Associated Injuries Critical | Glenoid Fractures Key | Floating Shoulder Concept
ANATOMICAL CLASSIFICATION
Critical Must-Knows
- High-energy injury - always look for associated thoracic and shoulder girdle injuries
- Floating shoulder = scapula neck + clavicle fracture disrupts superior shoulder suspensory complex
- Glenoid fractures are the most important - articular involvement determines outcome
- Most body fractures heal well conservatively - surgery for articular/neck displacement
- Ideberg classification for glenoid fossa fractures guides surgical decision-making
Clinical Pearls
- "80-95% have associated injuries - ribs, lung, clavicle, brachial plexus
- "Scapulothoracic dissociation = devastating - high mortality, look for it
- "Glenoid step more than 4mm or fragment more than 25% = surgical indication
- "Lateral border offset more than 20mm or angulation more than 40 degrees = ORIF neck
Clinical Imaging
Imaging Gallery
Critical Scapula Fracture Exam Points
Associated Injuries
80-95% have associated injuries. Prioritize ATLS assessment. Rib fractures (52%), pulmonary contusion (47%), clavicle fractures (23%), brachial plexus injury (12%). High mortality rate (10-15%).
Floating Shoulder
Scapula neck + clavicle fracture = double disruption of superior shoulder suspensory complex. Creates instability. Often requires surgical stabilization of clavicle or both.
Glenoid Articular
Ideberg classification guides treatment. Step off more than 4mm, fragment more than 25% of surface, or instability = surgical indication. These affect long-term shoulder function.
Scapulothoracic Dissociation
Lateral scapula displacement on CXR. Associated with vascular injury, brachial plexus avulsion, massive soft tissue trauma. High mortality - often forequarter amputation needed.
Quick Decision Guide
| Fracture Pattern | Key Finding | Treatment |
|---|---|---|
| Body/spine - minimally displaced | Less than 1cm displacement | Sling, early ROM, physio |
| Glenoid neck - isolated | Less than 1cm medialization, less than 40 degrees angulation | Conservative - sling, early motion |
| Glenoid neck - displaced | More than 2cm medialization OR more than 40 degrees angulation | ORIF via posterior approach |
| Floating shoulder | Clavicle + scapula neck fracture | Clavicle ORIF (minimum) plus or minus scapula |
| Glenoid fossa - displaced | Step more than 4mm, fragment more than 25% | ORIF for articular congruity |
| Scapulothoracic dissociation | Lateral scapula displacement on CXR | Life-threatening - angiography, stabilization |
SCAPULASCAPULA - Associated Injuries
| S | Spine fractures Cervical and thoracic spine injuries |
| C | Clavicle fractures 23% - creates floating shoulder |
| A | Arterial (subclavian) Vascular injury in severe cases |
| P | Pulmonary contusion 47% - common thoracic injury |
| U | Upper extremity nerve 12% brachial plexus injury |
| L | Lateral rib fractures 52% - most common association |
| A | Acromioclavicular injury May be concomitant |
| S | Spine fractures Cervical and thoracic spine injuries | P | Pulmonary contusion 47% - common thoracic injury | A | Acromioclavicular injury May be concomitant |
| C | Clavicle fractures 23% - creates floating shoulder | U | Upper extremity nerve 12% brachial plexus injury | ||
| A | Arterial (subclavian) Vascular injury in severe cases | L | Lateral rib fractures 52% - most common association |
Hook:SCAPULA fractures mean look for all these injuries - high-energy trauma signature
GOSSGOSS - Glenoid Neck Surgery Indications
| G | Glenopolar angle less than 20 degrees Significant angulation |
| O | Offset more than 20mm Lateral border medialization |
| S | Subluxation of humeral head GH joint instability |
| S | SSSC disruption (double) Floating shoulder injury |
| G | Glenopolar angle less than 20 degrees Significant angulation | S | Subluxation of humeral head GH joint instability |
| O | Offset more than 20mm Lateral border medialization | S | SSSC disruption (double) Floating shoulder injury |
Hook:GOSS criteria help decide when neck fractures need surgery
SSSCSSSC - Superior Shoulder Suspensory Complex
| S | Scapular spine Forms the ring superiorly |
| S | Superior strut (clavicle) Links to axial skeleton |
| S | Scapular neck/glenoid Articulation with humerus |
| C | Coracoid + CC ligaments Completes the ring |
| S | Scapular spine Forms the ring superiorly | S | Scapular neck/glenoid Articulation with humerus |
| S | Superior strut (clavicle) Links to axial skeleton | C | Coracoid + CC ligaments Completes the ring |
Hook:The SSSC is a bone-ligament ring - 2 disruptions = floating shoulder = instability
4-25-40-204-25-40-20 Rule
| 4 | 4mm step Glenoid articular step threshold for surgery |
| 25 | 25% fragment Glenoid fragment size threshold for surgery |
| 40 | 40 degree angulation Glenoid neck angulation threshold |
| 20 | 20mm offset Lateral border medialization threshold |
| 4 | 4mm step Glenoid articular step threshold for surgery | 40 | 40 degree angulation Glenoid neck angulation threshold |
| 25 | 25% fragment Glenoid fragment size threshold for surgery | 20 | 20mm offset Lateral border medialization threshold |
Hook:4mm step, 25% fragment, 40 degrees angulation, 20mm offset - four surgical thresholds
Overview and Epidemiology
Scapula fractures are uncommon injuries that typically result from high-energy trauma. The scapula is protected by thick muscle coverage and significant force is required to fracture it.
Mechanism of injury:
- Motor vehicle accidents - most common (50-70%)
- Falls from height
- Direct blow (crush injuries)
- Sports (uncommon - typically low energy)
Key principle: The scapula fracture itself is often less important than the associated injuries. Always perform a thorough trauma assessment.
High-Energy Trauma Marker
A scapula fracture indicates massive energy transfer. Maintain high suspicion for associated injuries. Mortality rate is 10-15%, primarily from associated thoracic and head injuries rather than the scapula fracture itself.
Historical Perspective
Traditionally, scapula fractures were treated almost universally conservatively with good results. The shift to surgical treatment in selected cases is based on better understanding of outcomes with significantly displaced glenoid neck and articular fractures.
Anatomy and Biomechanics
Bony anatomy:
- Body - flat triangular bone, thin (2-7mm)
- Spine - posterior ridge, divides supraspinatus from infraspinatus
- Acromion - lateral extension of spine, articulates with clavicle
- Coracoid process - anterior projection, muscle and ligament attachments
- Glenoid fossa - articular surface for humeral head
- Glenoid neck - transition between glenoid and body
Superior Shoulder Suspensory Complex (SSSC):
SSSC Concept
The Superior Shoulder Suspensory Complex is a bone-ligament ring that suspends the upper extremity from the axial skeleton. Components: glenoid process, coracoid, CC ligaments, clavicle (distal), AC joint, acromion. Single disruption = stable. Double disruption = floating shoulder = unstable.
Muscular attachments (17 muscles):
- Rotator cuff: supraspinatus, infraspinatus, teres minor, subscapularis
- Scapulohumeral: deltoid (partial), coracobrachialis, biceps (long head)
- Axioscapular: trapezius, levator scapulae, rhomboids, serratus anterior
- Scapulothoracic: pectoralis minor, omohyoid
Neurovascular relationships:
- Suprascapular nerve (in suprascapular notch - injury in coracoid fractures)
- Axillary nerve (quadrangular space)
- Subscapular nerves and vessels
- Brachial plexus runs anterior to scapula
Classification Systems
Anatomic Classification (most practical)
| Location | Frequency | Typical Management |
|---|---|---|
| Body/Spine | 50-60% | Conservative (thick muscle coverage aids healing) |
| Glenoid neck | 25% | Conservative vs ORIF depending on displacement |
| Glenoid fossa | 10% | ORIF if displaced more than 4mm or more than 25% involvement |
| Acromion | 8% | Conservative unless significantly displaced |
| Coracoid | 3-7% | ORIF if displaced more than 1cm or associated AC dislocation |
| Scapular spine | Rare | Usually with body fractures |
Clinical Significance
Glenoid fractures are most important prognostically - they affect glenohumeral joint function. Glenoid neck fractures matter when significantly displaced or combined with clavicle injury (floating shoulder).
Clinical Presentation and Assessment
Primary Survey: Scapula fractures are high-energy injuries. ATLS protocol is mandatory.
ATLS First
Complete the primary survey before focusing on the scapula fracture. Life-threatening chest injuries, hemorrhage, and neurological injuries take priority.
History:
- Mechanism (MVA, fall from height, direct blow)
- Associated symptoms (chest pain, dyspnea, neurological symptoms)
- Pre-injury function
- Hand dominance
Physical examination:
Physical Examination Findings
| Finding | Significance | Associated Condition |
|---|---|---|
| Posterior shoulder swelling | Local hematoma | Body/neck fracture |
| Flattened shoulder contour | Significant displacement | Displaced glenoid neck |
| Lateral scapula on CXR | Scapulothoracic dissociation | Life-threatening injury |
| Subcutaneous emphysema | Pneumothorax | Rib fractures, lung injury |
| Absent pulses/expanding hematoma | Vascular injury | Subclavian/axillary injury |
| Sensory/motor deficit | Brachial plexus injury | High-energy trauma |
Associated injuries to look for:
- Rib fractures (52%)
- Pulmonary contusion (47%)
- Pneumothorax (38%)
- Clavicle fractures (23%)
- Brachial plexus injury (12%)
- Humeral fractures (11%)
- Spine fractures (8%)
- Subclavian artery injury (rare but serious)
Differential Diagnosis - Posterior Shoulder / Scapular Region Pain After Trauma
| Condition | Discriminating features | Confirming investigation |
|---|---|---|
| Scapular body/neck fracture | High-energy mechanism, posterior tenderness, painful but congruent glenohumeral joint | AP/Y-view radiograph plus CT |
| Glenoid fossa fracture | Haemarthrosis, articular step, possible subluxation | CT with 3D reconstruction |
| Scapulothoracic dissociation | Flail arm, absent pulse, gross lateral scapular displacement on CXR | CXR scapular index plus CT angiography |
| Posterior glenohumeral dislocation | Locked internal rotation, light-bulb sign, often post-seizure/electrocution | Axillary lateral or CT - empty glenoid |
| Proximal humerus fracture | Anterolateral tenderness, deformity at surgical neck | AP and scapular-Y radiographs |
| Acromioclavicular joint injury | Point tenderness over AC joint, step deformity, painful cross-body adduction | AP / Zanca view weighted radiograph |
| Rotator cuff tear / cuff contusion | Weakness rather than bony tenderness, lower-energy mechanism | Ultrasound or MRI |
| Scapulothoracic crepitus / scapular winging (non-fracture) | No acute fracture; long thoracic or spinal accessory nerve palsy | Clinical examination plus EMG if persistent |
Scapulothoracic Dissociation
Look at the chest X-ray for lateral displacement of the scapula compared to the contralateral side. This indicates massive soft tissue disruption, likely vascular injury, and brachial plexus avulsion. High mortality. May require forequarter amputation.
Investigations
Standard imaging:
Trauma series (AP pelvis/chest/lateral C-spine):
- Chest X-ray often first to show scapula fracture
- Look for lateral scapula displacement (scapulothoracic dissociation)
- Associated rib fractures, pneumothorax
Dedicated scapula views:
- True AP scapula (Grashey view) - 30-40 degree posterior oblique
- Scapula Y-view (lateral) - shows glenoid neck and body
- Axillary lateral - glenoid rim fractures
Glenopolar Angle
The glenopolar angle is measured on the true AP or Y-view. Draw a line through the most superior and inferior glenoid points. Draw a second line from the inferior glenoid to the most superomedial angle of the scapula. Normal = 30-45 degrees. Less than 20 degrees suggests significant displacement requiring surgery.
CT imaging:
Essential for:
- All glenoid fractures (articular surface assessment)
- Surgical planning for displaced neck fractures
- Complex/comminuted patterns
- Assessment of lateral border offset
3D CT reconstruction:
- Excellent for visualizing fracture pattern
- Helps plan surgical approach and fixation strategy
CT angiography:
Indications:
- Scapulothoracic dissociation
- Expanding hematoma
- Absent or diminished pulses
- Suspected subclavian/axillary injury
Management
Conservative management:
The majority of scapula fractures (80-90%) are treated conservatively with good outcomes.
- Sling immobilization for comfort
- Ice, analgesia
- Address associated injuries first
- Gentle pendulum exercises as pain allows
- Wean from sling
- Active assisted ROM
- Progress as pain allows
- Avoid extremes of motion
- Once radiographic callus visible
- Progressive resistance exercises
- Rotator cuff strengthening
- Full ROM and strength expected
- Sport-specific rehabilitation
- Most return to pre-injury function
Surgical indications:
Surgical Indications by Fracture Type
| Fracture Type | Indication for Surgery |
|---|---|
| Glenoid fossa | Step more than 4mm, fragment more than 25% of surface, subluxation |
| Glenoid neck | Angulation more than 40 degrees, medialization more than 20mm, glenopolar angle less than 20 degrees |
| Floating shoulder | Double SSSC disruption - stabilize at minimum the clavicle |
| Acromion | Displaced fractures impinging on rotator cuff, reducing subacromial space |
| Coracoid | Displacement more than 1cm, associated with AC joint disruption |
| Body/spine | Rarely surgical - consider if lateral border more than 20mm displaced |
Surgical approaches:
Modified Judet Approach (most common)
- Patient lateral or prone
- Incision along scapular spine, curves distally along lateral border
- Develop interval between infraspinatus and teres minor
- Excellent exposure of glenoid neck, body, spine
- Can extend for glenoid fossa
Key structures:
- Suprascapular nerve (protected by staying below spine)
- Infraspinatus and teres minor (preserve vascularity)
- Axillary nerve (inferior limit)
The Judet approach provides excellent access to the scapula body and neck.
Fixation methods:
- 3.5mm reconstruction plates (can be contoured)
- Lag screws for simple patterns
- Locking plates for osteoporotic bone
- Suture anchors for small rim fragments
Floating Shoulder Management
For floating shoulder, the traditional approach is to fix the clavicle first. This is technically easier and often provides sufficient stability. If residual scapula displacement persists after clavicle fixation, address the scapula neck. Some advocate fixing both primarily.
Surgical Technique
Patient Positioning
Modified Lateral Decubitus (Most Common):
- Beanbag support at 30-45 degrees
- Arm supported in traction or on mayo stand
- Allows anterior and posterior access
- C-arm from cephalad direction
Prone:
- Alternative for posterior-only approach
- Better visualization of medial border
- Limited anterior access
Positioning depends on approach requirements and associated injuries.
Complications
Complications
| Complication | Incidence | Prevention/Management |
|---|---|---|
| Shoulder stiffness | 5-15% | Early motion protocols, physiotherapy |
| Malunion | Variable | Rarely symptomatic for body; affects glenoid function |
| Nonunion | Rare (less than 1%) | Rich blood supply protects; treat with bone graft if symptomatic |
| Suprascapular nerve injury | 5-10% surgical | Careful retraction, identify nerve |
| Glenohumeral arthritis | 10-20% glenoid fx | Related to articular step-off; minimize displacement |
| Infection | 1-2% | Standard precautions, prophylactic antibiotics |
Stiffness:
- Most common complication
- Related to prolonged immobilization and associated injuries
- Prevention: early motion when safe
Post-traumatic arthritis:
- Primarily in glenoid fossa fractures
- Related to residual step-off
- Emphasizes importance of anatomic reduction for articular fractures
Suprascapular Nerve
The suprascapular nerve passes through the suprascapular notch and supplies supraspinatus and infraspinatus. Injury causes external rotation and abduction weakness. Protect during posterior approaches by staying inferior to the scapular spine.
Long-term outcomes:
- Body fractures: generally excellent outcomes regardless of treatment
- Neck fractures: good outcomes if displacement parameters respected
- Glenoid fractures: outcomes correlate with reduction quality
Postoperative Care and Rehabilitation
Post-ORIF protocol:
- Sling for comfort and protection
- Gentle pendulum exercises
- No active elevation or external rotation
- Wound management
- Wean sling as comfort allows
- Active assisted ROM
- Progress to active ROM
- Avoid loaded activities
- Full active ROM expected
- Progressive strengthening
- Rotator cuff rehabilitation
- Light functional activities
- Confirm radiographic healing
- Sport-specific training
- Return to full activities typically 4-6 months
- High-impact activities may take longer
Key rehabilitation principles:
- Balance protection of repair with early motion
- Rotator cuff function critical for outcome
- Address associated injuries (rib, clavicle) in rehab plan
- Patient education about expected timeline
Outcomes and Prognosis
Outcomes by fracture type:
| Fracture Type | Outcome | Notes |
|---|---|---|
| Body/spine | Excellent | Conservative treatment adequate |
| Glenoid neck (isolated) | Good | Conservative if meets displacement criteria |
| Glenoid neck (floating) | Good | With surgical stabilization |
| Glenoid fossa (reduced) | Good-Excellent | Key is anatomic reduction |
| Glenoid fossa (malreduced) | Fair-Poor | Develops arthritis |
Prognostic factors:
- Associated injuries (head, chest) - major determinant of mortality
- Articular reduction quality - major determinant of shoulder function
- Patient age and bone quality
- Rehabilitation compliance
Long-term Function
Most patients with scapula body fractures return to full function. Glenoid fossa fractures have variable outcomes depending on reduction quality. The presence of glenohumeral subluxation at presentation is a poor prognostic factor.
Evidence Base
- Pooled 520 fractures from 22 case series: scapula fractures comprise less than 1% of all fractures and 3-5% of shoulder-girdle fractures.
- Approximately 90% of patients had associated injuries.
- Both operatively and non-operatively treated fractures achieved largely good functional results when treated by appropriate indication; operative infection and secondary-surgery rates were low.
- Glenoid fossa and scapular neck fractures were the patterns most commonly treated operatively.
- About 25% had a concomitant clavicle or acromioclavicular injury.
- Plate-and-screw fixation through a posterior (Judet) approach was most common; complication rate was low.
- Good to excellent functional results in approximately 85% of operatively treated cases at a mean of 49.9 months.
- Floating shoulder (ipsilateral scapular neck plus clavicle fracture) is not inherently unstable.
- Mean Constant score 76 for the conservatively treated group versus 71 for the operative group.
- Caudal (inferior) dislocation of the glenoid was the key poor-prognostic finding: Constant 42 with it versus 85 without.
- In the absence of caudal glenoid displacement, conservative treatment gave a good functional outcome.
- 22 patients had ORIF more than 3 weeks (mean 30 days) after injury for displaced intra-articular fractures, glenohumeral medialisation, angular deformity, or double SSSC lesions.
- Mean DASH score 14 at a mean follow-up of 27 months.
- 13 of 16 followed patients returned to previous work and recreation without restriction.
- No wound complications, infection, or nonunion occurred.
- Annual incidence of scapular fractures was 10 per 100,000 inhabitants over a 10-year period across two Swedish counties.
- 30% of scapular fractures involved the glenoid cavity.
- The most common intra-articular pattern was the anterior chip (rim) fracture, associated with shoulder dislocation in about two-thirds of cases.
- This series underpins the Ideberg glenoid-fossa classification used to guide surgical planning.
- Operative thresholds used: medial/lateral displacement of 20mm or more, angulation of 45 degrees or more, double SSSC disruption, or glenopolar angle of 22 degrees or less.
- Scapular neck angulation corrected from a mean 38.7 degrees pre-operatively to 3.6 degrees; mean post-operative glenopolar angle 35.4 degrees.
- Mean DASH score 11.4 and mean Subjective Shoulder Value 88.9; 10 of 11 returned to pre-injury work.
- No infections or neurovascular injuries with a less invasive single-column approach.
Clinical Decision Scenarios
Use these scenarios to practise clinical reasoning and management decisions
Scenario 1: Isolated Glenoid Neck Fracture
"A 35-year-old motorcyclist is brought to ED after high-speed accident. GCS 15, hemodynamically stable. Chest X-ray shows multiple left rib fractures and a scapula fracture. CT shows a glenoid neck fracture with 15mm medialization. How do you manage this patient?"
Scenario 2: Floating Shoulder
"A 42-year-old presents after falling from scaffolding. X-rays show a displaced midshaft clavicle fracture and CT reveals a glenoid neck fracture with 25mm medialization and glenopolar angle of 15 degrees. How do you approach this 'floating shoulder' injury?"
Scenario 3: Scapulothoracic Dissociation
"A 28-year-old is brought in after a motorcycle vs truck collision. There is massive left shoulder swelling, the arm is flail, and there is no radial pulse. Chest X-ray shows the left scapula displaced 4cm lateral to the chest wall. What is your diagnosis and immediate management?"
MCQ Practice Points
Epidemiology Question
Q: What percentage of patients with scapula fractures have associated injuries? A: 80-95%. Scapula fractures are high-energy injuries. Rib fractures are most common (52%), followed by pulmonary contusion (47%) and clavicle fractures (23%).
Anatomy Question
Q: What is the superior shoulder suspensory complex (SSSC)? A: A bone-ligament ring connecting the upper extremity to the axial skeleton. Components: glenoid, coracoid, CC ligaments, clavicle, AC ligaments, acromion. Two disruptions = floating shoulder = unstable.
Classification Question
Q: What Ideberg type is an anterior glenoid rim fracture? A: Type Ia. Type Ib is posterior rim. These rim fractures are often associated with shoulder instability and may require treatment directed at the instability rather than just the fracture.
Surgical Indication Question
Q: What glenoid articular step-off is an indication for ORIF? A: More than 4mm step-off or more than 25% articular surface involvement. These thresholds are based on data showing increased rates of post-traumatic arthritis with larger incongruities.
Critical Diagnosis Question
Q: On chest X-ray, what finding suggests scapulothoracic dissociation? A: Lateral displacement of the scapula compared to the contralateral side. This indicates complete disruption of the scapulothoracic connection with likely vascular injury and brachial plexus avulsion.
Guidelines, Registries & Global Practice
Global epidemiology
| Metric | Figure | Source population |
|---|---|---|
| Annual incidence | ~10 per 100,000 per year | Two Swedish counties, Ideberg 1995 |
| Share of all fractures | Less than 1% | Pooled case series, Zlowodzki/Cole 2006 |
| Share of shoulder-girdle fractures | 3-5% | Pooled case series, Zlowodzki/Cole 2006 |
| Glenoid (intra-articular) involvement | ~30% | Ideberg 1995 |
| Associated injuries | ~90% (range 80-95%) | Zlowodzki/Cole 2006 |
| Demographics | Peak in young men from high-energy trauma; older women from low-energy falls | Ideberg 1995 |
Scapula fractures are uncommon worldwide and almost always a marker of high-energy transfer; injury patterns therefore track regional trauma epidemiology (road-traffic and motorcycle trauma in much of Asia, Africa and Latin America; falls and vehicle crashes in higher-income settings).
Guidance, side by side
There is no single dedicated international guideline for scapula fractures; management is anchored on the AO Foundation principles plus society trauma-system standards. Recommendations are largely concordant because the evidence base is uniformly low (level IV).
| Body / source | Position on scapula fractures | Evidence level |
|---|---|---|
| AO Foundation | Non-operative for most body/neck fractures; ORIF for displaced intra-articular glenoid, large lateral-border displacement/angulation, low glenopolar angle, or double SSSC disruption; posterior (Judet) approach standard | Expert consensus / level IV |
| AAOS (USA) | No condition-specific clinical practice guideline; managed within polytrauma and shoulder-trauma principles, ATLS-first | Consensus |
| BOA / BOAST (UK) | No scapula-specific BOAST; governed by BOAST polytrauma and open-fracture standards and trauma-network triage to a major trauma centre | Consensus / standard of care |
| NICE (UK) | No scapula-specific guidance; covered by NICE major-trauma pathways (NG39/NG40) emphasising ATLS, imaging and network transfer | Consensus |
| EFORT / European | Reflects AO principles; emphasises CT for glenoid and surgical-threshold measurement | Expert consensus |
Key Cross-Guideline Agreement
Across AO, AAOS, BOA and EFORT the consensus is identical at the level that examiners test: complete ATLS first, image associated injuries, treat most fractures non-operatively, and reserve surgery for displaced articular glenoid fractures, grossly displaced necks (glenopolar angle 22 degrees or less, displacement 20mm or more, angulation 40-45 degrees or more) and unstable double SSSC disruptions.
Registry evidence
Scapula fractures are not implant-survival procedures, so the major arthroplasty registries (NJR, AJRR, AOANJRR, SHAR, Norwegian, NZJR) do not track them directly. Epidemiology instead comes from national trauma databases: a US National Trauma Data Bank analysis of 9,453 scapular fractures (Baldwin et al., J Trauma 2008) showed that, after adjusting for injury severity, upper-extremity, thoracic and pelvic-ring injuries remained significantly associated with scapula fracture, while many other "associations" reflected overall injury severity rather than the scapula fracture itself.
Global practice variation
- High-resource settings: ready CT and 3D reconstruction, sub-specialist shoulder/trauma surgeons, and trauma-network transfer make selective ORIF (Judet or single lateral-column approach) routine for displaced patterns.
- Limited-resource settings: CT may be scarce and most fractures are managed non-operatively with sling and early motion, which is supported by the evidence for the majority of body and minimally displaced neck fractures.
- Scapulothoracic dissociation is a universal surgical emergency requiring immediate vascular assessment regardless of setting; outcomes depend on access to vascular surgery and ICU support.
Exam Context
For any board, be ready to justify management on biomechanical thresholds and evidence level rather than a national pathway. State that the evidence is predominantly level IV, that most fractures heal well non-operatively, and that operative thresholds (glenoid step greater than 4mm or fragment greater than 25%, glenopolar angle 22 degrees or less, lateral-border displacement 20mm or more, double SSSC disruption) are consensus-based and consistent across AO, AAOS, BOA and EFORT.
SCAPULA FRACTURES
Clinical summary
KEY FACTS
- •1% of all fractures - high-energy mechanism required
- •80-95% have associated injuries - ATLS protocol mandatory
- •10-15% mortality (from associated chest/head injuries)
- •Most body fractures (50-60%) treated conservatively
- •Peak age 25-40, M:F ratio 2:1
- •MVA most common mechanism (50-70%)
CLASSIFICATION
- •Anatomic: Body (50-60%), Neck (25%), Glenoid fossa (10%), Processes (8%)
- •Ideberg (glenoid): I (rim), II (transverse), III (oblique), IV (horizontal), V (combined), VI (comminuted)
- •SSSC: double disruption = floating shoulder = unstable
- •Ada-Miller (neck): Type I (anatomic neck), Type II (through body)
- •Body fractures: usually heal well with conservative treatment
SURGICAL THRESHOLDS (4-25-40-20 Rule)
- •Glenoid fossa: step more than 4mm OR fragment more than 25% of surface
- •Glenoid neck: angulation more than 40 degrees OR medialization more than 20mm
- •Glenopolar angle less than 20 degrees (normal 30-45 degrees)
- •Floating shoulder: fix clavicle minimum, consider scapula if residual displacement
- •Humeral head subluxation = surgical indication
- •GH instability with rim fracture = consider Bankart repair
FLOATING SHOULDER
- •Double SSSC disruption (usually clavicle + scapula neck fracture)
- •Creates unstable glenoid segment - weight causes medialization
- •Treatment: stabilize clavicle FIRST (easier, restores length)
- •Reassess scapula after clavicle fixation under fluoroscopy
- •Add scapula ORIF if persistent displacement more than 20mm
- •Some advocate fixing both primarily - evidence mixed
SCAPULOTHORACIC DISSOCIATION
- •Lateral scapula displacement on CXR (compare to contralateral)
- •Complete soft tissue disruption - massive energy transfer
- •Associated vascular injury (subclavian/axillary), brachial plexus avulsion
- •High mortality (10-20%) and amputation rate (20%)
- •Immediate CT angiography, vascular surgery consultation
- •May need forequarter amputation if limb non-salvageable
ASSOCIATED INJURIES (Remember SCAPULA)
- •Spine fractures (cervical/thoracic) - 8%
- •Clavicle fractures - 23% (creates floating shoulder)
- •Arterial injury (subclavian) - rare but serious
- •Pulmonary contusion - 47% (most common thoracic)
- •Upper extremity nerve (brachial plexus) - 12%
- •Lateral rib fractures - 52% (most common association)
SURGICAL APPROACHES
- •Modified Judet (posterior): along spine/lateral border
- •Interval: infraspinatus-teres minor (preserves cuff)
- •Protect suprascapular nerve (stay below spine)
- •Deltopectoral (anterior): for isolated anterior rim
- •Positioning: lateral decubitus 30-45° or prone
- •Fixation: 3.5mm recon plates, lag screws, locking plates
TRAPS AND PEARLS
- •Always complete ATLS trauma assessment first
- •Look for associated chest injuries - ribs, pneumothorax
- •Glenoid fractures affect long-term function most
- •Body fractures heal well conservatively
- •Modified Judet = standard posterior approach
- •Glenopolar angle less than 20° = surgical indication