Partial Shoulder Replacement

Partial Shoulder Replacement is a shoulder arthroplasty in which the damaged humeral head is replaced while the patient's natural glenoid socket is preserved. In medical terminology, the operation is most commonly called shoulder hemiarthroplasty.

The normal shoulder is a ball-and-socket joint. The humeral head forms the ball and articulates with the shallow glenoid socket of the scapula. In a total shoulder replacement, both sides are resurfaced with prosthetic components. In a partial replacement, only the humeral side receives an implant.

This makes the procedure fundamentally different from both anatomic total shoulder replacement and reverse shoulder replacement. A partial replacement retains native glenoid cartilage and therefore depends on that cartilage continuing to tolerate contact with the artificial humeral head.

What Is Shoulder Hemiarthroplasty?

The word hemiarthroplasty literally refers to replacement of one side of a joint.

In the shoulder, this usually means replacement of the humeral head while leaving the glenoid untouched. A metal or other prosthetic head articulates directly against the patient's natural glenoid cartilage.

The surgeon may use a conventional stemmed prosthesis, a shorter metaphyseal component or a resurfacing implant that preserves much of the patient's original humeral head and shaft.

These procedures share the same key principle: the natural glenoid remains part of the bearing surface.

How Is It Different From Total Shoulder Replacement?

An anatomic total shoulder replacement resurfaces both sides of the glenohumeral joint. The humeral head is replaced and a polyethylene glenoid component is implanted into the socket.

Partial replacement leaves the glenoid untouched.

For a patient with primary osteoarthritis affecting both sides of the joint, this distinction is extremely important. High-quality evidence and current orthopedic guidelines indicate that anatomic total shoulder replacement generally provides better pain relief and function than hemiarthroplasty when the rotator cuff is intact and glenoid replacement is technically appropriate.

Partial replacement should therefore not be presented simply as a smaller version of total shoulder replacement that is automatically preferable because less bone is replaced.

It is a different operation with narrower modern indications.

How Is It Different From Reverse Shoulder Replacement?

Reverse Shoulder Replacement replaces both sides of the joint and deliberately reverses the normal ball-and-socket geometry.

The glenoid receives a metal ball, while the humerus receives a concave polyethylene socket.

Reverse replacement allows the deltoid to elevate the arm when the rotator cuff is severely deficient.

A standard partial shoulder replacement preserves normal shoulder geometry and normally depends much more on a functional rotator cuff to center and move the humeral head appropriately.

The two procedures therefore solve very different mechanical problems.

Why Would the Surgeon Preserve the Glenoid?

Preserving the natural glenoid avoids implantation of a polyethylene socket component.

This can preserve glenoid bone and remove the possibility of prosthetic glenoid loosening.

That can be attractive in a younger patient who may need revision decades later, in a patient whose glenoid cartilage remains healthy or in a shoulder where the glenoid has insufficient bone for secure component fixation.

However, preserving the glenoid creates another issue: natural cartilage must articulate against the artificial humeral component.

If that cartilage progressively wears, the patient can develop painful glenoid erosion and may ultimately require conversion to total or reverse shoulder arthroplasty.

Why Is Partial Shoulder Replacement Less Common Today?

Shoulder hemiarthroplasty once had a much larger role in shoulder reconstruction.

Several developments have reduced its routine use.

Modern anatomic total shoulder replacement provides highly reliable pain relief for osteoarthritis when the rotator cuff functions and glenoid anatomy permits implantation. Reverse shoulder replacement has also become increasingly successful for cuff-deficient shoulders, complex fractures and revision cases.

This leaves hemiarthroplasty occupying a more selective space.

It remains a valuable operation when there is a clear reason not to replace the glenoid, but it should not automatically be chosen simply because it preserves more native anatomy.

Types of Partial Shoulder Replacement

There are several forms of partial shoulder arthroplasty.

The classic procedure is stemmed hemiarthroplasty, in which the humeral head is removed and replaced with a metallic head attached to a stem that sits inside the humeral canal.

Short-stem or metaphyseal designs preserve more humeral shaft bone.

Resurfacing hemiarthroplasty leaves most of the humeral head in place and covers the damaged surface with a cap-like prosthesis.

Modern implants can also use different bearing materials, including traditional metal and selected pyrocarbon designs.

The appropriate implant depends on the indication, bone quality, age and future revision considerations.

Stemmed Shoulder Hemiarthroplasty

Traditional shoulder hemiarthroplasty uses a humeral stem extending into the upper arm bone.

The damaged humeral head is removed at the anatomical neck.

The surgeon prepares the canal and inserts the stem at an orientation designed to reproduce normal shoulder anatomy.

A prosthetic head is attached to the stem.

The implant can be cemented or press-fit according to bone quality and implant design.

Stemmed implants have extensive historical experience and remain useful in fracture reconstruction, severe humeral-head destruction and certain revision situations.

Short-Stem Hemiarthroplasty

Short-stem implants occupy less of the humeral shaft.

They rely more on fixation within the upper humerus.

The main theoretical advantage is preservation of humeral bone, which can simplify future revision and reduce some stem-related problems.

Good proximal bone quality is important.

Fractures, severe deformity or poor bone can make a longer stem more appropriate.

Resurfacing Hemiarthroplasty

Resurfacing hemiarthroplasty replaces only the articular surface of the humeral head.

The surgeon reshapes the damaged head and fits a cap over it rather than removing the entire head and inserting a stem.

This preserves humeral bone and can maintain anatomy.

AAOS patient guidance recognizes resurfacing as an option particularly when the glenoid cartilage is intact, there is no fresh fracture of the humeral head or neck and preserving humeral bone is desirable.

Resurfacing can be attractive in selected younger patients, but the native glenoid remains exposed to wear just as it does after stemmed hemiarthroplasty.

Pyrocarbon Hemiarthroplasty

Pyrocarbon is a carbon-based material with mechanical properties that differ from conventional metallic bearing surfaces.

It has attracted interest for younger or active patients because of the possibility that its interaction with native glenoid cartilage may be more favorable than traditional metal in some situations.

Recent systematic reviews show encouraging improvements in pain, function and range of motion with pyrocarbon shoulder implants at early and intermediate follow-up.

However, glenoid erosion still occurs radiographically, and long-term comparative evidence remains limited.

Pyrocarbon should therefore be viewed as a promising implant material for selected patients rather than a proven solution that eliminates glenoid wear.

Metallic Hemiarthroplasty

Traditional shoulder hemiarthroplasty usually uses a cobalt-chromium or other metallic humeral head.

These implants have decades of clinical experience.

The major challenge is not usually the durability of the metal head itself.

The important long-term problem is the natural glenoid cartilage on the opposite side.

A 2025 systematic review of metallic hemiarthroplasty with more than ten years of follow-up found that patients generally improved after surgery, but long-term revision rates varied widely and symptomatic glenoid erosion was a leading reason for failure.

What Conditions Can Partial Shoulder Replacement Treat?

Potential indications include humeral-head osteonecrosis, isolated humeral-sided arthritis, severe glenoid bone deficiency preventing secure glenoid implantation, selected younger patients where bone preservation is particularly important, complex fractures and certain revision or salvage situations.

The procedure is not routinely the best choice for ordinary primary osteoarthritis affecting both sides of the joint.

It is also not generally appropriate when severe irreparable rotator cuff dysfunction creates unstable shoulder mechanics.

The surgeon needs to identify a reason why preserving the native glenoid is preferable to total or reverse replacement.

Partial Shoulder Replacement for Osteoarthritis

Primary glenohumeral osteoarthritis damages cartilage on both the humeral head and glenoid over time.

If both surfaces are significantly arthritic, replacing only the humeral side leaves one diseased surface untreated.

This explains why anatomic total shoulder replacement usually provides better pain relief in patients with primary osteoarthritis and an intact cuff.

Current AAOS guidance strongly supports the more favorable short- to mid-term pain and functional outcomes of total shoulder arthroplasty compared with hemiarthroplasty for glenohumeral osteoarthritis.

Hemiarthroplasty may still be considered when the glenoid cannot safely accept a component or when specific age, bone and activity considerations justify preservation.

Partial Shoulder Replacement for Humeral-Head Osteonecrosis

Osteonecrosis, also called avascular necrosis, can destroy the humeral head while the glenoid remains relatively preserved.

This creates one of the more logical situations for partial replacement.

When collapse becomes advanced and joint-preserving procedures are no longer adequate, hemiarthroplasty can replace the damaged humeral surface without automatically resurfacing a healthy socket.

The surgeon still needs to evaluate the glenoid carefully because secondary degenerative change can develop.

Recent comparative evidence in shoulder osteonecrosis suggests that both hemiarthroplasty and anatomic total replacement can be effective, with selection depending on glenoid involvement, complications and patient characteristics.

Partial Shoulder Replacement for Proximal Humerus Fracture

Historically, hemiarthroplasty was a major treatment for displaced three- and four-part proximal humerus fractures that could not be reconstructed reliably.

The broken humeral head was replaced, while the greater and lesser tuberosities were repaired around the prosthesis.

The final outcome depended heavily on tuberosity healing because those fragments carry rotator cuff attachments.

If the greater tuberosity migrated or failed to unite, shoulder elevation and rotation could remain poor despite a well-fixed implant.

This dependence on tuberosity healing is one reason reverse shoulder replacement has become more popular for complex fractures in older adults.

Does Hemiarthroplasty Still Have a Role for Shoulder Fractures?

Yes, but the role is more selective.

In many patients older than approximately 65 years with unreconstructable displaced three- or four-part fractures, reverse shoulder arthroplasty now offers more predictable functional results than hemiarthroplasty.

Hemiarthroplasty can still be considered when glenoid cartilage is healthy and the patient is younger, tuberosity reconstruction is expected to be reliable or reverse replacement is undesirable for anatomical or patient-specific reasons.

The decision requires expertise in both fracture surgery and shoulder arthroplasty.

Partial Shoulder Replacement for Young Patients

Young patients create a difficult problem because any shoulder replacement may need to function for decades.

Avoiding a glenoid component can preserve glenoid bone and eliminate polyethylene glenoid loosening as an immediate concern.

This historical rationale made hemiarthroplasty attractive.

However, young active patients can also place substantial load on the natural glenoid, increasing concern for progressive erosion.

Modern systematic reviews show that hemiarthroplasty can provide long implant survival in some younger cohorts, but survivorship alone does not mean that pain and function remain ideal.

The patient needs a balanced discussion of bone preservation versus glenoid wear.

Partial Shoulder Replacement for Avascular Necrosis in Younger Adults

A younger adult with advanced humeral-head collapse but relatively healthy glenoid cartilage can represent a reasonable hemiarthroplasty candidate.

Potential causes of osteonecrosis include corticosteroid exposure, trauma, sickle cell disease, alcohol-related factors and other medical conditions.

The underlying cause can also influence bone quality and future joint progression.

Resurfacing or stemmed hemiarthroplasty can be considered according to remaining humeral bone.

If the glenoid is already substantially damaged, total replacement can be more appropriate.

Partial Shoulder Replacement With Severe Glenoid Bone Loss

Sometimes the natural glenoid is abnormal enough that routine total shoulder replacement cannot obtain safe fixation.

This creates a paradox: the glenoid surface is not necessarily healthy, but placing a conventional component can be technically dangerous or impossible.

In selected situations, hemiarthroplasty can avoid an unstable glenoid component.

Modern reverse shoulder systems with augments, bone grafting and custom reconstruction have reduced the number of cases in which this is necessary.

Partial replacement therefore functions more as a selective salvage or bone-preserving strategy rather than a routine answer to severe glenoid disease.

Hemiarthroplasty as a Salvage Procedure

A 2025 systematic review and a 2026 meta-analysis confirm that hemiarthroplasty still has a role as a salvage reconstruction when failed previous shoulder arthroplasty cannot be reliably converted to another total or reverse implant.

Examples include catastrophic glenoid bone loss, infection-related situations after appropriate treatment or circumstances where stable glenoid fixation is impossible.

Pain can improve, but functional outcomes are typically more modest than those expected after uncomplicated primary shoulder replacement.

Patients undergoing salvage hemiarthroplasty should therefore receive very different counseling from a patient having an elective primary resurfacing procedure.

Partial Shoulder Replacement and the Rotator Cuff

A standard anatomic hemiarthroplasty relies substantially on functioning rotator cuff mechanics.

The rotator cuff centers the humeral prosthetic head against the native glenoid.

A massive irreparable cuff tear can allow the humeral head to migrate upward.

This can lead to poor mechanics, erosion and limited elevation.

Reverse shoulder replacement is generally more appropriate when severe cuff deficiency dominates the clinical problem.

Cuff Tear Arthropathy and Partial Replacement

Traditional hemiarthroplasty was historically used in certain cuff tear arthropathy patients.

Extended-head or cuff tear arthropathy prostheses were designed to articulate with the glenoid and parts of the acromial arch.

Today, reverse shoulder replacement usually offers more reliable elevation for patients with severe cuff tear arthropathy and a functional deltoid.

Hemiarthroplasty can still be considered in unusual selected patients where reverse replacement is contraindicated or glenoid fixation is impossible.

Partial Shoulder Replacement and the Glenoid

The native glenoid is the defining feature of the operation.

Before recommending partial replacement, the surgeon needs to decide whether its cartilage is sufficiently healthy to remain a long-term bearing surface.

Standard X-rays demonstrate joint-space narrowing and erosion.

CT shows glenoid shape and bone stock.

MRI can provide additional information about cartilage and soft tissues in selected cases.

The surgeon should not assume the glenoid is healthy simply because the procedure is called “partial.”

Glenoid Erosion

Glenoid erosion means progressive wear of the natural socket after hemiarthroplasty.

It can occur gradually as the artificial humeral head articulates against native cartilage and bone.

Radiographic wear does not always cause symptoms.

However, symptomatic glenoid erosion is one of the most important long-term reasons for conversion to total or reverse shoulder replacement.

The risk depends on diagnosis, implant material, shoulder mechanics and the condition of the glenoid at the time of surgery.

Why Can Glenoid Erosion Become Painful?

As cartilage is lost, the prosthetic humeral head begins to articulate against increasingly exposed bone.

The joint can become painful and stiff.

The glenoid can also remodel or erode asymmetrically, changing shoulder mechanics.

A patient who initially obtained excellent relief can therefore develop gradually increasing deep joint pain years later.

New pain after a long symptom-free period should trigger updated radiographs rather than being attributed automatically to muscles or age.

Does Pyrocarbon Prevent Glenoid Erosion?

Current evidence does not justify saying that pyrocarbon completely prevents glenoid wear.

Recent systematic reviews report encouraging clinical results and relatively low revision rates at early- and mid-term follow-up.

However, radiographic glenoid erosion remains documented.

A 2026 systematic review of pyrocarbon shoulder implants reported high pooled survivorship, particularly for stemmed pyrocarbon hemiarthroplasty, but emphasized heterogeneity and the need for better long-term comparative evidence.

The material is therefore promising but not a guarantee against future glenoid disease.

Partial Shoulder Replacement vs Resurfacing

Both procedures preserve the glenoid.

The difference is primarily how much humeral bone is replaced.

Conventional hemiarthroplasty removes the humeral head and attaches a prosthetic head to a stem or short-stem implant.

Resurfacing retains most of the head and caps its surface.

Resurfacing preserves more bone and can simplify later conversion in selected patients, but it requires adequate humeral-head bone stock and cannot correct every deformity.

Partial Shoulder Replacement vs Anatomic Total Shoulder Replacement

For primary osteoarthritis with an intact rotator cuff and a suitable glenoid, anatomic total shoulder replacement generally provides better pain relief and function.

Partial replacement avoids a glenoid implant and preserves glenoid bone, but the remaining natural cartilage can become a source of pain.

The decision is therefore not simply “less surgery versus more surgery.”

It is a trade-off between glenoid-component risks and native-glenoid wear.

Partial Shoulder Replacement vs Reverse Shoulder Replacement

Partial replacement preserves normal ball-and-socket orientation and depends on rotator cuff function.

Reverse replacement changes the biomechanics so the deltoid can elevate the arm with less dependence on the cuff.

Reverse is therefore generally preferred for severe cuff deficiency, cuff tear arthropathy and many complex fractures in older adults.

Partial replacement remains more anatomically conservative when the glenoid and cuff are suitable.

Does Partial Shoulder Replacement Preserve More Bone?

Yes, particularly with resurfacing and short-stem techniques.

Preserving glenoid bone can also be valuable for future revision.

However, bone preservation should not be considered an advantage if the preserved surface is already diseased and continues to cause pain.

The correct objective is durable function, not simply minimizing the amount of implanted material.

Can Partial Shoulder Replacement Delay a Total Replacement?

It can in selected patients.

A well-functioning hemiarthroplasty can provide years of useful shoulder function before any revision becomes necessary.

Some patients never require conversion.

Others develop glenoid wear and need another operation.

Partial replacement should therefore be chosen because it is an appropriate definitive treatment for the current shoulder rather than automatically viewed as a temporary stage before total replacement.

Establishing the Correct Diagnosis

The surgeon first determines why the shoulder hurts.

Pain can come from osteoarthritis, osteonecrosis, fracture deformity, rotator cuff disease, cervical nerve compression or another condition.

A partial replacement should not be planned simply because the humeral head looks abnormal on one image.

Symptoms, examination and imaging need to point toward a humeral-side problem that the procedure can realistically solve.

Shoulder Examination

Active and passive range of motion are measured.

Rotator cuff strength is tested.

The surgeon evaluates whether the humeral head remains centered or has migrated because of cuff failure.

Deltoid function and neurological status are also assessed.

The examination helps distinguish stiffness caused by arthritis from weakness caused by tendon or nerve pathology.

X-Rays

X-rays are fundamental.

They show humeral-head collapse, osteophytes, glenoid joint-space loss, fracture deformity and previous implants.

Axillary and other specialized views demonstrate glenoid wear more clearly.

The surgeon looks specifically for evidence that the socket has enough preserved cartilage and bone to justify leaving it untreated.

CT Scan

CT provides detailed assessment of bone.

It is useful for glenoid version, erosion, bone deficiency and old fracture deformity.

Three-dimensional reconstruction can be particularly helpful when deciding whether the glenoid can accept a component.

A patient initially thought to need partial replacement can occasionally become a total or reverse candidate after more precise CT assessment.

MRI

MRI evaluates rotator cuff tendons, muscle quality, cartilage, osteonecrosis and other soft tissues.

It can be particularly helpful in younger patients or when cuff function is uncertain.

Advanced osteonecrosis can also be characterized.

MRI is less essential when advanced arthritis and cuff condition are already clear clinically and radiographically, but it remains a valuable selective tool.

Ultrasound

Ultrasound provides a dynamic and cost-effective way to examine the rotator cuff.

It can be useful when MRI is unavailable or contraindicated.

The quality of the examination depends on operator expertise.

A major cuff tear discovered before hemiarthroplasty can fundamentally alter implant choice.

Confirming Glenoid Cartilage Condition

This step is central to patient selection.

The surgeon assesses joint space on radiographs and cartilage on advanced imaging when necessary.

Even with careful imaging, the final cartilage condition is sometimes best appreciated during surgery.

Patients should understand that the surgical plan can occasionally change if the glenoid is more damaged than expected.

Evaluating the Rotator Cuff

The supraspinatus, infraspinatus and subscapularis are particularly important in anatomic shoulder mechanics.

A small repairable cuff tear does not necessarily exclude hemiarthroplasty.

A massive irreparable tear is different.

The surgeon should determine whether the shoulder can remain mechanically balanced after a humeral-only replacement.

Evaluating the Subscapularis

The subscapularis frequently needs to be released during the common deltopectoral approach.

It must then heal reliably if it is repaired.

Pre-existing subscapularis deficiency can increase instability and functional problems.

Previous surgery can compromise the tendon.

The surgeon therefore reviews prior operations carefully.

Evaluating Bone Quality

Bone quality influences fixation.

Resurfacing requires enough strong humeral-head bone to support the cap.

Stemless or short-stem implants require adequate proximal humeral bone.

Severe osteoporosis, fracture or deformity can favor a longer stem or cemented component.

The implant should match the remaining bone rather than being selected purely according to the least invasive design.

Evaluating Osteonecrosis

When osteonecrosis is the indication, the surgeon assesses the extent of humeral-head collapse.

The glenoid must also be evaluated for secondary degeneration.

Earlier-stage disease may not need replacement at all.

A young patient with limited collapse can sometimes undergo a joint-preserving procedure rather than arthroplasty.

Fracture Planning

Fracture hemiarthroplasty requires detailed assessment of the greater and lesser tuberosities.

These fragments contain rotator cuff attachments.

The ability to reconstruct them anatomically strongly affects outcome.

CT can help define comminution.

In an older patient with poor bone and unrepairable tuberosities, reverse shoulder arthroplasty can be more predictable.

Previous Surgery

Prior operative reports should be reviewed.

Hardware, anchor placement, cuff repair and previous stabilization procedures can alter anatomy.

Revision hemiarthroplasty cases require information about existing components and glenoid damage.

Unexpected implant systems or bone loss can turn a planned operation into a much more complex procedure.

Nonsurgical Treatment

For degenerative shoulder conditions, surgery is generally considered after appropriate nonsurgical treatment has failed to provide acceptable relief.

Options can include activity modification, medication, physiotherapy and selected injections.

A destroyed or collapsed humeral head cannot be restored by therapy, but symptoms can still sometimes be managed without immediate replacement.

The patient's level of disability should justify the operation.

Corticosteroid Injection

Injections can reduce pain temporarily.

They do not regenerate cartilage or reverse humeral-head collapse.

Injection timing relative to arthroplasty needs to be discussed with the surgeon because infection risk is an important consideration around joint replacement.

Patients should disclose all recent shoulder injections during surgical planning.

Medical Optimization

Medical conditions such as diabetes, cardiovascular disease and pulmonary disease should be optimized.

Elective shoulder arthroplasty provides time to address modifiable risks.

The objective is not to create a perfectly healthy patient but to reduce preventable complications.

Anaesthesia assessment also identifies issues relevant to the interscalene block and general anaesthesia.

Smoking and Nicotine

Smoking increases concern for wound healing, infection and soft-tissue repair.

It can be particularly relevant when the subscapularis or fracture tuberosities need to heal.

Stopping nicotine before and after surgery is strongly encouraged.

Blood-Thinning Medication

Anticoagulants and antiplatelet medication need an individualized plan.

Patients should never stop important medication independently.

The surgeon, anaesthetist and prescribing clinician coordinate interruption or continuation according to bleeding and clotting risk.

Dental and Other Infections

Active significant infections should be treated before elective prosthetic implantation when possible.

Patients should inform the team about dental infections, skin infections or urinary symptoms.

The surgeon will determine whether treatment needs to be delayed.

Planning Rehabilitation

Physical therapy depends on the procedure.

A resurfacing case with strong soft tissues can progress differently from fracture hemiarthroplasty with tuberosity repair.

The local therapist should receive a written protocol.

For international patients, arranging rehabilitation before travel is particularly important.

Preparing the Home

For the first weeks, the operated arm has limited use.

Front-opening clothing, prepared food and help with household tasks can reduce difficulty.

Patients should plan how they will bathe and dress safely.

A recliner or elevated sleeping position is useful for many people during early recovery.

Work Planning

Desk work can often resume relatively early.

Manual work requires much longer recovery.

Patients who lift or work overhead should expect months before unrestricted duties.

The surgeon should discuss actual job tasks rather than giving the same work date to everyone.

Partial Shoulder Replacement is usually performed through an open shoulder approach in which the surgeon exposes the glenohumeral joint, removes or resurfaces the damaged humeral head and implants a prosthetic humeral component while preserving the natural glenoid.

The exact technique differs according to whether a stemmed, short-stem or resurfacing implant is used.

The surgeon also evaluates the rotator cuff, glenoid cartilage and soft-tissue balance before finalizing the reconstruction.

Anaesthesia

General anaesthesia is commonly combined with an interscalene nerve block.

The nerve block provides powerful early pain relief.

The arm may feel numb or heavy during the first postoperative hours.

Oral analgesia is started according to the postoperative plan as the block begins to wear off.

Patient Positioning

The patient is usually placed in the beach-chair or semi-seated position.

The entire shoulder and arm are prepared for surgery.

This position allows the surgeon to manipulate the arm while exposing both the humeral head and glenoid.

Anaesthesia carefully manages blood pressure because the head is positioned above the heart.

Deltopectoral Approach

The deltopectoral approach is commonly used.

The incision is made along the front of the shoulder.

The surgeon works through the natural interval between the deltoid and pectoralis major muscles.

The deltoid is therefore not routinely cut in half.

This approach provides broad access while preserving the major deltoid attachment.

Subscapularis Management

The subscapularis lies at the front of the joint and often must be released to expose the humeral head.

Several techniques exist, including tendon peel, tenotomy and lesser tuberosity osteotomy.

The tendon or bone fragment is generally repaired after implantation when appropriate.

This repair influences early rehabilitation because excessive external rotation can stress the healing subscapularis.

Opening the Joint

After the capsule is opened, the humeral head is exposed.

The surgeon assesses the cartilage, deformity and remaining rotator cuff.

The glenoid is inspected directly.

If the socket is substantially more damaged than expected, the surgeon may reconsider whether preserving it remains appropriate.

This possibility should be discussed before surgery.

Removing the Humeral Head

In conventional hemiarthroplasty, the damaged head is cut at the anatomical neck.

The cut aims to reproduce the patient's natural anatomy.

Incorrect height, version or head size can alter soft-tissue tension and joint mechanics.

The removed humeral head can also provide useful information about the original anatomy.

Humeral Canal Preparation

For a stemmed implant, the surgeon opens the humeral canal and gradually shapes it for the prosthesis.

Trial stems help determine size.

The goal is secure fixation without fracture.

The final component can be press-fit or cemented.

Bone quality and fracture anatomy influence the choice.

Restoring Humeral Version

The humeral head naturally faces backward by a certain amount.

The prosthetic head needs to reproduce appropriate version.

Excessive or insufficient rotation can alter stability and cuff mechanics.

The surgeon also restores head height and offset.

These anatomical details influence the quality of the final result as much as the implant brand itself.

Selecting Humeral Head Size

A prosthetic head that is too large can overstuff the joint, increase stiffness and place excessive pressure on the glenoid.

A head that is too small can reduce stability or alter cuff tension.

Modern modular implants provide multiple head diameters and thicknesses.

The surgeon uses anatomy, trial components and soft-tissue balance to select the most appropriate combination.

Stemmed Hemiarthroplasty

Once the canal is prepared, the stem is inserted.

A modular head is attached.

Trial reduction confirms stability and motion.

The final implant is then seated.

Stemmed hemiarthroplasty is particularly useful when humeral anatomy is severely damaged or when fracture reconstruction requires a stable central implant.

Short-Stem Hemiarthroplasty

A short stem preserves more distal humeral bone.

Preparation focuses on the metaphyseal region.

Adequate proximal bone is essential.

The procedure avoids some stem-related challenges but still requires accurate anatomical reconstruction.

Future revision can potentially be easier because more humeral shaft bone remains untouched.

Resurfacing Technique

Resurfacing does not remove the entire humeral head.

The surgeon places a guide and prepares only the damaged articular surface.

A cap-like prosthesis is fitted over the remaining bone.

Correct sizing is critical because overstuffing can increase glenoid pressure and stiffness.

Resurfacing cannot compensate well for severe deformity or insufficient humeral bone.

Pyrocarbon Hemiarthroplasty

Pyrocarbon implants can be used in stemmed or certain resurfacing configurations depending on the system.

The surgical principles remain similar: restore humeral anatomy, preserve the glenoid and maintain balanced rotator cuff mechanics.

The different bearing material is intended to interact more favorably with native cartilage.

It does not eliminate the need for accurate sizing or correct patient selection.

Evaluating the Glenoid During Surgery

The surgeon inspects cartilage quality directly.

Minor surface wear can sometimes still be compatible with hemiarthroplasty.

Severe full-thickness cartilage loss creates a major concern because the artificial humeral head would continue articulating with exposed glenoid bone.

The surgical team should have an alternative plan when preoperative imaging leaves uncertainty.

Why the Glenoid Is Not Resurfaced

The defining choice in partial replacement is to preserve the native socket.

This can be done because the cartilage is healthy, because the patient is young and bone preservation is prioritized or because glenoid implantation is technically unsafe.

The decision should always have a specific rationale.

Leaving an obviously arthritic glenoid untreated simply to make the surgery “less invasive” generally leads to inferior pain relief.

Fracture Hemiarthroplasty Technique

In complex proximal humerus fracture cases, the humeral head fragments are removed.

The stem is positioned to recreate height and version.

The tuberosities are then reconstructed around the prosthesis using strong sutures.

Bone graft can be placed between fragments.

Healing of the greater tuberosity is particularly important because it restores the attachment of supraspinatus and infraspinatus.

Tuberosity Repair

The greater and lesser tuberosities are positioned around the implant.

Heavy sutures secure the fragments to each other, the humeral shaft and sometimes the prosthesis.

Correct height is crucial.

A tuberosity that heals too high, too low or too far posteriorly can compromise cuff mechanics.

This is why fracture hemiarthroplasty outcomes depend heavily on surgical technique and biological healing.

Cemented Stem

Bone cement can provide immediate fixation.

It is particularly useful in osteoporotic fracture cases or when press-fit stability is inadequate.

The cement mantle should support the stem without interfering with fracture healing where tuberosities need to unite.

The surgeon protects the surrounding bone during cement pressurization.

Cementless Stem

Press-fit fixation relies on mechanical stability followed by bone ingrowth.

It is widely used when bone quality is sufficient.

Porous or coated surfaces encourage biological integration.

Stemless and short-stem implants use similar bone-preserving concepts but depend even more on proximal bone quality.

Trial Reduction

The shoulder is temporarily reduced with trial components.

The surgeon checks stability, motion and soft-tissue tension.

The humeral head should articulate smoothly with the native glenoid.

Overstuffing is avoided.

The final component is selected only after the reconstruction behaves appropriately.

Subscapularis Repair

After the implant is positioned, the subscapularis is repaired if it was detached.

A strong repair contributes to anterior stability and internal rotation.

The rehabilitation protocol protects the tendon during the early healing period.

Patients should understand that much of the early restriction after shoulder replacement protects soft tissues rather than the metal prosthesis itself.

Wound Closure

The deltopectoral interval is restored.

Deeper layers and skin are closed.

A sterile dressing is placed.

The arm is supported in a sling.

The patient then moves to the recovery unit.

How Long Does Partial Shoulder Replacement Take?

A straightforward primary partial shoulder replacement often takes approximately one to two hours.

Resurfacing can sometimes be shorter.

Complex fracture hemiarthroplasty or revision surgery can take considerably longer because reconstruction and implant removal require additional work.

The total time in the operating department is longer because anaesthesia, positioning and postoperative recovery are included.

Recovery Room

After surgery, the patient is monitored while anaesthesia wears off.

Pain, blood pressure, breathing and neurological status are checked.

The arm can remain numb from the regional block.

Patients should avoid trying to use the numb limb because muscle control remains limited.

Same-Day or Overnight Care

Many modern elective shoulder arthroplasties can be performed with same-day discharge in medically suitable patients.

An overnight stay remains common.

Fracture cases, medically complex patients and revisions can require longer hospitalization.

Safety and home support should determine discharge rather than a fixed package schedule.

Pain Control

Pain is usually most significant during the first days.

The nerve block can provide excellent early relief.

Multimodal medication is used as the block wears off.

The patient should follow the prescribed schedule rather than waiting until pain becomes severe.

Ice can also reduce swelling and discomfort.

Sling

The arm is placed in a sling.

Sling duration varies with the subscapularis repair, fracture reconstruction and surgeon protocol.

Two to six weeks is a common broad range.

The sling is protective but should not lead to unnecessary stiffness of the elbow, wrist and hand.

Hand, Wrist and Elbow Movement

These joints are usually moved early.

Movement helps circulation and reduces stiffness.

The shoulder itself follows a more controlled protocol.

Patients need clear instruction about what counts as safe elbow movement versus active use of the shoulder.

Occupational Therapy

Patients learn how to dress, bathe and use the sling with one hand.

This is especially useful for people who live alone.

The therapist can recommend temporary equipment and home modifications.

Safe independence is an important discharge milestone.

Walking

Walking is encouraged soon after surgery.

The shoulder procedure does not restrict leg weight bearing.

The main concern is avoiding falls.

Using the operated arm instinctively to catch a fall can damage the repair.

Wound Care

The incision is kept clean and dry according to the dressing protocol.

Increasing redness, drainage or fever should be reported.

A little postoperative swelling or bruising can be expected.

Immersion in pools or baths waits until the wound is fully healed.

Before Discharge

The patient should understand medication, sling use, wound care and allowed exercises.

A physiotherapy plan should be available.

The first follow-up visit should already be scheduled.

International patients need documentation they can take to their local therapist and physician.

Partial Shoulder Replacement recovery usually requires approximately three to six months for major functional improvement, while strength and comfort can continue improving for six to twelve months.

Recovery is determined by more than the implant.

The subscapularis and other soft tissues need to heal.

Fracture patients need tuberosities and bone fragments to unite.

Muscles weakened by months of pain need to rebuild.

A small skin scar can therefore heal long before the shoulder is ready for unrestricted loading.

First 24–72 Hours

The sling remains in place.

Pain medication is used as prescribed.

Finger, wrist and elbow movement begins.

Walking and ordinary lower-body activity are encouraged.

Shoulder exercises are limited to those specifically authorized by the surgeon.

First Two Weeks

The incision heals and swelling gradually decreases.

Sleep remains difficult for many patients.

Patients commonly use a recliner or several pillows.

Passive or assisted shoulder motion can begin depending on the surgical technique.

The first postoperative visit checks wound healing and reviews X-rays.

Weeks 2–6

The shoulder remains in a protection phase.

Passive range of motion progresses.

Some protocols begin active-assisted movement during this period, while fracture or subscapularis repairs can require more caution.

The patient should not lift meaningful weight simply because pain has improved.

The biological soft-tissue repair is not mature yet.

Sling Removal

Sling use is often reduced gradually.

An uncomplicated elective hemiarthroplasty can discontinue it earlier than a fracture reconstruction.

Patients can first stop using it at home and continue wearing it in crowded environments.

The treating surgeon's protocol takes priority.

Weeks 6–12

Active shoulder movement becomes more prominent.

The patient gradually raises the arm using their own muscles.

Strengthening begins when soft-tissue healing is adequate.

Daily activities become easier.

Sudden heavy lifting and forceful overhead activity remain inappropriate.

Months 3–6

Strength and endurance improve substantially.

Patients begin returning toward recreational activities.

Work progression depends on physical demands.

The shoulder generally becomes much more useful during this period, although stiffness and muscular fatigue can still occur.

Months 6–12

Improvement can continue for a year.

Patients become more confident using the arm.

Final range of motion depends on preoperative stiffness, rotator cuff condition and surgical indication.

A fracture patient can have a different final result from a patient treated for isolated humeral-head osteonecrosis.

Partial Shoulder Replacement Recovery Time

A broad patient-facing estimate is 12–24 weeks for major recovery.

Basic self-care returns much sooner.

Desk work can resume within weeks.

Heavy work and demanding sport take several months.

The phrase “recovered” therefore needs to be tied to a particular activity rather than a single calendar date.

Recovery After Resurfacing Hemiarthroplasty

Resurfacing preserves more humeral bone but still requires significant soft-tissue healing.

The patient should not assume recovery is dramatically shorter simply because there is no long humeral stem.

Subscapularis management and surgical exposure remain important.

Rehabilitation progression is therefore broadly similar to other anatomic shoulder arthroplasty pathways.

Recovery After Fracture Hemiarthroplasty

Fracture cases are different.

Tuberosity healing becomes central.

The rehabilitation programme protects these fragments while trying to prevent excessive stiffness.

Aggressive early rotation or elevation can jeopardize healing.

Final strength and rotation are influenced by where the tuberosities unite.

Pain After Partial Shoulder Replacement

Pain is generally strongest during the first postoperative days.

The original deep arthritic or collapse-related pain should gradually improve.

Muscular and incisional discomfort can last several weeks.

Therapy can cause temporary soreness.

Pain that worsens after a period of good improvement or is accompanied by fever, drainage or sudden weakness deserves reassessment.

Sleeping

Many patients sleep partly upright initially.

A pillow beneath the elbow can support the arm.

Sleeping on the operated side is usually uncomfortable early.

Side sleeping returns gradually once the incision is healed, sling restrictions are lifted and direct pressure no longer causes significant pain.

Dressing

Front-opening shirts are easiest initially.

The operated arm enters the sleeve first.

The non-operated arm performs most of the dressing work.

Overhead clothing is introduced later as active shoulder motion improves.

Showering

Showering resumes according to wound instructions.

The patient should avoid actively lifting the operated arm beyond restrictions.

A detachable shower head can make hygiene easier.

Falls are a particularly important risk in wet bathrooms, so support and nonslip surfaces are useful.

Driving

Driving should wait until the sling is no longer required, sedating pain medication has stopped and the patient can control the vehicle safely with both arms.

There is no universal week.

The operated side, transmission type, range of motion and local regulations all matter.

Desk Work

Many patients return to light office work in roughly two to four weeks.

Remote work can allow an earlier gradual return.

The arm should be supported and repetitive keyboard activity increased gradually.

Transportation can delay return even if computer work itself is comfortable.

Physical Work

Manual occupations require more time.

Repeated lifting, pushing, pulling and overhead work can load the subscapularis and shoulder joint substantially.

Three to six months or longer can be necessary.

Very heavy occupational activity can remain restricted according to implant and surgeon recommendations.

Physiotherapy

Rehabilitation progresses from protected mobility toward active movement and strengthening.

Scapular control remains important.

The therapist should know whether the patient received stemmed hemiarthroplasty, resurfacing or fracture reconstruction.

A generic shoulder-strengthening programme can advance too quickly.

Passive Motion

Passive movement allows the joint to move without strong contraction of the repaired shoulder muscles.

It helps limit stiffness during the early phase.

External rotation can be restricted to protect the subscapularis.

The exact permitted range depends on surgical technique.

Active-Assisted Motion

The patient begins helping the shoulder move while receiving support from the opposite arm, a cane or therapist.

This transition restores neuromuscular control gradually.

Movement quality matters more than forcing maximum range.

Active Motion

The shoulder eventually moves under its own muscle power.

Weakness is expected.

The therapist watches for compensatory shrugging.

Rotator cuff and deltoid coordination gradually improves.

Strengthening

Strengthening commonly begins around the second or third postoperative month, depending on the operation.

Resistance starts low.

The cuff, deltoid and scapular muscles are progressively loaded.

Heavy weight training is much later.

Returning to the Gym

Lower-body and cardiovascular training can resume earlier if the shoulder is protected.

Upper-body exercise should follow the rehabilitation plan.

Heavy bench press, overhead press and pull-ups are not early goals.

Patients should also avoid exercises that place excessive compressive load on the native glenoid.

Swimming

Swimming can return after adequate motion and strength are restored.

Repetitive overhead strokes require more endurance than ordinary daily activity.

The patient can begin with shorter, lower-intensity sessions.

Golf

Golf commonly returns gradually.

Putting and chipping precede full swings.

The shoulder experiences rotational force during a full swing, so the patient should regain sufficient motion and control first.

Racquet Sports

Tennis and similar sports place more demand on the shoulder.

Groundstrokes return before repeated overhead serves.

High-intensity competitive play may not be appropriate for every implant recipient.

Sport-specific goals should be discussed before surgery.

Intimacy

Sexual activity can generally resume when pain is controlled and the shoulder can remain protected.

The patient should avoid supporting substantial body weight through the operated arm during the early recovery phase.

Positions requiring extreme extension or external rotation should also respect subscapularis precautions.

Long-Distance Travel

Travel can be considered once the patient is medically stable.

Luggage handling is a major practical issue because lifting with the operated arm remains restricted.

International patients should remain near the treating center until early wound and implant assessment are complete.

A clear rehabilitation plan should be in place before returning home.

Long-Term Activity

Most patients can use the shoulder for ordinary daily activities and moderate recreation.

Heavy repetitive loading can accelerate wear on the natural glenoid.

There is no universally proven permanent kilogram limit.

The surgeon should provide recommendations according to implant, bone quality and patient goals.

How Successful Is Partial Shoulder Replacement?

Partial Shoulder Replacement can produce substantial pain relief and functional improvement in carefully selected patients.

The phrase carefully selected is particularly important.

Hemiarthroplasty performs differently depending on whether it is used for osteonecrosis, primary osteoarthritis, fracture or salvage revision.

Pooling all indications into one success percentage would therefore be misleading.

The condition of the natural glenoid is one of the strongest long-term determinants of whether the shoulder remains comfortable.

Outcomes for Primary Osteoarthritis

For ordinary primary glenohumeral osteoarthritis, anatomic total shoulder replacement generally provides superior pain relief and function compared with hemiarthroplasty when the cuff is intact and glenoid implantation is appropriate.

This is reflected in strong AAOS guidance.

Partial replacement can still work, but leaving an arthritic socket untreated creates an ongoing pain source.

The operation should therefore not be selected simply because it sounds less invasive.

Outcomes for Osteonecrosis

Hemiarthroplasty remains useful for selected osteonecrosis patients with preserved glenoid cartilage.

Pain and movement can improve substantially.

Recent comparative evidence suggests both hemiarthroplasty and anatomic total shoulder replacement can be effective for advanced osteonecrosis, with trade-offs in complications and revision.

The degree of glenoid involvement remains important in deciding which option best matches the patient.

Outcomes for Younger Patients

Systematic evidence in patients younger than 65 demonstrates that both hemiarthroplasty and anatomic total shoulder replacement can provide substantial improvements and long implant survivorship.

A meta-analysis reported hemiarthroplasty survivorship above 80% at ten years and meaningful long-term survival beyond that.

However, implant survival does not equal perfect comfort.

Progressive glenoid wear can reduce pain relief even when the humeral prosthesis remains technically well fixed.

Long-Term Metallic Hemiarthroplasty Outcomes

A 2025 systematic review evaluated metallic shoulder hemiarthroplasties with at least ten years of follow-up.

Patients generally experienced improvements in pain, function and motion.

However, postoperative scores were often modest compared with modern expectations, and revision rates varied substantially between studies.

Symptomatic glenoid erosion was repeatedly identified as a major reason for revision.

These results explain why metallic hemiarthroplasty has become a more selective option for arthritic shoulders.

Pyrocarbon Outcomes

Pyrocarbon data are increasingly encouraging.

A 2025 systematic review and meta-analysis involving more than 900 patients found substantial improvements in forward elevation, external rotation and shoulder outcome scores, with a pooled reoperation rate around 8%.

A newer 2026 systematic review including more than 1,100 pyrocarbon cases reported high pooled implant survival and relatively low revision rates, particularly for stemmed pyrocarbon hemiarthroplasty.

However, glenoid wear remained variable and the evidence consisted largely of nonrandomized studies.

Long-term comparative follow-up remains necessary before pyrocarbon can be considered definitively superior to conventional alternatives.

Glenoid Erosion and Clinical Outcome

Radiographic erosion does not always produce immediate symptoms.

Some shoulders show significant wear on X-ray while patients remain functionally satisfied.

Other patients develop deep progressive pain and stiffness.

A long-term study published in 2025 found a high prevalence of radiographic glenoid erosion after hemiarthroplasty, but only a subset required revision.

This distinction is important when interpreting follow-up imaging.

How Long Can Partial Shoulder Replacement Last?

There is no universal expiration date.

Some hemiarthroplasties function for decades.

Long-term survivorship depends on diagnosis, patient age, implant design, glenoid wear and cuff integrity.

For younger anatomical shoulder replacements, systematic evidence has reported more than 80% survival beyond ten years in hemiarthroplasty cohorts.

Modern pyrocarbon data are encouraging but currently have shorter overall follow-up.

What Causes Long-Term Failure?

Painful glenoid erosion is one of the most important causes.

Rotator cuff failure can also destabilize an anatomic hemiarthroplasty.

Other causes include infection, stiffness, instability, humeral component loosening, fracture and incorrect implant sizing.

In fracture patients, tuberosity nonunion can produce a poor functional result even when the implant itself remains stable.

Rotator Cuff Failure

A patient can initially have a good cuff and later develop degenerative tearing.

Loss of cuff function alters joint mechanics.

The prosthetic head can migrate superiorly.

Pain and weakness can progress.

Conversion to reverse shoulder arthroplasty is frequently the most useful revision strategy when severe cuff failure develops.

Revision to Total Shoulder Replacement

If the rotator cuff remains functional and the primary problem is painful glenoid wear, conversion to an anatomic total shoulder replacement can sometimes be considered.

The feasibility depends on glenoid bone stock and humeral component position.

In modern revision practice, reverse arthroplasty has become increasingly common because many failed hemiarthroplasties involve cuff problems, bone loss or complex anatomy.

Revision to Reverse Shoulder Replacement

A 2024 systematic review of more than 1,000 shoulders undergoing revision reverse arthroplasty after failed anatomic total replacement or hemiarthroplasty found substantial improvements in pain, forward elevation and function.

However, revision carried meaningful complication and reoperation rates.

This supports reverse replacement as an important salvage option while reinforcing that conversion is more complex than uncomplicated primary arthroplasty.

Salvage Hemiarthroplasty Outcomes

Hemiarthroplasty itself can also be used as a salvage procedure after failed previous total or reverse arthroplasty when reconstruction of the glenoid is impossible.

Recent reviews show that pain can improve, but functional gains tend to be modest.

Complication and reoperation rates remain clinically important.

Patients in this situation should not expect the same outcome as someone undergoing primary hemiarthroplasty for isolated humeral-head disease.

Traditional Metallic Humeral Heads

Cobalt-chromium and other metallic alloys have been standard materials for humeral heads.

They provide a smooth, durable surface and extensive clinical experience.

The limitation is not that the metal itself wears out quickly.

Rather, a hard prosthetic surface continues articulating against natural glenoid cartilage, which can progressively erode.

Pyrocarbon

Pyrocarbon has elastic and tribological properties that have generated interest for articulation against native cartilage.

Its use is particularly focused on younger or more active patients where glenoid preservation is desirable.

Current evidence shows promising short- and mid-term results.

Long-term evidence is still developing.

The material should therefore be discussed as an option rather than marketed as a guarantee against revision.

Stemmed Humeral Components

Stemmed implants provide fixation within the humeral canal.

They are available in different lengths and geometries.

Longer stems can be useful for fractures and revision reconstruction.

Modern modular systems allow independent adjustment of head size and offset.

Short-Stem Components

Short stems preserve more bone.

They can reduce some challenges associated with long stem removal during future revision.

They require adequate proximal humeral bone.

A short stem is not automatically better if the patient's anatomy requires more distal fixation.

Stemless Components

Stemless shoulder implants rely on fixation within the proximal humerus.

They maximize preservation of the humeral shaft.

They are used mainly when proximal bone quality is good.

Severe osteoporosis, fracture and major deformity can make stemless fixation unsuitable.

Resurfacing Caps

Resurfacing implants fit over the prepared humeral head.

The procedure preserves the shaft and much of the head-neck anatomy.

Correct sizing is critical.

Oversized components can overstuff the shoulder and increase pressure on the glenoid.

Modular Humeral Heads

Modular heads come in multiple diameters, thicknesses and offsets.

This allows the surgeon to reproduce the patient's anatomy.

Correct restoration helps balance the rotator cuff and joint capsule.

Modularity also provides options during revision.

Convertible Platforms

Some humeral stems are designed so a future revision can change the upper components without removing a well-fixed stem.

A hemiarthroplasty can sometimes be converted to another shoulder configuration while preserving part of the implant.

This can reduce bone loss and operative difficulty.

The feasibility depends on stem position, compatibility and the reason for revision.

Cemented Fixation

Cement provides immediate stem stability.

It remains useful in poor bone quality and fracture reconstruction.

Future removal can be more demanding.

The surgeon balances immediate fixation against future revision considerations.

Cementless Fixation

Porous-coated implants allow bone to grow onto or into the component.

This creates biological fixation.

It is commonly used in elective arthroplasty when bone quality is sufficient.

Stable initial seating is required for successful ingrowth.

Computer Planning

Three-dimensional planning is most useful when anatomy is abnormal.

Although partial replacement does not require glenoid component implantation, CT planning can still evaluate socket wear, humeral deformity and whether hemiarthroplasty is actually appropriate.

Modern software can help compare partial, anatomic and reverse reconstruction strategies before surgery.

Navigation and Robotics

Computer navigation and robotics play a smaller role in partial shoulder replacement than in procedures requiring precise glenoid component placement.

Their use is evolving.

Patients should not select a hemiarthroplasty primarily because a center advertises robotics.

Patient selection, anatomical restoration and surgeon experience remain more clinically important.

Implant Brand Selection

Several reputable manufacturers produce shoulder arthroplasty systems.

The best implant is not simply the one with the highest price or newest marketing campaign.

Long-term evidence, availability of revision components, surgeon familiarity and anatomical fit matter.

For international patients, future access to implant information is also important.

The patient should receive documentation of the manufacturer and component sizes before returning home.