Proximal Humerus Fractures: Comprehensive Guide to Epidemiology, Classification, & Surgical Anatomy

Introduction & Epidemiology

Proximal humerus fractures (PHF) represent a significant proportion of orthopedic trauma, accounting for approximately 5-6% of all fractures and 25-30% of humeral fractures. Their incidence is biphasic, with a peak in younger, active individuals sustaining high-energy trauma, and a much larger peak in elderly, osteoporotic patients following low-energy falls. The increasing average age of the population, coupled with higher prevalence of osteoporosis, is driving an upward trend in PHF incidence, posing a substantial healthcare burden. Women are affected more commonly than men, particularly in the post-menopausal age group, with a female-to-male ratio of approximately 2-3:1, reflecting the gender disparity in osteoporosis prevalence.

Clinical presentation typically involves severe pain, swelling, ecchymosis, and loss of shoulder function after trauma. Initial assessment requires careful neurovascular examination, particularly evaluating axillary nerve function (deltoid sensation over the lateral shoulder and strength with shoulder abduction) and radial pulse. The integrity of the brachial plexus should also be assessed. Associated injuries, such as rotator cuff tears, brachial plexus injury, or vascular compromise (e.g., axillary artery), must be ruled out. Open fractures, though rare, necessitate immediate surgical consultation due to the risk of infection and the need for urgent debridement.

Radiographic evaluation typically includes a standard trauma series of the shoulder: anteroposterior (AP) view in the plane of the scapula, a scapular Y-view, and an axillary view. For complex fracture patterns, significant comminution, articular involvement, or preoperative planning for surgical intervention, computed tomography (CT) scans with 3D reconstructions are invaluable for accurate characterization of fragment displacement, comminution, and glenoid involvement.

Classification of PHF is critical for guiding management and prognostication. The most widely adopted system is the Neer classification , based on the number of displaced bony segments (>1 cm displacement or >45° angulation):
* One-part fractures: All fragments are minimally displaced. This constitutes the majority of PHF.
* Two-part fractures: One fragment (surgical neck, greater tuberosity, or lesser tuberosity) is displaced relative to the remaining part. Examples include a surgical neck fracture where the head and tuberosities remain as one unit, or an isolated displaced greater tuberosity fracture.
* Three-part fractures: Two fragments are displaced relative to the humeral head. This commonly involves a surgical neck fracture combined with a displaced greater or lesser tuberosity.
* Four-part fractures: All four major segments (humeral head, greater tuberosity, lesser tuberosity, and humeral shaft) are displaced relative to each other. This pattern carries a high risk of humeral head avascular necrosis (AVN).
* Fracture-dislocations: Any of the above patterns accompanied by glenohumeral joint dislocation.

While the Neer classification is foundational, its inter- and intra-observer reliability can be variable, particularly for three- and four-part patterns. The AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen / Orthopaedic Trauma Association) classification provides a more detailed alphanumeric system (e.g., 11-A, 11-B, 11-C), categorizing fractures by location (extra-articular, intra-articular) and complexity. Type 11-A are extra-articular unifocal, 11-B are extra-articular bifocal, and 11-C are intra-articular fractures. Type C fractures, especially C3, are highly complex and often involve significant articular damage. The Codman's concept of the "four fragments" (humeral head, greater tuberosity, lesser tuberosity, and humeral shaft) underpins most modern classification systems, highlighting the major insertions of the rotator cuff muscles and their deforming forces. Understanding these classifications is paramount for surgical decision-making and communication among orthopedic surgeons.

Surgical Anatomy & Biomechanics

A thorough understanding of the surgical anatomy of the proximal humerus is indispensable for successful management of PHF, particularly in avoiding iatrogenic injury and achieving stable fixation.

Bony Anatomy

The proximal humerus comprises the humeral head, anatomical neck, surgical neck, greater tuberosity, lesser tuberosity, and bicipital groove.
* Humeral Head: Approximately one-third of a sphere, it articulates with the glenoid fossa. Its orientation relative to the shaft (retroversion, inclination) is critical for shoulder function.
* Anatomical Neck: The demarcation between the humeral head and the tuberosities, representing the attachment of the joint capsule. Fractures here are rare and highly unstable.
* Surgical Neck: Located distal to the tuberosities, it is the most common site of proximal humerus fractures. Its relatively thin cortex makes it vulnerable to fracture.
* Greater Tuberosity: Located laterally, it is the insertion site for the supraspinatus, infraspinatus, and teres minor tendons (SIT). Displaced greater tuberosity fragments are pulled superiorly and posteriorly.
* Lesser Tuberosity: Located medially, it serves as the insertion for the subscapularis tendon. Displaced lesser tuberosity fragments are pulled medially and anteriorly.
* Bicipital Groove: Lies between the greater and lesser tuberosities, housing the long head of the biceps tendon. Its orientation can guide plate placement.

Vascular Supply

The vascularity of the humeral head is supplied primarily by branches of the axillary artery. The most critical vessels are:
* Anterior Circumflex Humeral Artery (ACHA): This vessel, located anteriorly, gives off the arcuate artery (ascending branch) , which runs superiorly in the bicipital groove, entering the humeral head posteromedially. The arcuate artery is a major intraosseous blood supply to the humeral head.
* Posterior Circumflex Humeral Artery (PCHA): Larger than the ACHA, it courses posteriorly around the surgical neck. It supplies the posterior deltoid and gives rise to multiple ascending branches that contribute to the humeral head supply, especially in the posteromedial aspect.
* Deltoid and Rotator Cuff Attachments: Perforating branches from the deltoid and rotator cuff musculature also contribute to the periosteal blood supply.

Fractures that significantly disrupt the medial calcar and the integrity of the PCHA and ACHA, particularly four-part fractures or fracture-dislocations, are at high risk for avascular necrosis (AVN) of the humeral head due to compromise of these critical vessels.

Neural Anatomy

Several nerves are at risk during PHF and their surgical management:
* Axillary Nerve: The most commonly injured nerve in PHF, either primarily from trauma or iatrogenically during surgery. It wraps around the surgical neck of the humerus, approximately 5-7 cm distal to the acromion, and innervates the deltoid and teres minor muscles, providing sensation over the lateral shoulder (regimental patch area). It is vulnerable during plate placement or extensive soft tissue dissection around the surgical neck.
* Musculocutaneous Nerve: Arises from the lateral cord of the brachial plexus and innervates the biceps and brachialis. It is less commonly injured but can be at risk with anterior approaches or deep dissection.
* Radial Nerve: Although primarily at risk with midshaft humerus fractures, its course in the spiral groove makes it susceptible if the fracture extends more distally or with extensive lateral soft tissue stripping.
* Brachial Plexus: Can be injured in high-energy trauma, especially with fracture-dislocations, leading to more widespread neurological deficits.

Muscular Deforming Forces & Biomechanics

The muscles inserting on the proximal humerus exert significant deforming forces on fracture fragments, influencing the fracture pattern and making reduction challenging:
* Supraspinatus (on greater tuberosity): Pulls the greater tuberosity superiorly and posteriorly.
* Infraspinatus & Teres Minor (on greater tuberosity): Primarily external rotators, also contribute to superior/posterior pull of the greater tuberosity.
* Subscapularis (on lesser tuberosity): Pulls the lesser tuberosity medially and anteriorly, and internally rotates the arm.
* Pectoralis Major (on humeral shaft, distal to surgical neck): Pulls the humeral shaft medially and anteriorly, often creating an adduction deformity.
* Deltoid: Contributes to abduction. If the surgical neck is fractured, the deltoid can distract the shaft distally relative to the head.
* Biceps (long head): Traverses the bicipital groove and can interfere with reduction of tuberosity fragments.

Understanding these forces is crucial for achieving anatomical reduction, as counteracting these pulls is fundamental to operative technique. For example, in a surgical neck fracture, the humeral head is often abducted by the rotator cuff, while the shaft is adducted by the pectoralis major.

Indications & Contraindications

The decision between operative and non-operative management of proximal humerus fractures is complex, balancing fracture pattern, patient factors, and surgeon expertise.

Non-Operative Management

Non-operative management remains the mainstay for the majority of PHF.
* Indications:
* Minimally displaced one-part fractures: This accounts for 80-85% of all PHF. Displacement <1 cm and angulation <45 degrees are generally considered acceptable.
* Stable two-part surgical neck fractures: Especially in elderly patients, if acceptable alignment can be maintained in a sling.
* Elderly, low-demand patients: Even with moderately displaced fractures, if functional expectations are modest and surgical risks outweigh potential benefits.
* Patients with significant medical comorbidities: Who are poor candidates for general anesthesia or prolonged surgery.
* Patients with poor bone quality: Where robust internal fixation is unlikely to be achieved.
* Patient preference: After comprehensive discussion of risks, benefits, and alternatives.

• Treatment: Immobilization in a sling for 3-6 weeks, followed by progressive rehabilitation. Emphasis on early passive range of motion (PROM) within pain limits to prevent stiffness, followed by active-assisted and active range of motion, and progressive strengthening.

Operative Management

Surgical intervention is generally reserved for displaced, unstable fractures, or specific patient populations where functional recovery is paramount.

• Indications:
  • Displaced two-part, three-part, or four-part fractures:
    • Surgical neck fractures: Angulation >45 degrees, displacement >1 cm, or significant rotational deformity, especially in younger, active individuals.
    • Greater tuberosity fractures: Displacement >5 mm (or 3 mm in young, active patients), particularly if associated with rotator cuff dysfunction, as this can lead to impingement and loss of abduction strength.
    • Lesser tuberosity fractures: Usually associated with posterior dislocation, or if significantly displaced and causing internal rotation weakness.
  • Fracture-dislocations: Require reduction of the dislocation and stabilization of the fracture.
  • Open fractures: Mandate urgent surgical debridement and stabilization.
  • Vascular injury: Requires immediate vascular repair and fracture stabilization.
  • Neurological injury with acute nerve compression or worsening deficit: Though rare, may necessitate exploration and decompression.
  • Young, active patients: With displaced fractures, aiming for anatomical reduction and restoration of function.
  • Pathologic fractures: Often require stabilization and biopsy/oncologic management.
  • Failed non-operative treatment: Including progressive displacement or nonunion.

Contraindications

• Absolute Contraindications:
  • Active infection in the surgical field.
  • Severe medical comorbidities that render the patient unfit for surgery and anesthesia.
  • Non-viable soft tissues preventing adequate wound closure.
• Relative Contraindications:
  • Severe osteoporosis precluding stable fixation. In such cases, arthroplasty may be considered.
  • Extremely comminuted fractures where anatomical reduction and stable fixation are unattainable, particularly in the elderly.
  • Non-compliant patient who cannot adhere to post-operative rehabilitation protocols.
  • Patient preference against surgery.

Summary Table: Operative vs. Non-Operative Indications

Pre-Operative Planning & Patient Positioning

Careful pre-operative planning is crucial for optimizing outcomes in PHF, especially for surgical cases.

Pre-Operative Planning

1. Clinical Assessment: Reconfirm neurovascular status, assess skin integrity, and document any pre-existing shoulder pathology. Evaluate patient's medical comorbidities, functional demands, and social support.
2. Imaging Review:
   • Radiographs (AP, scapular Y, axillary): Confirm fracture pattern, displacement, and comminution.
   • CT scan with 3D reconstruction: Essential for complex patterns (3- and 4-part fractures, articular involvement), assessing head split, impaction, and tuberosity comminution. Provides invaluable information for determining screw length and trajectories, and identifying specific reduction challenges.
3. Implant Selection:
   • Locking Plates (e.g., PHILOS plate, LCP Proximal Humerus Plate): The most common choice for displaced surgical neck, 2-, 3-, and selected 4-part fractures. Provides angular stability, good purchase in osteoporotic bone.
   • Intramedullary Nails: Less common for complex PHF; typically reserved for specific patterns such as surgical neck fractures with shaft extension, or patients with poor compliance where a rigid construct is beneficial.
   • External Fixation: Rarely used, mostly for open fractures with significant soft tissue injury or as a temporary measure in polytrauma.
   • Arthroplasty (Hemiarthroplasty or Reverse Shoulder Arthroplasty): Considered for severely comminuted 4-part fractures, head-split fractures, fracture-dislocations with significant articular damage, failed ORIF, or patients with pre-existing rotator cuff deficiency. RSA is gaining favor in the elderly, low-demand patient with complex fractures, especially if the cuff is compromised.
4. Templating: Use radiographs or CT images to estimate appropriate plate size, length, and screw trajectories. Plan screw length, especially subchondral screws, to avoid joint penetration.
5. Assessment of Bone Quality: Critical for predicting fixation stability. DXA scans or qualitative assessment from CT can guide implant choice and augmentation strategies (e.g., cement augmentation).
6. Surgical Approach: Determine the optimal approach (deltopectoral, deltoid-splitting) based on fracture pattern and planned fixation. The deltopectoral approach is standard for most ORIF with plates.

Patient Positioning

The choice of patient position significantly impacts surgical access, imaging, and overall ease of the procedure.
1. Beach Chair Position:
* Description: The patient is seated in a semi-recumbent position, with the torso elevated (typically 30-70 degrees). The head is supported, and the neck is slightly flexed and extended to the side. The affected arm is draped free to allow full range of motion.
* Advantages: Excellent access for the deltopectoral approach, allows for easy assessment of shoulder range of motion during surgery, and provides a clear operative field for both anterior and superior structures. Facilitates fluoroscopy in AP and outlet views.
* Disadvantages: Risk of cerebral hypoperfusion (avoid excessive head elevation), potential for brachial plexus stretch with arm traction. Requires careful padding of pressure points.
2. Lateral Decubitus Position:
* Description: Patient lies on their unaffected side, with the affected arm draped free and often placed in a traction device.
* Advantages: Can be used for specific approaches (e.g., deltoid-splitting for IMN) or in cases of significant soft tissue injury anteriorly. Allows easier access for posterior approaches if needed.
* Disadvantages: More challenging for anterior approaches, difficult to assess glenohumeral motion.
3. Fluoroscopy: Essential for intraoperative assessment of reduction and implant placement. The C-arm must have unrestricted access for AP and axillary/outlet views throughout the procedure. Ensure no cables or tubing interfere with imaging.
4. Tourniquet: Generally not recommended for PHF surgery due to the risk of compromising the already tenuous blood supply to the humeral head. Hemostasis is achieved with careful dissection and electrocautery.
5. Sterile Prep and Drape: A wide sterile field from the neck to the mid-humerus, including the shoulder and arm, is essential to allow for full arm manipulation.

Detailed Surgical Approach / Technique

The majority of displaced proximal humerus fractures requiring operative intervention are managed with Open Reduction Internal Fixation (ORIF) using a locking plate system, typically via a deltopectoral approach.

Deltopectoral Approach

This is the workhorse approach for ORIF of PHF, providing excellent exposure of the anterior aspect of the proximal humerus while respecting critical neurovascular structures.

1. Incision: A curvilinear incision is made from the coracoid process, extending distally along the anterior deltoid and pectoralis major muscles for 8-12 cm, centered over the bicipital groove.
2. Superficial Dissection: The subcutaneous tissue is incised, and cutaneous nerves are identified and protected. The cephalic vein, which lies in the deltopectoral groove, is identified. It is generally retracted laterally with the deltoid; however, it can be ligated if necessary.
3. Internervous Plane: The deltopectoral interval is identified between the deltoid muscle (innervated by the axillary nerve, C5-C6) laterally and the pectoralis major muscle (innervated by the medial and lateral pectoral nerves, C5-T1) medially. This true internervous plane allows for safe entry into the shoulder joint and proximal humerus without muscle transection.
4. Deep Dissection:
   • The medial border of the deltoid is retracted laterally. The lateral border of the pectoralis major is retracted medially.
   • The clavipectoral fascia is incised longitudinally to expose the underlying conjoint tendon (coracobrachialis and short head of biceps) and subscapularis muscle.
   • The anterior circumflex humeral vessels often cross the surgical neck and need to be identified. While some small branches may be ligated, care must be taken to preserve larger vessels, especially the ascending branch (arcuate artery), to minimize the risk of AVN.
   • The long head of the biceps tendon is identified within its groove and used as a landmark. The plate will be positioned just lateral to this groove.
   • The axillary nerve is identified and protected. It typically courses approximately 5-7 cm distal to the lateral acromial edge. Its course must be respected during distal plate placement and screw insertion.
5. Exposure of Fracture Site: The fracture hematoma is evacuated. The fracture fragments (humeral head, tuberosities, shaft) are carefully identified. The subscapularis may need to be partially released from the lesser tuberosity or incised in line with its fibers for access, especially in fracture-dislocations.

Reduction Techniques

Achieving and maintaining anatomical reduction is paramount for optimal outcomes.
1. Indirect Reduction: Gentle longitudinal traction on the arm, with appropriate rotation, can often aid in fragment alignment.
2. Direct Reduction:
* Joy-sticks (K-wires): K-wires can be temporarily inserted into the humeral head and shaft fragments to gain control and manipulate them into reduction.
* Reduction Forceps: Clamp forceps (e.g., Verbrugge, pointed reduction forceps) can be used to hold fragments in place after reduction.
* Suture Lasso Techniques: Non-absorbable sutures (e.g., FiberWire) can be passed through the rotator cuff tendons (supraspinatus, subscapularis) and around the tuberosity fragments to lasso and reduce them. These sutures can then be used to augment fixation by passing them through plate holes.
* Head Impaction: If the humeral head is significantly impacted, it may need to be disimpacted and restored to its anatomical position.
* Calcar Reconstruction: The posteromedial calcar of the humeral head is crucial for stability. Restoration of the calcar with reduction, impaction, or bone graft can prevent varus collapse.
3. Intraoperative Fluoroscopy: Continuous or intermittent fluoroscopy (AP, lateral, and axillary views) is used to confirm adequate reduction and ensure correct plate and screw placement.

Fixation (Locking Plate - PHLP)

1. Plate Selection and Placement:
   • A pre-contoured locking plate (e.g., a proximal humerus locking plate, PHLP) is selected.
   • The plate is applied to the lateral aspect of the humerus, slightly posterior to the bicipital groove. Its superior edge should be positioned approximately 5-8 mm distal to the superior-most aspect of the humeral head to prevent impingement with the acromion.
   • Ensure the plate sits flush against the bone.
2. Initial Temporary Fixation: K-wires are often used through plate holes to temporarily hold the plate in position and maintain reduction.
3. Distal Shaft Fixation:
   • At least 3-4 bicortical locking screws are inserted into the humeral shaft distally. These provide robust fixation to the shaft. Ensure screws do not violate the axillary nerve path.
4. Humeral Head Fixation:
   • Multiple divergent locking screws are inserted into the humeral head, aiming for maximal subchondral bone purchase.
   • Calcar Screws: At least two, preferably three, calcar screws are directed inferomedially towards the medial calcar. These screws are critical for preventing varus collapse, particularly in osteoporotic bone. They provide strong support against compressive forces.
   • Screw length must be carefully measured to avoid intra-articular penetration, which can cause significant chondral damage and pain. Fluoroscopy in multiple planes is essential.
5. Tuberosity Fixation (Suture Augmentation):
   • Once the head and shaft are fixed, the tuberosities are reduced and secured. Suture lasso techniques (using non-absorbable braided sutures, e.g., FiberWire) are crucial.
   • Sutures are passed through the rotator cuff tendons attached to the tuberosities and then through specific holes in the plate, tying them down to pull the tuberosities anatomically against the head and stabilize the rotator cuff insertions. This significantly enhances the stability of tuberosity reduction and decreases cutout risk.
6. Bone Grafting: In cases of severe comminution or metaphyseal defects, cancellous autograft or allograft can be placed to fill voids and promote healing, particularly in osteoporotic bone.
7. Final Checks: Fluoroscopy to confirm final reduction and hardware position. Confirm no intra-articular screw penetration. Check for full, smooth range of motion to rule out impingement or soft tissue entrapment.
8. Wound Closure: Irrigation of the wound, anatomical layered closure, and sterile dressing.

Complications & Management

Proximal humerus fractures, especially surgically managed ones, are associated with a notable rate of complications. Proactive recognition and management are crucial for salvage.

Table of Common Complications

Detailed Discussion of Key Complications

1. Avascular Necrosis (AVN) of the Humeral Head:

   • Pathogenesis: Disruption of the critical vascular supply, primarily the anterior and posterior circumflex humeral arteries, often at the anatomical neck. Four-part fractures and fracture-dislocations have the highest risk. Disruption of the medial calcar fragment is a strong predictor.
   • Clinical Presentation: Persistent pain, loss of motion, and eventual collapse of the humeral head leading to glenohumeral arthritis. Can be asymptomatic in early stages.
   • Diagnosis: Radiographs (sclerosis, cysts, collapse), MRI (early detection of marrow changes).
   • Management: In early stages, protected weight-bearing and observation. Once symptomatic collapse occurs, arthroplasty is typically indicated. Hemiarthroplasty (HA) is historically used, but Reverse Shoulder Arthroplasty (RSA) is increasingly favored, especially in older patients or those with existing rotator cuff deficiency, due to more predictable pain relief and functional outcomes.

2. Nonunion / Malunion:

   • Nonunion: Failure of the fracture to heal after an appropriate period (typically 6 months). Risk factors include severe comminution, poor bone quality, inadequate fixation, infection, and excessive motion.
   • Malunion: Healing in an unacceptable anatomical position (e.g., varus collapse, excessive angulation, tuberosity malposition). This can lead to pain, restricted range of motion, and impingement.
   • Management:
     • Nonunion: Revision ORIF with bone grafting (autograft or allograft), plate exchange, or conversion to arthroplasty if the bone stock is insufficient or function is severely compromised. Biological augmentation (e.g., bone morphogenetic proteins) may be considered.
     • Malunion: Physiotherapy for mild cases. For symptomatic malunion (pain, impingement, significant functional deficit), corrective osteotomy may be considered in younger patients. In older patients or those with severe deformity, arthroplasty (HA or RSA) is often the salvage procedure.

3. Screw Cutout / Loss of Fixation:

   • Pathogenesis: Often due to inadequate bone quality, poor screw purchase, or varus collapse (loss of medial column support). Screws penetrate the articular cartilage, causing pain and glenoid damage.
   • Clinical Presentation: Acute onset of pain, crepitus, loss of reduction, and increased instability.
   • Management: Depends on timing and severity. Early cutout may necessitate revision ORIF with augmentation (e.g., cement, additional screws) or conversion to arthroplasty. If the fracture has healed but screws are prominent, hardware removal may suffice.

4. Infection:

   • Pathogenesis: Contamination during surgery, compromised soft tissue envelope, or patient comorbidities.
   • Clinical Presentation: Localized pain, warmth, redness, swelling, purulent discharge, fever, elevated inflammatory markers.
   • Management:
     • Acute Infection: Urgent surgical debridement, thorough irrigation, and intravenous antibiotics guided by cultures. If fixation is stable, implants may be retained.
     • Chronic Infection: May require multiple debridements, prolonged antibiotics, and potentially implant removal with placement of an antibiotic spacer, followed by delayed reconstruction (e.g., arthroplasty) once infection is controlled.

5. Axillary Nerve Injury:

   • Pathogenesis: Can occur primarily during trauma (fracture displacement, dislocation) or iatrogenically during surgical exposure, retraction, or screw insertion. Most iatrogenic injuries are neuropraxias due to stretch or compression.
   • Clinical Presentation: Weakness in deltoid and teres minor, loss of sensation over the lateral shoulder.
   • Management: Most neuropraxias resolve spontaneously within 3-6 months. Observation and physiotherapy are initially recommended. If no recovery after 3-6 months, EMG/NCS studies are performed. Surgical exploration and nerve repair/grafting may be considered if a complete lesion or laceration is suspected.

Post-Operative Rehabilitation Protocols

Post-operative rehabilitation is as critical as surgical fixation in achieving optimal functional outcomes for PHF. The protocol must be individualized, balancing the need for fracture healing with the prevention of stiffness, and taking into account fracture stability, bone quality, patient compliance, and implant strength.

General Principles

• Protection: Initial protection of the fracture site to allow for biological healing and implant integration.
• Gradual Progression: Slowly increase stress on the healing tissues and joint.
• Pain Management: Crucial for patient participation in therapy.
• Patient Education: Ensure the patient understands the rationale behind each phase and their role in the recovery process.

Phases of Rehabilitation

Phase 1: Immediate Post-Op to 4-6 Weeks (Protection & Early Controlled Motion)

• Goals: Protect fixation, minimize pain and swelling, prevent shoulder stiffness without jeopardizing fracture healing.
• Immobilization:
  • Arm placed in a sling for comfort and protection (e.g., a simple arm sling or an abduction pillow sling, depending on surgeon preference and fracture stability). The sling is worn continuously, except for exercises and hygiene.
• Early Motion (within pain limits):
  • Hand, Wrist, Elbow ROM: Encourage active range of motion for distal joints to prevent stiffness and promote circulation.
  • Pendulum Exercises: Gentle, gravity-assisted swings of the arm in flexion, extension, and circular patterns. These initiate passive motion of the glenohumeral joint.
  • Passive Range of Motion (PROM): Initiated early (usually within the first week post-op) by a therapist or with the unaffected arm.
    • Forward Flexion: Up to 90-120 degrees, respecting pain.
    • External Rotation: Up to 30-45 degrees, arm at side.
    • Internal Rotation & Abduction: Often restricted initially, depending on fracture pattern and stability, as these motions can stress tuberosity fixation. Avoid resisted internal rotation in lesser tuberosity fractures.
  • Scapular Mobilization: Gentle scapular glides and retraction exercises to maintain mobility of the scapulothoracic joint.
  • Isometric Exercises: Very gentle isometric contractions of the deltoid and rotator cuff (submaximal, avoiding pain) can be introduced towards the end of this phase, only if fracture stability is confirmed .
• Restrictions: No active shoulder elevation, abduction, or internal rotation against resistance. No lifting, pushing, or pulling. Avoid weight-bearing through the affected arm.

Phase 2: 4-6 Weeks to 12 Weeks (Active Motion & Gentle Strengthening)

• Goals: Restore full non-painful active range of motion, initiate gentle strengthening.
• Motion Progression:
  • Active-Assistive Range of Motion (AAROM): Progress from PROM to AAROM using pulleys, sticks, or the contralateral hand to assist motion.
  • Active Range of Motion (AROM): Gradually progress to full active range of motion in all planes as pain allows and fracture healing progresses.
• Strengthening:
  • Isometric Exercises: Progress isometric strengthening for deltoid and rotator cuff in multiple planes (flexion, extension, abduction, internal and external rotation).
  • Resistance Exercises: Begin with light resistance bands or very light weights for rotator cuff strengthening (internal/external rotation) and scapular stabilization exercises.
  • Periscapular Strengthening: Focus on exercises for rhomboids, trapezius, and serratus anterior to establish a stable scapular base.
• Restrictions: Continue to avoid heavy lifting, sudden movements, or forceful pushing/pulling. Avoid activities that place significant stress on the fracture site.

Phase 3: 12 Weeks Onwards (Advanced Strengthening & Return to Function)

• Goals: Achieve maximal strength, endurance, and functional use of the shoulder; return to activities of daily living and recreational sports.
• Strengthening:
  • Progressive resistive exercises with increasing weights and resistance bands for all major muscle groups around the shoulder (deltoid, rotator cuff, biceps, triceps).
  • Focus on eccentric strengthening.
  • Functional Training: Incorporate functional movements that mimic daily activities and sport-specific drills.
  • Proprioceptive Training: Exercises to improve joint position sense and stability.
• Return to Activity: Gradual return to full activities, including sport, typically occurs 6-12 months post-surgery, depending on fracture healing, patient progress, and demands. Full contact sports or overhead activities may take longer.
• Considerations: Hardware removal may be considered after 12-18 months if symptomatic impingement or prominence.

Throughout all phases, careful monitoring for signs of complications (e.g., stiffness, infection, loss of reduction) is essential, and the protocol should be adjusted based on clinical and radiographic findings. Communication between the surgeon, physical therapist, and patient is paramount for successful rehabilitation.

Summary of Key Literature / Guidelines

The management of proximal humerus fractures has evolved significantly, driven by advancements in surgical techniques, implant design, and evidence-based research.

1. The Neer Classification: Published by Charles Neer in the 1970s, this classification system remains foundational. Neer's extensive work highlighted the importance of blood supply and the deforming forces of the rotator cuff, providing a framework for understanding fracture patterns and guiding early treatment algorithms. While its inter-observer reliability has been debated, it forms the basis for much of the clinical discussion surrounding PHF.

2. The PROXIMAL Trial (Proximal Fracture of the Humerus: A randomised controlled trial of surgical vs non-surgical treatment): This landmark multicenter randomized controlled trial (RCT) published in 2015 compared surgical treatment (ORIF with a locking plate) to non-surgical treatment for displaced proximal humerus fractures in older adults. The trial found no statistically significant difference in patient-reported outcomes (Oxford Shoulder Score) at 2 years between the surgical and non-surgical groups. This study significantly impacted clinical practice, emphasizing the efficacy of non-operative management for many displaced fractures in the elderly, challenging the prevailing notion that all displaced fractures benefit from surgery. It underscored the importance of patient selection and the potential for complications with surgical intervention.

3. The CLASSIC Trial (Can't Lift Arm Seriously, So Treat with Internal Fixation or Conservative Treatment): Another significant RCT, published in 2017, investigated displaced three- or four-part PHF in patients aged 60 years or older. It similarly found no statistically significant benefit of surgical fixation (locking plate) over non-operative treatment regarding shoulder function and quality of life at 2 years. The CLASSIC trial reinforced the findings of the PROXIMAL trial and further solidified the role of non-operative management for a substantial proportion of elderly patients with complex PHF, highlighting the challenges of achieving superior outcomes with surgery in this fragile population.

4. Meta-analyses and Systematic Reviews: Numerous meta-analyses have synthesized the evidence from various studies comparing surgical and non-surgical treatments, as well as different surgical modalities (e.g., plating vs. nailing vs. arthroplasty). While some early studies showed a trend favoring surgery for specific patterns or in younger patients, the overall consensus, particularly for the elderly, low-demand patient, points towards equivalent functional outcomes with non-operative management, often with fewer complications . These reviews generally support a more conservative approach when possible, considering the risks inherent to surgery.

5. Role of Arthroplasty: The literature supports the increasing role of shoulder arthroplasty for complex PHF, particularly in elderly patients with severely comminuted four-part fractures, head-split fractures, or significant articular involvement, where the risk of AVN or fixation failure with ORIF is high.

   • Hemiarthroplasty (HA): Historically used, it provides pain relief but functional outcomes can be variable, often limited by tuberosity healing and rotator cuff function.
   • Reverse Shoulder Arthroplasty (RSA): Gaining prominence, especially for older patients with poor bone quality, pre-existing rotator cuff deficiency, or significant comminution that makes tuberosity repair unreliable. RSA typically offers more predictable pain relief and functional elevation compared to HA, independent of rotator cuff integrity.

6. Current Guidelines and Consensus: While formal universally adopted guidelines akin to those for hip fractures are still evolving for PHF, the trend in orthopedic trauma management emphasizes:

   • Individualized Treatment: Tailoring the approach based on fracture pattern, patient age, functional demands, bone quality, medical comorbidities, and patient preference.
   • Shared Decision-Making: Comprehensive discussion with the patient about the risks, benefits, and alternatives of operative and non-operative management, particularly for elderly patients with displaced fractures where outcomes may be similar.
   • Early Motion: Regardless of treatment method, early controlled mobilization (passive, active-assisted) is crucial to prevent stiffness, but must be balanced with fracture stability.

The evidence base suggests that while surgical techniques have improved, the ultimate functional outcome for many PHF, especially in the elderly, may not be dramatically superior to well-managed non-operative care. Therefore, a judicious and patient-centered approach, grounded in the latest evidence, is paramount.