The Shoulder Problems a Replacement Actually Fixes

When do you need a shoulder replacement?

When the joint surface itself has worn out, and nonsurgical care has stopped holding the line. Osteoarthritis is a degenerative joint disease in which cartilage breaks down 1Ref 1National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) (2023).Osteoarthritis.What a replacement targets: osteoarthritis is the most common form of arthritis, a degenerative joint disease involving breakdown of cartilage, becoming more common with age and in women after age 50.. A replacement resurfaces that worn joint. That is its whole job. It is the right call when the cartilage is gone, the pain is constant rather than positional, and the shoulder has stopped doing the things a life needs it to do.

The confusion this page exists to fix is anatomical. The shoulder is a joint wrapped in tendons, and almost everything that hurts there is the wrapping rather than the joint. Impingement, rotator cuff tendinitis, cuff tears, frozen shoulder — all produce pain in roughly the same region, and not one is treated by resurfacing the joint.

A replacement is an answer to a worn-out joint surface. If the joint surface is not the problem, it is not the answer — however bad the shoulder is.

That is not an argument against the operation. For the shoulder it does fit, it fits well, and the shoulder replacement indications are worth stating precisely. Which is what most of this page is for.

What a replacement actually replaces

The shoulder is a ball at the top of the arm bone sitting in a shallow socket on the shoulder blade. Both surfaces are coated in cartilage. Osteoarthritis is the breakdown of that cartilage, and it is the most common form of arthritis, growing more common with age and in women after fifty 1Ref 1National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) (2023).Osteoarthritis.What a replacement targets: osteoarthritis is the most common form of arthritis, a degenerative joint disease involving breakdown of cartilage, becoming more common with age and in women after age 50.. A replacement resurfaces the ball, and usually the socket. Nothing more.

Glenohumeral joint — the ball-and-socket joint itself, as distinct from the tendons, bursa, and capsule surrounding it. This is the joint a replacement replaces.

A worn joint surface behaves differently from the tendon problems around it, and the differences are the useful part:

• The pain is not positional in the same way. Tendon pain has an arc — a range where it bites, and ranges where it does not. A worn surface hurts through the range, at rest, and at night.
• The stiffness is mechanical. The surfaces do not glide, so the shoulder does not move whether the person moves it or someone else does.
• It grinds. Bone on bone produces a coarse, audible crunch rather than a click.

That distinction, between the joint and its wrapping, is what the imaging is being asked to sort out — and why a plain X-ray, which shows the joint space, answers a different question than an MRI.

Impingement is not a replacement problem

Shoulder impingement, also called rotator cuff tendinitis, is irritation of the cuff tendons and the bursa in the space beneath the tip of the shoulder blade, and its management is nonsurgical: rest, anti-inflammatories, physical therapy, injections 2Ref 2American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Shoulder Impingement / Rotator Cuff Tendinitis.Shoulder impingement and rotator cuff tendinitis as a tendon and bursa problem rather than a joint-surface problem, managed nonsurgically with rest, anti-inflammatories, physical therapy, and injections.. A replacement does not go near that space. And the operation that does go there — subacromial decompression — turns out not to help.

CSAW is worth knowing by name. It randomized people with subacromial shoulder pain three ways: decompression surgery, a placebo arthroscopy indistinguishable from the patient's side, and no treatment. Decompression provided no clinically important benefit over either 3Ref 3Beard DJ, Rees JL, Cook JA, et al. (CSAW) (2018).Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial.Arthroscopic subacromial decompression provided no clinically important benefit over placebo arthroscopy or over no treatment for subacromial shoulder pain — the placebo-controlled evidence that shoulder pain from impingement is not a surgical problem..

In a placebo-controlled surgical trial, subacromial decompression gave no clinically important benefit over sham arthroscopy or over no treatment 3Ref 3Beard DJ, Rees JL, Cook JA, et al. (CSAW) (2018).Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial.Arthroscopic subacromial decompression provided no clinically important benefit over placebo arthroscopy or over no treatment for subacromial shoulder pain — the placebo-controlled evidence that shoulder pain from impingement is not a surgical problem..

That is a remarkable result and it should change how anyone hears a shoulder recommendation. It does not mean shoulder surgery does not work. It means this operation, for this problem, was largely doing what the belief in it was doing. Someone whose shoulder hurts from impingement is not a candidate for a replacement — and was not a good candidate for a decompression either. They are a candidate for the unglamorous thing the evidence supports 2Ref 2American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Shoulder Impingement / Rotator Cuff Tendinitis.Shoulder impingement and rotator cuff tendinitis as a tendon and bursa problem rather than a joint-surface problem, managed nonsurgically with rest, anti-inflammatories, physical therapy, and injections..

A rotator cuff tear is a tendon problem

Rotator cuff tears are among the most common causes of shoulder pain, accounting for nearly two million visits a year in the United States. Many are managed without surgery — anti-inflammatories, injections, physical therapy — and most tears do not heal on their own 4Ref 4American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Rotator Cuff Tears.Rotator cuff tears as a common cause of shoulder pain (nearly 2 million US visits per year); many are managed nonsurgically with anti-inflammatories, injections, and physical therapy, and most tears do not heal on their own.. Both halves of that sentence matter. The tendon stays torn, and the shoulder often works anyway.

That pairing is one of the most counterintuitive facts in orthopedics, and it dismantles a common piece of reasoning: the MRI says torn, tears do not heal, therefore it must be fixed. The first two clauses are true; the conclusion does not follow. A torn tendon that has stopped hurting and lets someone reach a top shelf is a shoulder that has adapted.

None of this is a replacement question either. The cuff is a tendon; the replacement is a joint surface.

The one place they meet. When a cuff has been gone long enough that the ball begins riding against the underside of the shoulder blade, the joint surface does get involved — and that is where a reverse shoulder replacement enters, an implant designed to work without a functioning cuff. A real operation for a real problem, far down a road most torn cuffs never travel.

A stiff shoulder is not a worn-out shoulder

Frozen shoulder is a capsule problem, and it has a natural history almost nothing else in orthopedics can claim: it moves through freezing, frozen, and thawing stages and usually resolves over one to three years, with range-of-motion physical therapy as the primary treatment 5Ref 5American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Frozen Shoulder (Adhesive Capsulitis).Frozen shoulder progresses through freezing, frozen, and thawing stages and usually resolves over one to three years, with range-of-motion physical therapy as the primary treatment — a capsule problem with a finite natural history.. A shoulder that recovers on its own, given a brutal amount of time, is not a shoulder that needs replacing.

"One to three years" is not a comfort and should not be delivered as one. It is the truth, and it reframes what the treatments are for: making an interval survivable, perhaps shortening it — not rescuing a joint from destruction.

The UK FROST trial tested the three real options against each other for primary frozen shoulder: early structured physiotherapy, manipulation under anaesthesia, and arthroscopic capsular release. At twelve months, patient-reported outcomes were broadly similar across all three. Arthroscopic release carried more complications, and manipulation came out most cost-effective 6Ref 6Rangan A, Brealey SD, Keding A, et al. (UK FROST) (2020).Management of adults with primary frozen shoulder in secondary care (UK FROST): a multicentre, pragmatic, three-arm, superiority randomised clinical trial.In primary frozen shoulder, early structured physiotherapy, manipulation under anaesthesia, and arthroscopic capsular release produced broadly similar patient-reported outcomes at 12 months; arthroscopic release carried more complications and manipulation was most cost-effective..

Three treatments, one destination. When the options land in the same place at a year, the tiebreakers become risk, cost, and what a person is willing to go through.

This belongs on a page about replacements because frozen shoulder is one of the most misread shoulders there is. It is agonizing, profoundly stiff, and the stiffness feels mechanical enough to pass for a joint that has seized. It has not. The surface underneath is usually intact.

When a replacement is the right call

When four things line up. The joint surface is genuinely worn — arthritis in the shoulder joint, visible as lost joint space rather than inferred from pain. The pain is present at rest and at night, not only through an arc of movement. A real course of nonsurgical care has been tried and has stopped working. And the loss is functional: sleep, dressing, reaching, work — the things a person cannot route around.

Notice what is not on that list. Not the severity of the pain by itself; a frozen shoulder can hurt more than an arthritic one. Not the MRI report; tendon findings sit in shoulders that work fine 4Ref 4American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Rotator Cuff Tears.Rotator cuff tears as a common cause of shoulder pain (nearly 2 million US visits per year); many are managed nonsurgically with anti-inflammatories, injections, and physical therapy, and most tears do not heal on their own.. Arthritis is the thing that does not reverse, and a replacement addresses it directly.

Said the other way round — the part that gets lost after a decade of headlines about orthopedic surgery being oversold — for a shoulder that meets those criteria, the conservative-care-first argument has already been made and has run out. Continuing to make it is not caution. It is a different way of failing the same person.

The same reasoning drives hip replacement indications, for the same structural reason: both are ball-and-socket joints, and both operations replace a surface that has genuinely gone. When the surface is gone, the sequence of care has reached its end — and that is not a defeat.

What to ask before scheduling

Every useful question here reduces to one: which structure is the target? Which of my findings is the arthritis, and which is the cuff? Does the X-ray show lost joint space, or does the MRI show a tendon? Have I actually completed a course of nonsurgical care, or have I only heard it recommended? And which implant is being proposed, and why that one?

• "What does my X-ray show about the joint space?" This is what a replacement turns on. Tendon findings on an MRI are a separate conversation, and shoulder imaging answers different questions depending on the test ordered.
• "Anatomic or reverse, and why?" The two implants solve different problems. Shoulder replacement recovery and reverse shoulder replacement recovery are different rehab paths, and "why that one" reveals what the surgeon believes is wrong.
• "What has the nonsurgical course actually been?" Not what was suggested. What was done, for how long, and what it changed.
• "What is the case for waiting, and against?" Questions about implant longevity belong here, answered honestly both ways.

Most shoulder pain — including pain that is severe and long-running — comes from the tendons and capsule around the joint rather than from the joint surface 2Ref 2American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Shoulder Impingement / Rotator Cuff Tendinitis.Shoulder impingement and rotator cuff tendinitis as a tendon and bursa problem rather than a joint-surface problem, managed nonsurgically with rest, anti-inflammatories, physical therapy, and injections.4Ref 4American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Rotator Cuff Tears.Rotator cuff tears as a common cause of shoulder pain (nearly 2 million US visits per year); many are managed nonsurgically with anti-inflammatories, injections, and physical therapy, and most tears do not heal on their own.5Ref 5American Academy of Orthopaedic Surgeons (OrthoInfo) (2024).Frozen Shoulder (Adhesive Capsulitis).Frozen shoulder progresses through freezing, frozen, and thawing stages and usually resolves over one to three years, with range-of-motion physical therapy as the primary treatment — a capsule problem with a finite natural history.. That is the more likely problem, and the better one to have.