CLAVICLE FRACTURES - CLASSIFICATION and MANAGEMENT
Location Determines Treatment | Midshaft Most Common | Displacement Key Factor
ALLMAN CLASSIFICATION
Critical Must-Knows
- Displacement and shortening are key surgical indications for midshaft fractures
- COTS study showed improved union rates but no functional difference at 1 year
- Type II lateral clavicle fractures are unstable - CC ligaments torn
- Floating shoulder = scapula neck + clavicle - surgical stabilization often needed
- Plate position: superior vs anteroinferior - both acceptable, different complications
Examiner's Pearls
- "Edinburgh study changed practice - 15% nonunion rate for displaced midshaft
- "Neer Type II lateral = CC ligament disruption = unstable = surgery
- "Shortening over 2cm correlates with poor functional outcomes
- "Medial clavicle fractures - CT for posterior displacement (vascular risk)
Clinical Imaging
Imaging Gallery
Critical Clavicle Fracture Exam Points
Displaced Midshaft
Shortening greater than 2cm and 100% displacement are key surgical indications. COTS/Edinburgh data showed improved union with ORIF but similar long-term function.
Lateral Classification
Neer Type II has CC ligament disruption = unstable = high nonunion rate. Type I (lateral to CC) and Type III (articular) are usually stable.
Medial Fractures
Posterior displacement is dangerous - CT essential. Risk to great vessels and trachea. Physis closes at 23-25 years - beware SC dislocation in young adults.
Floating Shoulder
Clavicle + scapula neck fracture = double disruption of superior shoulder suspensory complex. Often requires clavicle fixation for stability.
Quick Decision Guide
| Fracture Pattern | Key Finding | Stability | Treatment |
|---|---|---|---|
| Midshaft - minimal displacement | Less than 100% displacement, shortening less than 2cm | Good prognosis | Sling, early ROM, union expected |
| Midshaft - significantly displaced | Greater than 2cm shortening, 100% displacement | Higher nonunion risk | Discuss surgery - similar function at 1yr |
| Lateral Type II | CC ligament disruption, unstable fragment | Unstable | Surgical fixation - hook plate or sutures |
| Medial with posterior displacement | CT shows posterior fragment near vessels | Dangerous | CT angiogram, likely open reduction |
| Floating shoulder | Clavicle + scapula neck fracture | Complex instability | Clavicle ORIF stabilizes construct |
COTS - Midshaft ORIF Benefits
Memory Hook:COTS study showed ORIF gives better union but COmparable long-Term Score
PLATE - Surgical Indications
Memory Hook:PLATE the clavicle when these indications are met
NEER - Lateral Clavicle Types
Memory Hook:Type II = II ligaments torn (trapezoid + conoid) = Instability
2-2-2 Rule for Midshaft Surgery
Memory Hook:If shortening exceeds 2cm, decide within 2 weeks or double your trouble
Overview and Epidemiology
Clavicle fractures are among the most common orthopaedic injuries, representing approximately 4-5% of all fractures. The clavicle is a unique bone that serves as the only bony connection between the upper limb and the axial skeleton.
Mechanism of injury:
- Direct blow - fall onto the point of the shoulder (most common)
- Indirect - FOOSH (fall on outstretched hand) transmits force
- High-energy - motor vehicle accidents, sports injuries
Bimodal distribution:
- Young males (high-energy sports/trauma)
- Elderly (low-energy falls with osteoporosis)
S-Shaped Anatomy
The clavicle is S-shaped with the medial curve convex anteriorly and the lateral curve convex posteriorly. The junction of these curves (middle third) is the thinnest point and lacks ligamentous attachments, explaining the high fracture rate here.
Anatomy and Biomechanics
Bony anatomy:
- First bone to ossify (5th week in utero)
- Last bone to fuse (medial physis closes 23-25 years)
- S-shaped: medial 2/3 convex anteriorly, lateral 1/3 convex posteriorly
- Middle third is the thinnest with no ligamentous attachments
Muscular attachments:
- SCM (sternocleidomastoid) - inserts medial third, elevates medial fragment
- Trapezius - inserts lateral third, may elevate lateral fragment
- Deltoid - originates from lateral third
- Pectoralis major - originates from medial third, depresses fragment
Critical relationships:
Neurovascular Structures
Subclavian vessels and brachial plexus pass directly posterior to the middle third. The subclavius muscle and clavipectoral fascia provide protection. Acute vascular injury rare but posterior medial displacement is dangerous.
Ligamentous structures:
- Coracoclavicular (CC) ligaments - trapezoid (lateral) and conoid (medial) - key stabilizers
- Acromioclavicular ligament - horizontal stability of AC joint
- Sternoclavicular ligaments - anchor medial clavicle
Deforming Forces
In midshaft fractures: medial fragment elevates (SCM pull) and retracts posteriorly (trapezius). Lateral fragment depresses (weight of arm) and medializes (pectoralis/deltoid). This creates the classic "step-off" deformity.
Vascular supply:
- Periosteal vessels (branches of suprascapular, thoracoacromial, internal thoracic)
- Nutrient artery enters near middle third
- Comminuted fractures disrupt blood supply - higher nonunion risk
Classification Systems
Allman Classification (by location - most commonly used)
| Group | Location | Frequency | Key Features |
|---|---|---|---|
| I | Middle third | 80% | Between CC ligaments and costoclavicular ligament |
| II | Lateral third | 15% | Lateral to CC ligaments |
| III | Medial third | 5% | Medial to costoclavicular ligament |
Group I Significance
Middle third fractures occur at the junction of the two curves where the bone is thinnest and has no ligamentous attachments. This explains both the high incidence and propensity for displacement.
Clinical Presentation and Assessment
History:
- Mechanism (fall onto shoulder, direct blow, FOOSH)
- High vs low energy
- Hand dominance
- Occupation and activity level
- Associated injuries (floating shoulder, chest trauma)
Physical examination:
Physical Examination Findings
| Finding | Significance | Action Required |
|---|---|---|
| Visible/palpable deformity | Displacement present | Assess degree of shortening |
| Skin tenting | Impending open fracture | Urgent - relative surgical indication |
| Neurovascular deficit | Brachial plexus/vascular injury | Urgent surgical exploration |
| Dyspnea/chest pain | Pneumothorax | Chest X-ray, tube thoracostomy if needed |
| Ipsilateral shoulder pain | Floating shoulder | Full shoulder girdle imaging |
Neurovascular examination:
- Brachial plexus assessment (especially lateral cord - musculocutaneous, median)
- Radial, ulnar, median nerve function
- Distal pulses, capillary refill
- Signs of venous congestion
Associated Injuries
Look for floating shoulder (clavicle + scapula neck), AC joint injury, pneumothorax (especially with first rib fracture), and brachial plexus injury (particularly in high-energy trauma).
Signs of significant displacement:
- Obvious step-off deformity
- Shortening (compare to contralateral side)
- Tenting of skin
- Pain with any shoulder movement
Investigations
Radiographic Examples
Standard imaging:
AP Clavicle X-ray:
- 15-degree cephalic tilt provides best view
- Assess displacement, shortening, comminution
- Measure shortening by comparing to contralateral side
45-degree cephalic tilt view:
- Separates clavicle from overlying ribs/scapula
- Better assessment of displacement and comminution
Shortening Measurement
Measure clavicle length on AP X-ray from sternal to acromial end. Compare to contralateral side. More than 2cm shortening is a key surgical threshold. CT provides more accurate measurement if needed.
When to order CT:
CT Indications in Clavicle Fractures
| Indication | Rationale |
|---|---|
| Medial clavicle fracture | Assess posterior displacement, vascular proximity |
| Complex lateral fracture | Define CC ligament attachment, fracture pattern |
| Floating shoulder | Define scapula fracture pattern for surgical planning |
| Comminuted midshaft (surgical planning) | Accurate shortening measurement, fragment assessment |
CT angiogram:
- Indicated for medial fractures with posterior displacement
- Any concern for vascular injury (expanding hematoma, pulse deficit)
Chest X-ray:
- Rule out pneumothorax
- Especially with first rib fracture or high-energy mechanism
Management
Conservative management:
Most clavicle fractures can be treated conservatively with excellent outcomes.
- Simple sling for comfort (arm sling preferred over figure-of-8)
- Ice, analgesia
- Gentle pendulum exercises when pain allows
- Wean from sling as pain allows
- Active ROM exercises below 90 degrees
- Avoid heavy lifting
- Progressive strengthening once clinical union
- Return to non-contact sports typically 8-12 weeks
- Contact sports delayed until radiographic union (12-16 weeks)
Figure-of-8 vs Sling
Simple arm sling is preferred over figure-of-8 brace. A Cochrane review showed no difference in outcomes, and figure-of-8 braces cause axillary discomfort and skin problems. Only advantage is cosmetic improvement of posture.
Surgical Technique
Plate and screws - gold standard for midshaft fractures
Superior plating:
- Easier exposure
- Better cosmesis
- Plate prominence, hardware irritation common
Anteroinferior plating:
- Less prominence
- Subcutaneous suture line
- More difficult exposure
- Protected from direct trauma
Plate selection:
- 3.5mm reconstruction plate (can be contoured)
- Precontoured clavicle plates (anatomic)
- Locking plates for osteoporotic bone or comminution
Plate Position
Superior plating is most common but has higher hardware prominence. Anteroinferior plating is biomechanically similar with less prominence but technically more demanding. Both acceptable - surgeon preference.
Complications
Complications by Treatment Type
| Complication | Conservative Rate | Surgical Rate | Management |
|---|---|---|---|
| Nonunion | 5-15% | 1-2% | Bone grafting, revision ORIF |
| Malunion | Variable | Rare | Accept most; osteotomy if symptomatic |
| Hardware irritation | N/A | 20-40% | Hardware removal at union |
| Infection | N/A | 1-2% | Antibiotics, debridement if deep |
| Neurovascular injury | Rare | 0.5-1% | Intraop recognition, vascular repair |
| Refracture | Rare | 1-2% | After hardware removal; wait 12 weeks |
Nonunion:
Risk factors for nonunion:
- Displacement greater than 100%
- Shortening greater than 2cm
- Comminution
- Female sex
- Older age
- Smoking
- Refracture
Nonunion Management
Clavicle nonunion treatment: plate fixation + bone grafting (iliac crest or local autograft). Address biomechanical (length, alignment) and biological (vascularity, bone quality) factors.
Malunion:
- Shortening, angulation, and rotation
- Usually well tolerated
- Surgery only for symptomatic cases (shoulder dysfunction, cosmesis)
- Corrective osteotomy with plate fixation
Hardware-Related Complications
Plate prominence is the most common reason for hardware removal (20-40% of patients). Counsel patients preoperatively. Anteroinferior plating may reduce this but is technically more demanding.
Postoperative Care and Rehabilitation
Post-ORIF protocol:
- Sling for comfort
- Gentle pendulum exercises
- No active elevation
- Wound care
- Wean sling
- Active assisted ROM
- Progress to active ROM as tolerated
- No lifting greater than 2-3kg
- Progressive strengthening
- Return to desk work usually possible
- No heavy lifting or contact sports
- Confirm radiographic union
- Return to full activities
- Contact sports typically 4-6 months
- Hardware removal if symptomatic (12+ months)
Key rehabilitation principles:
- Early pendulum exercises prevent stiffness
- Progressive loading only after clinical union
- Hardware removal is optional unless symptomatic
- Full sports clearance requires radiographic union
Return to Sport
Athletes can return to non-contact sports at 8-12 weeks with clinical union and adequate ROM. Contact sports require radiographic union, typically 4-6 months. Elite athletes may have earlier return with protective padding.
Outcomes and Prognosis
Prognosis by fracture type:
| Fracture Type | Conservative Union | ORIF Union | Notes |
|---|---|---|---|
| Undisplaced midshaft | 95%+ | 98-99% | Conservative treatment preferred |
| Displaced midshaft | 85% | 98% | ORIF faster union, similar function |
| Neer Type I lateral | 90%+ | 95%+ | Conservative preferred |
| Neer Type II lateral | 67-78% | 90-95% | ORIF strongly preferred |
| Medial clavicle | 90%+ | 95%+ | Conservative unless displaced posteriorly |
COTS Study Summary
Canadian Orthopaedic Trauma Society (COTS) 2007: RCT comparing ORIF vs conservative for displaced midshaft. ORIF showed lower nonunion (2.2% vs 15.1%), faster union, better early function. No difference in DASH scores at 1 year. Changed practice toward considering surgery for displaced fractures.
Factors affecting outcomes:
- Degree of shortening (more than 2cm worse outcomes)
- Smoking (delays union, increases complications)
- Age and bone quality
- Compliance with rehabilitation
- Patient expectations and activity demands
Evidence Base
- ORIF reduced nonunion (2.2% vs 15.1%) and improved early function compared to conservative treatment for displaced midshaft fractures.
- 15.1% nonunion rate for displaced (Edinburgh 2B) midshaft fractures treated conservatively. Challenged the 'benign fracture' paradigm.
- At 5-year follow-up, no significant difference in DASH scores between operative and non-operative groups.
- Plate fixation superior to conservative treatment for displaced midshaft fractures (OR 0.14 for nonunion). No difference for non-displaced fractures.
- No difference in outcomes between figure-of-8 bandage and arm sling. Sling had fewer complications and better comfort.
Exam Viva Scenarios
Practice these scenarios to excel in your viva examination
Scenario 1: Displaced Midshaft Fracture
"A 25-year-old male cyclist presents after a fall onto his right shoulder. X-ray shows a displaced midshaft clavicle fracture with 2.5cm shortening and 100% displacement. He is a manual laborer. How would you manage this patient?"
Scenario 2: Lateral Third Fracture
"A 45-year-old woman presents with a lateral third clavicle fracture. X-rays show the fracture between the CC ligaments with significant displacement of the medial fragment. What is your assessment and management?"
Scenario 3: Medial Clavicle Injury
"An 18-year-old presents with a medial clavicle injury after a rugby tackle. There is swelling at the sternoclavicular area, the patient reports difficulty swallowing, and the arm is held adducted. X-rays are difficult to interpret. What are your concerns and management?"
MCQ Practice Points
Classification Question
Q: What percentage of clavicle fractures occur in the middle third? A: 80%. The middle third is the thinnest portion of the clavicle, at the junction of the two curves, and lacks ligamentous attachments - making it the most vulnerable to fracture.
Anatomy Question
Q: At what age does the medial clavicle physis close? A: 23-25 years. This is the last physis in the body to fuse. Injuries in young adults appearing as SC dislocations are often physeal fracture-separations.
Surgical Indication Question
Q: What shortening threshold is a key indication for ORIF of midshaft clavicle fractures? A: Greater than 2cm shortening. Along with 100% displacement, this is associated with higher nonunion rates and functional impairment.
Evidence Question
Q: What was the key finding of the COTS study regarding operative vs non-operative treatment of displaced midshaft clavicle fractures? A: ORIF resulted in lower nonunion rates (2.2% vs 15.1%) and faster union, but no significant difference in functional scores at 1 year.
Lateral Fracture Question
Q: Which Neer classification type of lateral clavicle fracture has the highest nonunion rate? A: Type II (22-33% nonunion). The CC ligament disruption leaves the medial fragment unstable and elevated by the trapezius.
Australian Context
Clavicle fractures are common in Australian contact sports including AFL and rugby, with increasing incidence in cycling-related trauma. Management follows international evidence-based guidelines, with the COTS study influencing Australian practice toward considering surgical fixation for significantly displaced midshaft fractures. Public hospital waiting lists may influence timing of elective ORIF. Return to work considerations vary by occupation, with clerical workers typically managing with sling immobilization for 2-4 weeks, while manual laborers often require surgical fixation for earlier return to full duties at 8-12 weeks. WorkCover implications should be considered for occupational injuries.
CLAVICLE FRACTURES
High-Yield Exam Summary
CLASSIFICATION
- •Allman: I (80% middle), II (15% lateral), III (5% medial)
- •Neer lateral: I (stable), II (unstable - CC disrupted), III (articular)
- •Robinson: 2A (aligned), 2B (displaced) - key for prognosis
- •Edinburgh: expanded Robinson - includes comminution assessment
KEY NUMBERS
- •Greater than 2cm shortening = consider ORIF
- •15% nonunion rate for displaced midshaft (conservative)
- •22-33% nonunion for Neer Type II (lateral)
- •23-25 years = medial physis closure age
SURGICAL INDICATIONS
- •Open fracture, neurovascular compromise
- •Impending skin perforation (tenting)
- •Shortening greater than 2cm, 100% displacement
- •Neer Type II lateral fracture
- •Floating shoulder (relative)
- •Polytrauma needing early mobilization
COTS STUDY SUMMARY
- •ORIF reduces nonunion: 2.2% vs 15.1%
- •Faster union with surgery
- •Better early function with ORIF
- •NO DIFFERENCE in DASH at 1 year
SURGICAL OPTIONS
- •Superior plate: easier exposure, more prominence
- •Anteroinferior plate: less prominence, harder
- •IM nail: smaller incision, migration risk
- •Hook plate (lateral): needs removal at 3-6 months
TRAPS AND PEARLS
- •Medial injury in less than 25yo = physeal, not SC dislocation
- •Posterior medial displacement = CT angio, vascular risk
- •Figure-of-8 no better than sling - sling preferred
- •Floating shoulder = consider clavicle fixation
- •Hook plate = plan for routine removal