High-yield overview
ATFL and CFL Insufficiency
Weakest, injured first (inversion + plantarflexion)ATFL
Injured with severe sprains (inversion + dorsiflexion)CFL
Acute sprains progress to chronic instability20-40%
85-90% good/excellent outcomesBrostrom-Gould
Ankle Sprain Grades
Grade I
PatternLigament stretch, no macroscopic tear
TreatmentRICE, early mobilization
Grade II
PatternPartial ligament tear
TreatmentBrace 4-6 weeks, rehabilitation
Grade III
PatternComplete ligament rupture
TreatmentBrace, rehabilitation ± surgery
Critical Must-Knows
- ATFL: Weakest lateral ligament. Resists inversion in plantarflexion. Most commonly injured.
- CFL: Injured in severe sprains. Resists inversion in dorsiflexion. Crosses both ankle and subtalar joints.
- Anterior Drawer: Tests ATFL integrity. Compare to contralateral side.
- Talar Tilt: Tests CFL integrity. Performed in neutral dorsiflexion.
- Brostrom-Gould: Direct ATFL repair + inferior extensor retinaculum augmentation. Gold standard surgical treatment.
Clinical Pearls
- "ATFL is weakest - always injured first (ACP order)
- "Anterior drawer tests ATFL, talar tilt tests CFL
- "Rehabilitation first - majority stabilize without surgery
- "Brostrom repair is gold standard (85-90% success)
- "Reconstruction for revision, heavy athletes, or generalized laxity
Critical Anatomy
Lateral ligament injury order: ATFL → CFL → PTFL (weakest to strongest).
- ATFL is weakest - injured with inversion in plantarflexion (most common mechanism).
- CFL is next - injured with greater force (inversion in dorsiflexion). Crosses ankle AND subtalar joints.
- PTFL is strongest - only injured in severe ankle dislocations.
- Remember: ACP = Anterior, Calcaneofibular, Posterior (weakest to strongest).
At a Glance Table
| Feature | Details |
|---|---|
| Definition | Chronic mechanical and/or functional instability of the lateral ankle complex |
| Epidemiology | 23,000 ankle sprains/day (US); 20-40% develop chronic instability |
| Key Ligaments | ATFL (most common), CFL, PTFL (rare) |
| Mechanism | Inversion injury, typically in plantarflexion |
| Key Exam | Anterior drawer (ATFL), Talar tilt (CFL) |
| First-Line Treatment | Rehabilitation: proprioceptive training + peroneal strengthening |
| Surgical Gold Standard | Brostrom-Gould repair (85-90% success) |
| Reconstruction Indications | Failed Brostrom, generalized ligamentous laxity, revision, heavy athletes |
Mnemonic
ACPLateral Ligaments - ACP
| A | ATFL Anterior talofibular - weakest, most commonly injured |
| C | CFL Calcaneofibular - crosses ankle AND subtalar joints |
| P | PTFL Posterior talofibular - strongest, rarely injured |
| A | ATFL Anterior talofibular - weakest, most commonly injured |
| C | CFL Calcaneofibular - crosses ankle AND subtalar joints |
| P | PTFL Posterior talofibular - strongest, rarely injured |
Hook:ACP = Anterior to Posterior = Weakest to Strongest. Like the alphabet, A comes first (injured first).
Mnemonic
ATEStress Test Interpretation - ATE
| A | Anterior Drawer Tests ATFL - anterior translation of talus |
| T | Talar Tilt Tests CFL - inversion stress in neutral dorsiflexion |
| E | External Rotation Tests Syndesmosis - NOT lateral ligaments |
| A | Anterior Drawer Tests ATFL - anterior translation of talus |
| T | Talar Tilt Tests CFL - inversion stress in neutral dorsiflexion |
| E | External Rotation Tests Syndesmosis - NOT lateral ligaments |
Hook:ATE my ankle! Know which ligament each stress test assesses.
Mnemonic
SCAR - LSCAR - Lateral Ankle Surgery Complications
| S | Stiffness Especially dorsiflexion - avoid over-tightening repair |
| C | Chronic pain May indicate missed OCD or impingement |
| A | And nerve injury Superficial peroneal most common |
| R | Recurrence 5-10% - may need reconstruction |
| S | Stiffness Especially dorsiflexion - avoid over-tightening repair | A | And nerve injury Superficial peroneal most common |
| C | Chronic pain May indicate missed OCD or impingement | R | Recurrence 5-10% - may need reconstruction |
Hook:SCAR reminds you of the main complications that can leave a mark on outcomes.
Overview/Epidemiology
Lateral ankle instability is the most common sports injury worldwide, affecting athletes across all sports and age groups.
Epidemiology
Incidence
- 23,000 ankle sprains per day in the United States
- 1 per 10,000 person-days in general population
- Up to 30% of all sporting injuries
- Most common in basketball, soccer, and volleyball
Natural History
- 20-40% of acute sprains develop chronic instability
- Risk factors: incomplete rehabilitation, ligamentous laxity
- 55% have residual symptoms at 6 months
- Recurrence rate without treatment: 70-80%
Demographics
- Peak incidence: 15-35 years (active population)
- Equal male:female ratio in general population
- Higher female incidence in specific sports
- Prior ankle sprain strongest risk factor
Types of Instability
- Mechanical Instability: Objective ligament laxity on stress testing
- Functional Instability: Subjective feeling of giving way despite normal stress tests
- Combined: Most patients have elements of both
Risk Factors for Chronic Instability
- Previous ankle sprain (strongest predictor)
- Incomplete or inadequate rehabilitation
- Generalized ligamentous laxity (Beighton score greater than 4)
- High-demand sports (basketball, soccer, netball)
- Hindfoot varus malalignment
- Cavovarus foot deformity
- Peroneal weakness or dysfunction
Pathophysiology and Mechanisms
Lateral Ankle Ligament Complex
The lateral ankle ligaments originate from the lateral malleolus and provide stability against inversion and anterior translation of the talus.
Lateral Ankle Ligaments - Detailed Anatomy
| Ligament | Origin | Insertion | Function | Injury Order |
|---|---|---|---|---|
| Anterior border of lateral malleolus | Talar neck (anterolateral) | Resists anterior translation + inversion in plantarflexion | 1st (weakest) | |
| Tip of lateral malleolus | Lateral calcaneus | Resists inversion in dorsiflexion; crosses ankle + subtalar | 2nd | |
| Medial surface of lateral malleolus | Posterior talus | Resists posterior translation; strongest ligament | 3rd (rarely injured) |
ATFL Anatomy (Most Important)
- Length: 20-25mm
- Width: 10-12mm
- Orientation: Horizontal in plantarflexion → becomes vertical in dorsiflexion
- Variants: 1-3 bands (2 bands most common)
- Strength: Weakest of the three (58-90N failure load)
CFL Anatomy
- Length: 20-25mm
- Crosses two joints: Ankle AND subtalar (unique feature)
- Orientation: 10-45° posterior to long axis of fibula
- Key relationship: Lies deep to peroneal tendons
- Clinical significance: CFL injury affects subtalar stability
Biomechanics of Injury
Injury Mechanism
The typical mechanism is inversion injury in plantarflexion:
- In plantarflexion, the narrower posterior talus sits in the mortise → less bony stability
- ATFL becomes the primary restraint → first to fail
- With continued force, CFL then fails
- PTFL only fails with severe trauma/dislocation
Dynamic Stabilizers
- Peroneus longus and brevis: Primary dynamic stabilizers
- Extensor digitorum longus: Secondary support
- Proprioceptive afferents: Critical for neuromuscular control
- Peroneal reaction time: Delayed in chronic instability
Classification Systems
Ankle Sprain Grading
Ankle Sprain Classification
| Grade | Pathology | Clinical Findings | Stability | Treatment |
|---|---|---|---|---|
| Microscopic tear, stretch injury | Mild swelling, tenderness | Stable | RICE, early mobilization | |
| Partial macroscopic tear | Moderate swelling, ecchymosis | Mild laxity | Brace 4-6 weeks, physio | |
| Complete rupture ATFL ± CFL | Severe swelling, ecchymosis | Frank instability | Brace, physio ± surgery |
Grade I and II injuries typically heal with conservative treatment. Grade III injuries may require surgical intervention if chronic instability develops.
Clinical Assessment
History
Key Questions:
- Initial injury: mechanism, treatment, rehabilitation
- Symptoms: giving way episodes, pain, swelling
- Functional limitation: sports, uneven ground, stairs
- Prior treatment: physiotherapy duration, bracing
- Red flags: locking (loose body), medial pain (deltoid), persistent swelling (OCD)
Physical Examination
Observation
- Swelling: lateral ankle, anterolateral gutter
- Ecchymosis: may indicate recent episode
- Hindfoot alignment: varus predisposes to lateral sprains
- Cavus foot: associated with instability
- Muscle wasting: peroneal atrophy suggests chronic injury
Inspection findings help assess the chronicity and severity of instability.
Investigations
Imaging Protocol
Standard Views
- Weight-bearing AP: Mortise alignment, OCD
- Mortise view: Lateral clear space
- Lateral: Talar dome, anterior impingement
Stress Radiographs (If Indicated)
- Anterior drawer stress: Greater than 10mm translation significant
- Talar tilt stress: Greater than 10° or greater than 5° vs. contralateral
- Useful for objective documentation
- Compare to contralateral side
Standard weight-bearing views are essential first-line imaging.
Associated Pathology to Exclude
| Condition | Frequency | Investigation | Clinical Significance |
|---|---|---|---|
| Osteochondral lesion (OCD) | 20-25% | MRI, CT | Address at surgery |
| Peroneal tendon pathology | 15-20% | MRI, ultrasound | May need concurrent repair |
| Anterior impingement | 10-15% | Lateral X-ray, MRI | Debride at arthroscopy |
| Syndesmosis injury | 5-10% | X-ray, MRI | Different treatment |
| Subtalar instability | Variable | Stress views | Consider reconstruction |
Differential Diagnosis of the "Unstable" or Painful Lateral Ankle
Differentiating Lateral Ankle Instability from Mimics
| Diagnosis | Key Distinguishing Feature | Best Test | Why It Matters |
|---|---|---|---|
| Recurrent giving-way; positive anterior drawer/talar tilt | Clinical stress tests; stress radiographs | Index diagnosis - guides rehab vs surgery | |
| Retromalleolar pain/clicking; pain on resisted eversion, not true giving-way | Dynamic ultrasound; MRI | Needs tendon repair/groove deepening, not ligament repair alone | |
| Deep ankle pain, catching/locking, effusion rather than instability | MRI / CT | Often coexists; must address arthroscopically at surgery | |
| Pain proximal to joint line; positive external rotation/squeeze test | ER stress test; weight-bearing CT | Different treatment - stabilisation, not lateral repair | |
| Anterolateral pain on dorsiflexion, no objective laxity | MRI; diagnostic arthroscopy | Treated by debridement, not ligament repair | |
| Hindfoot 'rolling' on uneven ground; CFL involvement | Broden/stress views; clinical exam | May need reconstruction crossing the subtalar joint |
Management Algorithm
Algorithm
Treatment Decision Framework
First-Line for ALL Patients
Duration: 3-6 months minimum before considering surgery
Components:
-
Proprioceptive Training
- Wobble board exercises
- Single-leg stance progressions
- Sport-specific balance training
-
Peroneal Strengthening
- Resisted eversion exercises
- Theraband programs
- Functional strengthening
-
Ankle Bracing
- Semi-rigid brace for sport
- Lace-up brace for daily activities
- Taping for specific activities
-
Activity Modification
- Avoid uneven terrain initially
- Gradual return to sport
Success Rate: 70-80% of patients stabilize with rehabilitation alone.
Conservative treatment remains the cornerstone of management.
Treatment Algorithm Summary
- All patients: Rehabilitation first (3-6 months)
- Persistent symptoms: Brostrom-Gould repair
- Failed Brostrom/Generalized laxity/Heavy athlete: Anatomic reconstruction
- Revision surgery: Consider reconstruction with allograft
Surgical Technique
Brostrom-Gould Repair (Gold Standard)
Patient Positioning
- Position: Supine with bump under ipsilateral hip
- Tourniquet: High thigh (250-300mmHg)
- Leg position: Slight internal rotation for lateral access
Equipment
- Standard foot and ankle set
- Suture anchors (2.4-3.0mm)
- Non-absorbable braided suture
- Fluoroscopy (optional)
Approach
- Curvilinear incision over lateral malleolus
- Length: 4-6cm
- Identify and protect superficial peroneal nerve branches
Proper positioning and nerve protection are essential for successful repair.
Nerve at Risk
The superficial peroneal nerve is at risk with lateral ankle approaches. It typically crosses the surgical field 5-10cm proximal to the tip of the lateral malleolus. Always identify and protect this nerve to avoid sensory deficit.
Complications
Complications by Type
Intraoperative Complications
| Complication | Incidence | Prevention | Management |
|---|---|---|---|
| Superficial peroneal nerve injury | 2-5% | Careful dissection, identify before incision | Neurolysis, reassurance |
| Sural nerve injury | 1-2% | Posterior incision extension awareness | Reassurance (usually neuropraxia) |
| Inadequate tissue quality | 5-10% | Pre-op MRI assessment | Convert to reconstruction |
| Anchor pull-out | Rare | Proper technique, bone quality assessment | Re-anchor or transosseous sutures |
Nerve identification is the key to preventing intraoperative complications.
Postoperative Care
Rehabilitation Protocol
Immobilization Phase
Goals:
- Wound healing
- Pain and swelling control
- Prevent DVT
Protocol:
- Below-knee backslab or CAM boot
- Non-weight bearing or touch weight bearing
- Elevation, ice
- Ankle pumps (within splint if able)
Follow-up:
- Wound check at 10-14 days
- Remove sutures
- Transition to CAM boot
Early immobilization protects the healing repair.
Expected Outcomes
| Outcome Measure | Brostrom-Gould | Anatomic Reconstruction |
|---|---|---|
| Good/Excellent results | 85-90% | 80-90% |
| Return to sport | 85-95% | 80-90% |
| Recurrence rate | 5-10% | 5-15% |
| Time to sport | 4-6 months | 6-9 months |
Outcomes
Results by Treatment Type
Conservative Treatment
- 70-80% stabilize without surgery
- Best results with supervised physiotherapy
- Proprioceptive training key to success
- Peroneal strengthening essential
- Bracing for sport may be permanent
Brostrom-Gould Repair
- 85-90% good/excellent results
- Gold standard surgical treatment
- Preserves subtalar motion
- Lower revision rate than non-anatomic
- Return to sport: 4-6 months
Anatomic Reconstruction
- 80-90% good results
- Reserved for failures, laxity, heavy athletes
- Longer rehabilitation (6-9 months)
- Allograft reduces donor site morbidity
- Higher revision rate than primary Brostrom
Prognostic Factors
Favourable:
- Single ligament injury (ATFL only)
- Good tissue quality
- Normal hindfoot alignment
- Compliant patient
- Supervised rehabilitation
Unfavourable:
- Combined ATFL + CFL injury
- Generalized ligamentous laxity
- Hindfoot varus or cavovarus
- Associated OCD
- Poor compliance
Controversies and Areas of Uncertainty
Open vs Arthroscopic Repair
- Meta-analyses show comparable stability with lower wound morbidity arthroscopically
- Longer-term durability and learning-curve data still maturing
- No high-level RCT establishes clear superiority of either approach
Suture-Tape / InternalBrace Augmentation
- Biomechanically stronger and allows earlier loading
- Clinical benefit over standard repair is small and short-term
- Concern about over-constraint and cost-effectiveness remains unresolved
Repair vs Reconstruction in Laxity
- Higher failure with direct repair in generalised laxity (Beighton ≥4)
- Optimal threshold to choose graft reconstruction is not standardised
- Augmented repair may bridge the gap but lacks long-term comparative data
Unresolved Questions
- Early surgery in elite athletes: Whether acute repair of complete Grade III ruptures in high-level athletes shortens return-to-sport versus functional treatment remains debated; most evidence still favours rehabilitation first.
- Optimal rehabilitation dose: The ideal duration, supervision intensity, and balance/neuromuscular protocol are not standardised across guidelines.
- Defining "failed" conservative treatment: The 3-6 month threshold is pragmatic rather than evidence-defined.
- Role of weight-bearing CT and dynamic imaging in routine assessment is evolving and not yet consensus practice.
Evidence Base
Landmark
Broström L - Original Anatomic Repair
Key Findings:
- Original description of direct delayed anatomic repair of ruptured lateral ligaments
- Established that scarred ligament ends could be re-apposed years after injury with good results
- Foundation for all modern anatomic lateral ankle stabilization
Clinical Implication: The Broström repair remains the basis of the gold-standard anatomic technique for chronic lateral ankle instability (foundational classic; pre-PubMed era).
Source: Acta Chir Scand 1966
Landmark
Gould N, Seligson D, Gassman J - Gould Modification
Key Findings:
- Added advancement of the inferior extensor retinaculum (IER) over the repaired ATFL
- Reinforces the repair and limits inversion, adding a proprioceptive contribution
- Converted the Broström into the 'Broström-Gould' construct
Clinical Implication: IER augmentation (Gould modification) is now standard practice with most open Broström repairs (foundational classic; limited PubMed indexing).
Source: Foot Ankle 1980
Level I
Doherty C et al - Incidence and Prevalence of Ankle Sprain (Meta-analysis)
Key Findings:
- Meta-analysis of 181 prospective studies; ankle sprain incidence higher in females than males (13.6 vs 6.94 per 1000 exposures)
- Highest incidence in indoor/court sports; children at higher risk than adolescents or adults
- Lateral ankle sprain was the most common subtype overall
Clinical Implication: Lateral ankle sprain is the dominant pattern worldwide, with female and indoor/court-sport athletes at greatest risk - shaping prevention and counselling.
Source: Sports Med 2014
Guideline
Gribble PA et al - International Ankle Consortium Position Statement
Key Findings:
- Consensus selection criteria defining chronic ankle instability (CAI) for research and practice
- Requires a history of at least one significant sprain plus recurrent 'giving way', recurrent sprains, or feelings of instability
- Standardised CAI definition to harmonise the literature
Clinical Implication: Provides the internationally accepted operational definition of CAI - distinguish mechanical from functional instability when diagnosing and consenting.
Source: J Athl Train 2014
Level I
de Vries JS et al - Interventions for Chronic Ankle Instability (Cochrane Review)
Key Findings:
- Seven randomised trials; insufficient high-quality evidence to favour any single surgical or conservative technique
- After surgical reconstruction, early functional rehabilitation gave earlier return to work and sport than 6 weeks of immobilisation
- Chronic lateral instability follows roughly 10-20% of acute sprains
Clinical Implication: Supports early functional rehabilitation over prolonged immobilisation postoperatively, and a conservative-first strategy given limited comparative surgical evidence.
Source: Cochrane Database Syst Rev 2006
Level I
Moorthy V et al - Open vs Arthroscopic Broström (Meta-analysis)
Key Findings:
- Six comparative studies; arthroscopic repair gave slightly higher AOFAS and Karlsson scores and lower VAS pain
- No difference in postoperative anterior drawer, talar tilt, or overall complications
- Wound-related complications were significantly lower with arthroscopic repair (OR 0.25)
Clinical Implication: Arthroscopic Broström offers comparable stability with fewer wound complications, making it a valid alternative to open repair in experienced hands.
Source: J Foot Ankle Surg 2020
Level IV
Cho BK et al - Suture-Tape Augmented Modified Broström in Generalised Laxity
Key Findings:
- 28 patients with generalised ligamentous laxity (Beighton ≥4); 2-year follow-up
- FAOS improved 63.2 to 90.6 and talar tilt 16.2° to 3.6°; anterior translation 12.1 mm to 4.2 mm
- Only 1 patient (3.6%) had recurrent subjective and mechanical instability
Clinical Implication: Suture-tape augmentation is an effective option to reinforce the repair in patients with generalised laxity who are at higher risk of stretch-out.
Source: Foot Ankle Int 2017
Level III
Wang AH et al - Arthroscopic vs Open Modified Broström in Joint Laxity
Key Findings:
- 64 CLAI patients with generalised joint laxity (Beighton ≥4); 24-month follow-up
- No difference in functional scores or stress radiographs between arthroscopic and open repair
- Arthroscopic group returned to work earlier; failure rates 23.3% vs 16.1% (not significant)
Clinical Implication: Even in generalised laxity, arthroscopic and open modified Broström give similar short-term outcomes - but note the appreciable failure rate, supporting augmentation or reconstruction in this group.
Source: Knee Surg Sports Traumatol Arthrosc 2023
Viva Scenarios
Use these scenarios to practise clinical reasoning and management decisions
CLINICAL SCENARIOStandard
Recurrent Ankle Sprains in Athlete
CLINICAL PROMPT
"A 25-year-old basketball player presents with recurrent left ankle 'giving way' episodes despite 6 months of physiotherapy. He reports 3-4 episodes per month during games. Examination shows positive anterior drawer test compared to the contralateral side. What is your assessment and management plan?"
PRACTICAL APPROACH
This is chronic lateral ankle instability with failed conservative treatment. The positive anterior drawer indicates ATFL insufficiency.
Assessment:
- Confirm rehabilitation was supervised and comprehensive
- Assess for CFL involvement (talar tilt test)
- Check hindfoot alignment (varus predisposes)
- Evaluate for generalized laxity (Beighton score)
- X-rays to exclude OCD, loose bodies
- MRI to assess ligament quality and associated pathology
Management:
I would offer Brostrom-Gould repair - direct ATFL repair with inferior extensor retinaculum augmentation. This is the gold standard with 85-90% good/excellent results.
Post-operative protocol: Protected weight bearing 4-6 weeks, CAM boot, then progressive rehabilitation with proprioceptive training. Return to sport expected at 4-6 months with ankle brace.
KEY CLINICAL POINTS
Rehabilitation trial mandatory before surgery
Brostrom-Gould is gold standard surgical treatment
Assess for associated pathology (OCD, peroneal issues)
85-90% good/excellent results expected
COMMON PITFALLS
Operating without adequate rehabilitation trial
Using reconstruction when Brostrom is adequate
Missing associated pathology (OCD, impingement)
FURTHER QUESTIONS
"When would you consider reconstruction instead of repair?"
"How do you assess tissue quality intraoperatively?"
"What is your return to sport protocol?"
CLINICAL SCENARIOStandard
Failed Brostrom Repair
CLINICAL PROMPT
"A 30-year-old female netball player presents 18 months after a Brostrom repair with recurrent instability. She has hypermobile joints (Beighton score 6/9). Stress testing shows persistent ATFL laxity. How do you approach this case?"
PRACTICAL APPROACH
This is a failed Brostrom repair in a patient with generalized ligamentous laxity. The high Beighton score suggests the native tissue repair has stretched out.
Assessment:
- Review operative notes from index procedure
- MRI to assess remaining ligament tissue and exclude other pathology
- Assess hindfoot alignment and exclude cavovarus
- Evaluate peroneal function
Management:
Given the generalized laxity and failed primary repair, I would recommend anatomic reconstruction rather than revision Brostrom. My preference would be semitendinosus allograft reconstruction to avoid donor site morbidity.
Key principles:
- Anatomic tunnel placement in fibula, talus, and calcaneus
- Graft tensioning in neutral dorsiflexion and eversion
- Interference screw or suture anchor fixation
- Recreate both ATFL and CFL
Rehabilitation is longer (6-9 months) with protected weight bearing for 6 weeks.
KEY CLINICAL POINTS
Generalized laxity is a risk factor for Brostrom failure
Reconstruction indicated for failed repair, laxity, heavy athletes
Allograft reduces donor site morbidity
Longer rehabilitation than primary repair
COMMON PITFALLS
Repeat Brostrom in patient with generalized laxity
Non-anatomic reconstruction (restricts subtalar motion)
Not addressing underlying laxity
FURTHER QUESTIONS
"What graft options would you consider?"
"How does recovery differ from primary Brostrom?"
"What is your long-term prognosis for return to sport?"
CLINICAL SCENARIOStandard
Acute Severe Ankle Sprain
CLINICAL PROMPT
"A 22-year-old soccer player sustains an inversion injury during a match. He has significant lateral swelling, ecchymosis, and tenderness over the ATFL. He cannot weight bear. Anterior drawer appears positive but is difficult to assess due to guarding. How do you manage this acute injury?"
PRACTICAL APPROACH
This is an acute Grade III lateral ankle sprain with suspected complete ATFL rupture based on the mechanism, clinical findings, and apparent positive anterior drawer.
Acute Assessment:
- Ottawa Ankle Rules to determine need for X-ray
- X-ray to exclude fracture (lateral malleolus, base 5th metatarsal, anterior process calcaneus)
- Clinical exam under analgesia if needed for accurate assessment
- Assess syndesmosis (external rotation stress test)
Acute Management:
- RICE protocol: Rest, Ice, Compression, Elevation
- Functional bracing: Semi-rigid or lace-up ankle brace
- Weight bearing as tolerated with crutches
- Early mobilization: Begin ROM exercises within pain tolerance
Rehabilitation (Critical):
- Supervised physiotherapy starting early
- Proprioceptive training from week 2
- Peroneal strengthening program
- Sport-specific training before return
Prognosis: 80% of acute sprains heal well with functional treatment. 20-40% may develop chronic instability requiring further intervention.
KEY CLINICAL POINTS
Ottawa Ankle Rules guide imaging decisions
Functional treatment superior to immobilization for acute sprains
Early mobilization and rehabilitation are key
20-40% may develop chronic instability
COMMON PITFALLS
Over-treating with prolonged immobilization
Missing associated fractures
Rushing return to sport without rehabilitation
Not warning about chronic instability risk
FURTHER QUESTIONS
"When would you consider acute surgical repair?"
"What are the Ottawa Ankle Rules?"
"How long before return to sport?"
MCQ Practice Points
MCQ: Weakest Lateral Ligament
Q: Which lateral ankle ligament is injured first during an inversion injury?
A: The ATFL (anterior talofibular ligament) is the weakest and most commonly injured. It is injured with inversion in plantarflexion - the most common ankle sprain mechanism. Remember ACP order: Anterior → Calcaneofibular → Posterior (weakest to strongest).
MCQ: Stress Test Interpretation
Q: A patient has a positive talar tilt test but negative anterior drawer. Which ligament is injured?
A: The CFL (calcaneofibular ligament) is injured. The talar tilt test assesses CFL integrity (inversion stress in dorsiflexion), while the anterior drawer tests ATFL. This pattern is unusual as ATFL is typically injured first, so consider other pathology.
MCQ: Gould Modification
Q: What does the Gould modification add to the original Brostrom repair?
A: The Gould modification adds augmentation with the inferior extensor retinaculum (IER). The IER is advanced over the ATFL repair and anchored to the fibula, providing additional restraint and improved proprioceptive input. This is now standard with all Brostrom repairs.
MCQ: Reconstruction Indications
Q: When is anatomic reconstruction preferred over Brostrom repair for lateral ankle instability?
A: Reconstruction is indicated for: (1) Failed Brostrom repair, (2) Generalized ligamentous laxity (Beighton score greater than 4), (3) Heavy/high-demand athletes, and (4) Poor quality native tissue. These patients have higher failure rates with direct repair.
MCQ: CFL Unique Feature
Q: What is unique about the calcaneofibular ligament compared to other lateral ankle ligaments?
A: The CFL crosses two joints - both the ankle joint AND the subtalar joint. This means CFL injury affects subtalar stability as well as ankle stability. The ATFL and PTFL only cross the ankle joint.
Guidelines, Registries & Global Practice
Global Epidemiology
- Ankle sprain is among the most common musculoskeletal injuries worldwide; the lateral ankle sprain is the dominant subtype (Doherty meta-analysis of 181 prospective studies).
- Incidence is higher in females than males (13.6 vs 6.94 per 1000 exposures) and in indoor/court sports (basketball, volleyball, netball, handball).
- Approximately 20-40% of acute sprains progress to chronic instability; the Cochrane review cites ~10-20% developing chronic lateral instability.
- A prior sprain remains the single strongest predictor of recurrence regardless of region or healthcare setting.
Side-by-Side Guidelines & Consensus
| Body / Statement | Diagnostic Position | Management Emphasis |
|---|---|---|
| International Ankle Consortium (CAI definition) | History of ≥1 significant sprain plus recurrent giving-way, recurrent sprains, or feelings of instability | Distinguish mechanical vs functional instability; structured outcome measures |
| IOC / sports-medicine consensus | Clinical diagnosis; stress imaging for objective laxity | Functional treatment + neuromuscular/proprioceptive rehabilitation first-line for acute and chronic injury |
| BOA / BOAST (UK) | Ottawa rules for acute imaging; clinical exam primary | Early functional rehabilitation; surgery for refractory instability |
| AAOS / AOFAS practice (US) | Stress views and MRI for surgical planning | Anatomic repair (Broström-Gould) as gold standard; reconstruction for failures/laxity |
| AO Foundation | Exclude associated osteochondral and syndesmotic injury | Anatomic restoration of ATFL/CFL footprints; address concomitant pathology |
Registry & Outcome Notes
- Unlike arthroplasty, lateral ankle stabilisation is not tracked in national joint registries (NJR, AOANJRR, SHAR); evidence derives from cohort series, meta-analyses, and consensus statements rather than registry survivorship.
- Reported recurrence after anatomic repair is broadly 5-15%, higher with generalised laxity - the rationale for suture-tape augmentation or reconstruction in selected patients.
High- vs Limited-Resource Practice Variation
- High-resource settings: Ready access to MRI, stress imaging, arthroscopy, and suture-tape/InternalBrace augmentation; arthroscopic Broström increasingly favoured for lower wound morbidity.
- Limited-resource settings: Diagnosis is largely clinical (Ottawa rules, stress testing); supervised neuromuscular rehabilitation and bracing carry the management burden, with open anatomic repair the mainstay where surgery is indicated.
- The conservative-first, rehabilitation-led pathway is universal and equally valid across all settings - the major global driver of good outcomes.
LATERAL ANKLE INSTABILITY
Clinical summary
ANATOMY - ACP
- •ATFL: Weakest, injured first, resists inversion in plantarflexion
- •CFL: Crosses ankle AND subtalar, injured second
- •PTFL: Strongest, only injured in dislocations
- •ACP order = Anterior to Posterior = Weakest to Strongest
EXAMINATION
- •Anterior drawer = ATFL (anterior translation)
- •Talar tilt = CFL (inversion in dorsiflexion)
- •External rotation = Syndesmosis (NOT lateral ligaments)
- •Always compare to contralateral side
TREATMENT ALGORITHM
- •FIRST: Rehabilitation 3-6 months (majority stabilize)
- •SECOND: Brostrom-Gould repair (85-90% success)
- •THIRD: Reconstruction if failed Brostrom/laxity/heavy athlete
- •Gould modification = IER augmentation (always do this)
KEY NUMBERS
- •20-40%: Acute sprains → chronic instability
- •70-80%: Stabilize with rehabilitation alone
- •85-90%: Good results with Brostrom-Gould
- •4-6 months: Return to sport after Brostrom