High-yield overview
Posterolateral Most Common | LCL Always Injured | Early Motion Essential
2ndMost common large joint dislocation
90%Are posterolateral
SimpleNo associated fracture
ComplexWith associated fracture
CLASSIFICATION
Simple
PatternNo fracture, ligament injury only
TreatmentReduction, assess stability, early motion
Complex
PatternWith associated fracture(s)
TreatmentAddress fractures and ligaments
Posterolateral
PatternMost common direction (90%)
TreatmentStandard reduction technique
Other
PatternPosterior, lateral, anterior, divergent
TreatmentPattern-specific reduction
Critical Must-Knows
- Posterolateral is the most common direction (90%)
- LCL complex always injured - primary lateral restraint
- Simple dislocations usually stable after reduction
- Complex patterns - terrible triad, coronoid, Monteggia variant
- Early motion is essential to prevent stiffness
Clinical Pearls
- "LCL fails first, then anterior capsule, then MCL (outside-to-inside pattern)
- "Simple dislocations: if stable through 30-130° = non-operative
- "Check for associated fractures - radial head, coronoid are commonly missed
- "PLRI (posterolateral rotatory instability) is chronic sequela of LCL injury
Critical Elbow Dislocation Exam Points
Simple vs Complex
Simple = no fracture, ligament injury only. Typically stable after reduction with early motion. Complex = with fracture(s), includes terrible triad, requires addressing all structures.
Horii Circle
Soft tissue disruption pattern: LCL complex fails first (Stage 1), then anterior/posterior capsule (Stage 2), then MCL (Stage 3). Understanding this helps guide treatment.
Stability Assessment
After reduction, test stability under fluoro. Stable through 30-130° arc = non-operative. If redislocates before 60° extension = likely needs surgery.
Early Motion Critical
Stiffness is the enemy. Start motion within 1 week for simple dislocations. Prolonged immobilization leads to contracture. Use hinged brace if stability concerns.
Quick Decision Guide
| Pattern | Key Finding | Treatment |
|---|---|---|
| Simple dislocation | Stable after reduction (30-130°) | Early ROM in hinged brace, non-operative |
| Simple dislocation | Unstable after reduction | Consider operative LCL repair |
| Terrible triad | Dislocation + radial head + coronoid | Fix/replace RH, repair LCL, +/- coronoid |
| Radial head fracture-dislocation | Mason IV | Address radial head + ligaments |
| Anterior dislocation | Olecranon impales trochlea | Reduce carefully, assess for olecranon fracture |
| Divergent dislocation | Radius and ulna separate | Reduce, high likelihood of instability |
| Chronic dislocation | Unreduced over 3 weeks | Complex reconstruction required |
Mnemonic
HORII - CHORII - Circle of Instability
| H | Half of circle (lateral) Stage 1 - LCL complex disruption |
| O | Opening (capsule) Stage 2 - Anterior and posterior capsule |
| R | Remaining half (medial) Stage 3 - MCL disruption |
| I | Inside to outside Injury propagates lateral to medial |
| I | Instability increases Each stage = more instability |
| H | Half of circle (lateral) Stage 1 - LCL complex disruption | I | Inside to outside Injury propagates lateral to medial |
| O | Opening (capsule) Stage 2 - Anterior and posterior capsule | I | Instability increases Each stage = more instability |
| R | Remaining half (medial) Stage 3 - MCL disruption |
Hook:HORII described the circle - injury moves from lateral (outside) to medial (inside)
Mnemonic
REDUCE - RREDUCE - Reduction Steps
| R | Relax patient Adequate sedation/anesthesia essential |
| E | Extend elbow slightly To disengage olecranon from humerus |
| D | Distraction Apply traction along forearm |
| U | Unlock coronoid May need slight hyperextension briefly |
| C | Correct rotation Supinate to correct posterolateral |
| E | Extend then flex Apply pressure to olecranon, flex elbow |
| R | Relax patient Adequate sedation/anesthesia essential | D | Distraction Apply traction along forearm | C | Correct rotation Supinate to correct posterolateral |
| E | Extend elbow slightly To disengage olecranon from humerus | U | Unlock coronoid May need slight hyperextension briefly | E | Extend then flex Apply pressure to olecranon, flex elbow |
Hook:REDUCE the elbow with controlled technique
Mnemonic
STABLE - PSTABLE - Post-Reduction Assessment
| S | Stress test varus/valgus Test ligamentous integrity |
| T | Through arc of motion Check ROM and when it redislocates |
| A | Assess under fluoro Visualize joint concentricity |
| B | Block to motion? Suggests associated fracture |
| L | Lateral pivot shift Test for PLRI pattern |
| E | Extension limit noted 30° safe extension = good prognosis |
| S | Stress test varus/valgus Test ligamentous integrity | A | Assess under fluoro Visualize joint concentricity | L | Lateral pivot shift Test for PLRI pattern |
| T | Through arc of motion Check ROM and when it redislocates | B | Block to motion? Suggests associated fracture | E | Extension limit noted 30° safe extension = good prognosis |
Hook:Is the elbow STABLE? Test it thoroughly
Mnemonic
TERRIBLE TRIAD - CTERRIBLE TRIAD - Components and Treatment
| T | Three components Dislocation, radial head, coronoid |
| E | Every structure injured Plus LCL always disrupted |
| R | Radial head first Fix or replace as priority |
| R | Repair LCL always Key to restoring stability |
| I | Instability common High rate without proper treatment |
| B | Buttress coronoid Fix if unstable after RH and LCL |
| L | Later problems common Stiffness and arthritis if incomplete |
| E | External fixator backup Hinged fixator if still unstable |
| T | Three components Dislocation, radial head, coronoid | R | Repair LCL always Key to restoring stability | L | Later problems common Stiffness and arthritis if incomplete |
| E | Every structure injured Plus LCL always disrupted | I | Instability common High rate without proper treatment | E | External fixator backup Hinged fixator if still unstable |
| R | Radial head first Fix or replace as priority | B | Buttress coronoid Fix if unstable after RH and LCL |
Hook:The TERRIBLE TRIAD requires systematic treatment of all components
Overview and Epidemiology
Elbow dislocations are the second most common large joint dislocation after the shoulder. They range from simple ligamentous injuries to complex fracture-dislocations with significant instability.
Mechanism of injury:
- Fall on outstretched hand (FOOSH) - most common
- Axial load with elbow slightly flexed
- Valgus and supination moment
- Creates posterolateral dislocation
- Direct trauma - less common
- Sports injuries - common in young adults
- Motor vehicle accidents - often high-energy, complex patterns
FOOSH Mechanism
The classic mechanism is a fall on outstretched hand with the elbow in slight flexion. The axial load creates a valgus and supination moment, driving the ulna posterolaterally relative to the humerus. This explains why posterolateral dislocation is most common.
Types:
- Simple (50-60%): No associated fracture, ligament injury only
- Complex (40-50%): With associated fracture(s)
- Terrible triad
- Radial head fracture-dislocation
- Coronoid fracture-dislocation
- Transolecranon fracture-dislocation
Anatomy and Biomechanics
Bony anatomy:
- Ulnohumeral joint: primary elbow stability (hinge)
- Radiocapitellar joint: secondary stabilizer
- Coronoid: anterior buttress of ulnohumeral joint
- Olecranon: posterior buttress
- Trochlea: articulates with greater sigmoid notch
Ligamentous anatomy:
Lateral Collateral Ligament (LCL) Complex:
- Lateral ulnar collateral ligament (LUCL) - most important component
- Origin: lateral epicondyle
- Insertion: supinator crest of ulna
- Primary restraint to posterolateral rotatory instability (PLRI)
- Radial collateral ligament (RCL) - blends with annular ligament
- Annular ligament - stabilizes radial head to ulna
Medial Collateral Ligament (MCL) Complex:
- Anterior bundle - most important
- Origin: medial epicondyle
- Insertion: sublime tubercle
- Primary valgus stabilizer
- Posterior bundle - tightens in flexion
- Transverse ligament - minimal contribution
O'Driscoll's Horii Circle
The soft tissue injury in elbow dislocation follows a predictable pattern described by the Horii circle. Disruption proceeds from lateral to medial: Stage 1 (LCL), Stage 2 (anterior/posterior capsule), Stage 3 (MCL). The LCL complex is ALWAYS injured in posterolateral dislocation.
Stages of instability (O'Driscoll):
- Stage 1: PLRI - LCL disruption, elbow subluxes posterolaterally
- Stage 2: Incomplete dislocation - capsule disrupted, elbow perches
- Stage 3A: Complete dislocation - MCL posterior bundle torn
- Stage 3B: Gross instability - entire MCL torn (anterior bundle)
Static vs dynamic stabilizers:
- Static: ligaments, bony congruity
- Dynamic: muscles crossing elbow (triceps, biceps, brachialis, flexors/extensors)
Classification Systems
Primary Classification
| Type | Definition | Incidence |
|---|---|---|
| Simple | No fracture, ligament injury only | 50-60% |
| Complex | With associated fracture(s) | 40-50% |
Simple dislocation:
- Ligamentous injury only
- Usually stable after closed reduction
- Excellent prognosis with early motion
Complex dislocation:
- Fracture + dislocation
- Includes terrible triad, radial head, coronoid patterns
- Usually requires operative treatment
- Higher complication rates
Classification into simple vs complex guides treatment approach and prognosis.
Clinical Presentation and Assessment
History:
- Mechanism of injury
- Any spontaneous reduction
- Previous elbow problems
- Time since injury
- Hand dominance, occupation
Physical examination:
Physical Examination Findings
| Finding | Significance | Action |
|---|---|---|
| Obvious deformity | Unreduced dislocation | Assess NV, reduce urgently |
| Olecranon prominence posteriorly | Posterior dislocation | Confirm with X-ray, reduce |
| Vascular compromise | Arterial injury/kinking | Urgent reduction |
| Nerve deficit (median/ulnar) | Nerve injury/entrapment | Document, usually resolves with reduction |
| Open wound | Open dislocation | Antibiotics, urgent OR |
| Severe swelling | High energy, compartment risk | Monitor compartments |
Differential diagnosis:
Differential Diagnosis of the Acutely Deformed/Painful Elbow
| Condition | Discriminating feature | Key investigation |
|---|---|---|
| Simple elbow dislocation | Loss of normal three-point bony relationship; ulna posterior to trochlea, no fracture | AP and lateral radiograph |
| Complex fracture-dislocation (terrible triad / Monteggia variant) | Dislocation PLUS radial head and/or coronoid and/or olecranon fracture | Radiograph + CT for fragment characterisation |
| Supracondylar / distal humerus fracture | Deformity with crepitus; intact ulnohumeral articulation on lateral film, fracture line proximal to joint | Radiograph (look for fat-pad sign, fracture proximal to joint) |
| Isolated radial head/neck fracture | Localised lateral tenderness, painful rotation, joint reduced and congruent | Radiograph; radiocapitellar (Greenspan) view |
| Pulled elbow (radial head subluxation, young child) | Arm held pronated and slightly flexed, refusal to use; normal radiograph | Clinical; radiograph usually normal |
| Septic arthritis / acute haemarthrosis (atraumatic) | Fever or no clear trauma, global swelling, congruent joint on film | Aspiration, inflammatory markers |
| Chronic PLRI (recurrent) | Recurrent clicking/giving way, positive pivot-shift, reduced at rest | Stress radiographs / examination under anaesthesia |
Pre-reduction assessment:
- Neurovascular status - median, ulnar, radial nerves; brachial artery
- Skin integrity - open vs closed
- Associated injuries - ipsilateral limb
- Deformity pattern - helps predict direction
Neurovascular Injury
Document neurovascular status before and after reduction. The ulnar nerve is most commonly injured (transient paresthesias in 10-20%). Brachial artery injury is rare but can occur, especially with anterior dislocations or open injuries.
Investigations
Pre-reduction imaging:
Standard views:
- AP elbow (or attempt)
- Lateral elbow
- Often difficult to obtain true views due to deformity
Radiographic assessment:
- Confirm dislocation and direction
- Look for associated fractures (radial head, coronoid)
- Assess any bony fragment position
Don't Delay Reduction
Do not delay reduction waiting for imaging if neurovascular compromise is present. A single lateral view can confirm dislocation. Reduce urgently, then obtain post-reduction imaging.
Post-reduction imaging:
Essential:
- AP and lateral elbow - confirm concentric reduction
- Look carefully for:
- Radial head fracture (often subtle)
- Coronoid fracture (often seen on lateral)
- Any joint widening suggesting interposed fragments
- Concentric reduction (radiocapitellar alignment)
CT imaging:
Indications:
- Suspected associated fracture not clear on X-ray
- Complex dislocation patterns
- Surgical planning
- Any joint incongruency on plain films
CT assessment:
- Fracture characterization (radial head, coronoid)
- Fragment count and size
- Associated injuries
Management
Algorithm
Reduction technique:
1. Preparation
- Adequate analgesia/sedation (or general anesthesia)
- Assistant for counter-traction
- Fluoroscopy available if possible
- Document pre-reduction neurovascular status
2. Positioning
- Patient supine, arm abducted
- Assistant holds upper arm for counter-traction
- Operator controls forearm
3. Reduction Maneuver (Posterolateral)
- Apply longitudinal traction along forearm
- Slight supination to correct rotational component
- Flex elbow while applying pressure to olecranon
- May need brief hyperextension to unlock coronoid
- Guide olecranon over trochlea into reduced position
- Palpable/audible clunk confirms reduction
4. Post-Reduction Assessment
- Confirm reduction with fluoroscopy/X-ray
- Test stability through ROM
- Document neurovascular status
- Splint in stable position
Reduction Technique
For posterolateral dislocation: Apply longitudinal traction with the forearm supinated (corrects the lateral rotation). Apply pressure to olecranon while flexing the elbow. The olecranon slides over the trochlea and reduces with a palpable clunk.
Post-reduction stability assessment:
After reduction, assess stability under fluoroscopy:
-
Flexion-extension arc: Move through ROM
- Note angle at which elbow redislocates
- Stable if maintains reduction 30-130°
- Unstable if redislocates before 60° extension
-
Valgus stress test: Test MCL integrity
-
Varus stress test: Test LCL integrity
-
Lateral pivot shift (if awake): Tests for PLRI
Key Stability Threshold
If the elbow is stable through 30° extension, it can be managed non-operatively with early motion. If it redislocates before 60° extension, operative stabilization is usually needed.
Surgical Technique
Kocher (Lateral) Approach
Indications:
- LCL repair
- Radial head fixation/replacement
- Lateral coronoid access
Technique:
- Incision from lateral epicondyle to ulna
- Identify anconeus-ECU interval
- Elevate anconeus from posterior ulna
- Expose LCL complex (usually avulsed from lateral epicondyle)
- Address radial head
- Repair LCL with suture anchors
The lateral approach provides excellent access to the lateral stabilizers.
Complications
Complications of Elbow Dislocation
| Complication | Incidence | Management |
|---|---|---|
| Stiffness | 20-30% | Early motion, physio, capsular release if severe |
| Recurrent instability | 1-2% simple, higher complex | LCL reconstruction, address all structures |
| Heterotopic ossification | 5-10% | Prophylaxis (indomethacin), excision if limiting |
| Post-traumatic arthritis | 5-10% | Activity modification, eventual arthroplasty |
| Chronic PLRI | Variable | LCL reconstruction |
| Nerve injury (ulnar) | 10-20% transient | Usually resolves, may need exploration |
| Vascular injury | Rare | Urgent vascular repair |
| Compartment syndrome | Rare | Emergency fasciotomy |
Stiffness:
- Most common complication
- Prevention is key - early motion
- Flexion contracture most common pattern
- Treatment: physiotherapy, dynamic splinting, surgical release
Posterolateral rotatory instability (PLRI):
- Chronic sequela of untreated/inadequately healed LCL
- Patient has apprehension or frank instability
- Treatment: LCL reconstruction
Stiffness Prevention
The elbow is prone to stiffness after injury. Most activities require 30-130° arc and 50° supination/pronation. Early motion within the first week significantly reduces stiffness risk. A functional arc for most activities is 30-130°.
Heterotopic ossification:
- Risk factors: head injury, burns, delayed surgery, aggressive physio
- Prophylaxis: indomethacin 25mg TDS x 3 weeks (or radiation)
- Excision if mature and limiting function
Postoperative Care and Rehabilitation
Simple dislocation (non-operative):
Day 0-5
- Posterior splint at 90°
- Elevation, ice
- Finger motion
Day 5-14
- Convert to hinged elbow brace
- Begin active ROM in brace
- Flexion-extension exercises
- Light supination/pronation
Week 2-6
- Progressive ROM
- May wean from brace if stable
- Target functional ROM
- No valgus/varus stress
Week 6-12
- Full ROM expected
- Begin strengthening
- Progressive activity
- May resume light sport
3+ months
- Full activity
- Sports clearance
- Final outcome assessment
Post-operative (LCL repair/complex):
- More protected initially
- Hinged brace with extension block if needed
- Motion started early but within safe arc
- Progress based on stability and healing
Functional ROM
Functional elbow ROM for most activities: 30-130° flexion-extension and 50° supination/pronation. Focus rehabilitation on achieving this functional arc. Some terminal limitation may be well-tolerated.
Outcomes and Prognosis
Outcomes by type:
| Type | Good/Excellent | Key Factors |
|---|---|---|
| Simple, stable | 90-95% | Early motion critical |
| Simple, unstable treated | 85-90% | Quality of repair |
| Complex (terrible triad) | 70-80% | Address all structures |
| Complex (other) | 60-80% | Pattern-dependent |
Prognostic factors:
- Simple vs complex (simple better)
- Time to reduction
- Time to motion initiation
- Quality of reduction
- Associated injuries
- Patient compliance
Simple Dislocation Prognosis
Simple elbow dislocations that are stable after reduction have excellent prognosis (over 90% good/excellent outcomes) with early motion protocol. The key is avoiding prolonged immobilization.
Evidence Base
Level IV
O'Driscoll, Bell & Morrey - Posterolateral Rotatory Instability
Key Findings:
- First description of posterolateral rotatory instability (PLRI) of the elbow in five patients. Identified laxity of the ulnar part of the lateral collateral ligament (LUCL) as the essential lesion, producing transient rotatory subluxation of the ulnohumeral joint with the annular ligament intact. Defined the pivot-shift (posterolateral rotatory-instability) test; operative repair of the LUCL eliminated instability in all five.
Clinical Implication: The LCL/LUCL complex is the primary lateral restraint and the structure that fails first in posterolateral dislocation. This underpins the staged 'Horii circle' (lateral-to-medial) understanding of soft-tissue disruption and makes LCL repair the cornerstone of operative stabilisation.
Source: J Bone Joint Surg Am 1991;73(3):440-6
Level I
Josefsson et al. - Surgical vs Non-surgical Ligament Treatment (RCT)
Key Findings:
- Prospective randomised trial of 30 adults with simple elbow dislocation examined under anaesthesia, then randomised to surgical ligament repair versus non-operative care. All elbows had medial and most had combined medial and lateral collateral ligament rupture. At follow-up both groups had generally good results with no statistically significant difference - surgical repair conferred no advantage over closed treatment.
Clinical Implication: Foundational evidence that routine ligament repair is not required for simple elbow dislocations. Closed reduction followed by functional rehabilitation is the standard of care; surgery is reserved for residual instability.
Source: J Bone Joint Surg Am 1987;69(4):605-8
Level IV
Mehlhoff, Noble, Bennett & Tullos - Simple Dislocation Outcomes
Key Findings:
- Long-term review of 52 adults with simple elbow dislocation treated by closed reduction (mean follow-up 34 months). 60% reported residual symptoms; flexion contracture greater than 30 degrees in 15%, residual pain in 45%. Prolonged immobilisation was strongly associated with larger flexion contracture (p less than 0.001) and more severe pain.
Clinical Implication: Even 'simple' dislocations leave residual symptoms in the majority - counsel patients accordingly. The duration of immobilisation, not the injury alone, drives stiffness: early active motion is the single most important rehabilitation factor.
Source: J Bone Joint Surg Am 1988;70(2):244-9
Level IV
Pugh, Wild, Schemitsch, King & McKee - Terrible Triad Protocol
Key Findings:
- Defined the standard surgical protocol for the terrible triad in 36 consecutive elbows: radial head fixation or replacement, coronoid fixation where feasible, lateral collateral ligament repair, and selective MCL repair or hinged external fixation. At a mean of 34 months the mean Mayo Elbow Performance Score was 88; 28 of 36 (78%) were excellent or good and concentric stability was restored in 34 of 36. Eight patients required reoperation.
Clinical Implication: A systematic, layered repair (bone first, then ligaments) restores enough stability to permit early motion and is the reference treatment for the terrible triad. Outcomes are good but markedly less predictable than simple dislocation, with a meaningful reoperation rate.
Source: J Bone Joint Surg Am 2004;86(6):1122-30
Level IV
Sanchez-Sotelo, Morrey & O'Driscoll - LCL Repair vs Reconstruction for PLRI
Key Findings:
- 44 patients with posterolateral rotatory instability followed at a mean of six years after 12 direct LCL repairs or 33 tendon-graft reconstructions. Surgery restored stability in all but five; mean Mayo Elbow Performance Score 85, with 86% subjectively satisfied. Augmented tendon-graft reconstruction gave better and durable results compared with simple repair (p = 0.04), and outcomes did not deteriorate with time.
Clinical Implication: Chronic PLRI from a missed or inadequately healed LCL injury is reconstructable with good intermediate results, but graft reconstruction outperforms direct repair in the chronic setting. Prevention through correct acute LCL management remains preferable.
Source: J Bone Joint Surg Br 2005;87(1):54-61
Level I
Iordens et al. - FuncSiE Multicentre RCT (early mobilisation)
Key Findings:
- Multicentre randomised trial of 100 adults with simple elbow dislocation comparing immediate active mobilisation with 3 weeks of plaster immobilisation. At 6 weeks the early-mobilisation group had less disability (DASH 12 vs 19) and a larger flexion-extension arc (121 vs 102 degrees) and returned to work sooner (10 vs 18 days). No recurrent dislocations occurred and the complication rate did not differ; 1-year DASH was equivalent.
Clinical Implication: Highest-level modern evidence that immediate active mobilisation is safe for simple elbow dislocations and accelerates functional recovery without increasing instability. Routine plaster immobilisation is not justified.
Source: Br J Sports Med 2017;51(6):531-8
Level III
Stoneback et al. - Incidence of Elbow Dislocation (NEISS)
Key Findings:
- National (US) Electronic Injury Surveillance System analysis estimated an elbow dislocation incidence of 5.21 per 100,000 person-years. The highest rate (43.5% of cases) occurred in 10-19 year-olds (6.87 per 100,000); incidence was essentially equal between sexes. Nearly half (44.5%) of dislocations in those aged 10 or older were sports-related - football and wrestling in males, gymnastics and skating in females.
Clinical Implication: Elbow dislocation is predominantly an injury of active adolescents and young adults, most often sustained in sport. This shapes counselling on activity resumption and informs the priority on restoring a functional, stiffness-free arc of motion.
Source: J Bone Joint Surg Am 2012;94(3):240-5
Clinical Decision Scenarios
Use these scenarios to practise clinical reasoning and management decisions
CLINICAL SCENARIOStandard
Scenario 1: Simple Posterior Elbow Dislocation
CLINICAL PROMPT
"A 25-year-old man falls while skateboarding, landing on his outstretched hand. He presents with obvious elbow deformity. X-rays confirm a posterior elbow dislocation with no fracture. How do you manage this injury?"
PRACTICAL APPROACH
This young man has sustained a **simple posterolateral elbow dislocation** from a classic FOOSH mechanism. This is the most common type of elbow dislocation. **Initial Assessment:** - **Neurovascular examination** - document median, ulnar, radial nerve function and pulses before any manipulation - **Skin integrity** - confirm closed injury - **X-rays** confirm dislocation without fracture (simple dislocation) **Reduction:** I would reduce this in the emergency department with adequate sedation. My technique: 1. Patient supine, arm abducted 2. Assistant provides counter-traction on upper arm 3. Apply **longitudinal traction** along the forearm 4. **Supinate** slightly to correct the posterolateral rotation 5. Apply **pressure to the olecranon** while **flexing** the elbow 6. The elbow should reduce with a palpable clunk **Post-Reduction Assessment:** - Confirm reduction with X-ray - **Assess stability** through range of motion: - Move from flexion to extension - Note the angle at which elbow feels unstable or redislocates - **Stable if maintains reduction to 30° extension** - Re-examine neurovascular status **Management (assuming stable):** - Posterior splint at 90° for **5-7 days** comfort only - Convert to **hinged elbow brace** - Begin **early active ROM within first week** - This is critical - prolonged immobilization causes stiffness - Progress ROM over 6 weeks - Avoid varus/valgus stress for 6 weeks **Prognosis:** Simple dislocations that are stable after reduction have **excellent prognosis** (over 90% good/excellent) with early motion. The main risk is stiffness from prolonged immobilization.
KEY CLINICAL POINTS
This is a simple posterolateral dislocation - most common type
Document neurovascular status before and after reduction
Reduction: traction, supination, pressure on olecranon, flex
Post-reduction: assess stability through ROM
Stable to 30° extension = good prognosis
Splint for comfort only, short period
Early motion within first week is critical
Prolonged immobilization causes stiffness
Excellent prognosis with early motion
Hinged brace allows motion while protecting
COMMON PITFALLS
Not documenting neurovascular status pre-reduction
Not assessing post-reduction stability
Prolonged immobilization (over 2-3 weeks)
Missing associated fracture on X-ray
Not starting early ROM
FURTHER QUESTIONS
"What if the elbow redislocated at 50° extension?"
"How would you manage if there was an associated radial head fracture?"
CLINICAL SCENARIOChallenging
Scenario 2: Unstable Simple Dislocation
CLINICAL PROMPT
"You reduce a simple posterior elbow dislocation in a 35-year-old woman. After reduction, under sedation, you assess stability. The elbow redislocates when you extend beyond 50 degrees. What is your management?"
PRACTICAL APPROACH
This patient has an **unstable simple elbow dislocation**. Despite having no fracture, the elbow redislocates at 50° extension, which is before the 60° threshold we consider acceptable for non-operative management. **Understanding the Instability:** The soft tissue injury follows the **Horii circle**: - Stage 1: LCL complex - Stage 2: Anterior and posterior capsule - Stage 3: MCL The fact that it redislocates suggests significant ligamentous injury, likely through Stage 3. The **LCL is always injured** in posterolateral dislocation. **Immediate Management:** - Confirm reduction with X-ray - Splint in 90° flexion (stable position) - CT scan to definitively exclude occult fracture **Treatment Options:** Given instability beyond 60° extension, I would recommend **operative stabilization**, specifically: **Surgical Plan:** 1. **Lateral approach** (Kocher interval) 2. **Repair LCL complex** to lateral epicondyle - Suture anchors or through bone tunnels - Identify and repair the LUCL specifically 3. **Assess stability** after LCL repair under fluoroscopy 4. If still unstable: - Consider **MCL repair** via medial approach - Rare to need both in simple dislocation 5. If borderline stable: - Consider **hinged external fixator** for 4-6 weeks **Rationale for Surgery:** - Instability before 60° extension suggests significant ligament injury - Non-operative treatment with this degree of instability risks: - Recurrent dislocation - Chronic posterolateral rotatory instability (PLRI) - Need for later reconstruction rather than repair **Postoperative:** - Hinged brace with extension block initially - Early ROM within safe arc - Progress ROM as healing allows - Protect repair for 6 weeks
KEY CLINICAL POINTS
Instability before 60° extension = likely needs surgery
LCL is always injured in posterolateral dislocation
CT to rule out occult fracture before surgery
Surgical approach: lateral for LCL repair
LCL repair to lateral epicondyle with anchors
Assess stability after LCL repair
May need MCL repair if still unstable (rare)
Hinged external fixator if borderline
Early motion still important after surgery
Protect repair for 6 weeks
COMMON PITFALLS
Attempting non-operative treatment despite instability
Not recognizing LCL injury as the primary problem
Missing occult fracture
Not assessing stability after LCL repair
Prolonged immobilization after surgery
FURTHER QUESTIONS
"What is the long-term risk if this is treated non-operatively?"
"How would you manage chronic PLRI?"
CLINICAL SCENARIOCritical
Scenario 3: Terrible Triad Injury
CLINICAL PROMPT
"A 45-year-old woman falls down stairs. Her elbow was dislocated and has been reduced in the emergency department. CT shows a Mason Type III radial head fracture with 5 fragments and a small coronoid tip fracture. How do you approach this injury?"
PRACTICAL APPROACH
This patient has the **terrible triad of the elbow** - the most significant complex elbow dislocation pattern. It comprises: 1. Elbow dislocation (now reduced) 2. Radial head fracture (Mason Type III, 5 fragments) 3. Coronoid fracture (tip) 4. **LCL rupture** (always present by definition) **Understanding the Injury:** The terrible triad is notorious for instability and poor outcomes if not treated properly. All components must be addressed systematically. **Initial Assessment:** - Confirm neurovascular status - Assess reduction on X-ray - CT (already obtained) for surgical planning - Splint in 90° flexion **Surgical Plan - Address All Components:** **Approach:** Begin with **lateral approach** (Kocher or lateral column) - this provides access to radial head and LCL. **1. Radial Head:** With 5 fragments, this is **unreconstructable**. I would perform **radial head arthroplasty**: - Excise the fragments - Size the prosthesis appropriately (avoid overstuffing) - Insert modular metallic prosthesis **2. LCL Complex:** The LCL is **always ruptured** - repair is essential: - Identify the torn LUCL - Repair to lateral epicondyle using suture anchors - This is often the key to restoring stability **3. Coronoid:** After radial head and LCL addressed, **assess stability under fluoroscopy**: - If stable - small tip fracture may not need fixation - If unstable - consider **suture lasso** technique for tip fracture - Captures fragment through capsule attachment **4. Final Stability Assessment:** - Test through full ROM under fluoroscopy - Note stable arc - If still unstable despite all above: - Consider **MCL repair** (usually heals if lateral structures addressed) - May need **hinged external fixator** as salvage **Postoperative:** - Hinged brace with extension block based on stable arc - Early ROM within safe arc is still critical - Progress motion as stability allows - Expect more guarded prognosis than simple dislocation
KEY CLINICAL POINTS
This is the terrible triad - must address all components
Four components: dislocation, radial head, coronoid, LCL
LCL is always ruptured by definition
Lateral approach provides access to most structures
5 fragments = unreconstructable radial head = arthroplasty
LCL repair is essential for stability
Coronoid tip - may not need fixation if stable after other structures
Assess stability after each step
May need hinged external fixator if unstable
Prognosis more guarded than simple dislocation
COMMON PITFALLS
Treating as simple dislocation
Attempting ORIF of unreconstructable radial head
Not repairing the LCL
Ignoring the coronoid fracture
Not assessing stability systematically
FURTHER QUESTIONS
"What if the coronoid was basal rather than tip?"
"What is the expected outcome for terrible triad?"
MCQ Practice Points
Direction Question
Q: What is the most common direction of elbow dislocation? A: Posterolateral - accounts for approximately 90% of elbow dislocations. The mechanism (FOOSH with valgus and supination moment) drives the ulna posterior and lateral to the humerus.
Classification Question
Q: What differentiates simple from complex elbow dislocation? A: Simple = no fracture (ligament injury only). Complex = with associated fracture (radial head, coronoid, olecranon). Simple dislocations are usually stable after reduction with excellent prognosis.
Horii Circle Question
Q: In what order do structures fail in posterolateral elbow dislocation? A: According to the Horii circle, injury progresses from lateral to medial: Stage 1 (LCL complex), Stage 2 (anterior/posterior capsule), Stage 3 (MCL). The LCL is always injured first.
Stability Question
Q: What is the threshold for stable vs unstable simple elbow dislocation? A: If the elbow maintains reduction through 30° extension to full flexion, it is considered stable for non-operative treatment. If it redislocates before 60° extension, operative stabilization is usually recommended.
Complications Question
Q: What is the most common complication of elbow dislocation? A: Stiffness - occurs in 20-30% to some degree. Prevention through early motion is key. Prolonged immobilization (greater than 3 weeks) significantly increases stiffness risk.
Guidelines, Registries & Global Practice
Global epidemiology
| Measure | Figure | Source |
|---|---|---|
| Overall incidence | 5.21 per 100,000 person-years (US NEISS) | Stoneback 2012 (PMID 22298056) |
| Peak age group | 10-19 years (6.87 per 100,000; 43.5% of cases) | Stoneback 2012 |
| Sex distribution | Essentially equal (rate ratio 1.02) | Stoneback 2012 |
| Sport-related (age 10+) | 44.5% (football/wrestling in males; gymnastics/skating in females) | Stoneback 2012 |
| Simple vs complex | Roughly half of dislocations are simple (no fracture) | Josefsson 1987 (PMID 3571318) |
Elbow dislocation is the second most common large-joint dislocation after the shoulder and is predominantly an injury of active adolescents and young adults.
Guidance and evidence, side by side
There is no single dedicated international society guideline for elbow dislocation comparable with hip-fracture pathways; practice is driven by high-level trial and consensus evidence that is broadly concordant across regions.
| Domain | Position | Evidence basis |
|---|---|---|
| Simple dislocation, stable after reduction | Closed reduction then early active mobilisation; avoid prolonged immobilisation | Level I RCT (FuncSiE, PMID 26175020) and Level I (Josefsson, PMID 3571318) - no benefit from routine ligament repair or plaster |
| Duration of immobilisation | As short as comfort allows (days, not weeks); immobilisation beyond ~1-2 weeks increases stiffness | Level IV (Mehlhoff, PMID 3343270): immobilisation strongly linked to flexion contracture |
| Complex (terrible triad) | Systematic operative repair - radial head, coronoid, LCL +/- MCL/hinged fixator | Level IV reference protocol (Pugh/King/McKee, PMID 15173283); endorsed by AO Foundation and elbow-surgeon consensus |
| Chronic PLRI | Lateral ligament reconstruction (tendon graft preferred over direct repair) | Level IV (Sanchez-Sotelo, PMID 15686238) |
| Open / neurovascular compromise | Emergent reduction and surgical management (general trauma/BOA-style principles) | Open-fracture and limb-threatening-injury principles (BOAST, AO) |
Registry evidence
Elbow dislocation is a soft-tissue / fracture-dislocation injury and is not tracked by the arthroplasty joint registries (NJR, AJRR, AOANJRR, SHAR, NZJR), which capture joint replacement rather than acute trauma. Epidemiology therefore derives from national injury-surveillance datasets (e.g. the US NEISS database) rather than implant registries.
Global practice variation
- High-resource settings: ready access to fluoroscopy, CT for complex patterns, radial head arthroplasty and hinged external fixators; early supervised hand-therapy-led mobilisation is standard.
- Limited-resource settings: reliance on plain radiographs and closed reduction; restricted access to radial head prostheses and hinged fixators may favour fixation or, where unavoidable, excision strategies and longer protected mobilisation.
- Convergent core: across all settings the principles are identical - reduce promptly, document neurovascular status before and after, classify simple versus complex, test the stable arc, and mobilise early.
Exam Context
Be prepared to discuss reduction technique, stability assessment, simple vs complex classification, and terrible triad management. Understanding the Horii circle, the FuncSiE early-mobilisation evidence, and when to operate are key viva topics across FRCS, FRACS, EBOT and ABOS.
ELBOW DISLOCATIONS
Clinical summary
CLASSIFICATION
- •Simple = no fracture, ligament injury only
- •Complex = with fracture(s)
- •Posterolateral = 90% (most common)
- •LCL always injured in posterolateral
HORII CIRCLE (INJURY PROGRESSION)
- •Stage 1: LCL complex (lateral)
- •Stage 2: Anterior/posterior capsule
- •Stage 3A: Posterior MCL
- •Stage 3B: Entire MCL (medial)
REDUCTION TECHNIQUE
- •Document NV status before and after
- •Adequate sedation essential
- •Traction + supination + olecranon pressure + flex
- •Confirm with X-ray
STABILITY ASSESSMENT
- •Test ROM under sedation/anesthesia
- •Stable if maintains reduction to 30° extension
- •Unstable if redislocates before 60° extension
- •Unstable = likely needs operative repair
SIMPLE DISLOCATION MANAGEMENT
- •If stable: early motion, hinged brace
- •Begin ROM within first week
- •Avoid prolonged immobilization (greater than 3 weeks)
- •If unstable: LCL repair
TERRIBLE TRIAD PROTOCOL
- •Dislocation + radial head + coronoid + LCL
- •1. Fix/replace radial head
- •2. Repair LCL (always injured)
- •3. Fix coronoid if still unstable
- •4. Consider hinged fixator if needed