hip works.
The hip is a ball-and-socket joint. It has two main parts:
- The ball: the rounded top of the thighbone (the femur), called the femoral head
- The socket: a cup-shaped area in the pelvis called the acetabulum
The ball fits into the socket and allows the leg to move in many directions: forward, backward, sideways, and rotationally. Several other structures help the joint work smoothly:
- Cartilage is a smooth, slippery tissue that covers the bone surfaces so they glide against each other without friction.
- The synovial membrane produces a thin fluid that lubricates the joint.
- Ligaments (sometimes called the hip capsule) hold the ball firmly inside the socket.
When any of these structures break down, whether from arthritis, injury, or other causes, the joint can stiffen, hurt, and lose its range of motion. A total hip replacement addresses the damage to the ball and the socket at the same time.
What Gets Replaced in a Total Hip Replacement?
An implanted artificial hip is designed to do the job the natural joint used to do. The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) describes the implant as having four main components:
- A metal stem that fits into the hollow center of the thighbone
- A metal or ceramic ball that replaces the damaged femoral head
- A metal socket (cup) that replaces the worn surface of the acetabulum
- A liner inside the socket (made of plastic, ceramic, or metal) that lets the ball glide smoothly
Together, these parts recreate the movement of the original joint. Modern implants are designed to last many years, though wear rates and longevity vary from person to person.
Types of Hip Replacement Surgery
When people hear “hip replacement,” they often picture one standard procedure, but there are actually a few related options. Knowing the differences helps when talking with a surgeon.
Total Hip Replacement (THA)
This is the standard and most common type. Both the ball (femoral head) and the socket (acetabulum) are replaced with artificial parts. It is the procedure most often recommended for advanced arthritis or serious joint damage.
Partial Hip Replacement (Hemiarthroplasty)
In a partial hip replacement, only the ball portion of the joint is replaced. The natural socket is left in place if it is still healthy. This approach is most often used after certain hip fractures, particularly in older adults, when replacing only the ball is enough to restore function.
Hip Resurfacing
Hip resurfacing is a more conservative option. Instead of removing the femoral head, the surgeon caps it with a smooth metal covering. The socket is still resurfaced with an implant. Resurfacing is offered in select cases, usually for younger, more active patients whose bone quality is strong. It is less common today than it once was, and not everyone is a good candidate for it.
Your orthopedic surgeon will discuss which option fits your individual situation best, based on your age, health, activity level, and the condition of your hip joint.
Surgical Approaches to Total Hip Replacement
Surgeons can reach the hip joint from slightly different directions. This is called the surgical approach. The main approaches are:
- Anterior approach. The incision is made at the front of the hip. This approach is sometimes associated with a faster early recovery in certain patients.
- Posterior approach. The incision is made at the back or side of the hip. It has been the most common approach for many years and gives the surgeon excellent access to the joint.
- Lateral approach. The incision is made on the side of the hip.
Each approach has its own strengths, and the choice often depends on the patient’s anatomy, the surgeon’s training, and the type of implant being used. Detailed comparisons of recovery and outcomes between approaches are covered in Blog 3 of this cluster.
Hip Implant Materials and Fixation
Modern hip implants come in several material combinations, known as bearing surfaces, and they can be held in place in different ways.
Common Bearing Surfaces
- Metal-on-polyethylene (metal ball, plastic liner): the most common combination
- Ceramic-on-polyethylene (ceramic ball, plastic liner)
- Ceramic-on-ceramic (both ball and liner made of ceramic)
The right combination depends on factors like age, activity level, and anatomy. All modern bearing surfaces used in the U.S. are regulated and cleared by the U.S. Food and Drug Administration.
How Implants Are Fixed in Place
Implants stay secure in one of three ways:
- Cemented. A medical-grade bone cement holds the implant in place immediately.
- Uncemented (press-fit). The implant has a textured surface that natural bone grows into over time. This is often used in younger, more active patients.
- Hybrid. A combination. Most commonly, the stem in the thighbone is cemented, while the socket in the pelvis is press-fit.
There is no single “best” method. Surgeons make the choice based on bone quality, age, and other individual factors.
Who Might Need a Hip Replacement?
Total hip replacement is usually considered when ongoing pain and stiffness interfere with daily life and other treatments no longer provide relief. The most common conditions that lead to surgery include:
- Osteoarthritis. The most common cause. Cartilage gradually wears down with age, allowing bones to rub against each other.
- Rheumatoid arthritis. An autoimmune condition in which the body’s immune system attacks joint tissues, causing inflammation and damage.
- Post-traumatic arthritis. Arthritis that develops after a serious hip injury or fracture.
- Avascular necrosis (osteonecrosis). A loss of blood supply to the femoral head, which leads to bone death and collapse.
- Hip fractures. Particularly in older adults, where a broken hip can make joint replacement the best path to restoring mobility.
- Childhood hip disease complications. Conditions like developmental dysplasia of the hip can cause joint damage later in life.
The decision to move forward with surgery is personal and is made together with an orthopedic specialist. The detailed evaluation process is covered in Blog 2 of this cluster.
Early Warning Signs of Hip Joint Damage
Hip problems often develop gradually. Some of the early signs that a hip joint may be wearing out include:
- Ongoing pain in the hip, groin, or thigh that does not ease with rest
- Pain that disturbs sleep
- Stiffness when getting up from a chair or the car
- Trouble walking long distances, climbing stairs, or putting on shoes and socks
- Limited improvement from medication, physical therapy, or injections
Not everyone with these symptoms will need surgery, and many people manage hip pain well with conservative treatments. Still, ongoing symptoms are a signal to speak with a healthcare provider sooner rather than later. The Arthritis Foundation offers more information on hip pain and when to seek evaluation.
Your Hip Replacement Journey at a Glance
Each patient’s path is different, but most hip replacement journeys follow a similar arc:
- Initial consultation. A primary care doctor or orthopedic specialist evaluates symptoms and medical history.
- Imaging and evaluation. X-rays and other tests confirm joint damage and its severity. The full diagnostic process is explained in Blog 2.
- Shared decision-making. The patient and surgeon review surgical and non-surgical options. Candidacy depends on overall health, not age alone.
- Pre-surgery preparation. Health checks, medication review, and home preparation happen in the weeks before surgery.
- Surgery. The damaged joint is replaced with an implant. Details of the procedure are covered in Blog 3.
- Recovery and rehabilitation. Physical therapy and gradual return to daily activities happen over weeks to months.
Is Hip Replacement Right for Everyone?
Hip replacement is common and generally successful, but it is still major surgery. Most people who have it experience significant pain relief and improved mobility, according to the Hospital for Special Surgery. Outcomes, however, vary from person to person, and some activities may be restricted afterward, especially high-impact sports.
Deciding to have a hip replacement is a personal decision made with the guidance of an orthopedic specialist. It usually comes after other treatments have been tried and ongoing pain is affecting quality of life.
If you are starting to research hip replacement for yourself or a family member, understanding the basics covered in this article is a strong first step. The rest of this cluster goes deeper into the causes and diagnosis, the procedure itself, and the questions patients most often ask.
Frequently Asked Questions
What is the difference between a total hip replacement and a partial hip replacement?
A total hip replacement replaces both the ball (femoral head) and the socket (acetabulum) of the hip joint with artificial components. A partial hip replacement, also called hemiarthroplasty, replaces only the ball and leaves the natural socket in place. Partial replacements are most often used after certain hip fractures, particularly in older adults.
What is a hip implant made of?
A typical hip implant has four parts: a metal stem placed in the thighbone, a metal or ceramic ball that replaces the femoral head, a metal socket that fits into the pelvis, and a liner (plastic, ceramic, or metal) that lets the ball glide smoothly inside the socket. All materials used in the U.S. are regulated and cleared by the FDA.
How do I know if I might need a hip replacement someday?
Early signs include hip, groin, or thigh pain that does not ease with rest, pain that interferes with sleep, stiffness that limits everyday movement, and reduced benefit from medication or physical therapy. Not everyone with these symptoms needs surgery, but ongoing pain is a good reason to see a healthcare provider. Deeper information on evaluation and diagnosis is in Blog 2 of this cluster.
Disclaimer: This article is for general informational and educational purposes only. It is not intended as medical advice, diagnosis, or treatment. Always talk with a qualified healthcare professional for guidance about your individual situation. The information presented here does not replace a consultation with a licensed medical provider.
