Mandatory fasting (NPO) for 8 hours, preoperative imaging including X-rays and CT scan, baseline laboratory investigations (CBC, coagulation profile, electrolytes), cardiac clearance for high-risk patients, antibiotic prophylaxis within 60 minutes of incision, and informed surgical consent.
Immediate post-operative stabilization in the PACU, pain management via patient-controlled analgesia, immobilization in a shoulder sling for 4-6 weeks, initiation of physical therapy within 24 hours focusing on pendulum exercises, wound care, and follow-up clinical assessment at 2 and 6 weeks post-discharge.
Comprehensive Clinical Guide: Shoulder Hemiarthroplasty
Shoulder hemiarthroplasty represents a cornerstone intervention in orthopedic surgery, specifically designed to address pathologies involving the humeral head while preserving the integrity of the native glenoid. Unlike total shoulder arthroplasty (TSA), which replaces both the humeral head and the glenoid fossa, hemiarthroplasty focuses exclusively on the proximal humerus. This guide serves as an authoritative resource for clinicians, residents, and medical professionals regarding the indications, surgical technique, and longitudinal management of this procedure.
1. Introduction and Overview
Hemiarthroplasty of the shoulder involves the surgical replacement of the proximal humeral articular surface with a prosthetic component. This procedure is indicated when the humeral articular surface is compromised, but the glenoid cartilage remains healthy or is not suitable for resurfacing.
The primary clinical objective is to restore joint kinematics, alleviate pain, and improve functional range of motion (ROM). By preserving the native glenoid, the procedure avoids the long-term complications associated with glenoid component loosening or wear, which are primary failure modes in total shoulder arthroplasty.
2. Technical Specifications and Mechanisms
The prosthetic components for hemiarthroplasty typically consist of a metallic humeral stem and a modular humeral head.
Key Component Design
- The Humeral Stem: Can be monoblock or modular, cementless (press-fit) or cemented. Modern stems are designed to match the anatomical neck-shaft angle (typically 130° to 135°) to restore normal biomechanics.
- The Humeral Head: Usually manufactured from Cobalt-Chrome or Titanium alloys. The head radius of curvature must be carefully matched to the patient’s native anatomy to prevent overstuffing the joint, which can lead to secondary glenoid erosion.
- Fixation Methods:
- Cemented: Preferred in patients with poor bone quality (osteoporosis) to ensure immediate stability.
- Press-fit: Utilizes porous coating to encourage biological osseointegration, preferred in younger, active patients with high bone density.
3. Clinical Indications and Usage
The decision to perform a hemiarthroplasty is predicated on a thorough clinical and radiographic assessment.
Primary Indications
- Complex Proximal Humerus Fractures: Specifically three- and four-part fractures where the risk of osteonecrosis of the humeral head is high.
- Avascular Necrosis (AVN): Ficat stages II and III, where the humeral head has collapsed but the glenoid surface remains intact.
- Severe Humeral Head Chondrolysis: Post-traumatic or idiopathic degeneration where the glenoid is pristine.
- Failed Internal Fixation: Cases where previous ORIF (Open Reduction Internal Fixation) of the proximal humerus has resulted in malunion or nonunion.
Patient Selection Criteria
| Criteria | Recommendation |
|---|---|
| Age | Generally preferred for younger, active patients to avoid glenoid wear. |
| Bone Quality | Must be sufficient to support the humeral stem. |
| Rotator Cuff Status | Intact or repairable rotator cuff is essential for stability. |
| Glenoid Status | Must show minimal to no arthritic changes. |
4. Pre-Operative Preparation
Preparation is critical to minimizing intraoperative complications and ensuring optimal component sizing.
- Imaging: Standard AP, Axillary, and Scapular Y-views. A CT scan with 3D reconstruction is mandatory to assess bone stock and fracture patterns.
- Medical Optimization: Assessment of cardiovascular health, diabetes control (HbA1c < 7.0), and smoking cessation (at least 4 weeks prior to surgery) to reduce infection risk.
- Informed Consent: Detailed discussion regarding the risk of secondary glenoid erosion and potential for conversion to TSA.
5. The Procedure: Step-by-Step
Surgical Approach: The Deltopectoral Approach
The deltopectoral approach is the gold standard, providing excellent exposure to the humeral head and the rotator cuff interval.
- Incision: Skin incision from the coracoid process down the deltopectoral groove.
- Exposure: Identification of the cephalic vein (retracted laterally with the deltoid). The clavipectoral fascia is incised.
- Dislocation: The rotator cuff interval is opened. The arm is externally rotated to expose the humeral head.
- Osteotomy: The humeral head is resected at the anatomical neck (or as determined by the fracture pattern).
- Reaming and Preparation: The humeral canal is reamed to the appropriate diameter.
- Trialing: A trial prosthesis is inserted to check for stability, tension, and range of motion.
- Final Implantation: The definitive stem is placed (cemented or press-fit). The modular head is attached.
- Closure: Careful repair of the subscapularis and the rotator cuff interval is vital for post-operative stability.
6. Post-Operative Recovery Protocol
The recovery timeline is highly dependent on whether the procedure was for a fracture (requiring tuberosity healing) or for chronic degeneration.
- Phase I (0–6 Weeks): Immobilization in a sling. Passive range of motion (PROM) exercises only. Focus on elbow and wrist ROM.
- Phase II (6–12 Weeks): Transition to active-assisted ROM (AAROM). Initiation of gentle cuff strengthening.
- Phase III (3–6 Months): Progressive resistance training. Return to overhead activities as tolerated.
7. Risks and Complications
| Complication | Mitigation Strategy |
|---|---|
| Glenoid Erosion | Proper sizing of the humeral head; avoiding over-tensioning. |
| Periprosthetic Fracture | Careful reaming and cortical protection during stem insertion. |
| Infection | Strict sterile technique; prophylactic IV antibiotics. |
| Stiffness/Adhesive Capsulitis | Early, supervised physical therapy and compliance. |
| Nerve Injury | Careful retraction of the axillary nerve. |
8. Alternative Treatments
- Total Shoulder Arthroplasty (TSA): Replacing the glenoid with a polyethylene component. Better for primary osteoarthritis.
- Reverse Total Shoulder Arthroplasty (RTSA): Indicated for rotator cuff arthropathy; reverses the joint mechanics.
- ORIF (Internal Fixation): Preferred for younger patients with reconstructible humeral fractures to preserve native anatomy.
- Non-Operative Management: Indicated for low-demand, elderly patients with stable fracture patterns.
9. Frequently Asked Questions (FAQ)
1. How long does a shoulder hemiarthroplasty last?
In well-selected patients, the implant can last 15–20 years. Longevity depends on activity level and the integrity of the native glenoid.
2. Can I play sports after surgery?
Low-impact activities like swimming or cycling are generally encouraged. High-impact sports (contact sports, heavy weightlifting) are discouraged to prevent glenoid wear.
3. What is the difference between TSA and Hemiarthroplasty?
TSA replaces both sides of the joint (ball and socket). Hemiarthroplasty replaces only the ball (humeral head).
4. Is the recovery painful?
Post-operative pain is managed with regional nerve blocks and multimodal analgesia. Most patients notice significant pain relief from the underlying arthritis within 6 weeks.
5. What happens if the glenoid wears out later?
If the patient develops symptomatic glenoid arthritis later, a secondary conversion to a total shoulder arthroplasty can be performed.
6. Do I need physical therapy?
Yes, physical therapy is mandatory for a successful outcome. Without it, the shoulder is at high risk of post-operative stiffness.
7. What is the success rate?
Success rates for pain relief are very high (exceeding 90%). Functional outcomes vary based on the initial condition of the rotator cuff.
8. Will I set off airport metal detectors?
It is possible. Patients are provided with a medical implant card to facilitate security screening.
9. Can I sleep on my shoulder after surgery?
Patients are generally advised to avoid sleeping on the operative side for at least 3 months to allow for soft tissue healing.
10. When can I return to work?
This depends on the physical demands of your job. Sedentary work may resume within 2–4 weeks; heavy manual labor may require 6 months or longer.
10. Conclusion
Shoulder hemiarthroplasty remains a vital tool in the orthopedic surgeon’s armamentarium. By carefully selecting patients with preserved glenoid cartilage and executing precise surgical technique, surgeons can provide significant pain relief and restore function to patients suffering from complex humeral pathologies. Success is heavily reliant on a multidisciplinary approach involving the surgeon, the patient, and a dedicated physical therapy team to ensure long-term clinical success.
Disclaimer: This guide is for educational purposes only and does not constitute medical advice. Always consult with a board-certified orthopedic surgeon for individual clinical decisions.