SC Joint Injury | Anterior vs Posterior | Mediastinal Emergency | Reconstruction Risk
INJURY CLASSIFICATION
Critical Must-Knows
- Sternoclavicular joint is a saddle-type synovial joint with the least bony stability of any major joint
- Posterior dislocation is a surgical emergency - mediastinal compromise of vessels, trachea, oesophagus
- CT scan (with vascular contrast) is the investigation of choice - plain films miss up to 50 percent
- Anterior dislocations: most managed non-operatively with sling and analgesia
- Reconstruction risks: instability, recurrent dislocation, implant-related complications, medial clavicle resection concerns
Clinical Pearls
- "Posterior SC dislocation = trauma call, not clinic referral
- "CT with IV contrast to define both bony anatomy and mediastinal structure involvement
- "Anterior SC dislocations are common and stable - do not reduce operatively unless chronic instability
- "Atraumatic SC subluxation in young women is usually multidirectional laxity, not trauma
Critical Sternoclavicular Joint Exam Points
Posterior = Emergency
Posterior dislocation can compress mediastinal structures including brachiocephalic vessels, internal jugular vein, common carotid, subclavian vessels, trachea, oesophagus, vagus and phrenic nerves. Dyspnoea, dysphagia, stridor, hoarseness, or arm ischaemia mandates urgent reduction.
CT is Investigation of Choice
Plain radiographs miss up to 50 percent of SC dislocations. CT (ideally with IV contrast) demonstrates direction, displacement, and relationship to mediastinal structures. Serendipity view is obsolete.
Reconstruction Risks
SC joint reconstruction is high-risk: recurrent instability, implant migration, neurovascular injury, prominent hardware, medial clavicle resection complications, and infection. Reserve for symptomatic chronic instability.
Anterior is Usually Conservative
Anterior dislocations are common and generally stable after closed reduction. Operative stabilisation has high failure and complication rates - non-operative management is the default.
Quick Decision Guide
| Feature | Anterior SC Dislocation | Posterior SC Dislocation |
|---|---|---|
| Frequency | Anterior 3:1 more common | Posterior 1:3 ratio, much less common |
| Mediastinal compromise | Rare, not an emergency | Common - vessels, trachea, oesophagus at risk |
| First-line management | Sling, analgesia, early mobilisation | Urgent closed reduction under GA with thoracic backup |
| Key pearl | Stable after reduction, even if re-subluxes cosmetically | Treat as trauma emergency, do not delay CT |
MEDIASTINUMPosterior SC Dislocation Warning Signs
| M | Mediastinal shift Trachea or vessel deviation on imaging |
| E | Engorged neck veins SVC or brachiocephalic vein compression |
| D | Dyspnoea and stridor Tracheal compromise |
| I | Intimal injury suspicion Vascular injury may be occult |
| A | Absent or weak arm pulse Subclavian or brachiocephalic compromise |
| S | Swallowing difficulty Oesophageal impingement |
| T | Tracheal compression signs Cyanosis, respiratory distress |
| I | Intubate carefully Anaesthesia requires awake fibreoptic |
| N | Neurological signs Vagus, phrenic, brachial plexus |
| U | Urgent reduction Time-critical, surgical standby |
| M | Mediastinal imaging CT with contrast before theatre |
| M | Mediastinal shift Trachea or vessel deviation on imaging | I | Intimal injury suspicion Vascular injury may be occult | T | Tracheal compression signs Cyanosis, respiratory distress | U | Urgent reduction Time-critical, surgical standby |
| E | Engorged neck veins SVC or brachiocephalic vein compression | A | Absent or weak arm pulse Subclavian or brachiocephalic compromise | I | Intubate carefully Anaesthesia requires awake fibreoptic | M | Mediastinal imaging CT with contrast before theatre |
| D | Dyspnoea and stridor Tracheal compromise | S | Swallowing difficulty Oesophageal impingement | N | Neurological signs Vagus, phrenic, brachial plexus |
Hook:MEDIASTINUM signs warn of posterior SC dislocation compressing vital structures.
FORCEFULAnterior SC Dislocation Mechanism
| F | Fall onto shoulder Indirect force through clavicle |
| O | Outstretched arm Leverage force on medial clavicle |
| R | Road traffic collision High-energy, restraint injury |
| C | Contact sport Direct blow to medial clavicle |
| E | Energy displaces medially Clavicle levered out of manubrium |
| F | Forward vector Most commonly anterior displacement |
| U | Under 25 years Often physeal injury mimicking dislocation |
| L | Ligaments torn Anterior capsule, costoclavicular, interclavicular |
| F | Fall onto shoulder Indirect force through clavicle | C | Contact sport Direct blow to medial clavicle | U | Under 25 years Often physeal injury mimicking dislocation |
| O | Outstretched arm Leverage force on medial clavicle | E | Energy displaces medially Clavicle levered out of manubrium | L | Ligaments torn Anterior capsule, costoclavicular, interclavicular |
| R | Road traffic collision High-energy, restraint injury | F | Forward vector Most commonly anterior displacement |
Hook:FORCEFUL injury with a forward vector gives an anterior SC dislocation.
STERNALSC Joint Anatomy and Stability
| S | Saddle synovial joint Ginglymoarthrodial, intra-articular disc |
| T | Thick articular disc Fibrocartilage, divides joint in two |
| E | Extra-articular ligaments Interclavicular, costoclavicular, capsular |
| R | Range small 40 degrees elevation, 30 degrees rotation |
| N | No bony constraint Stability entirely ligamentous |
| A | Anterior capsule weakest Anterior dislocations more common |
| L | Ligament reconstruction risky High failure, hardware complications |
| S | Saddle synovial joint Ginglymoarthrodial, intra-articular disc | R | Range small 40 degrees elevation, 30 degrees rotation | L | Ligament reconstruction risky High failure, hardware complications |
| T | Thick articular disc Fibrocartilage, divides joint in two | N | No bony constraint Stability entirely ligamentous | ||
| E | Extra-articular ligaments Interclavicular, costoclavicular, capsular | A | Anterior capsule weakest Anterior dislocations more common |
Hook:STERNAL anatomy: ligamentous stability is the only thing keeping the SC joint reduced.
Overview and Epidemiology
Why This Matters
The sternoclavicular joint is the only true articulation between the upper limb and the axial skeleton. It is the least stable major joint in the body because more than 50 percent of the medial clavicle articular surface sits outside the manubrial socket, leaving stability entirely ligamentous. Posterior dislocations are rare but life-threatening because the medial clavicle can directly compress the brachiocephalic vein, common carotid, subclavian vessels, trachea, oesophagus, and vagus/phrenic nerves.
Mechanism of Injury
- Indirect high-energy trauma: Force applied to the lateral shoulder (most common)
- Road traffic collisions: Restrained driver/passenger, lateral compression
- Contact and collision sport: Direct blow to medial clavicle or shoulder
- Fall onto outstretched hand: Force transmitted medially through clavicle
- Atraumatic subluxation: Multidirectional laxity in young patients
Clinical Impact
- Anterior: Cosmetic prominence, mild pain, often well-tolerated
- Posterior: Mediastinal emergency - dyspnoea, dysphagia, vascular compromise
- Chronic instability: Functional limitation in overhead athletes
- Physeal injury: In adolescents, medial clavicle physeal separation mimics dislocation
Pathophysiology
Sternoclavicular Joint Anatomy and Stability
The SC joint is a saddle-type (sellar) synovial joint with a complete intra-articular disc of fibrocartilage. The medial clavicle is larger than the manubrial fossa, with only a small portion articulating. Stability depends on the anterior and posterior capsular ligaments (the posterior capsule is the strongest single restraint), the interclavicular ligament (between both clavicles across the suprasternal notch), the costoclavicular (rhomboid) ligament (between clavicle and first rib), and the intra-articular disc. The costoclavicular ligament is the primary restraint to medial-lateral displacement and is the key structure to reconstruct in chronic instability.
SC Joint Ligaments and Their Function
| Ligament | Origin-Insertion | Primary Function | When Injured |
|---|---|---|---|
| Anterior capsule | Anterior manubrium to anterior clavicle | Resists posterior displacement | First torn in anterior dislocation |
| Posterior capsule | Posterior manubrium to posterior clavicle | Strongest restraint to anterior displacement | Failed in posterior dislocation |
| Costoclavicular (rhomboid) | First rib to clavicle (medial) | Resists medial-lateral and superior-inferior | Key to reconstruction in chronic instability |
| Interclavicular | Clavicle to clavicle across suprasternal notch | Resists superior displacement | Torn in complete dislocations |
| Intra-articular disc | First rib to clavicle through joint | Shock absorber, force transmission | Often torn in dislocation, may block reduction |
Biomechanics of Dislocation
Indirect force to lateral shoulder drives medial clavicle
Clavicle pivots at costoclavicular ligament
Anterior force vector (most common) = anterior dislocation, posterior capsule intact
Posterior force vector (less common, high-energy) = posterior dislocation, posterior capsule torn
Direct blow to medial clavicle can drive it posteriorly
Mediastinal Vulnerability
Posterior to medial clavicle: brachiocephalic vein, common carotid, subclavian artery and vein
Deeper plane: trachea, oesophagus, vagus nerve, phrenic nerve, thoracic duct (left)
Physeal injury in adolescents often mimics posterior dislocation on imaging - real structure is medial clavicular physis (last to fuse at 23-25 years)
Classification and Types
Classification by Direction of Displacement
| Type | Frequency | Mechanism | Urgency |
|---|---|---|---|
| Anterior SC dislocation | Most common (3:1 vs posterior) | Indirect force, anterior vector | Usually non-operative |
| Posterior SC dislocation | Less common | Indirect high-energy or direct posterior blow | Emergency - mediastinal risk |
| Atraumatic subluxation | Common in young hypermobile patients | Spontaneous or with minor movement | Reassurance, physiotherapy |
Posterior dislocations are surgical emergencies. Always image with CT to confirm direction and exclude mediastinal compromise.
Clinical Assessment
History
- Mechanism: High-energy trauma, contact sport, MVC, fall
- Posterior red flags: Dyspnoea, stridor, dysphagia, voice change, arm paraesthesia or ischaemia
- Prior episodes: Recurrent subluxation suggests multidirectional laxity
- Age: Under 25 years - consider physeal injury rather than true dislocation
Examination
- Inspect: Visible asymmetry, swelling, ecchymosis, skin tethering
- Palpate: Medial clavicle position relative to suprasternal notch and contralateral side
- Posterior signs: Neck vein engorgement, tracheal deviation, pulses, neuro exam
- Provocative test: Arm elevation in extension stresses the joint
Posterior Dislocation - Do Not Miss These Signs
Always assess and document in any SC joint injury:
- Respiratory distress, stridor, voice change
- Neck vein distension (SVC or brachiocephalic vein compression)
- Subclavian and axillary pulses, capillary refill
- Brachial plexus sensation and motor (C5-T1)
- Swallowing difficulty (oesophageal impingement)
- Phrenic nerve (diaphragm screening with ultrasound or fluoroscopy if intubated)
- Vagus (recurrent laryngeal - voice change)
A posterior SC dislocation with any of these signs mandates urgent reduction with cardiothoracic or vascular surgery on standby.
Examination Findings - Anterior vs Posterior
| Finding | Anterior SC Dislocation | Posterior SC Dislocation |
|---|---|---|
| Visible/palpable deformity | Prominent medial clavicle, often visible lump | Depression or sulcus at SC joint |
| Mediastinal compression signs | Rare | Common - dyspnoea, stridor, dysphagia, venous congestion |
| Skin changes | Erythema, swelling, possible skin tenting | May have skin dimple, cyanosis, surgical emphysema |
| Range of motion | Painful but usually full | Markedly limited by pain and mediastinal symptoms |
Differential Diagnosis of Medial Clavicular Pain or Deformity
| Condition | Direction of Deformity | Discriminating Finding | Key Test / Imaging |
|---|---|---|---|
| Anterior SC dislocation | Anterior prominence | Lateral compression reproduces pain, palpable step | CT confirms anterior position |
| Posterior SC dislocation | Loss of medial clavicle contour | Mediastinal signs, asymmetric pulses | CT with IV contrast to define mediastinal relationship |
| Medial clavicle physeal injury | Anterior or posterior | Adolescent (under 25), mechanism matches trauma | CT shows physeal line; MRI can confirm physis |
| Atraumatic SC subluxation | Variable, often bilateral | Multidirectional laxity, no high-energy event | Clinical; imaging normal or minor asymmetry |
| Sternoclavicular osteoarthritis | No acute deformity | Insidious pain, crepitus, older patient | X-ray and CT show joint space narrowing, osteophytes |
| Condensing osteitis of clavicle | No acute deformity | Middle-aged women, pain without laxity | X-ray: sclerosis of medial clavicle |
| Friedrich disease (AVN medial clavicle) | No acute deformity | Insidious medial clavicle pain | MRI shows AVN changes |
| Septic SC arthritis | Swelling, warmth, fluctuance | Fever, IVDU, immunocompromise, recent infection | Bloods, joint aspiration, MRI |
Atraumatic SC Subluxation in Young Patients
Atraumatic SC joint subluxation is common in young, hypermobile women and is not a dislocation. The medial clavicle subluxes spontaneously or with minor movements and reduces. It does not require reduction, immobilisation, or surgery. Education, reassurance, and avoidance of provocative positions are the appropriate management. Operating on this condition has high failure and complication rates.
Investigations
Imaging Protocol
Views: AP chest, serendipity view (40-degree cephalic tilt) - now largely superseded
Sensitivity: Plain films miss up to 50 percent of SC dislocations
Role: Initial screen, exclude associated rib or lung injury
Limitations: Cannot define direction accurately; cannot assess mediastinal relationship
Indication: All suspected SC dislocations
Acquisition: Thin-slice (1 mm) CT from chin to diaphragm, with IV contrast
Findings: Direction of dislocation, distance displaced, relationship to mediastinal vessels, trachea, oesophagus
Reconstructions: 3D and multiplanar reformats for surgical planning
Advantage: Definitive diagnosis, vessel mapping, surgical planning
Indication: Posterior dislocation with pulse deficit, expanding haematoma, or asymmetry
Findings: Vessel compression, intimal injury, pseudoaneurysm, occlusion
Outcome: Joint surgical planning with vascular surgery
Pre-op: Image sharing and on-table angiography as needed
Indication: Adolescents to distinguish physeal injury from true dislocation
Findings: Physeal oedema, intact ligaments, no true joint disruption
Role: Conservative treatment justification, avoids operation on physis
Imaging Pearl
Plain films cannot reliably diagnose or exclude SC dislocation. Any patient with clinical suspicion (mechanism, deformity, mediastinal symptoms) requires CT with IV contrast. Do not delay CT to obtain multiple plain views - the serendipity view is a historical curiosity.
Management Algorithm
Anterior SC Joint Dislocation
Goal: Symptom relief and return to function. Most are stable and well-tolerated even if the medial clavicle remains prominent.
Treatment Protocol
Analgesia: Oral paracetamol, NSAID, short opioid course if needed
Sling: Broad-arm sling for 1-3 weeks for comfort
Ice and rest: First 48-72 hours
Counselling: Explain that the lump may persist cosmetically; this is acceptable
Progressive ROM: Pendulum, then active-assisted, then active
Strengthening: Rotator cuff and scapular stabilisers at 3-4 weeks
Avoid: Heavy lifting, contact sport for 6-12 weeks
Sport-specific rehab: Overhead athletes, throwers, contact sports
Surgery reserved for: Persistent instability, functional limitation, failure of rehab
Realistic outcome: Most return to full function with acceptable cosmesis
Anterior Pearl
Do not operate on a first-time anterior SC dislocation. Operative reduction and stabilisation has high failure and complication rates (recurrent instability, hardware failure, neurovascular injury). Even if the medial clavicle remains prominent, function is generally excellent with conservative care. Surgery is reserved for chronic, symptomatic instability that has failed structured rehabilitation.
Complications
| Complication | Incidence | Risk Factors | Management |
|---|---|---|---|
| Vascular injury (posterior) | Up to 30 percent of posterior dislocations | High-energy mechanism, sharp displaced fragment | Vascular surgery, repair or bypass |
| Tracheal compression | Reported in case series | Posterior displacement, delayed reduction | Urgent reduction, possible tracheostomy |
| Oesophageal injury | Rare | Penetrating component, sharp posterior fragment | Contrast study, surgical repair |
| Recurrent instability | 20-30 percent after reconstruction | Ligamentous laxity, hypermobility, inadequate rehab | Revision reconstruction or resection |
| K-wire migration | Catastrophic when it occurs | Use of K-wires across SC joint | Avoid K-wires; use plates or tendon graft |
| Hardware irritation / failure | Up to 50 percent with plates | Thin soft tissue cover, repetitive motion | Removal of hardware once ligaments healed |
| Subclavian vein thrombosis | Rare | Posterior compression, intimal injury | Anticoagulation, vascular intervention |
K-Wire Migration - Never Use for SC Joint
K-wires and Kirschner wires across the sternoclavicular joint have migrated into the heart, aorta, pulmonary artery, lung, oesophagus, trachea, and spinal cord, with multiple reported deaths. Use plate fixation, suture anchors, or tendon graft reconstruction. If a wire is used (rare salvage scenarios), it must have a secure bend at the lateral end, and the patient must be followed with serial imaging until removal.
Outcomes and Prognosis
Outcomes by Management Strategy
| Strategy | Indication | Expected Outcome | Long-term Function |
|---|---|---|---|
| Anterior - non-operative | First-time anterior dislocation | 90 percent good function, acceptable cosmesis | Excellent return to sport and work |
| Posterior - closed reduction | Acute posterior dislocation, stable after reduction | Good function, low recurrence if costoclavicular intact | Excellent if reduced within 24-48 hours |
| Posterior - open reduction | Failed closed, mediastinal compromise | Good but with surgical morbidity | Good if vascular or visceral injury addressed |
| Chronic - reconstruction | Failed non-operative, symptomatic instability | 70-80 percent good-to-excellent | Variable; re-operation common |
Prognostic Factors
Best prognosis: Acute anterior dislocation treated conservatively, acute posterior dislocation reduced within 24 hours with intact costoclavicular ligament, low-demand patient
Poor prognosis: Delayed posterior dislocation, failed closed reduction, multiple reconstruction attempts, hypermobility syndromes, contact athletes returning to high-impact sport
Key threshold: 24-48 hours for posterior dislocation - outcomes decline significantly with delay due to mediastinal compression and soft tissue contracture
Evidence Base and Key Trials
Acute traumatic retrosternal dislocation of the clavicle
- Classic retrospective series of acute traumatic posterior (retrosternal) SC dislocations - early recognition and closed reduction produced good outcomes
- Delayed diagnosis beyond 24-48 hours significantly increased the need for open reduction and the rate of complications
- Mediastinal vascular compression was a recurring feature in unreduced posterior dislocations
Sternoclavicular joint dislocation: a systematic review and meta-analysis
- Systematic review and meta-analysis of sternoclavicular joint dislocations - synthesises treatment outcomes across the published series
- Posterior dislocations are uncommon but carry substantially higher morbidity than anterior dislocations, with mediastinal compromise the key concern
- Operative reconstruction is reserved for chronic symptomatic instability; most anterior dislocations are managed non-operatively with good functional outcomes
Treatment of traumatic posterior sternoclavicular dislocations
- Consecutive series of traumatic posterior SC dislocations treated with closed or open reduction - CT was the diagnostic test of choice
- Majority of cases reduced closed within 24-48 hours; open reduction reserved for those failing closed methods
- Vascular and oesophageal injuries were uncommon but required pre-operative CT angiography to identify
Sternoclavicular epiphyseal separation with adjacent clavicular fracture
- Classic first description of medial clavicular epiphyseal (physeal) separation - adolescents presenting with apparent SC dislocation more often have a physeal injury than a true joint dislocation
- True SC dislocation requires disruption of the strong posterior capsule and costoclavicular ligament, which is uncommon in skeletally immature patients
- Physeal injury is more often stable after closed reduction and rarely requires operative fixation
Posterior sternoclavicular joint injuries in the adolescent population: a meta-analysis
- Meta-analysis of posterior SC joint injuries in adolescents - most are actually medial clavicular physeal separations rather than true joint dislocations
- CT is the imaging modality of choice; physeal separations are usually managed with closed reduction and rarely require operative fixation
- Vascular and mediastinal complications are rare but require prompt recognition; overall outcomes after appropriate treatment are excellent
Exam Viva Scenarios
Use these scenarios to practise clinical reasoning and management decisions
Scenario 1: Posterior SC Dislocation After Rugby Tackle
"A 22-year-old rugby player presents to the emergency department after a direct tackle to his left shoulder. He has pain over the medial clavicle, difficulty breathing, and a change in his voice. On examination, there is a palpable depression at the left SC joint, the left arm is cooler than the right, and the left radial pulse is diminished. What is your immediate assessment and management?"
Scenario 2: Anterior SC Dislocation in a 19-Year-Old Cyclist
"A 19-year-old competitive cyclist falls over his handlebars during a race and presents to the emergency department with a visible lump over the medial end of his right clavicle. He has no dyspnoea, dysphagia, voice change, or vascular symptoms. CT confirms anterior SC dislocation with the medial clavicle displaced anterior to the manubrium and no mediastinal compromise. He is keen to return to competitive cycling. How do you manage this?"
MCQ Practice Points
Anatomy Question
Q: What is the primary ligamentous restraint to anterior and posterior translation at the sternoclavicular joint? A: The posterior capsule is the strongest restraint to anterior displacement, and the anterior capsule and costoclavicular (rhomboid) ligament together resist posterior displacement. The costoclavicular ligament is the primary restraint to medial-lateral displacement and is the key structure to reconstruct in chronic instability.
Diagnosis Question
Q: What is the investigation of choice for suspected sternoclavicular joint dislocation? A: CT scan with IV contrast. Plain radiographs miss up to 50 percent of dislocations, and the serendipity view is largely obsolete. CT demonstrates direction, displacement, and relationship to mediastinal structures. CT angiography is added if vascular injury is suspected.
Emergency Question
Q: A patient has a posterior SC dislocation with dyspnoea, dysphagia, and diminished radial pulse. What is your immediate management? A: This is a mediastinal emergency. Follow ATLS, establish IV access, send bloods, obtain urgent CT with IV contrast, and contact cardiothoracic and vascular surgery. The dislocation requires reduction under general anaesthesia in theatre with surgical backup, ideally within 24 hours.
Management Question
Q: What is the first-line management of an acute anterior SC dislocation? A: Non-operative management with sling, analgesia, and physiotherapy. Operative reduction and stabilisation has high failure and complication rates and is reserved for chronic symptomatic instability. Even if the medial clavicle remains prominent, function is generally excellent.
Reconstruction Question
Q: Why are K-wires contraindicated in sternoclavicular joint reconstruction? A: K-wires have migrated into the heart, aorta, pulmonary artery, lung, oesophagus, trachea, and spinal cord, with multiple reported deaths. Use plate fixation, suture anchors, or autologous tendon graft reconstruction (figure-of-8 sternocleidomastoid or hamstring graft).
Paediatric Question
Q: A 17-year-old presents after a fall with apparent anterior SC dislocation. What is the most likely true diagnosis? A: Medial clavicle physeal separation. The medial clavicular physis is the last in the body to fuse (around 23-25 years) and is the weakest link in the SC region in adolescents. True joint dislocation requires disruption of the strong posterior capsule and costoclavicular ligament, which is uncommon before skeletal maturity. The injury is usually stable after closed reduction and remodels over time.
Guidelines, Registries & Global Practice
Global Epidemiology
- SC dislocations are rare, representing under 1 percent of all joint dislocations and 3 percent of shoulder-girdle injuries
- Anterior dislocations are 3 to 1 more common than posterior
- Posterior dislocations are predominantly high-energy - road traffic collisions, contact sport, falls from height
- Mediastinal compromise is reported in a quarter to a third of posterior dislocations in published series
Practice Variation by Resource Setting
- High-resource: 24-hour access to CT, vascular and cardiothoracic surgery, and image intensifier for closed reduction
- Limited-resource: Closed reduction under sedation in the emergency department may be necessary if theatre and vascular backup are unavailable - transfer to a tertiary centre is preferred if any mediastinal signs
- Universal principle: Posterior SC dislocation requires urgent reduction; do not delay transfer for a CT that is not available locally
- Reconstruction: Concentrated in specialist shoulder units; soft tissue techniques preferred over hardware
Society and Reference Guidance (Side by Side)
| Source | Diagnosis emphasis | Acute treatment | Surgery / reconstruction |
|---|---|---|---|
| BOA / BOAST (UK) | CT with contrast in any suspected SC dislocation | Posterior: closed reduction in theatre with thoracic backup; anterior: conservative | Soft tissue reconstruction (figure-of-8 tendon graft) for failed non-operative |
| AAOS (US) | CT for direction and mediastinal assessment | Posterior: urgent closed or open reduction; anterior: sling and rehab | Tendon graft preferred; plates reserved for failed soft tissue; avoid K-wires |
| ESSKA / EFORT (European) | CT or MRI in suspected dislocation, MRI for physeal assessment | Posterior: closed reduction under GA, thoracic surgery standby | Tendon reconstruction (sternocleidomastoid, palmaris longus, hamstring) |
| Australian Shoulder and Elbow Society | CT with contrast; vascular surgery consult for posterior | Posterior: closed reduction in theatre; anterior: non-operative | Soft tissue reconstruction with suture anchors preferred |
Registry and Evidence Note
There is no dedicated registry for sternoclavicular joint dislocation. Evidence is dominated by small retrospective case series and technique papers. The major arthroplasty registries (NJR, AJRR, AOANJRR) do not capture SC joint reconstruction, as it is uncommon. Practice is principle-based: CT with contrast for diagnosis, urgent closed reduction of posterior dislocations with cardiothoracic backup, and soft tissue reconstruction for chronic instability using tendon graft rather than hardware.
Documentation Essentials (Globally Applicable)
Record in every SC joint injury:
- Direction of dislocation (anterior or posterior) on CT
- Mediastinal structure assessment (vessels, trachea, oesophagus)
- Pulses, capillary refill, and neurological exam in the affected arm
- Voice, breathing, and swallowing symptoms at presentation
- Plan for closed versus open reduction and surgical team involved
- Counselling about recurrence, hardware, and re-operation risks if reconstruction is performed
Posterior SC dislocation with missed mediastinal injury is a recurring source of severe morbidity and litigation worldwide. Document the CT findings, the surgical team involved, and the reduction technique in every case.
Controversies & Areas of Uncertainty
Soft tissue versus plate reconstruction
Soft tissue reconstruction (figure-of-8 tendon graft, suture anchors) is biomechanically and biologically appealing but has higher reported re-dislocation rates in some series. Plate fixation provides initial stability at the cost of frequent hardware-related re-operation. There are no head-to-head trials.
When to operate on anterior dislocation
Some surgeons advocate operative stabilisation of first-time anterior dislocations in young, high-demand athletes, but complication rates are high and re-dislocation is common. Most guidance reserves surgery for chronic, symptomatic instability that has failed structured non-operative care.
Tendon graft choice
Sternocleidomastoid (in situ), hamstring (semitendinosus, gracilis), and palmaris longus have all been described. There is no clear winner. Sternocleidomastoid is convenient but limited in length; hamstring is robust but adds donor morbidity; palmaris longus is thin and may be absent.
Medial clavicle resection: how much is safe?
Excessive resection destabilises the medial clavicle and worsens instability. The safe upper limit is generally cited as 1 to 1.5 cm in adults, with preservation of the costoclavicular ligament. Beyond this, reconstruction or arthrodesis may be required.
STERNOCLAVICULAR JOINT DISLOCATION
Clinical summary
Key Anatomy
- •Saddle-type synovial joint with intra-articular disc
- •Medial clavicle larger than manubrial fossa - stability is entirely ligamentous
- •Posterior capsule = strongest restraint to anterior displacement
- •Costoclavicular ligament = primary restraint to medial-lateral and reconstruction target
- •Medial clavicle physis is the last to fuse (23-25 years) - weakest link in adolescents
Diagnosis
- •Posterior = mediastinal emergency: dyspnoea, dysphagia, voice change, vascular signs
- •Anterior = cosmetic lump, often stable, rarely an emergency
- •CT with IV contrast is the investigation of choice - plain films miss up to 50 percent
- •Always assess pulses, voice, breathing, and swallowing in any SC injury
- •Serendipity view is largely obsolete - do not delay CT to obtain multiple plain views
Treatment Algorithm
- •Anterior (first time) = non-operative: sling, analgesia, physiotherapy, return to sport 8-12 weeks
- •Posterior (acute) = urgent closed reduction under GA with thoracic/vascular backup
- •Posterior (failed closed) = open reduction via supraclavicular approach with vascular control
- •Chronic instability = figure-of-8 tendon graft reconstruction; K-wires contraindicated
Reconstruction Risks
- •K-wire migration into heart, aorta, lung, oesophagus, spinal cord - never use
- •Plate fixation has high rate of hardware-related re-operation
- •Tendon graft reconstruction - 20-30 percent re-dislocation rate
- •Medial clavicle resection greater than 1.5 cm destabilises further
- •Reserve surgery for chronic, symptomatic instability after failed non-operative care
Complications and Pitfalls
- •Missed posterior SC dislocation with mediastinal injury is catastrophic
- •Attempting closed reduction without imaging or surgical backup risks vascular injury
- •Operating on atraumatic SC subluxation in hypermobile patients fails
- •Anterior SC dislocation in adolescent = medial clavicle physeal separation, not true dislocation
- •Document direction, mediastinal assessment, and reduction technique in every case