Location Determines Treatment | Midshaft Most Common | Displacement Key Factor
- Displacement and shortening are key surgical indications for midshaft fractures
- COTS 2007 found BOTH: significantly better Constant and DASH scores at all time-points (p=0.001, p<0.01) AND fewer nonunions/malunions. Later meta-analyses argue the functional gain may sit below the MCID - say that as the caveat, not as COTS' finding (PMID 17200303)
- 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
- “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)
Overview and Epidemiology
Clavicle fractures are among the most common orthopaedic injuries, roughly 4-5% of all fractures. The clavicle is a unique bone: it is the only bony connection between the upper limb and the axial skeleton.
Mechanism. A direct blow, a fall onto the point of the shoulder, is the most common. The other two routes are:
- Indirect - a fall on the outstretched hand transmits the force along the limb
- High-energy - motor vehicle accidents and sports injuries
Who. The distribution is bimodal. Young males break the clavicle in high-energy sport and trauma; the elderly break it in low-energy falls onto osteoporotic bone.
Anatomy and Biomechanics
The bone. The clavicle is the first bone to ossify, in the 5th week in utero, and the last to fuse: the medial physis closes at 23-25 years. It is S-shaped, the medial two-thirds convex anteriorly and the lateral third convex posteriorly. The junction of the two curves, the middle third, is the thinnest part of the bone and has no ligamentous attachments, which explains both the high fracture rate at that level and the fragments' propensity to displace.
Muscle attachments. Each attachment has a hand in how the fragments move:
- Sternocleidomastoid inserts on the medial third and elevates the medial fragment
- Trapezius inserts on the lateral third and may elevate the lateral fragment
- Deltoid originates from the lateral third
- Pectoralis major originates from the medial third and depresses the fragment
Deforming forces. In a midshaft fracture the medial fragment elevates, pulled by sternocleidomastoid, and retracts posteriorly, pulled by trapezius. The lateral fragment drops with the weight of the arm and is drawn medially by pectoralis major and deltoid. The two fragments therefore part company in opposite directions, which is the classic step-off deformity.
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.
Ligaments. The ligaments hold the clavicle at its two ends:
- The coracoclavicular ligaments, trapezoid laterally and conoid medially, are the key stabilisers
- The acromioclavicular ligament gives the AC joint its horizontal stability
- The sternoclavicular ligaments anchor the medial clavicle
Blood supply. The clavicle is fed by periosteal vessels, branches of the suprascapular, thoracoacromial and internal thoracic arteries, and by a nutrient artery entering near the middle third. Comminution disrupts this supply, which is why comminuted fractures carry a higher nonunion risk.
Floating shoulder and the superior shoulder suspensory complex. The "floating shoulder" is best understood through Goss's superior shoulder suspensory complex (SSSC): a bone-and-soft-tissue ring suspending the upper limb from the axial skeleton on two struts. The ring comprises the glenoid process, coracoid process, coracoclavicular ligaments, distal clavicle, acromioclavicular joint and acromion; the superior strut is the middle clavicle and the inferior strut is the lateral scapular body and spine.
The clinical rule follows from the ring. A single disruption is usually stable and can be treated non-operatively. A double disruption, two breaks in the ring or a ring break plus both struts, destabilises the complex; the classic example is an ipsilateral midshaft clavicle fracture plus a scapular neck fracture, where fixing the clavicle alone often restores enough stability to let the scapular neck heal. This framework, not the eponym, is what the examiner is after.
Classification Systems
Four systems are in use, and each answers a different question: Allman says where the fracture is, Robinson grades midshaft displacement, Neer grades lateral-third stability, and the Edinburgh classification is the most comprehensive.
The Allman classification is by location and is the most commonly used.
- Location
- Middle third
- Frequency
- 80%
- Key Features
- Between CC ligaments and costoclavicular ligament
- Location
- Lateral third
- Frequency
- 15%
- Key Features
- Lateral to CC ligaments
- Location
- Medial third
- Frequency
- 5%
- Key Features
- Medial to costoclavicular ligament
The paediatric clavicle. The adult displacement and shortening thresholds do not transfer to children. The paediatric clavicle has enormous remodelling potential and a thick osteogenic periosteal sleeve, so the vast majority of fractures, including markedly displaced or shortened midshaft fractures, are treated non-operatively with a sling and early motion, and unite and remodel reliably; greenstick patterns are common. Two specific entities need recognising rather than treating as adult fractures:
- The neonatal or obstetric clavicle fracture is the commonest fracture of birth (large baby, shoulder dystocia). It presents as pseudoparalysis or a lump, must be distinguished from brachial plexus (Erb) palsy and from osteomyelitis or non-accidental injury, and heals with simple support and no specific treatment.
- Congenital pseudarthrosis of the clavicle is a painless, atraumatic, almost always right-sided mid-clavicular gap with rounded sclerotic bone ends and no callus. It is a developmental anomaly, not a fracture and not the neurofibromatosis-associated lesion seen in the tibia, and is treated by excision, grafting and plating only if symptomatic.
Clinical Presentation and Assessment
History. The history sets the energy of the injury and what recovery will cost the patient:
- Mechanism (fall onto shoulder, direct blow, fall on the outstretched hand)
- High versus low energy
- Hand dominance
- Occupation and activity level
- Associated injuries (floating shoulder, chest trauma)
Examination. Significant displacement declares itself: an obvious step-off, shortening when compared with the contralateral side, and pain with any shoulder movement. Tenting of the skin is an impending open fracture and a relative surgical indication in its own right.
- Significance
- Displacement present
- Action Required
- Assess degree of shortening
- Significance
- Impending open fracture
- Action Required
- Urgent - relative surgical indication
- Significance
- Brachial plexus/vascular injury
- Action Required
- Urgent surgical exploration
- Significance
- Pneumothorax
- Action Required
- Chest X-ray, tube thoracostomy if needed
- Significance
- Floating shoulder
- Action Required
- Full shoulder girdle imaging
Neurovascular examination. It covers the plexus and the distal circulation:
- Brachial plexus, especially the lateral cord (musculocutaneous and median nerves)
- Radial, ulnar and median nerve function
- Distal pulses and capillary refill
- Signs of venous congestion
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).
Differential diagnosis. A painful, deformed shoulder girdle has several causes that can pass for a clavicle fracture, and each has a finding that separates it.
- Distinguishing Features
- Tenderness over AC joint, step at the joint not the shaft, positive cross-body adduction
- Confirming Investigation
- AP and Zanca views, weighted views if needed
- Distinguishing Features
- Medial swelling, dysphagia or venous congestion if posterior
- Confirming Investigation
- CT with angiography for posterior displacement
- Distinguishing Features
- Pain and bruising over proximal humerus, restricted glenohumeral movement
- Confirming Investigation
- AP, scapular-Y and axillary radiographs
- Distinguishing Features
- High-energy mechanism, scapular tenderness, double disruption
- Confirming Investigation
- Full shoulder girdle imaging, CT
- Distinguishing Features
- Low-energy mechanism, antecedent pain, history of malignancy
- Confirming Investigation
- Radiographs for lytic lesion, staging and biopsy as indicated
- Distinguishing Features
- Age under 25 years, mimics SC dislocation as physis still open
- Confirming Investigation
- CT to differentiate from true SC dislocation
Investigations
Radiographs. An AP clavicle view with 15-degree cephalic tilt gives the best view of the bone; on it, assess displacement, shortening and comminution, and measure the shortening against the contralateral side. A 45-degree cephalic tilt view throws the clavicle clear of the overlying ribs and scapula, for a better assessment of displacement and comminution.
Measuring shortening. Measure clavicle length on the AP radiograph from the sternal end to the acromial end and compare it with the other side. More than 2cm of shortening is the key surgical threshold, and CT gives a more accurate measurement if the decision turns on it.
CT. Four situations call for it, each for a different reason.
- Rationale
- Assess posterior displacement, vascular proximity
- Rationale
- Define CC ligament attachment, fracture pattern
- Rationale
- Define scapula fracture pattern for surgical planning
- Rationale
- Accurate shortening measurement, fragment assessment
CT angiogram. Indicated for a medial fracture with posterior displacement, where the great vessels and trachea are at risk, and for any concern about vascular injury: an expanding haematoma or a pulse deficit.
Chest radiograph. To rule out a pneumothorax, especially with a first rib fracture or a high-energy mechanism.
Management
The decision. Most clavicle fractures can be treated conservatively with excellent outcomes. The argument is over the completely displaced midshaft fracture, and the evidence has to be read in order. COTS (2007) randomised 132 patients with completely displaced midshaft fractures to plate fixation or a sling: fixation gave a lower nonunion rate (2 of 62 versus 7 of 49), faster union (16.4 versus 28.4 weeks) better Constant and DASH scores up to one year and a better cosmetic appearance, and it changed practice toward considering surgery for displaced fractures.
The later 22-RCT network meta-analysis put union at 96.7% with surgery against 88.9% without, a number needed to treat of about 10 to avoid one nonunion, while the functional gain did not reach the minimal clinically important difference. That is the honest counselling line: surgery makes union more likely, but the patient should not expect better function.
The protocol. A sling, analgesia and early movement, with loading and sport held back until the fracture has united.
- Simple arm sling for comfort
- 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)
Sling versus figure-of-8. A simple arm sling is preferred over a figure-of-8 brace. A Cochrane review showed no difference in outcomes, and figure-of-8 braces cause axillary discomfort and skin problems; their only advantage is a cosmetic improvement in posture.
Surgical Technique
The plate. Plate and screws are the gold standard for the midshaft fracture. The choice that matters is where the plate sits.
Superior plating is the most common. It is the easier exposure and gives better cosmesis, but the plate lies where it is most prominent, and hardware irritation is common. Anteroinferior plating is less prominent, leaves a subcutaneous suture line and is protected from direct trauma, at the price of a more difficult exposure. Biomechanically the two are similar, both are acceptable, and the choice is surgeon preference.
Plate selection.
- 3.5mm reconstruction plate, which can be contoured
- Precontoured clavicle plates, anatomic
- Locking plates for osteoporotic bone or comminution
Complications
- Conservative Rate
- 5-15%
- Surgical Rate
- 1-2%
- Management
- Bone grafting, revision ORIF
- Conservative Rate
- Variable
- Surgical Rate
- Rare
- Management
- Accept most; osteotomy if symptomatic
- Conservative Rate
- N/A
- Surgical Rate
- 20-40%
- Management
- Hardware removal at union
- Conservative Rate
- N/A
- Surgical Rate
- 1-2%
- Management
- Antibiotics, debridement if deep
- Conservative Rate
- Rare
- Surgical Rate
- 0.5-1%
- Management
- Intraop recognition, vascular repair
- Conservative Rate
- Rare
- Surgical Rate
- 1-2%
- Management
- After hardware removal; wait 12 weeks
Nonunion. The risk factors are the fracture's and the patient's:
- Displacement greater than 100%
- Shortening greater than 2cm
- Comminution
- Female sex
- Older age
- Smoking
- Refracture
Treatment is plate fixation with bone grafting, iliac crest or local autograft, and it has to address both the biomechanical problem (length and alignment) and the biological one (vascularity and bone quality).
Malunion. Shortening, angulation and rotation are usually well tolerated. Surgery is reserved for the symptomatic patient, with shoulder dysfunction or a cosmetic complaint, and takes the form of a corrective osteotomy with plate fixation.
Hardware. Plate prominence is the most common reason for hardware removal, in 20-40% of patients, and the patient should hear that before the operation rather than after it. Anteroinferior plating may reduce it, at the cost of the more demanding exposure.
Postoperative Care and Rehabilitation
After ORIF. The protocol runs in four stages.
- 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)
The principles. Early pendulum exercises prevent stiffness, and progressive loading waits for clinical union. Hardware removal is optional unless the patient is symptomatic.
Return to sport. Athletes can return to non-contact sport at 8-12 weeks with clinical union and adequate range of motion. Contact sport requires radiographic union, typically at 4-6 months; elite athletes may return earlier with protective padding.
Outcomes and Prognosis
Prognosis by fracture type. Union rates with and without fixation, by the pattern in front of you.
- Conservative Union
- 95%+
- ORIF Union
- 98-99%
- Notes
- Conservative treatment preferred
- Conservative Union
- 85%
- ORIF Union
- 98%
- Notes
- ORIF faster union, similar function
- Conservative Union
- 90%+
- ORIF Union
- 95%+
- Notes
- Conservative preferred
- Conservative Union
- 67-78%
- ORIF Union
- 90-95%
- Notes
- ORIF strongly preferred
- Conservative Union
- 90%+
- ORIF Union
- 95%+
- Notes
- Conservative unless displaced posteriorly
The company this fracture keeps. A clavicle fracture is only "isolated" until you check the scapula: with an ipsilateral scapular fracture it becomes a floating shoulder, a different problem with a different threshold for fixation. The lateral-third fractures sit next to acromioclavicular joint injuries and are graded by whether the coracoclavicular ligaments have failed - which is the same question in both. If it does not heal, the salvage belongs to nonunion management, and the neurovascular structure crossing the fracture line is set out in brachial plexus anatomy.
What changes the result. Five factors:
- 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
Guidelines, Registries & Global Practice
Global epidemiology
- Value
- Approximately 2.6-5%
- Source
- Population fracture series
- Value
- 65 of 75 injuries
- Source
- Nordqvist & Petersson 1995
- Value
- Male (sport/traffic mechanism)
- Source
- Nordqvist & Petersson 1995
- Value
- Midshaft approximately 80%, lateral approximately 15%, medial approximately 5%
- Source
- Allman / Robinson cohorts
- Value
- 6.2% (diaphyseal 4.5%, lateral 11.5%)
- Source
- Robinson 2004
The bimodal pattern - young men injured in sport or road trauma and older patients sustaining fragility injuries from low falls - is consistent across high-income population studies and shapes both management and counselling.
Guideline and society positions, side by side
- Position on displaced midshaft fractures
- Nonoperative care is the default; fixation reserved for absolute indications (open, neurovascular, skin compromise) and selected displaced fractures after shared decision-making
- Evidence basis
- RCT and meta-analysis evidence
- Position on displaced midshaft fractures
- No mandate for routine surgery; shared decision-making citing faster union and lower nonunion with surgery against hardware-related reoperation
- Evidence basis
- Level I RCTs
- Position on displaced midshaft fractures
- Predominantly nonoperative; surgery offered for high-risk displaced fractures and absolute indications, reflecting equivalence of long-term function
- Evidence basis
- Cochrane and RCT data
- Position on displaced midshaft fractures
- Individualised - operative fixation for completely displaced, shortened or comminuted fractures in active patients
- Evidence basis
- Network meta-analysis
Across all major bodies the recommendations have converged: surgery reliably improves union (number needed to treat approximately 10) and early function but does not deliver a patient-perceptible long-term functional gain, so the decision is shared and indication-led rather than mandatory.
Registry and high-level evidence
- The COTS multicentre RCT established lower nonunion and malunion with plate fixation of completely displaced fractures, but with hardware removal as the leading reoperation.
- The Axelrod network meta-analysis of 22 RCTs quantified union at 88.9% (nonoperative) versus 96.7% (operative), with functional differences below the minimal clinically important difference.
- The Nourian meta-analysis found superior and anteroinferior plating equivalent for union and function, with anteroinferior placement reducing symptomatic hardware and removal.
Global practice variation
- In high-resource settings, displaced fractures in athletes and manual workers are increasingly offered early fixation to shorten time to union and return to work, despite equivalent long-term function.
- In limited-resource settings, nonoperative management predominates given the low absolute nonunion risk and the cost, implant and theatre demands of fixation; this is an evidence-consistent choice rather than a compromise.
- Lateral Neer type II fractures attract a more uniformly operative stance worldwide because of their substantially higher nonunion risk.
MCQ Practice Points
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.
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.
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.
Q: What was the key finding of the COTS study regarding operative vs non-operative treatment of displaced midshaft clavicle fractures? A: Answer with what the trial concluded, then the caveat - in that order. COTS 2007 (PMID 17200303) concluded that plate fixation "results in improved functional outcome and a lower rate of malunion and nonunion": Constant and DASH were significantly better in the operative group at ALL time-points (p = 0.001 and p less than 0.01), union was faster (16.4 vs 28.4 weeks), nonunion 2 of 62 vs 7 of 49, and symptomatic malunion 0 vs 9. Patients were also more satisfied with shoulder appearance and with the shoulder overall.
The caveat, which is a LATER argument and not COTS' own: subsequent larger trials and meta-analyses suggest the functional difference at one year is small and may fall below the minimal clinically important difference, with the groups converging further beyond a year. Note also that the 2021 COTS trial finding "no between-group difference in DASH or Constant" was a DISTAL (Neer type II) clavicle trial, not this one - the two are easily conflated because both are COTS.
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.
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“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?”
“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?”
“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?”
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 of 62 vs 7 of 49 (COTS 2007)
- Faster union with surgery (16.4 vs 28.4 weeks)
- Better early Constant/DASH scores with ORIF
- Functional benefit below MCID - similar at 1 year (Axelrod NMA 2020)
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
Evidence Base
Canadian Orthopaedic Trauma Society (COTS) RCT
- Multicentre RCT of 132 patients with completely displaced midshaft fractures. Plate fixation reduced nonunion (2 of 62 operative vs 7 of 49 nonoperative) and symptomatic malunion (0 vs 9), shortened time to union (16.4 vs 28.4 weeks), and improved Constant and DASH scores at all time points up to 1 year.
Robinson - Risk of Nonunion (Edinburgh cohort)
- Prospective observational cohort of 868 nonoperatively treated clavicle fractures. Overall nonunion at 24 weeks was 6.2% (diaphyseal 4.5%, lateral 11.5%, medial 8.3%). Independent predictors of diaphyseal nonunion were lack of cortical apposition (displacement), comminution, female sex and advancing age.
Axelrod - Network Meta-analysis of 22 RCTs
- Network meta-analysis of 22 RCTs (1965 patients). Union at 1 year was 88.9% nonoperative versus 96.7% operative (NNT approximately 10 to avoid one nonunion). Functional gains with surgery did not reach the minimal clinically important difference for DASH; nonunion after nonoperative care was slightly above 10%.
Nourian - Anteroinferior vs Superior Plating Meta-analysis
- Meta-analysis of 34 studies (1494 patients). Union, nonunion, malunion and functional scores were equivalent for superior and anteroinferior plating, but superior plating had significantly more symptomatic hardware (17% vs 8%) and more frequent implant removal (11% vs 5%).
Lenza - Conservative Interventions (Cochrane)
- Cochrane review of 3 trials (354 participants). Figure-of-eight bandage showed no functional advantage over a simple arm sling and caused more pain and discomfort; low-intensity pulsed ultrasound did not accelerate union.
Nordqvist & Petersson - Shoulder Girdle Epidemiology
- Population-based study (Malmo, Sweden) of all shoulder girdle injuries in one year. Clavicle fractures were the commonest shoulder girdle injury in children (65 of 75) and frequent in adults (67 of 181), with adult injuries significantly more common in men and predominantly caused by traffic and sport.