PROXIMAL HUMERUS FRACTURES - NEER CLASSIFICATION
Four-Part Concept | Blood Supply Critical | PROFHER Shapes Treatment
NEER CLASSIFICATION
Critical Must-Knows
- Neer classification based on 4 parts: head, greater tuberosity, lesser tuberosity, shaft
- Displacement criteria: greater than 1cm translation or over 45° angulation
- Arcuate artery (from anterior circumflex) is main blood supply to head - at risk in displaced fractures
- PROFHER trial: No difference between operative and non-operative treatment at 2 years
- 85% are minimally displaced and treated non-operatively with good outcomes
Examiner's Pearls
- "Greater tuberosity displacement greater than 5mm in active patients warrants surgery
- "Elderly 4-part fracture = reverse shoulder arthroplasty (RSA) is gold standard
- "Valgus-impacted 4-part fractures have better blood supply - may be fixable
- "Axillary nerve at risk - assess deltoid and lateral shoulder sensation
Clinical Imaging
Imaging Gallery
Critical Proximal Humerus Fracture Exam Points
Blood Supply
Arcuate artery is terminal branch of anterior circumflex humeral artery. Enters at bicipital groove, runs in spiral to head. Disrupted in displaced fractures = AVN risk.
Neer Criteria
greater than 1cm displacement or over 45° angulation defines a displaced part. Count displaced parts, not fracture lines. 85% are 1-part (non-displaced).
PROFHER Evidence
Landmark UK trial: No functional difference at 2 years between surgical and non-surgical treatment for displaced fractures. Changed practice significantly.
Nerve at Risk
Axillary nerve runs 5-7cm below acromion. Test deltoid contraction and regimental badge sensation. At risk with anterior dislocation and surgery.
Quick Decision Guide
| Patient Profile | Fracture Pattern | Key Consideration | Treatment |
|---|---|---|---|
| Any age | 1-part (non-displaced) | 85% of all proximal humerus fractures | Sling, early ROM at 2 weeks |
| Young, active | 2-part surgical neck | greater than 1cm displacement or over 45° angulation | ORIF with plate or nails |
| Active patient | 2-part GT displacement greater than 5mm | Affects rotator cuff function | ORIF with screws/suture |
| Young (less than 65), good bone | 3-part or valgus-impacted 4-part | Head viability more likely | ORIF if reducible |
| Elderly (greater than 70) | Displaced 3-part or 4-part | High AVN risk, poor bone quality | Reverse shoulder arthroplasty |
| Elderly, low demand | Any displaced pattern | PROFHER supports non-op | Consider non-operative |
HGLSNeer Four-Part Classification
Memory Hook:HGLS: Head Gets Less blood Supply when parts are displaced - count the separated parts!
AAPAProximal Humerus Blood Supply
Memory Hook:AAPA: Anterior gives Arcuate - Posterior helper - AVN if Absent!
DRAGSSurgical Indications
Memory Hook:DRAGS: Displaced fractures DRAG young active patients to surgery if bone is good!
MANSComplications
Memory Hook:MANS: Malunion and AVN are the main concerns, Nerve injury and Stiffness complete the picture!
Overview and Epidemiology
Clinical Significance
Proximal humerus fractures are the third most common fracture in the elderly (after hip and distal radius). The PROFHER trial has fundamentally changed treatment approach - the majority can be treated non-operatively with equivalent outcomes to surgery.
Demographics
- Bimodal distribution: young males (high-energy), elderly females (low-energy)
- Peak incidence: 60-90 years
- Female predominance increases with age
- Strongly associated with osteoporosis
Mechanism
- Low-energy fall onto outstretched hand (elderly) - 80%
- High-energy trauma (young) - MVA, sports
- Pathological fractures in metastatic disease
- Associated injuries: rotator cuff, brachial plexus
Anatomy and Blood Supply
Blood Supply is Exam Critical
The arcuate artery (ascending branch of anterior circumflex humeral artery) provides the main blood supply to the humeral head. It enters the bone at the intertubercular groove and runs superiorly. Disruption leads to AVN - risk increases with displacement and number of parts.
Key Vascular Anatomy
| Vessel | Origin | Course | Clinical Significance |
|---|---|---|---|
| Anterior circumflex humeral | Axillary artery | Wraps anterior to surgical neck | Gives arcuate artery - main supply |
| Arcuate artery | Anterolateral ascending branch | Enters bicipital groove, spirals to head | Terminal vessel - no collaterals |
| Posterior circumflex humeral | Axillary artery | Through quadrangular space with axillary nerve | Minor head supply, greater tuberosity supply |
| Axillary artery | Subclavian continuation | Behind pectoralis minor | At risk in fracture-dislocations |
Four Parts of Proximal Humerus
- Articular segment (Head): Blood supply concern
- Greater tuberosity: Supraspinatus, infraspinatus, teres minor attach
- Lesser tuberosity: Subscapularis attachment
- Shaft: Pectoralis major, deltoid, latissimus attach
Muscle Forces
- Supraspinatus: Pulls GT superiorly
- Pectoralis major: Pulls shaft medially
- Subscapularis: Internally rotates LT
- Deltoid: May displace shaft laterally
Exam Trap: Axillary Nerve
The axillary nerve exits the quadrangular space and wraps around the surgical neck 5-7cm below the acromion. Always document deltoid function and regimental badge sensation. Incidence of injury is 5-10% in fractures, higher with dislocations.
Classification Systems
Neer Classification (1970)
Based on 4 anatomical segments and displacement criteria.
| Parts | Description | Blood Supply | Treatment Tendency |
|---|---|---|---|
| 1-Part | No fragment meets displacement criteria | Intact | Non-operative |
| 2-Part | One fragment displaced (usually surgical neck or GT) | Usually preserved | ORIF if indicated |
| 3-Part | Two fragments displaced (head + one tuberosity attached) | At risk | ORIF or arthroplasty |
| 4-Part | All fragments separated (head isolated) | High AVN risk | Arthroplasty preferred |
Key Point
Count displaced parts, not fracture lines. A fracture can have multiple lines but if only one segment is displaced greater than 1cm or over 45°, it is a 2-part fracture. The head-split pattern and anatomic neck fractures have highest AVN risk.
Clinical Assessment
History
- Mechanism: FOOSH (low-energy), MVA (high-energy)
- Arm position: Held adducted, supported by other hand
- Pre-injury function: Activity level, dominant hand
- Comorbidities: Osteoporosis, diabetes, rotator cuff disease
Examination
- Look: Swelling, ecchymosis (tracks to chest/arm), deformity
- Feel: Crepitus, localized tenderness
- Move: Severely limited by pain
- Neurovascular: Axillary nerve, brachial plexus, pulses
Mandatory Neurovascular Exam
Axillary nerve assessment is mandatory: Test deltoid contraction (arm abduction against resistance) and sensation over regimental badge area (lateral arm). Document before and after any manipulation or surgery.
Neurovascular Testing
| Structure | How to Test | Positive Finding | Injury Rate |
|---|---|---|---|
| Axillary nerve | Deltoid contraction, regimental badge sensation | Weak abduction, numbness lateral arm | 5-10% in fractures, higher with dislocation |
| Brachial plexus | Motor and sensory exam all distributions | Variable deficits multiple nerves | Rare in isolated fractures |
| Axillary artery | Radial pulse, capillary refill, Doppler | Absent pulse, cool pale hand | Rare - fracture-dislocation risk |
| Musculocutaneous nerve | Elbow flexion (biceps), lateral forearm sensation | Weak flexion, numbness | Rare |
Associated Injuries
In high-energy trauma, assess for ipsilateral clavicle fracture (floating shoulder), scapula fracture, rib fractures, and pulmonary injury. In elderly low-energy falls, consider other fragility fractures and need for bone health assessment.
Investigations
Imaging Protocol
Three views essential: True AP (Grashey), Scapular Y (Lateral), Axillary. These form the trauma series and allow assessment of all four parts and dislocation status.
Modified axillary view taken with patient leaning back over cassette - avoids need to abduct arm. Useful in acute trauma with limited mobility.
Recommended for all operative cases. 3D reconstructions help understand fracture pattern, articular involvement, head viability. Essential for 3-part and 4-part fractures.
Rarely indicated acutely. May help assess rotator cuff in subacute phase or evaluate blood supply to head (contrast enhancement).
Radiographic Views
| View | Technique | What It Shows | Key Assessment |
|---|---|---|---|
| True AP (Grashey) | 40° oblique to cassette | Glenohumeral joint space | Head location, displacement, dislocation |
| Scapular Y | 90° to Grashey | Lateral view of scapula | AP displacement, dislocation direction |
| Axillary | Beam through axilla | Glenoid and head relationship | Dislocation, GT/LT displacement |
| Velpeau | Patient leaning back | Modified axillary | When axillary not possible |
CT Scan Indications
Always get CT for: 3-part and 4-part fractures, head-split patterns, fracture-dislocations, pre-operative planning. CT with 3D reconstruction is superior for understanding complex patterns and identifying head viability in valgus-impacted fractures.
Management Algorithm
Non-Operative Management
Indications:
- 1-part (minimally displaced) fractures - 85% of all cases
- Elderly low-demand patients with displaced fractures (PROFHER evidence)
- Significant medical comorbidities precluding surgery
- Head-split or severely comminuted fractures in non-surgical candidates
Non-Operative Protocol
Collar and cuff or sling. Pendulum exercises begin immediately. Elbow, wrist, hand ROM.
Begin passive and active-assisted shoulder ROM. Supine exercises initially. X-ray at 2 weeks.
Progress to active ROM and strengthening. Most fractures clinically healed by 6-8 weeks.
Full strengthening program. Return to activities as tolerated. Some stiffness may persist.
PROFHER Impact
The PROFHER trial showed no difference in functional outcomes between surgical and non-surgical treatment for displaced proximal humerus fractures at 2 years. This has shifted practice toward more conservative management, especially in elderly patients.
Surgical Technique
ORIF with Locking Plate - Comprehensive Technique:
Consent Points
- Infection: 1-2% superficial, 0.5% deep
- Axillary nerve injury: 5-10% (document preop status)
- AVN: 3-14% (3-part), 15-35% (4-part)
- Screw penetration: 14% - may need removal
- Hardware failure/reoperation: 10-15%
- Stiffness: Very common - physio critical
Equipment Checklist
- Proximal humerus locking plate (system of choice)
- Locking and cortical screws - multiple lengths
- K-wires: 1.6mm and 2.0mm for temporary fixation
- Heavy sutures: No. 2 or 5 FiberWire/Ethibond
- Bone hook and elevator for reduction
- C-arm positioned from contralateral side
Patient Positioning:
Setup Checklist
30-45° trunk elevation. Head secured in padded headrest. Body shifted toward operative edge of table. Arm freely draped on arm board or mayo stand.
Avoid excessive lateral neck flexion - stretches plexus. Head in neutral rotation, supported centrally.
C-arm enters from contralateral side. Confirm AP, axillary, and Velpeau views achievable. Test imaging BEFORE draping.
Prep from nipple to neck, axilla to midline posteriorly. Free drape arm to allow full manipulation.
Positioning Pearl
Blood pressure can drop significantly in beach chair position (cerebral hypoperfusion). Keep MAP above 70mmHg, and avoid sudden position changes.
Arthroplasty Options
RSA is Now Preferred
Reverse shoulder arthroplasty (RSA) has largely replaced hemiarthroplasty for fractures. RSA provides reliable pain relief and function regardless of tuberosity healing, while hemiarthroplasty outcomes depend heavily on tuberosity healing.
Arthroplasty Comparison
| Option | Indications | Pros | Cons |
|---|---|---|---|
| Hemiarthroplasty | Young patient, good rotator cuff, good bone | Preserves native glenoid, revision possible | Outcomes depend on tuberosity healing, unpredictable |
| Reverse SA (RSA) | Elderly, rotator cuff deficient, 4-part fractures | Reliable outcomes, less dependent on tuberosities | Glenoid revision difficult, scapular notching |
| Total shoulder | Fracture with pre-existing OA (rare) | Address arthritis simultaneously | Complex surgery, rarely indicated acutely |
Tuberosity Reconstruction
In both hemiarthroplasty and RSA, tuberosity reconstruction is critical. Tuberosities should be fixed around the prosthesis using heavy non-absorbable sutures in a tension-band configuration. Tuberosity malunion or non-union is the most common cause of poor outcomes after shoulder arthroplasty for fracture.
Complications
Complications and Management
| Complication | Incidence | Risk Factors | Management |
|---|---|---|---|
| AVN | 15-35% (4-part) | Displacement, head vascularity | Close monitoring, arthroplasty if symptomatic |
| Malunion | Most common | Non-op treatment, inadequate reduction | Osteotomy if symptomatic, prevention key |
| Nonunion | 5-10% | Surgical neck fx, osteoporosis, smoking | Bone graft and fixation or arthroplasty |
| Stiffness | Common | Prolonged immobilization, adhesive capsulitis | Prevention with early ROM, may need MUA or release |
| Axillary nerve injury | 5-10% | Dislocation, surgical approach | Most recover - observe 3-6 months |
| Subacromial impingement | Variable | Plate or GT malposition | Hardware removal, tuberosity osteotomy |
| Screw penetration | Variable | Technical error | Remove offending screws |
AVN Risk Factors
AVN risk correlates with head ischemia: anatomic neck fractures (highest risk), head-split fractures, 4-part fractures (15-35%), 3-part fractures (3-14%). Valgus-impacted patterns have lower risk due to preserved medial soft tissue hinge.
Postoperative Care and Rehabilitation
ORIF Rehabilitation Protocol
Sling immobilization. Elbow, wrist, hand ROM. Pendulum exercises.
Begin passive and active-assisted ROM. Forward flexion in supine, ER to neutral.
Active ROM in all planes. X-ray confirmation of healing. Discontinue sling.
Progressive rotator cuff and deltoid strengthening. Return to activities 3-6 months.
Outcomes and Prognosis
Expected Outcomes by Treatment
| Treatment | Shoulder Function | Complications | Notes |
|---|---|---|---|
| Non-operative (1-part) | Good to excellent | Minimal | 85% of fractures, reliable outcomes |
| Non-operative (displaced) | Moderate | Stiffness, malunion | PROFHER supports in elderly |
| ORIF | Variable | Hardware issues, AVN | Best in young with good bone |
| Hemiarthroplasty | Unpredictable | Tuberosity dependent | Falling out of favor |
| RSA | Reliable | Scapular notching | Current gold standard for 4-part elderly |
Prognostic Factors
Key factors affecting outcome: Age (older = more stiffness), Initial displacement (correlates with soft tissue injury), Bone quality, Patient activity level, and Tuberosity healing (for arthroplasty). Function at 1-2 years is best predictor of long-term outcome.
Evidence Base
PROFHER Trial
- RCT of 250 patients: No significant difference in functional outcomes (Oxford Shoulder Score) at 2 years between surgical and non-surgical treatment for displaced proximal humerus fractures. Cost-effectiveness favored non-operative treatment.
RSA vs Hemiarthroplasty
- RSA provides better active forward flexion (130° vs 100°) and lower revision rates (3% vs 10%) compared to hemiarthroplasty for proximal humerus fractures. Tuberosity healing less critical for function with RSA.
Neer Classification Reliability
- Inter-observer reliability of Neer classification is only moderate (kappa 0.5-0.6). Adding CT improves reliability but still imperfect.
Locking Plate Complications
- Prospective multicenter study of 187 patients. 34% complication rate: screw perforation (14%), AVN (8%), impingement (6%). Calcar screw use reduced complications.
Australian Registry Data
- Shoulder arthroplasty for fracture: RSA has lower revision rates than hemiarthroplasty at all time points. 5-year revision rate RSA 4.2% vs hemiarthroplasty 7.8%.
Viva Scenarios
Exam Viva Scenarios
Practice these scenarios to excel in your viva examination
Scenario 1: Elderly Low-Energy Fall
"A 75-year-old woman presents after a fall at home. She has pain and inability to move her left shoulder. X-rays show a displaced 4-part proximal humerus fracture with the head in valgus position. She is otherwise healthy and independent with ADLs."
Scenario 2: Young Active Patient
"A 45-year-old competitive recreational tennis player falls during a match. He has a displaced 3-part fracture (greater tuberosity and surgical neck displaced) with moderate osteopenia. He is very keen to return to sport."
Scenario 3: Fracture-Dislocation
"A 60-year-old presents after high-speed MVA. On examination, the shoulder is squared-off with absent axillary nerve function. X-rays show a 3-part fracture-dislocation with the head posteriorly dislocated. CT confirms significant glenoid bone loss from a Hill-Sachs reverse lesion."
MCQ Practice Points
Blood Supply Question
Q: What is the main blood supply to the humeral head? A: The arcuate artery (ascending branch of the anterior circumflex humeral artery) provides 80% of blood supply. It enters at the intertubercular groove and is at risk in displaced fractures.
Classification Question
Q: In Neer classification, what defines a 'displaced part'? A: greater than 1cm translation or over 45° angulation. Count displaced parts (not fracture lines) - there are 4 anatomical parts: head, greater tuberosity, lesser tuberosity, and shaft.
AVN Risk Question
Q: What is the AVN rate in 4-part proximal humerus fractures? A: 15-35% for 4-part fractures, 3-14% for 3-part fractures. Valgus-impacted 4-part fractures have lower AVN risk due to preserved medial hinge.
PROFHER Trial Question
Q: What did the PROFHER trial demonstrate? A: No significant difference in functional outcomes (Oxford Shoulder Score) at 2 years between surgical and non-operative treatment for displaced proximal humerus fractures. Cost-effectiveness favored non-operative treatment.
Nerve at Risk Question
Q: Which nerve is most commonly injured in proximal humerus fractures? A: Axillary nerve (5-10% incidence). It wraps around the surgical neck 5-7cm below the acromion. Test deltoid contraction and regimental badge sensation.
Arthroplasty Question
Q: For a 75-year-old with a displaced 4-part fracture, what is the preferred arthroplasty option? A: Reverse shoulder arthroplasty (RSA). RSA provides more reliable outcomes than hemiarthroplasty because function is less dependent on tuberosity healing.
Australian Context
AOANJRR Data
- Australian Orthopaedic Association National Joint Replacement Registry
- RSA revision rates lower than hemiarthroplasty for fracture
- Valuable resource for discussing outcomes with patients
- Shoulder arthroplasty data increasingly comprehensive
PBS and Medications
- Bone health assessment for fragility fractures
- PBS-listed bisphosphonates and denosumab
- Vitamin D and calcium supplementation
- Orthogeriatric model for hip fractures extending to shoulder
Fragility Fracture Assessment
Any proximal humerus fracture from a low-energy mechanism in a patient over 50 should trigger bone health assessment. This includes DEXA scan, vitamin D levels, and consideration of anti-resorptive therapy. Follow Australian guidelines for secondary fracture prevention.
PROXIMAL HUMERUS FRACTURES
High-Yield Exam Summary
Key Anatomy
- •4 parts: Head, Greater tuberosity, Lesser tuberosity, Shaft
- •Arcuate artery (from anterior circumflex) = main blood supply
- •Axillary nerve 5-7cm below acromion - test deltoid and sensation
- •Pectoralis major displaces shaft medially
Neer Classification
- •Count DISPLACED parts (greater than 1cm or over 45°)
- •1-part = non-displaced = 85% of fractures = non-op
- •2-part = one displaced segment = consider ORIF if young/active
- •3-part = two displaced = ORIF vs arthroplasty
- •4-part = all separated = RSA in elderly
Treatment Algorithm
- •1-part: Sling and early ROM - excellent outcomes
- •2-part GT greater than 5mm: ORIF in active patients
- •2-part surgical neck: ORIF if young, consider non-op if elderly
- •3-part: ORIF if good bone and young, RSA if elderly
- •4-part: RSA preferred over hemiarthroplasty in elderly
Surgical Pearls
- •Deltopectoral approach - cephalic vein laterally
- •Plate 5-8mm below GT tip to avoid impingement
- •Calcar screw improves stability
- •Check screw penetration with fluoroscopy AP, axillary, Velpeau views
- •Tuberosity repair with heavy sutures critical for function
Complications
- •AVN: 15-35% in 4-part, 3-14% in 3-part
- •Malunion: Most common complication overall
- •Stiffness: Early ROM prevents adhesive capsulitis
- •Axillary nerve injury: Document before surgery, most recover