Partial Shoulder Endoprosthesis: Humeral Hemi-Arthroplasty Guide — Cost, Top Hospitals & Success Rates | MyMedicPlus

A partial shoulder endoprosthesis — also called a humeral hemi-arthroplasty (HA) — is an operation in which the damaged upper end (head) of the humerus (upper arm bone) is replaced with a metal implant while the natural glenoid (shoulder socket) surface of the scapula is left untouched. The term "partial" distinguishes it from a total shoulder replacement, which resurfaces both the humeral head and the glenoid, and from a reverse shoulder arthroplasty, which changes the normal ball-and-socket geometry by placing the ball component on the scapula side.

Hemi-arthroplasty of the shoulder was first described by Charles Neer II in 1953 for the treatment of complex proximal humerus fractures and subsequently refined for humeral head avascular necrosis, primary glenohumeral arthritis with an intact rotator cuff, and humeral head tumour resection. For fracture indications, the procedure is most commonly performed in elderly patients with 3- or 4-part proximal humerus fractures where the humeral head articular segment is so badly comminuted, displaced, or devascularised that neither open reduction and internal fixation (ORIF) nor non-operative management is likely to achieve a satisfactory outcome.

The operation is performed via the standard deltopectoral approach (the interval between the deltoid and pectoralis major muscles) under general anaesthesia or interscalene regional block. The fractured humeral head is excised and the medullary canal of the humerus is prepared to receive a stemmed metal implant. The implant head reproduces the anatomical offset and retroversion of the native humeral head. Crucially, the greater and lesser tuberosities — the bony attachments of the rotator cuff tendons — are reattached with heavy non-absorbable sutures, as their anatomical healing is the single most important determinant of functional outcome after humeral hemi-arthroplasty.

The primary indication for partial shoulder endoprosthesis in the fracture setting is a complex proximal humerus fracture in an elderly patient where other surgical options are unsuitable. Patient selection is guided by fracture classification and individual patient factors.

Neer Classification of Proximal Humerus Fractures:

• 1-part fractures: Undisplaced or minimally displaced (less than 1 cm displacement or less than 45 degrees of angulation in any fragment). Managed non-operatively in virtually all cases; HA is never indicated.
• 2-part fractures: One fragment significantly displaced. Usually managed with ORIF or non-operatively; HA rarely needed.
• 3-part fractures: Two fragments significantly displaced (greater tuberosity + surgical neck, or lesser tuberosity + surgical neck). HA is considered in elderly patients with osteoporotic bone when ORIF is unlikely to be stable. However, the PROFHER trial found no clear benefit of surgery over non-operative management even at this stage.
• 4-part fractures: All four major segments displaced (articular head, shaft, greater tuberosity, lesser tuberosity). The humeral head articular segment is at high risk of avascular necrosis due to disruption of its blood supply. HA is the most commonly performed surgical treatment, though reverse shoulder arthroplasty (RSA) is now preferred in many centres for older patients.
• 4-part fracture-dislocation: Dislocation of the articular head fragment from the glenoid with associated fracture. High risk of avascular necrosis; most cases are best treated surgically.
• Head-split fractures: The articular surface of the humeral head is itself fractured or impression-fractured. Standard ORIF is not feasible; HA or RSA is required.

Beyond fracture morphology, patient age, bone quality, pre-morbid function, activity demands, and rotator cuff integrity all influence the choice between HA, RSA, ORIF, and non-operative management.

Selection of the appropriate treatment for a complex proximal humerus fracture requires careful evaluation of the fracture, the patient, and the likely functional goals:

• Imaging assessment: Plain radiographs (true AP, axillary lateral, and scapular Y views) are obtained as first-line imaging. CT scan with 3D reconstruction is the gold standard for pre-operative planning, allowing precise measurement of tuberosity displacement, head fragment vascularisation (perforation of the medial calcar predicts retained vascularity), and glenoid morphology. MRI is rarely needed acutely but may be used in subacute or elective settings to assess rotator cuff integrity.
• Rotator cuff assessment: The functional state of the rotator cuff is a key determinant of whether HA or RSA is more appropriate. Intact or repairable cuff favours HA; massive irreparable rotator cuff tear strongly favours RSA, which does not depend on rotator cuff function for stability and elevation.
• Patient age and activity level: Younger, higher-demand patients (<65 years) with 4-part fractures may benefit more from ORIF or HA with anatomical reconstruction, as they place higher functional demands on the shoulder and have longer life expectancy. Older, lower-demand patients (>70 years) increasingly receive RSA as primary treatment given more predictable pain relief and functional outcomes in this group as demonstrated by contemporary literature.
• Bone quality (osteoporosis assessment): Dual-energy X-ray absorptiometry (DEXA) scan findings, age, and medication history (corticosteroids, bisphosphonates) inform implant fixation strategy and tuberosity repair technique.
• General medical fitness: Anaesthetic pre-assessment includes cardiovascular risk stratification (ASA classification, cardiac and pulmonary function), medication optimisation (antiplatelet and anticoagulant management), and nutritional assessment, as malnutrition impairs fracture healing and wound healing.

The technical performance of humeral hemi-arthroplasty — and especially the repair of the tuberosities — is directly predictive of functional outcome.

Implant Options:

• Cemented stems: Bone cement (polymethylmethacrylate, PMMA) is used to fix the implant stem within the humeral shaft. Provides immediate rigid fixation, which is beneficial in osteoporotic bone or when early mobilisation is planned. Standard for elderly patients with soft, cancellous proximal humeral bone. The cement also allows precise adjustment of implant height and retroversion intraoperatively.
• Cementless (press-fit) stems: The implant is designed to achieve primary stability by press-fitting within the diaphysis, with bone ingrowth into the porous-coated surface providing long-term biological fixation. Preferred in younger patients with good bone quality. Avoids cement-related complications (thermal injury, cement disease) and simplifies future revision if required.
• Fracture-specific stems: Shorter, metaphyseal-filling stems specifically designed for fracture indications, with fins, slots, or holes to facilitate tuberosity suture fixation directly to the implant. Examples include the Aequalis Fracture system (Tornier) and the Epoca stem (Synthes).

Critical Technical Steps:

• Implant height and retroversion: The prosthetic head must be seated at the correct height (typically just above the greater tuberosity level) and retroversion (generally 25–30 degrees) to restore the anatomical length-tension relationship of the rotator cuff musculature.
• Greater tuberosity (GT) repair: The supraspinatus, infraspinatus, and teres minor tendons insert on the greater tuberosity. The GT fragment is fixed anatomically posterior and inferior to the implant head using heavy non-absorbable sutures passed through drill holes in the implant or cemented bone. Greater tuberosity positioned more than 1 cm above the implant head or more than 5 mm posterior to the ideal position is associated with significantly inferior functional outcomes, including persistent pain, weakness, and risk of subacromial impingement.
• Autologous bone grafting: Cancellous bone harvested from the excised humeral head is packed around the tuberosity fragments and at the implant-bone junction to enhance healing.

When performed correctly in well-selected patients, partial shoulder endoprosthesis offers the following benefits:

• Reliable pain relief: The primary benefit of HA for complex proximal humerus fractures is consistent and durable elimination of acute fracture pain. Published series report satisfactory pain relief in 70–85% of patients at 2 years, regardless of whether functional outcome is excellent or only moderate.
• Avoidance of avascular necrosis complications: In 4-part fractures and head-split fractures, the humeral head articular segment has a very high rate of avascular necrosis if preserved. Early HA definitively removes the necrotic or at-risk segment and provides an immediate mechanical solution, avoiding the chronic pain and stiffness of established avascular necrosis that would otherwise require delayed arthroplasty under more difficult conditions.
• Functional improvement over ORIF in selected cases: In elderly osteoporotic patients with 4-part fractures, ORIF with locking plates is associated with high rates of hardware failure (cut-out of screws through soft bone), malunion, and avascular necrosis — reported in 10–40% of cases. HA avoids these specific failure modes and provides more predictable short-term functional recovery in this patient group.
• Revision flexibility: A primary humeral stem provides a foundation for conversion to total shoulder arthroplasty (by adding a glenoid component) or reverse shoulder arthroplasty in the future if the native glenoid develops significant arthritis or if rotator cuff function deteriorates, provided the stem remains well-fixed and in an appropriate position.
• Established safety record: Humeral hemi-arthroplasty is a well-characterised procedure with decades of published outcomes data, standardised implant systems, widely distributed surgical training, and established revision protocols.

The complication profile of humeral hemi-arthroplasty for fracture is substantially influenced by tuberosity healing quality and implant positioning:

• Greater tuberosity malunion or non-union: The most important and most frequently encountered problem following fracture HA. Tuberosity displacement — particularly superior migration of the GT — results in persistent subacromial impingement, severe rotator cuff dysfunction, inability to actively elevate the arm above shoulder height, and dramatically reduced functional scores. Published rates of GT malunion or non-union range from 10–40% in fracture HA series, directly accounting for the variable functional outcomes reported in the literature.
• Glenoid erosion: The metal humeral head articulates against the native cartilage of the glenoid. Over years, this can lead to progressive erosion of the glenoid surface (a phenomenon called "medialization"), resulting in increased pain and reduced range of motion. This is the primary reason for long-term failure of HA relative to total shoulder replacement, occurring in a significant proportion of patients beyond 10 years and potentially necessitating conversion to total or reverse shoulder arthroplasty.
• Instability: Prosthetic instability (subluxation or dislocation of the humeral head from the glenoid) can result from incorrect implant positioning, tuberosity failure with rotator cuff imbalance, or deltoid muscle dysfunction. Reported in approximately 3–5% of fracture HA cases.
• Infection (periprosthetic joint infection, PJI): Deep periprosthetic infection is a serious complication requiring washout, exchange arthroplasty, or implant removal. Incidence approximately 1–2% in primary shoulder arthroplasty. Risk factors include diabetes, immunosuppression, and prolonged operative time.
• Implant loosening: Aseptic loosening of the humeral stem is less common in the shoulder than in hip or knee arthroplasty, with published revision rates of 2–5% at 10 years.
• Nerve injury: The axillary nerve, which wraps around the surgical neck of the humerus, is at risk during the deltopectoral approach. Traction injury leads to deltoid weakness; incidence is approximately 1–2% with careful surgical technique.

Rehabilitation after partial shoulder endoprosthesis for fracture follows a structured three-phase protocol, with the pace of progression determined by tuberosity healing on serial radiographs:

• Phase 1 — Passive mobilisation (weeks 0–6): The arm is rested in a sling between therapy sessions. A physiotherapist guides passive pendulum exercises and gentle passive forward flexion and external rotation within pain-free limits. The primary goal is preventing joint stiffness and capsular contracture while protecting the tuberosity repair from excessive stress. Active use of the shoulder is strictly prohibited until radiographic evidence of tuberosity healing is confirmed, typically at 4–6 weeks.
• Phase 2 — Active-assisted mobilisation (weeks 6–12): Once tuberosity healing is confirmed on X-ray, active-assisted exercises begin using a pulley, a stick, or the opposite arm to assist the operated shoulder. Strengthening of the scapular stabilisers (serratus anterior, lower trapezius, rhomboids) is emphasised. Internal and external rotation strengthening commences with light resistance bands. Range of motion goals: forward flexion to 120 degrees, external rotation to 30–40 degrees.
• Phase 3 — Active strengthening (weeks 12 onward): Full active exercises with progressive resistance to rebuild deltoid, rotator cuff, and periscapular muscle strength. Sport-specific exercises for active patients are introduced at 4–6 months. Maximum functional recovery from fracture HA typically plateaus between 12 and 18 months post-operatively, though continued gradual improvement may occur beyond this point.
• Radiographic follow-up: X-rays are taken at 6 weeks (tuberosity healing check), 3 months, 6 months, and 12 months, then annually or as clinically indicated. CT is used to evaluate tuberosity position if X-ray findings are equivocal.
• Long-term monitoring: All shoulder arthroplasty patients should be enrolled in a national or regional arthroplasty register (such as the National Joint Registry in the UK or the Australian Orthopaedic Association National Joint Replacement Registry) to facilitate long-term implant surveillance and early identification of device-specific failure patterns.

The total cost of partial shoulder endoprosthesis encompasses the implant, surgery, hospitalisation, rehabilitation, and long-term follow-up:

• Implant cost: A fracture-specific humeral hemi-arthroplasty system (stem, head, and associated fixation tools) costs USD 3,500–8,000 at wholesale pricing depending on manufacturer, head size, and stem design. Total shoulder arthroplasty or reverse shoulder arthroplasty systems cost more due to the additional glenoid component.
• Surgical and anaesthetic fees: Surgeon and anaesthetist fees for a shoulder arthroplasty procedure (typically 90–150 minutes of operating time) vary from USD 3,000–8,000 in the United States private sector to USD 1,000–2,500 in medical tourism destinations at accredited facilities.
• Hospital stay: A 2–4 night inpatient stay is typical after elective shoulder arthroplasty. At private hospitals, ward costs range from USD 800–3,000 per night in the United States to USD 100–300 per night in India or Thailand.
• Approximate total costs:
  • United States (private): USD 20,000–45,000
  • United Kingdom (private): GBP 10,000–18,000
  • Germany: EUR 8,000–15,000
  • India (JCI/NABH-accredited): USD 4,000–8,000
  • Thailand (JCI-accredited): USD 5,000–10,000
• Rehabilitation costs: 3–6 months of physiotherapy (12–24 sessions) adds USD 1,500–4,000 in Western healthcare systems or USD 300–800 in medical tourism destinations.
• Revision surgery: Conversion of a failed HA to RSA (the most common revision scenario due to glenoid erosion) is a complex procedure with significantly higher costs than primary arthroplasty due to implant removal challenges, larger implant inventory requirements, and longer operating time.

Several treatment alternatives exist for complex proximal humerus fractures, and the optimal choice depends on fracture type, patient age, and bone quality. The PROFHER trial has particularly influenced the evidence base for this decision:

• Non-operative management: The PROFHER (PROximal Fracture of the Humerus: Evaluation by Randomisation) trial — a UK multicentre RCT published in the Lancet (2015) — randomised 250 patients with 3- or 4-part proximal humerus fractures to surgical treatment (HA or ORIF) versus non-operative management with a sling and physiotherapy. At 24 months, there was no significant difference in Oxford Shoulder Score, EQ-5D quality of life, or pain between the groups. This landmark finding challenged the widespread assumption that surgery confers functional superiority and has led many centres to adopt a conservative-first approach, particularly for 3-part fractures in elderly patients.
• Open reduction and internal fixation (ORIF) with locking plate: For 3- and some 4-part fractures in younger patients (<60–65 years) with good bone quality, anatomical ORIF using a locking proximal humerus plate (such as the Synthes PHILOS or DePuy Global PHF) preserves the native articular cartilage and avoids the lifelong implications of implant-related complications. However, in elderly osteoporotic patients, ORIF carries high rates of hardware failure (screw cut-out through the soft humeral head) and avascular necrosis, making HA or RSA preferable.
• Reverse shoulder arthroplasty (RSA): RSA — which reverses the shoulder's ball-and-socket geometry by placing a glenosphere on the scapula and a shallow cup on the humeral stem — does not depend on rotator cuff function for shoulder elevation, relying instead on the deltoid muscle. This makes it particularly effective in elderly patients with 3- or 4-part fractures, massive rotator cuff tears, or severe osteoporosis. Multiple prospective comparative studies and meta-analyses published between 2018 and 2024 demonstrate superior functional outcomes of RSA over HA for fracture indications in patients over 70, with better Constant Shoulder Scores, higher patient satisfaction, and lower reoperation rates. RSA is now preferred over HA at many high-volume shoulder arthroplasty centres for 3- and 4-part fractures in patients over 65–70 years of age.
• Intramedullary nailing: A retrograde or antegrade proximal humerus nail is a minimally invasive fixation option for 2-part surgical neck fractures with varus deformity in younger patients; it is not appropriate for 3- or 4-part fractures where comminution prevents stable fixation.