Partial hip replacement: Definition, Uses, and Clinical Overview

Posted on February 28, 2026 | by drhip

Partial hip replacement Introduction (What it is)

Partial hip replacement is a surgery that replaces the “ball” of the hip joint while leaving the socket in place.
Clinicians may also call it a hemiarthroplasty of the hip.
It is most commonly used after certain hip fractures, especially femoral neck fractures.
It can also be used in select non-fracture conditions when only the femoral head needs replacement.

Why Partial hip replacement used (Purpose / benefits)

Partial hip replacement is designed to restore hip function when the femoral head (the ball at the top of the thigh bone) is too damaged to heal reliably or to provide stable, comfortable movement. The central goal is to replace the broken or diseased femoral head with an artificial component so the hip can move again with less pain and better stability than it would have without reconstruction.

In general terms, Partial hip replacement may help by:

Providing a stable joint surface after fracture. Certain femoral neck fractures can disrupt blood supply to the femoral head, increasing the chance that the bone will not heal or will collapse later. Replacing the femoral head can bypass that problem in many cases.
Enabling earlier mobilization. In many clinical settings, replacing the damaged ball can support earlier standing and walking than strategies that rely on fracture healing. Specific weight-bearing plans vary by clinician and case.
Reducing pain from an irreparable femoral head. When the femoral head is severely damaged (for example, from fracture or collapse), replacing it can reduce pain generated by bone injury and joint incongruity.
Preserving the native socket. Because the acetabulum (hip socket) is not replaced, there is less implant hardware on the pelvic side compared with total hip replacement. Whether this is advantageous depends on the diagnosis, the socket cartilage condition, and patient factors.
Serving as a pragmatic option in time-sensitive situations. For some patients—particularly with displaced fractures—Partial hip replacement is a commonly used, time-tested reconstructive approach.

Outcomes and the balance of benefits depend on factors such as the condition of the acetabular cartilage, bone quality, overall health, baseline mobility, and surgical technique.

Indications (When orthopedic clinicians use it)

Typical scenarios where orthopedic clinicians consider Partial hip replacement include:

Displaced femoral neck fracture (intracapsular hip fracture), especially in older adults
Femoral head damage where reliable healing is unlikely (varies by fracture pattern and patient factors)
Failed internal fixation of a femoral neck fracture, where salvage reconstruction is needed
Selected cases of femoral head osteonecrosis (avascular necrosis) with femoral head collapse, when the socket is relatively preserved (varies by clinician and case)
Selected tumors or destructive lesions involving the femoral head/neck requiring resection and reconstruction (case-dependent)
Situations where a shorter operative plan may be prioritized due to overall health considerations (varies by clinician and case)

Contraindications / when it’s NOT ideal

Partial hip replacement is not ideal in every hip problem. Situations where it may be less suitable, or where another approach may be preferred, include:

Significant pre-existing arthritis or cartilage loss in the acetabulum (socket), which can lead to ongoing pain if the native socket is left in place
Inflammatory arthritis (for example, rheumatoid arthritis) where the socket is commonly affected (approach varies by clinician and case)
Advanced osteoarthritis affecting both the ball and socket, where total hip replacement is commonly considered
Active joint or systemic infection, because infection can compromise any implant-based reconstruction
Severe acetabular deformity or prior pelvic conditions where leaving the socket untouched may not address the source of symptoms
Marked hip instability risk due to severe neuromuscular disease or uncorrectable soft-tissue imbalance (management varies by clinician and case)
Younger, highly active patients with long expected lifespan and acetabular cartilage concerns, where implant strategy may differ (varies by clinician and case)

Clinical decision-making typically weighs fracture characteristics, cartilage status, functional goals, and overall health rather than relying on a single criterion.

How it works (Mechanism / physiology)

Partial hip replacement works by restoring a smooth, stable articulation at the hip when the native femoral head can no longer serve as a functional joint surface.

Key biomechanical and anatomic principles include:

Hip joint anatomy involved. The hip is a ball-and-socket joint made of the femoral head (ball) and the acetabulum (socket), lined with cartilage and supported by the labrum, capsule, and surrounding muscles (gluteals, short external rotators, iliopsoas, and others).
What is replaced. In Partial hip replacement, the damaged femoral head is removed and replaced with a metal (or occasionally ceramic, depending on system) prosthetic head attached to a stem placed into the femur.
What is not replaced. The acetabulum is typically left intact. This is a defining difference from total hip replacement.
Load transfer and stability. The implant stem transfers body weight from the artificial head down through the femur. Hip stability depends on component sizing, leg length/offset restoration, the integrity and repair of soft tissues, and surgical approach.
Motion and friction. The new femoral head moves against the native acetabular cartilage (unipolar designs) or through a combination of bearings (bipolar designs). Over time, cartilage wear patterns can vary by patient, activity level, and implant design; “onset” is immediate in the sense that the implant functions as soon as the joint is reconstructed.
Reversibility. The surgery is not reversible in the way a temporary therapy is. However, if symptoms develop from acetabular wear or other issues, conversion to total hip replacement may be considered in selected cases (varies by clinician and case).

Partial hip replacement Procedure overview (How it’s applied)

Partial hip replacement is a surgical procedure performed in an operating room with anesthesia support. The exact protocol varies by hospital, surgeon, fracture type, and patient health status, but a general workflow often includes:

Evaluation/exam
– History, physical examination, and review of baseline function
– Imaging, commonly X-rays; other imaging may be used depending on the case
– Assessment of medical risks and perioperative planning
Preparation
– Anesthesia planning (regional, general, or a combination; varies by clinician and case)
– Positioning and sterile preparation of the surgical field
– Selection of implant type (for example, cemented vs uncemented stem), often guided by bone quality and anatomy
Intervention
– Surgical approach to the hip (approach varies by surgeon preference and clinical scenario)
– Removal of the damaged femoral head
– Preparation of the femoral canal to accept the stem
– Placement of the femoral stem and prosthetic head (with or without bone cement, depending on the implant strategy)
– Trialing to assess stability, leg length, and soft-tissue tension, followed by final component placement
Immediate checks
– Assessment of hip stability through a range of motion
– Wound closure and postoperative imaging as needed to confirm component position
– Early monitoring for pain control, mobility readiness, and medical stability
Follow-up
– Scheduled clinical follow-ups to monitor healing, function, and any complications
– Rehabilitation planning, which varies by clinician and case and commonly involves physical therapy goals for safe mobility and strength

Types / variations

Partial hip replacement is not a single uniform implant. Common variations include design, fixation method, and surgical approach.

Unipolar hemiarthroplasty
A single prosthetic head articulates directly with the native acetabulum.
The head size is selected to match the patient’s anatomy as closely as possible.
Bipolar hemiarthroplasty
The implant has two potential motion interfaces: an inner bearing within the prosthetic head assembly and an outer articulation with the acetabulum.
In practice, how motion distributes between the inner and outer bearings can vary by activity, anatomy, and time.
Cemented vs uncemented femoral stems
Cemented fixation uses bone cement to secure the stem within the femur, often considered when bone quality is limited (varies by clinician and case).
Uncemented fixation relies on bone growing onto or gripping the implant surface; this depends on bone quality and implant design.
Surgical approaches (how the hip is accessed)
Common approaches include posterior, anterolateral, and direct anterior techniques.
Each approach has trade-offs related to exposure, muscle handling, and postoperative precautions; specific outcomes vary by clinician and case.
Materials and head options
Stems are commonly titanium or cobalt-chromium alloys; head components are often metal, and specific combinations vary by material and manufacturer.
Bipolar designs incorporate additional bearing materials (often including polyethylene) within the head assembly, depending on the system.

Pros and cons

Pros:

Preserves the native acetabulum, which may be beneficial when socket cartilage is in good condition
Commonly used for certain femoral neck fractures with established surgical workflows
Can provide a stable, immediately functioning joint reconstruction after femoral head removal
May reduce pain related to an irreparable femoral head fracture or collapse
Typically involves fewer components than total hip replacement
Can be converted to total hip replacement in selected cases if needed later (varies by clinician and case)

Cons:

The native acetabulum can develop cartilage wear over time, potentially causing persistent or new groin pain
Functional outcomes may be lower than total hip replacement for some diagnoses and patient profiles (varies by clinician and case)
Usual surgical risks apply, including infection, blood clots, anesthesia complications, fracture, and nerve or blood vessel injury
Hip dislocation is a recognized complication, with risk influenced by approach, soft tissues, and patient factors
Leg length or offset differences can occur and may affect gait or comfort
Some patients may ultimately require additional surgery, including conversion to total hip replacement (case-dependent)

Aftercare & longevity

Aftercare following Partial hip replacement typically focuses on safe mobility, protection of the healing soft tissues, and progressive return of function. Specific protocols differ across surgeons, implant types, and patient factors, so plans commonly reflect individual goals and risks rather than a single universal pathway.

Factors that commonly affect outcomes and longevity include:

Diagnosis and joint condition. A fracture with an otherwise healthy socket differs from long-standing joint disease; the acetabular cartilage condition is particularly relevant.
Bone quality and fixation method. Cemented versus uncemented stems have different mechanical principles, and performance can vary depending on bone strength and anatomy.
Rehabilitation participation and baseline function. Regaining walking confidence, balance, and hip strength often depends on structured rehab and the patient’s starting mobility level.
Weight-bearing status and activity profile. Short-term restrictions, if used, and longer-term activity levels influence comfort and wear patterns. Recommendations vary by clinician and case.
Comorbidities. Conditions such as osteoporosis, diabetes, vascular disease, or neurologic disorders can influence healing, fall risk, and overall recovery trajectory.
Follow-up and monitoring. Periodic clinical review and imaging (as chosen by the treating team) can help detect changes such as loosening, subsidence, or acetabular wear.
Implant design and materials. Head size, bipolar vs unipolar design, and bearing materials vary by material and manufacturer and may influence wear and stability characteristics.

Longevity is usually discussed in terms of sustained function and the absence of pain or mechanical failure. Over time, some patients may develop acetabular cartilage wear or other issues that prompt discussion of further treatment options; timelines vary widely by individual.

Alternatives / comparisons

Partial hip replacement is one option within a broader set of hip fracture and hip reconstruction strategies. Comparisons depend heavily on the underlying condition.

Non-operative management (observation/supportive care)
For many displaced femoral neck fractures, non-operative care is uncommon because it may not restore stable mobility.
It may be considered in limited situations based on overall health goals, medical stability, or patient preferences; specifics vary by clinician and case.
Internal fixation (pins, screws, or plates)
Often considered for certain non-displaced or minimally displaced femoral neck fractures, and in some younger patients where preserving the native femoral head is prioritized.
Fixation relies on bone healing; risks include nonunion and osteonecrosis, depending on fracture biology and displacement.
Total hip replacement (total hip arthroplasty)
Replaces both the femoral head and the acetabular socket.
It is commonly considered when the socket is arthritic, when higher functional demands are expected, or when fracture patterns and patient factors favor a total reconstruction.
It introduces an acetabular implant and a different set of trade-offs regarding wear, stability, and long-term revision patterns (varies by clinician and case).
Hip resurfacing
A bone-preserving option in selected patients, typically not used for typical hip fracture care and dependent on anatomy and implant availability; use varies by region and clinician.
Resection arthroplasty (Girdlestone procedure)
A salvage option in complex infection or reconstruction failure scenarios.
It can relieve infection or pain but typically sacrifices strength and hip stability compared with reconstructive arthroplasty.

In clinical practice, the “best” option is individualized, balancing fracture healing potential, cartilage condition, functional goals, and overall risk tolerance.

Partial hip replacement Common questions (FAQ)

Q: Is Partial hip replacement the same as a total hip replacement?
No. Partial hip replacement replaces the femoral head (ball) while leaving the native acetabulum (socket) in place. Total hip replacement replaces both sides of the joint, which can matter if the socket cartilage is already worn.

Q: What conditions most commonly lead to Partial hip replacement?
A common indication is a displaced femoral neck fracture, especially in older adults. It may also be used in selected cases of femoral head collapse or as a salvage procedure after failed fixation, depending on socket health and patient factors.

Q: How painful is recovery after Partial hip replacement?
Pain is expected after any major hip surgery, especially in the early postoperative period, but it is typically managed with a structured pain-control plan. The experience varies widely based on the preoperative injury, surgical approach, and individual pain sensitivity.

Q: How long does a Partial hip replacement last?
Longevity varies by clinician and case. Factors include acetabular cartilage condition, activity level, implant fixation, bone quality, and whether complications occur. Some patients do well long-term, while others may develop socket wear that leads to additional treatment.

Q: Is Partial hip replacement considered “safe”?
It is a commonly performed orthopedic procedure with well-recognized benefits and risks. Like all surgeries, it carries potential complications (such as infection, blood clots, dislocation, and fracture), and risk depends on health status, injury pattern, and perioperative care.

Q: Will I be able to walk right away?
Many patients begin standing and walking with assistance soon after surgery as part of hospital recovery pathways. The timing and allowed weight-bearing level vary by clinician and case, and are influenced by surgical findings, implant choice, and overall stability.

Q: When can someone drive or return to work after Partial hip replacement?
Timing depends on which side was operated on, pain control, reaction time, use of assistive devices, and the type of work. Clinicians commonly consider functional milestones and safety factors rather than a single fixed timeline, so this varies by clinician and case.

Q: Why would someone need a second surgery after Partial hip replacement?
Reasons can include persistent pain from acetabular cartilage wear, recurrent dislocation, infection, implant loosening, or fracture around the implant. In some cases, conversion to total hip replacement is considered to address socket-related symptoms; eligibility varies by clinician and case.

Q: Does Partial hip replacement limit activity long term?
Many people return to essential daily activities, but long-term activity recommendations are individualized. Implant stability, balance, fall risk, and socket cartilage condition all influence what activities are reasonable; guidance varies by clinician and case.

Q: Is the cost of Partial hip replacement predictable?
Costs can vary significantly depending on hospital setting, geographic region, implant system, anesthesia needs, length of stay, and rehabilitation requirements. Insurance coverage and out-of-pocket costs also vary widely, so exact ranges are not universal.