When you hear the terms total hip replacement and partial hip replacement, it is easy to assume that the difference is simply how much of the hip is replaced. In reality, the two procedures are used for different problems and involve different parts of the joint.
A total hip replacement replaces both the damaged ball and socket of the hip. A partial hip replacement, also called a hemiarthroplasty, replaces the damaged femoral head but leaves the natural socket in place.
The appropriate procedure depends on the underlying condition, the extent of joint damage, the patient's health and functional needs, and the expected benefits and risks. If you are exploring your options for hip replacement surgery, understanding this distinction can make the treatment discussion much easier to follow.
Total vs partial hip replacement at a glance
| Feature | Total hip replacement | Partial hip replacement |
|---|---|---|
| What is replaced? | Femoral head and hip socket | Femoral head only |
| Also called | Total hip arthroplasty (THA) | Hemiarthroplasty |
| Natural socket retained? | No | Yes |
| Common use | Advanced hip arthritis and other conditions affecting the whole joint | Selected hip fractures, particularly certain displaced femoral neck fractures |
| Main treatment goal | Replace damaged joint surfaces and relieve pain while improving function | Replace the damaged femoral head while preserving the natural socket |
What is a total hip replacement?
In a total hip replacement, the damaged surfaces of both sides of the hip joint are replaced with artificial components. The damaged femoral head is removed and replaced with an artificial ball attached to a stem.
The damaged surface of the socket is also replaced with an artificial cup, creating a new joint. This allows the replacement to address damage affecting both the ball and socket rather than replacing only the femoral head.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
What is a partial hip replacement?
A partial hip replacement, or hemiarthroplasty, replaces the damaged femoral head while leaving the patient's natural hip socket in place.
The artificial ball moves against the existing socket. Because the socket itself is not replaced, the operation is different from a total hip replacement even though both procedures replace the femoral head.
Partial replacement is particularly associated with certain hip fractures rather than the treatment of widespread osteoarthritis.
Why would someone need one instead of the other?
The underlying problem is one of the most important factors in choosing between the two procedures.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
When total hip replacement is commonly considered
Total hip replacement is commonly used when the hip joint itself has become severely damaged and both the femoral head and socket are affected.
A major example is advanced hip osteoarthritis, where deterioration of the joint surfaces can cause persistent pain, stiffness and significant loss of function.
Other conditions can also damage the hip joint sufficiently to require total replacement, depending on the individual circumstances.
When partial hip replacement is commonly considered
Partial hip replacement is most commonly used in selected patients with certain hip fractures, particularly fractures involving the femoral neck.
In these situations, the femoral head may be damaged or have its blood supply disrupted, while the natural socket may still be suitable for continued use.
Whether a patient receives a hemiarthroplasty or total hip replacement after a fracture depends on factors such as pre-injury mobility, overall health, cognitive status, activity level and surgical risk.
What happens during each procedure?
Although both operations involve replacing the femoral head, the procedures are not identical.
Total hip replacement
The surgeon removes the damaged femoral head and prepares the upper part of the thigh bone to receive the femoral component. The damaged surface of the socket is also prepared and replaced with an artificial acetabular component. The new ball and socket then work together as the replacement joint.
Partial hip replacement
The damaged femoral head is removed and replaced with an artificial femoral component. The natural acetabulum is left intact. The artificial ball therefore articulates with the patient's existing socket rather than with an artificial socket component.
Is total hip replacement always better than partial replacement?
Not necessarily. The two procedures are not interchangeable, and the appropriate choice depends on the condition being treated.
For someone with advanced osteoarthritis affecting the hip joint, replacing only the femoral head would not address damage to the socket. In that situation, total replacement may be considered because both joint surfaces are affected.
For a person with a suitable femoral neck fracture and a relatively healthy natural socket, replacing only the femoral head may be an appropriate option.
The question is therefore not simply which operation is “better,” but which procedure is appropriate for the condition being treated and the individual's circumstances.
Total hip replacement vs partial replacement after a hip fracture
The distinction becomes particularly important after a displaced femoral neck fracture. Both hemiarthroplasty and total hip replacement can be used in appropriately selected patients. Evidence suggests that total hip replacement can provide a modest functional advantage for some properly selected patients, while hemiarthroplasty may have a lower risk of dislocation or instability.
This is why the choice after a fracture involves balancing expected functional benefits against the patient's surgical and complication risks. Factors such as whether the person was independently mobile before the fracture, their general health, cognitive function and ability to participate in rehabilitation can all influence the decision.
What about recovery?
Both procedures require a period of healing and rehabilitation. The exact recovery experience varies according to the reason for surgery, the patient's health, muscle strength and mobility before the operation, and whether the surgery was planned or performed after an injury.
Patients undergoing hip replacement are generally encouraged to begin moving as soon as medically appropriate. Physiotherapy and progressive activity help restore strength, balance and mobility.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Recovery after a planned total hip replacement for arthritis can differ considerably from recovery after a hemiarthroplasty performed following a hip fracture, so it is difficult to assign one recovery timeline to both procedures.
Are the risks different?
Both procedures are major operations and share many potential risks, including infection, blood clots, bleeding, nerve or blood vessel injury, fracture around the implant and problems requiring further surgery.
There can also be differences between the procedures. For example, evidence in selected hip-fracture patients has found a higher risk of dislocation with total hip replacement compared with hemiarthroplasty, while total replacement may provide a small functional advantage in appropriately selected patients. The individual's medical condition and reason for surgery are therefore important when discussing risk.
Can a partial hip replacement later become a total hip replacement?
Yes, in some circumstances. Because the natural socket remains in place after hemiarthroplasty, problems involving that socket may develop later in some patients.
Persistent pain, progressive joint damage or other complications may lead to consideration of conversion to a total hip replacement.
However, not everyone who undergoes partial replacement will need another operation. The need for further surgery depends on the individual patient's circumstances and how the hip performs over time.
Which procedure is used for severe hip arthritis?
For advanced osteoarthritis affecting the hip joint, total hip replacement is generally the type of replacement considered because osteoarthritis can affect both the femoral head and the socket.
A partial replacement would leave the natural socket in place and therefore would not address widespread damage affecting both sides of an arthritic joint.
The final decision still requires an individual assessment because not every patient with hip arthritis needs joint replacement immediately.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Does age determine whether you receive a total or partial replacement?
Age can be relevant, particularly when surgery is being performed for a hip fracture, but it is not the only consideration. Doctors may consider the person's mobility before the injury, general health, cognitive function, activity level, other medical conditions and ability to tolerate and recover from surgery.
For planned hip replacement because of arthritis, the extent of joint damage and the effect of symptoms on daily life are particularly important.
The Bottom Line
Total and partial hip replacement are different procedures designed for different clinical situations. Total hip replacement replaces both the ball and socket of the hip and is commonly used when the entire joint has been substantially damaged, such as with advanced osteoarthritis. Partial hip replacement replaces only the femoral head and is most commonly used in selected patients with certain hip fractures where the natural socket remains suitable.
Neither procedure is automatically appropriate for everyone. The choice depends on the reason for surgery, the condition of the hip, overall health, mobility and the expected benefits and risks. For hip fractures in particular, the decision between hemiarthroplasty and total replacement is individualized because each option has different advantages and potential complications.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
