Principles and Indications for Hemiarthroplasty
- Core Concepts
- Definition – Replacement of the humeral head with a prosthetic component while the native glenoid socket is preserved.
- Keys to Success –
- Adequate exposure of the joint.
- Reliably identified surgical landmarks.
- Precise sizing, height, and retroversion of the implant.
- Preferred Surgical Approach – Deltopectoral. Exposure is optimised by lesser-tuberosity osteotomy rather than simple subscapularis tenotomy.
Indications (Primary Hemiarthroplasty)
- Primary osteoarthritis with poor glenoid bone stock or young, active patients at high risk of glenoid loosening.
- Avascular necrosis (AVN) of the humeral head with minimal glenoid involvement.
- Rheumatoid arthritis – especially < 50 years.
- Acute complex proximal-humerus fractures – 3-part (poor bone), 4-part, head-splitting, or > 40 % articular loss.
- Capsulorrhaphy arthropathy – minimal glenoid disease or low bone stock.
- Rotator-cuff arthropathy – if active elevation > 90° is present.
Contra-Indications
- Active infection, neuropathic joint, or brachial-plexus palsy.
- Unmotivated / non-compliant patient.
- Coraco-acromial-ligament deficiency (risk of superior escape).
- Inadequate glenoid bone stock (→ TSA).
- Massive irreparable cuff or deltoid dysfunction (→ Reverse TSA).
Surgical Procedure & Techniques
- Preparation & Positioning
- Beach-chair preferred (supine if converting from failed ORIF).
- Full pre-op work-up: labs, imaging, allergy/medication review.
Key Operative Steps
- Deltopectoral skin incision.
- Lesser-tuberosity osteotomy → humeral-head retrieval.
- Head resection – cut begins at medial supraspinatus insertion.
- Canal preparation – sequential rasps; trial stem.
- Implant parameters:
- Retroversion ≈ 30°.
- Height – GT 7-8 mm below prosthetic head; ~56 mm above pectoralis-major upper border.
- Head diameter – native measurement / contralateral X-ray.
- Tuberosity fixation (fractures) – anatomic reduction + heavy sutures + autograft.
- Layered closure; verify stability.
Prosthesis Options
Variant | Key Points | Typical Use |
Stemmed | Metal head + intramedullary stem; cemented preferred | Most cases, poor bone |
Resurfacing | Cap-like; bone-sparing | Young, focal chondral loss |
Stemless | Metaphyseal fixation only | Good bone, easy future revision |
Pyrocarbon heads | Low wear, bone-friendly | AVN / young OA |
“Ream & Run” Technique
- Concentric reaming of glenoid to a single smooth bowl; no glenoid implant.
- Aims for durable, high-demand shoulder without polyethylene problems.
Post-Op Care & Rehabilitation
Phase | Time-frame | Immobilisation | Motion / Therapy Goals |
1 | 0-6 wks | Abduction pillow, neutral rotation | Passive ABD/ADD/FLEX ≤ 90°, no IR/ER; scapular & elbow/hand work; CPM; pain control |
2 | 7-11 wks | None | Assisted → active motion > 90°, gentle rotation; begin strengthening, proprioception, hydro-therapy |
3 | ≥ 12 wks | None | Full ROM, resistive & eccentric loading, sport-/work-specific training |
Fracture cases with tuberosity repair remain in pillow 6 wks; active-assist begun cautiously to protect healing.
Outcomes, Complications & Prognosis
- Common Complications
- Periprosthetic infection (1-2 %).
- Axillary-nerve neuropraxia (~ 3 %).
- Glenoid erosion & progressive pain.
- Tuberosity non-union / migration (most frequent fracture failure).
- Instability, over-stuffing, stiffness, VTE, periprosthetic fracture.
- Risk Factors for Revision (359-case review)
- Female sex 81 %.
- Cuff/subscapularis failure ~ 25 %.
- Fracture sequelae 43 % (tuberosity issues 73 %).
- Glenoid erosion 35 % (esp. valgus or decentered components).
- Mean time to revision 3.4 yrs (55 % < 2 yrs).
- Prognosis by Diagnosis
- Best – Avascular necrosis (10-yr survival ≈ 95 %).
- Good – Primary OA, rheumatoid (< 50 yrs).
- Poor – Cuff-tear arthropathy, post-traumatic sequelae.
Early accurate positioning, centering the head, avoiding valgus and meticulous rehab are key to long-term success. If cuff/tuberosity integrity is doubtful, reverse TSA may outperform hemiarthroplasty.
Hemiarthroplasty vs Alternatives
Aspect | Hemiarthroplasty | Total SA | Reverse SA |
Glenoid component | No | Poly/metal | Glenoid baseplate + glenosphere |
Indications | Isolated humeral disease, young bone, fracture | Bi-compartment OA | Massive cuff tear ± arthritis, comminuted fractures |
Advantages | Bone-sparing, shorter op, easier revision | Pain relief, ROM | Stable despite cuff loss, less glenoid loosening |
Limitations | Glenoid wear, cuff-dependent | Glenoid loosening risk | Loss of external-rotation strength, higher instability |
Historical Milestones & Innovation
- 1893 – Péan: first shoulder prosthesis (platinum/ivory).
- 1950s – Neer: modern stemmed hemiarthroplasty, fracture indications.
- 1990s-2000s: Resurfacing & stemless designs; “Ream & Run.”
- 2010s-present: Pyrocarbon heads, patient-specific instruments, augmented-reality & robotic guidance.
Call to Action
If you experience shoulder pain, weakness, or notice abnormal movement of your shoulder blades, consult your healthcare provider for an assessment.
For advice on exercises and managing scapular dyskinesia, visit www.TheArmDoc.co.uk
Call: 020 3384 5588
Email: Info@TheArmDoc.co.uk
Disclaimer
This information is for educational purposes and does not replace medical advice. Always consult a healthcare professional for a diagnosis and treatment tailored to your specific needs.
© 2025 Arm Doc Education | Content for clinical reference only – not a substitute for personalised medical advice.