What Is Hip Resurfacing vs Total Hip Replacement?

Hip resurfacing and total hip replacement both treat severe hip arthritis, but they differ fundamentally in how much bone the surgeon removes. In a total hip replacement, the entire femoral head is cut away and replaced with a metal stem driven down into the thigh bone, topped with a ball that fits into a new socket. In hip resurfacing, the femoral head is trimmed and capped with a metal shell, leaving the natural neck and most of the thigh bone intact. That distinction shapes almost everything else about the two procedures, from who qualifies, to how the hip moves afterward, to what happens decades later if the implant fails.

How the Two Procedures Actually Work

In a total hip replacement (often called THA), the surgeon removes the ball at the top of the thigh bone and hollows out the upper shaft to accept a tapered metal stem. A ceramic or metal ball sits on top of the stem, and a new plastic, ceramic, or metal liner is pressed or cemented into the reamed-out hip socket. The combination of stem length, ball size, and socket angle determines the final geometry of the reconstructed hip.

In hip resurfacing (HRA), the socket side looks similar: the natural socket is reamed and fitted with a metal cup. But on the femoral side, the surgeon shaves the damaged cartilage off the ball, reshapes it slightly, and cements a hollow metal cap over it. The femoral neck stays, the shaft stays, and no stem goes down the canal. The resulting bearing is much larger in diameter than a typical total hip ball, which has consequences for stability and movement.

Bone Preservation and Biomechanics

The biggest selling point of resurfacing is that it leaves the proximal femur largely intact. A randomized study measuring bone mineral density in the upper thigh bone found that the resurfaced group’s bone density in the calcar region actually increased to about 105% of its pre-surgery level at one year, while the total hip replacement group dropped to roughly 82% in the same zone. That difference reflects how each implant transfers load: a resurfacing cap channels weight through the natural bone, while a stemmed implant bypasses the upper femur and sends force further down the shaft.¹

Resurfacing also tends to reproduce the patient’s original hip geometry more faithfully. A randomized trial found that the natural femoral offset was restored within a few millimeters in about 57% of resurfacing patients compared with 25% of those receiving a total hip replacement. Leg-length inequality was corrected to within a few millimeters in 86% of the resurfacing group versus 60% of the total hip group.² A separate case series confirmed that resurfacing produced the smallest discrepancy in femoral offset between the operated and non-operated sides.³ In practical terms, more precise restoration of offset and leg length means the hip muscles work at closer to their original mechanical advantage, which matters for gait and stability.

A 15-year randomized follow-up concluded that because resurfacing provides better femoral bone preservation and biomechanical reconstruction, it continues to have a role in selected patients when performed by experienced surgeons using validated implants.⁴

Who Is a Good Candidate for Each

Total hip replacement is the workhorse of hip surgery. It works across a wide range of ages, bone qualities, body types, and diagnoses. Surgeons have decades of data backing its use in virtually every patient population, and modern bearing surfaces last well past 20 years for most people.

Resurfacing is more selective. A review of patient selection evidence concluded that the best candidates are men under 65 with osteoarthritis and relatively normal bone shape.⁵ Bone quality matters because the cap is cemented onto the trimmed femoral head; if that bone is weak, it can fracture. For this reason, resurfacing is generally contraindicated in patients with osteoporosis.⁶

The gender gap in outcomes has been one of the most consistent findings in the resurfacing literature. Women tend to have smaller femoral heads, which means a smaller-diameter cap and bearing surface. Registry data from England and Wales showed predicted five-year revision rates in 55-year-old women of about 6 to 8% with resurfacing, compared with roughly 1.5% with a standard cemented total hip replacement. In men with large enough femoral heads, the gap narrowed considerably, and men with the largest head sizes approached the revision rates of conventional implants.⁷ This is why most surgeons today reserve resurfacing primarily for men with adequate bone stock.

Dislocation, Infection, and Other Complications

One area where resurfacing consistently outperforms total hip replacement is dislocation risk. The resurfacing bearing is much larger in diameter, which makes it inherently harder to pop out of the socket. A systematic review found dislocations occurred at about 0.9 per 1,000 person-years after resurfacing versus 4.4 per 1,000 person-years after total hip replacement.⁸ A network meta-analysis put the difference even more starkly, finding that standard total hip replacement carried over 13 times the dislocation risk and about twice the infection risk compared with resurfacing.⁹ A separate meta-analysis of randomized trials confirmed the dislocation advantage for resurfacing while finding no significant differences in revision rate, infection, or loosening between the two procedures.¹⁰

But resurfacing carries its own distinctive complication: femoral neck fracture. The trimmed femoral head sits under stress in the early weeks after surgery, and a fracture through the neck typically occurs within the first couple of months. A large series of Birmingham Hip Resurfacings reported a fracture rate of about 1.1%, with most fractures happening in the first few months.¹¹ The causes are usually poor positioning of the component or insufficient bone density.¹² This complication does not exist with total hip replacement, because the femoral head is removed entirely.

The Metal Ion Problem

Almost all resurfacing implants to date have used metal-on-metal bearings, where both the cap and the socket lining are cobalt-chromium alloy. That combination generates microscopic metal particles with every step, releasing cobalt and chromium ions into the bloodstream. In most patients these levels stay low, but poorly positioned or undersized components can produce excessive wear. An analysis of a large resurfacing series found that patients revised for problems related to metal debris had significantly higher blood levels of chromium and cobalt, along with significantly smaller components and more anteverted cups, compared with patients doing well.¹³

The most feared consequence of metal debris is the formation of pseudotumors, which are inflammatory soft-tissue masses that can grow around the implant and destroy muscle and bone. These are not cancers but can cause serious damage. In one major series of over 1,400 resurfacings, 1.8% of patients required revision for pseudotumor, and the cumulative revision rate for this problem climbed to about 4% at eight years.¹⁴ Pseudotumor management remains challenging, with limited consensus on optimal treatment.¹⁵

Awareness of these risks has pushed the development of ceramic-on-ceramic resurfacing designs that aim to eliminate the metal ion concern while preserving the biomechanical advantages of the resurfacing concept.¹⁶ These newer implants are still in relatively early clinical use, but they represent the direction the field is moving.

Long-Term Survival and Registry Data

National joint registries, which track hundreds of thousands of implants, provide the clearest picture of how these procedures hold up over time. A 2025 analysis of the National Joint Registry for England and Wales compared resurfacing against contemporary total hip replacement with matched patients over 18 years. Survival was about 93% for resurfacing and 94% for total hip replacement at that time point. Despite the apparently small gap, the adjusted hazard for revision was about 22% higher in the resurfacing group over the full study period.¹⁷

That average, however, masks important subgroup differences. Australian registry data showed that men under 65 with primary osteoarthritis had essentially equivalent five-year revision rates with resurfacing and total hip replacement, at roughly 2.5% and 2.8% respectively. The overall higher failure rate for resurfacing was driven heavily by women and by men with small component sizes.¹⁸ The takeaway from registry data is consistent: resurfacing can match total hip replacement’s durability in well-selected patients, but the margin for error in patient selection and surgical technique is much thinner.

Recovery and Functional Outcomes

A systematic review of biomechanical studies found that resurfacing patients showed faster functional recovery after surgery, with quicker improvements in hip range of motion, vertical ground reaction force during walking, and hip abduction strength.¹⁹ The more natural bone geometry and larger bearing likely contribute to this, since the hip muscles start from a position closer to their original anatomy.

In terms of patient-reported outcomes, the picture is mixed. At one year, a study of Birmingham Hip Resurfacing patients found significantly better pain scores and improvements across all general health domains compared with total hip replacement patients.²⁰ A register-based matched cohort found that resurfacing patients scored better on activities of daily living and sport/recreation subscales, though satisfaction, overall pain, and quality-of-life index scores were not significantly different between the two groups.²¹ Both procedures produce high satisfaction rates. One study found 97% of total hip replacement patients and 93% of resurfacing patients were satisfied or very satisfied, with no significant difference. But there was an interesting psychological gap: 60% of total hip replacement patients said they were generally careful with their artificial hip, avoiding sharp movements and extreme positions, while only 38% of resurfacing patients felt the same need for caution.²²

Return to Sport and High-Impact Activity

For younger, active patients, one of the central questions is what they can do with their new hip. This is where resurfacing has carved out its strongest niche. A prospective study of resurfacing patients found a 98% rate of returning to sports of any impact level and 82% for high-impact activities specifically. The authors concluded that resurfacing allows younger, more active patients to resume sports without restriction, noting that the return-to-sport rate appeared unmatched by conventional hip prostheses.²³

A case-control study directly comparing the two procedures in young men found that resurfacing patients achieved significantly higher activity scores across multiple metrics, including high-activity, lower-extremity, cycling, and impact-specific scales.²⁴ Even running at a competitive level has been documented after resurfacing, though the long-term effect of high-impact activity on implant wear remains uncertain.²⁵ That uncertainty is the honest caveat here: people can clearly run and play sports on a resurfaced hip, but nobody yet knows whether 20 years of pounding will accelerate wear or loosening compared with a more sedentary lifestyle.

What Happens When Resurfacing Fails

One of the original arguments for resurfacing was that it would make a future revision easier because so much bone is preserved on the femoral side. That claim has held up partially. Converting a failed resurfacing to a total hip replacement is generally straightforward on the femoral side, since the surgeon has a full canal to work with and can implant a standard stem. But the acetabular (socket) side can be more challenging, because resurfacing actually removes more bone from the socket than a standard total hip replacement does, and revising that component carries a risk of further bone loss.²⁶

Still, the outcomes of converting a failed resurfacing to a total hip replacement look encouraging. A study comparing these conversions with both primary total hip replacements and standard revision total hip replacements found that the conversion group achieved clinical and functional scores comparable to a first-time total hip replacement and significantly better than a typical revision. Complication rates in the conversion group were also far lower than in the standard revision group.²⁷ For the patient, this means a failed resurfacing does not condemn you to a difficult revision. It is closer in complexity and outcome to getting a first-time total hip replacement.

Why Surgeon Experience Matters More for Resurfacing

Resurfacing is a technically demanding operation. The surgeon has to work around the intact femoral head and neck while accurately positioning both components, and errors in alignment can lead to femoral neck fracture, edge loading, and excessive metal wear. A study of the learning curve among experienced hip specialists found that all femoral neck fractures occurred in the surgeon’s first 25 cases, and the overall complication rate dropped from about 5.6% in the first 25 procedures to 1.6% in the second 25.²⁸ This means that even surgeons who already do a high volume of hip replacements face a steep learning curve when they start resurfacing, and outcomes improve substantially with experience. If you are considering resurfacing, asking about your surgeon’s case volume is one of the most important things you can do.

Total hip replacement, by comparison, is a more forgiving procedure technically. The operation is standardized, instrumentation is mature, and the range of acceptable component positioning is wider. Surgeons at virtually any level of hip-surgery experience can achieve good results with a total hip replacement, while resurfacing outcomes are tightly linked to the surgeon’s skill and familiarity with the specific implant system.

How the Resurfacing Concept Has Evolved

Hip resurfacing is not a new idea. Early versions in the 1970s and 1980s used polyethylene liners, which wore out rapidly because the large-diameter bearing generated enormous volumes of plastic debris. The resulting bone destruction and implant loosening led most surgeons to abandon the procedure. Critically, the failure was not inherent to resurfacing as a concept but rather a consequence of inappropriate materials, poor design, and crude instrumentation.²⁹

The revival came in the late 1990s when modern metal-on-metal bearings made a large-diameter, low-wear articulation feasible. That second generation produced much better results and attracted widespread enthusiasm, but then ran into the metal ion and pseudotumor complications described above, leading to recall of some designs and regulatory tightening. The field now sits in a third phase, with ceramic-on-ceramic resurfacing designs entering clinical use and early registry data being collected. Each generation has been an overcorrection followed by a recalibration, and the procedure’s reputation has tracked those swings. For patients weighing the option today, the honest framing is that resurfacing with a proven implant in the right hands produces excellent results in well-selected patients, but it has a narrower safety margin than total hip replacement and a more troubled history with certain bearing surfaces.

Monitoring Metal-on-Metal Implants After Surgery

Patients who receive a metal-on-metal resurfacing typically need periodic blood tests to monitor cobalt and chromium levels, along with imaging if symptoms develop. Standard MRI struggles with metal implants because the magnetic field creates large artifacts that obscure surrounding tissue. Specialized metal artifact reduction sequences can shrink the artifact zone by roughly 60% compared with conventional techniques, making it possible to visualize the bone-implant interface and detect fluid collections or soft-tissue masses around the implant.³⁰ This surveillance burden is another practical difference between the two procedures: a standard total hip replacement with ceramic or polyethylene bearings rarely requires routine blood work or advanced imaging unless something goes wrong clinically, whereas a metal-on-metal resurfacing patient may be followed with blood draws for years.