Shoulder Replacement vs Resurfacing: Capping the Ball or Replacing It, and Who Each Suits

Shoulder resurfacing caps the worn ball of the shoulder with a thin metal crown and keeps the arm bone intact, while a shoulder replacement cuts off the worn head and seats a new one on a stem or a short stemless base, and usually fits a new socket as well. Resurfacing spares bone for a younger, active shoulder, but it treats the ball and largely leaves the socket, which is a big part of why stemless anatomic replacements have taken over most of the ground it once held¹.

When I was working out my own operation, a man at the pool told me he had “just a resurfacing” a decade back and asked why I could not have the same. My rotator cuff was gone, so resurfacing was never on my table and a reverse replacement was; but the question stuck, and it turns out to be the right one for a lot of arthritic shoulders. This is the plain comparison I wish someone had drawn for me: what each operation actually does, why bone is resurfacing’s strong card, why the socket is its weak one, and how it now sits against the modern alternatives. For the overview of all the options, start with what a shoulder replacement is; for the design that has largely replaced resurfacing, see the stemless replacement.

What is shoulder resurfacing?

Shoulder resurfacing (resurfacing arthroplasty) shaves off only the damaged surface of the ball and caps it with a metal crown, leaving the neck and shaft of the arm bone untouched. Because a metal cap still turns in the socket, it depends on a working rotator cuff to lift and steady the arm, exactly like an anatomic total replacement².

It is best understood as the bone-sparing cousin of the anatomic total: same principle of a smooth metal ball against the socket, but far less bone removed to get there. It shares the ordinary risks of shoulder surgery too, including infection in roughly 1 in 100 primary replacements. What it does not automatically do is deal with a socket that is also worn, which is where the comparison starts to matter.

What a shoulder replacement does, side by side

A shoulder replacement is the fuller operation: the surgeon removes the worn head, seats a new metal ball on a stem running down the arm bone or on a short stemless anchor, and resurfaces the socket with a smooth plastic (polyethylene) component. Most primary replacements take roughly 1.5 to 2 hours under a general anaesthetic combined with a regional nerve block that numbs the shoulder afterwards¹.

The step resurfacing skips is exactly the one a replacement builds in: taking the head off gives the surgeon a clear line to the socket, so an arthritic glenoid can be resurfaced in the same sitting. That is the trade at the heart of this decision. Resurfacing keeps more of your own bone; a replacement gives fuller access to fix the whole joint.

Bone stock: the case for resurfacing

Resurfacing’s real advantage is bone: by capping the head rather than cutting it off, it preserves the arm bone’s stock and its natural shape, which can make a later operation more straightforward. This weighs most for younger, active patients, because after the first decade the risk of needing a revision runs at roughly 1% per year, so a joint put in at 55 is far more likely to need redoing in a lifetime than one put in at 75¹.

That is the honest appeal, and it is a real one. If you are likely to outlive your first artificial shoulder, starting with the operation that leaves the most bone behind is a reasonable instinct. The question of timing and age is set out in full in shoulder replacement at what age.

The socket, and why resurfacing faded

The catch is the socket: with the head still in place a surgeon struggles to see and treat the glenoid, so resurfacing tends to leave an arthritic socket that can keep hurting. Leaving the socket is the main reason resurfacing has fallen out of favour as stemless anatomic replacements, which spare much of the same bone but still fit a proper socket component, have grown³.

In other words, the modern alternative quietly closed resurfacing’s advantage. A stemless design gives you bone preservation without giving up the socket, so the reason many surgeons once reached for a resurfacing has largely gone. That shift shows up in the implant designs now used most often across national registries⁴.

Which shoulder each one suits

Both resurfacing and an anatomic total replacement need a working rotator cuff, because in each a metal ball turns in the socket and relies on the cuff to lift and steady the arm; if the cuff is torn beyond repair, neither is the answer and a reverse replacement is. The rotator cuff, not age, is what mainly decides the operation¹.

This was the point that ended the pool conversation for me: my cuff was long past repairing, so no amount of bone preservation would have made a resurfacing work, and the deltoid-powered reverse design was the only sensible route. When the cuff is the problem, the whole resurfacing-versus-replacement question falls away; the case for the reverse is laid out in rotator cuff arthropathy and reverse replacement.

How long each lasts

Modern shoulder replacements have a strong track record, with pooled registry and study data putting overall survival at around 90% still in place at 10 years and anatomic total replacements at roughly 90% to 95%; humeral resurfacing has generally not matched that in registry data, partly because a left arthritic socket brings some shoulders back to surgery. After the first decade the risk of needing a revision runs at roughly 1% per year for any of them⁴.

So durability, like bone, no longer favours resurfacing the way it once seemed to. A replacement that lasts well and treats the whole joint is a hard thing to beat with an operation that leaves half the problem in place. The full longevity picture, and what a revision involves, is in how long a shoulder replacement lasts.

The honest bottom line and the cost

For most arthritic shoulders a stemless anatomic replacement now delivers resurfacing’s bone preservation without leaving the socket behind, which is why resurfacing has become a niche choice rather than a mainstream one. The cost sits in the same bracket either way: in the US the surgeon’s professional fee is commonly about $1,500 to $5,700, with an all-in estimate of roughly $15,000 to $30,000 once hospital, implant and anaesthesia are added, and UK private surgery is commonly £10,000 to £15,000².

In the UK it is a standard NHS operation, funded when clinically indicated because it is not cosmetic, though waiting times can be long⁵. If a surgeon does raise resurfacing with you, it is worth asking specifically how they plan to handle the socket and why they prefer it to a stemless total; the answer, not the label, is what should decide it.