What this decision is really about

Choosing between hip resurfacing and total hip replacement is not a question of old technology versus new, or cautious versus bold. Both procedures address the same underlying problem — a hip joint damaged beyond the point where non-surgical management reliably helps — and both can restore function, reduce pain, and allow a return to an active life. The difference lies in how each procedure achieves that, and which approach fits a particular patient's anatomy, age, activity level, and biology.

Total hip arthroplasty (THR) is by far the more commonly performed operation. It suits the widest range of patients and carries a longer accumulated evidence base. Modern implants — with highly cross-linked polyethylene or ceramic bearings and precision-fit cementless fixation — project survivorship of 25 to 30 years or more in appropriately selected patients. Hip replacement is, by most measures, one of the most successful elective operations in medicine.

Hip resurfacing arthroplasty (HRA) is a genuine and well-evidenced alternative, not a universal upgrade. It conserves more bone by capping the femoral head rather than removing it entirely, and in the right patient it can offer excellent long-term results. But 'the right patient' is a defined subset — not everyone who would prefer to keep more bone is actually a suitable candidate.

The reassuring starting point for anyone facing this decision is that both options, chosen correctly, perform well. The work of a specialist assessment is to determine which one performs best for you — and that requires evaluation by a surgeon experienced in both.

How each operation works at the hip joint

The hip joint is a ball-and-socket: the rounded femoral head sits inside the cup-shaped acetabulum, allowing a wide arc of movement. Both procedures address the same worn surfaces, but they do so very differently on the femoral side.

In total hip replacement, the femoral head and neck are removed entirely. A metal stem is fixed inside the femoral canal, a new ball is mounted on top of that stem, and a cup is pressed or cemented into the acetabulum. The natural bone of the upper femur is gone; its function is taken over by the implant.

In hip resurfacing, the femoral head is not removed. Instead, it is trimmed and shaped, then capped with a smooth metal covering — much as a dentist caps a damaged tooth rather than extracting it. The femoral neck remains intact. A matching metal cup is still inserted into the acetabulum exactly as in a total replacement.

That last point is worth underlining: the socket side of both procedures is essentially identical. The entire procedural difference lies on the femoral side — how much bone is removed and what remains when the operation is done.

Why does that matter? If a resurfacing implant eventually fails or wears out, revision surgery starts with the femoral head structure still present. That preserved bone stock is considered to make reconstruction technically more straightforward than revising a stem-based total replacement, where the femoral canal has already been occupied and shaped by the primary implant. Bone preservation, in other words, is not only an anatomical detail — it is a downstream surgical asset.

Which patients suit resurfacing — and which suit full replacement

Patient profile is where the two procedures diverge most sharply, and getting this right matters more than the choice of implant itself.

Who tends to suit hip resurfacing

HRA works best in patients who are younger — typically under 55 to 60 — highly active, and predominantly male. The anatomical reason is straightforward: resurfacing depends on the femoral head being large, round, and dense enough to support the capping component securely. Patients with good bone stock, no femoral head cysts, and no underlying metabolic bone disease generally meet that standard.

Beyond bone quality, activity level matters. Athletes who intend to return to high-impact sport — including contact sports such as hockey — often favour resurfacing because the preserved femoral neck allows a movement pattern closer to the natural hip and leaves more bone in reserve for any future revision.

Surgeon experience is a genuine suitability factor, not a caveat. HRA is technically more demanding than THR, and outcomes in published series are markedly better when performed by surgeons experienced in both procedures. A patient who is otherwise an ideal candidate but whose surgeon lacks that specific volume of resurfacing experience may actually be better served by a well-executed total replacement.

Who is better served by total hip replacement

THR carries a broader indication. Women with osteoporosis, older patients, those with renal impairment, a known metal sensitivity, or a smaller anatomical frame should generally proceed to total replacement rather than resurfacing. Significant femoral head deformity — including avascular necrosis that has compromised bone quality — typically rules HRA out, because the capping procedure depends on a viable femoral head remaining.

The metal-on-metal bearing used in all current resurfacing systems is also the reason kidney function and metal allergy are hard contraindications: cobalt and chromium ion accumulation poses a measurable systemic risk in susceptible patients, and modern THR bearings simply do not carry that concern.

Age as a guide, not a rule

A 2025 propensity-matched study of 70 patients per group aged 65 and over found that carefully selected HRA patients produced significantly higher HOOS-JR and modified Harris Hip Scores at one year and at final follow-up than their total-replacement counterparts. That finding challenges the idea that resurfacing is automatically inappropriate once a patient passes a certain age — but it reinforces rather than relaxes the selection criteria. The study's result held precisely because the patients chosen for resurfacing in that cohort met every bone-quality and activity threshold. Age alone is not a reliable guide; rigorous individual assessment is.

For patients who are uncertain which category they fall into, a specialist evaluation — ideally with a consultant who regularly performs both procedures — is the only reliable way to resolve the question.

What the long-term evidence shows

Survivorship data for both procedures is now substantial, though the two evidence bases are not symmetric in size or design.

For hip resurfacing, the Birmingham Hip Resurfacing system provides some of the most granular long-term data available. A 2025 study in the Journal of Bone and Joint Surgery reported survivorship free from aseptic revision of 98.6% at ten years and 97.4% at fifteen years — figures that compare favourably with any elective orthopaedic procedure. A 2024 systematic review adds breadth: across 26 long-term studies, survivorship ranged from 83% to 100%, with 25 of those 26 studies reporting ten-year survivorship above 83%.

The evidence base for total hip replacement is longer-running and draws from larger national joint registries spanning several decades. Modern THR implants — ceramic bearings, highly cross-linked polyethylene, and cementless titanium fixation — are projected to achieve 25 to 30 or more years of function in appropriately selected patients, and the sheer volume of follow-up data underpinning that estimate is considerably larger than what exists for resurfacing.

The honest limitation is that direct head-to-head data from randomised controlled trials comparing HRA and THR in equivalent populations remain scarce. Most comparative evidence is registry-based or retrospective, which makes it difficult to fully separate the effect of the implant from the effect of patient selection. Both procedures have also evolved substantially since many early comparative studies were conducted, reducing how directly those older figures translate to current surgical practice.

The survivorship numbers for each procedure are genuinely strong — but they were generated in carefully selected populations, and that selection is carrying a significant share of the result.

Risks, dislocation, and how surgical advances have changed the picture

Risk profiles for the two procedures are genuinely different — not one safer than the other in every respect, but different in kind.

Metal ions and monitoring in HRA

The metal-on-metal bearing in hip resurfacing releases cobalt and chromium ions into the bloodstream as the components wear. In the majority of patients with well-positioned implants, ion levels remain low and clinically inconsequential. The concern arises when levels climb: systemic health effects have been reported in patients where cobalt or chromium concentrations exceed approximately 50 ppb, and a separate phenomenon — adverse reaction to metal debris (ARMD), where local soft tissue reacts to ion accumulation — can occur at lower thresholds. For this reason, anyone with a resurfacing implant requires regular blood ion monitoring post-operatively, typically on an ongoing basis. Modern THR with ceramic or highly cross-linked polyethylene bearings carries no equivalent concern; metal ion release is not a feature of these bearing surfaces.

A separate risk unique to HRA is femoral neck fracture. The neck remains intact after resurfacing, and in patients with reduced bone density it can fracture under load — which is why osteoporosis is a firm contraindication.

Dislocation and surgical approach in THR

Historically, the larger femoral head used in resurfacing offered a meaningful advantage in dislocation resistance over conventional THR. That gap has narrowed substantially. Dual mobility cups, careful capsule repair, and computer navigation now allow total replacement to achieve dislocation rates that are clinically comparable to resurfacing in most patient groups.

Muscle-sparing posterior approaches have contributed further. The SPAIRE technique — which preserves the short external rotators rather than dividing them — reduces soft-tissue disruption at the time of THR, supporting earlier functional recovery and joint stability. Where traditional posterior approaches cut through these tendons and required a period of protected movement while tissue healed, SPAIRE leaves the posterior soft-tissue envelope substantially intact. Taken together, these surgical advances mean the recovery difference between a well-performed THR and hip resurfacing is considerably smaller than it was a decade ago.

Getting the right assessment before deciding

The most important question to put to any surgeon before deciding is whether they perform both procedures — and at what volume each year. Surgeon preference bias toward one option is a real clinical risk that patients are entitled to ask about directly. Beyond that, a thorough pre-operative assessment should cover imaging, bone density, activity targets, anatomical frame, and a full contraindication review — including metal sensitivity and renal function — before any recommendation is made. Neither procedure should be defaulted to without that groundwork.

For patients in Lincolnshire and across the East Midlands, that kind of structured, consultant-led assessment is available at Hip Replacement Lincolnshire's sites in Sleaford (NG34) and Grantham (NG31). Professor Paul Lee, whose clinical perspective informs much of the approach described in this article, assesses patients for both HRA and THR — including the SPAIRE muscle-sparing posterior approach for those where full replacement is the right route. Assessment does not require a GP referral or an NHS waiting list.

Hip Replacement Lincolnshire is part of the MSK Doctors group and accepts patients without referral. Book an assessment at hipreplacementlincolnshire.co.uk.