Proximal Humerus Fracture

Comprehensive Clinical Guide: Proximal Humerus Fracture (PHF)

1. Introduction and Overview

A Proximal Humerus Fracture (PHF) represents a significant clinical challenge in orthopedic trauma, accounting for approximately 5% to 6% of all adult fractures. As the population ages, the incidence of these fractures has risen sharply, particularly in the geriatric demographic, where it is often considered the third most common osteoporotic fracture after hip and distal radius fractures.

The proximal humerus is a complex anatomical region comprising the humeral head, the greater tuberosity, the lesser tuberosity, and the surgical neck. Because this region serves as the attachment point for the rotator cuff musculature (supraspinatus, infraspinatus, teres minor, and subscapularis), fractures here often disrupt the delicate biomechanical balance of the glenohumeral joint, leading to profound functional impairment if not managed with precision.

2. Technical Specifications and Mechanisms

Anatomical Foundations

The proximal humerus consists of four distinct segments defined by the Neer classification system:
* Articular surface: The humeral head.
* Greater Tuberosity: Attachment for the supraspinatus, infraspinatus, and teres minor.
* Lesser Tuberosity: Attachment for the subscapularis.
* Humeral Shaft: The distal diaphysis.

Etiology and Pathophysiology

The etiology of PHFs is typically bimodal. In younger patients, these fractures are usually the result of high-energy trauma (e.g., motor vehicle accidents, contact sports, or falls from significant heights). In the older population, the primary driver is low-energy trauma, often a simple fall from standing height, exacerbated by underlying osteoporosis or osteopenia.

The pathophysiology involves the failure of the bone to withstand mechanical load. When the force exceeds the structural integrity of the trabecular bone, a fracture occurs. Because the blood supply to the humeral head is primarily provided by the anterior and posterior circumflex humeral arteries, displacement of the fracture fragments—particularly in four-part fractures—carries a high risk of avascular necrosis (AVN).

3. Clinical Staging and Classification

The most widely utilized clinical tool for PHF is the Neer Classification System, which categorizes fractures based on the number of displaced parts (greater than 1 cm of displacement or 45 degrees of angulation).

AO/OTA Classification

The AO/OTA system provides a more granular alphanumeric coding based on the severity of the fracture and the degree of articular involvement, focusing on the vascularity of the humeral head.

4. Clinical Presentation and Diagnostic Protocol

Standard Presentation

• Pain: Acute, severe pain localized to the shoulder girdle.
• Physical Signs: Ecchymosis (often tracking down to the arm/chest wall), significant swelling, and restricted range of motion (ROM).
• Neurological Assessment: Mandatory evaluation of the axillary nerve, which is at the highest risk of injury in PHFs.

Diagnostic Imaging

1. Radiographs: The "Trauma Series" is essential:
   • True AP view of the glenohumeral joint.
   • Scapular Y view.
   • Axillary lateral view (to assess subluxation/dislocation).
2. Computed Tomography (CT): The gold standard for surgical planning. 3D reconstructions are critical in evaluating the degree of comminution and the position of the tuberosities.
3. MRI: Occasionally used to assess concomitant soft tissue injuries, such as rotator cuff tears or labral pathology.

5. Clinical Indications, Usage, and Management

Non-Operative Management

Reserved for one-part fractures or minimally displaced fractures.
* Protocol: Sling immobilization for 1–2 weeks, followed by early passive range of motion exercises to prevent adhesive capsulitis (frozen shoulder).

Operative Management

Indicated for displaced three-part and four-part fractures, or when the humeral head is dislocated (fracture-dislocation).
* Open Reduction Internal Fixation (ORIF): Utilizing locking plates and screws.
* Hemiarthroplasty: Replacing the humeral head with a metal prosthesis.
* Reverse Total Shoulder Arthroplasty (RTSA): Increasingly common for complex four-part fractures in elderly patients with poor bone quality or pre-existing rotator cuff deficiency.

6. Risks, Side Effects, and Contraindications

Potential Complications

• Avascular Necrosis (AVN): Occurs due to disruption of the circumflex humeral arteries.
• Malunion/Non-union: Failure of bone healing, often due to poor vascularity or excessive micromotion.
• Axillary Nerve Injury: Often presents as numbness in the "regimental badge" area of the lateral shoulder.
• Adhesive Capsulitis: Common in patients who delay physical therapy due to pain.

Contraindications for Surgery

• Severe Comorbidities: Patients where anesthesia poses a higher risk than the fracture itself.
• Active Infection: Absolute contraindication for internal fixation or arthroplasty.
• Severe Osteoporosis: May render internal fixation impossible, favoring arthroplasty or prolonged conservative management.

7. Prognosis and Long-Term Outlook

The prognosis is largely dependent on the fracture pattern, age of the patient, and the quality of the initial reduction. While many patients regain acceptable function, full pre-injury range of motion is rarely achieved in complex four-part fractures. Long-term success is highly correlated with early, aggressive physical therapy once the fracture has achieved clinical stability.

8. Frequently Asked Questions (FAQ)

1. How long does it take for a proximal humerus fracture to heal?
Most fractures show clinical healing on radiographs within 6 to 12 weeks, though remodeling and full functional recovery can take up to a year.

2. Do all proximal humerus fractures require surgery?
No. Approximately 80% of these fractures are minimally displaced and can be treated non-operatively with excellent results.

3. What is the "regimental badge" sign?
It refers to the area of skin over the deltoid muscle. Numbness here is a clinical indicator of axillary nerve injury, a known complication of PHF.

4. Why is a CT scan necessary if I’ve already had an X-ray?
X-rays provide a 2D view. A CT scan allows the surgeon to visualize the exact displacement of the tuberosities, which is critical for determining if surgery is required.

5. What is the biggest risk of a four-part fracture?
The primary risk is Avascular Necrosis (AVN) of the humeral head, where the bone dies due to a lack of blood supply.

6. When should physical therapy start?
Usually, gentle passive range of motion can start within 1–2 weeks, provided the fracture is stable. Active movement is typically delayed until 6 weeks post-injury.

7. Can I drive with a proximal humerus fracture?
Driving is generally contraindicated until the patient has full control of the vehicle, is off narcotic pain medication, and has received clearance from their orthopedic surgeon.

8. What is a Reverse Total Shoulder Arthroplasty?
It is a procedure where the ball and socket of the shoulder are reversed. It is highly effective for complex fractures in older patients because it does not rely on the rotator cuff for stability.

9. Will I have permanent stiffness in my shoulder?
Some degree of stiffness is common, especially if the fracture was severe. Consistent physical therapy is the best defense against long-term loss of motion.

10. Are there specific exercises I should avoid?
During the initial healing phase, you should avoid heavy lifting, pushing, or pulling motions. Always follow the specific "weight-bearing" restrictions provided by your clinical team.

9. Conclusion

Proximal humerus fractures represent a delicate balance between orthopedic structural integrity and functional mobility. A methodical approach—starting with accurate radiographic assessment, moving through precise classification, and concluding with a tailored surgical or rehabilitative plan—is essential for achieving optimal patient outcomes. As clinical techniques in RTSA and locking plate technology continue to evolve, the prognosis for even complex fractures continues to improve, provided the patient is compliant with the long-term rehabilitative requirements.

Disclaimer: This guide is intended for educational purposes for healthcare professionals and students. It does not replace clinical judgment or institutional protocols. Always consult with a board-certified orthopedic surgeon regarding specific patient care.

Related Clinical Integration

In a modern clinical setting, the management of a Proximal Humerus Fracture requires a multidisciplinary approach that integrates pharmacological pain control, specialized orthopedic hardware, and evidence-based surgical interventions. Initial stabilization is typically achieved using a Shoulder Immobilizer / Sling / مثبت كتف / حمالة ذراع (الأطراف الصناعية والجبائر التقويمية) or a Shoulder Immobilizer with Abduction Pillow / مثبت كتف مع وسادة إبعاد (الأطراف الصناعية والجبائر التقويمية), while acute pain management is addressed through a regimen of Morphine Sulfate / مورفين سلفات 10mg/ml, OxyContin / أوكسي كونتين 20mg, Advil / أدفيل 200mg, or Celcox / سيلكوكس 100mg. For complex or pathological cases, surgical intervention may necessitate procedures such as Cemented Hemiarthroplasty for Pathologic Fracture / رأب نصف المفصل الملحوم لكسر مرضي (عملية كبرى في غرف العمليات) or the utilization of specialized hardware like the Calcaneal Locking Plate (Perimeter) / صفيحة تثبيت الكعب (محيطية). Clinicians should refer to comprehensive resources such as Operative Management of Shoulder Fractures: Scapula & Humerus, [Operative Management of Shoulder Girdle Fractures: Clavicle, Scapula, and Proximal Humerus](https