High-yield overview
Rim vs Body | Bone Loss Assessment Critical | Fix If Unstable
20-25%Bone loss threshold for instability
10%Of shoulder fractures
85%Associated with dislocation
IdebergStandard classification system
MAIN FRACTURE TYPES
Rim Fracture
PatternBony Bankart, anteroinferior
TreatmentArthroscopic or open based on size
Ideberg Type I
PatternRim avulsion fracture
TreatmentFix if large, address instability
Ideberg Type II-V
PatternBody fractures various patterns
TreatmentORIF via posterior or anterior approach
Critical Must-Knows
- Bone loss over 20-25% of glenoid width causes recurrent instability
- Most glenoid fractures occur with anterior dislocation (bony Bankart)
- Ideberg classification describes fracture patterns through glenoid body
- CT with 3D essential for bone loss quantification and surgical planning
- Off-track lesion assessment combines glenoid bone loss with Hill-Sachs
Clinical Pearls
- "25% glenoid bone loss = inverted pear glenoid on en-face view
- "Glenoid track concept: On-track Hill-Sachs engages in ROM, off-track does not
- "Bony Bankart larger than 20-25% needs bone augmentation
- "Posterior glenoid fractures associated with posterior instability
Clinical Imaging
Imaging Gallery
Critical Glenoid Fracture Exam Points
Bone Loss Threshold
20-25% glenoid bone loss is the critical threshold. Below this, soft tissue repair may suffice. Above this, bone augmentation (Latarjet, bone graft) is needed as soft tissue alone will fail.
CT is Essential
3D CT with subtraction of humeral head allows accurate measurement of glenoid bone loss. Use the best-fit circle method or measure against contralateral glenoid. AP X-ray underestimates bone loss.
Associated Injuries
85% occur with dislocation. Always assess for Hill-Sachs lesion (glenoid track concept), rotator cuff tear (especially older patients), and neurovascular injury (axillary nerve).
Instability is Key
The goal of treatment is to restore stability, not just anatomic reduction. A well-reduced but unstable glenoid will fail. Address bone loss and soft tissue deficiency together.
At a Glance - Management by Bone Loss
| Bone Loss | Pattern | Treatment | Key Consideration |
|---|---|---|---|
| Under 15% | Small bony Bankart | Arthroscopic Bankart repair | May include fragment if reducible |
| 15-20% | Moderate rim defect | Arthroscopic with anchors vs open Bankart | Consider bone block if contact sport |
| 20-25% | Significant bone loss | Latarjet or bone graft (Eden-Hybinette) | Soft tissue alone will fail |
| Over 25% | Severe bone loss | Latarjet preferred | Inverted pear glenoid configuration |
| Ideberg II-V | Glenoid body fracture | ORIF (posterior approach usually) | Goal is articular congruity |
Mnemonic
CIRCLEGlenoid Bone Loss Assessment
| C | CT scan essential 3D CT with humeral head subtraction |
| I | Inverted pear at 25% Over 25% bone loss appearance |
| R | Reference contralateral Compare to uninjured side |
| C | Calculate percentage Bone loss as % of inferior diameter |
| L | Look for Hill-Sachs Glenoid track concept |
| E | Engage or not (on-track) Determines surgical strategy |
| C | CT scan essential 3D CT with humeral head subtraction | R | Reference contralateral Compare to uninjured side | L | Look for Hill-Sachs Glenoid track concept |
| I | Inverted pear at 25% Over 25% bone loss appearance | C | Calculate percentage Bone loss as % of inferior diameter | E | Engage or not (on-track) Determines surgical strategy |
Hook:Draw a CIRCLE on the glenoid to measure bone loss!
Mnemonic
IDEALSIdeberg Classification
| I | Type I - rim avulsion Anterior or posterior rim fracture |
| D | Type II - Down (transverse) Exits through lateral scapula |
| E | Type III - Exit superior Oblique through superior glenoid |
| A | Type IV - Across (horizontal) Horizontal through body, medial exit |
| L | Type V - Combined (I+IV) Combination pattern |
| S | Type VI - Severe comminution Comminuted glenoid body |
| I | Type I - rim avulsion Anterior or posterior rim fracture | E | Type III - Exit superior Oblique through superior glenoid | L | Type V - Combined (I+IV) Combination pattern |
| D | Type II - Down (transverse) Exits through lateral scapula | A | Type IV - Across (horizontal) Horizontal through body, medial exit | S | Type VI - Severe comminution Comminuted glenoid body |
Hook:IDEALS classification helps you describe glenoid body fractures!
Mnemonic
TRACKGlenoid Track Concept
| T | Track measurement 0.83 x glenoid width - bone loss |
| R | Risk of engagement Hill-Sachs may engage if larger than track |
| A | Address bipolar lesions Both glenoid and humeral defects |
| C | Calculate HSI Hill-Sachs Interval measurement |
| K | Key decision point On-track vs Off-track guides surgery |
| T | Track measurement 0.83 x glenoid width - bone loss | C | Calculate HSI Hill-Sachs Interval measurement |
| R | Risk of engagement Hill-Sachs may engage if larger than track | K | Key decision point On-track vs Off-track guides surgery |
| A | Address bipolar lesions Both glenoid and humeral defects |
Hook:Keep the shoulder on TRACK to prevent re-dislocation!
Overview and Epidemiology
Glenoid fractures represent a spectrum from small rim avulsions (bony Bankart) to complex body fractures (Ideberg types). Understanding the distinction between rim fractures causing instability and body fractures affecting articular congruity is essential.
Two main categories:
- Rim fractures (bony Bankart): Associated with anterior instability, bone loss is the critical factor
- Body fractures (Ideberg): Articular fractures affecting joint congruity, require reduction and fixation
Mechanism of injury:
- Anterior dislocation: most common mechanism for rim fractures
- Direct trauma: high-energy impact to shoulder
- FOOSH: fall with axial loading through shoulder
- Sports injury: contact sports, rugby, American football
Bony Bankart vs Body Fracture
Bony Bankart is an avulsion of the anteroinferior glenoid rim with the labrum and capsule attached - the key issue is instability. Body fractures (Ideberg II-V) are articular fractures where joint congruity and stability both matter.
Anatomy and Biomechanics
Glenoid anatomy:
- Shallow, pear-shaped articular surface
- Inferior width: approximately 25mm
- Superior-inferior height: approximately 35mm
- Retroversion: 5-7° relative to scapular body
- Inferior tilt: varies but affects stability
Pear-Shaped Glenoid
The normal glenoid is pear-shaped (wider inferiorly). Loss of anterior bone changes this to an inverted pear - a sign of significant bone loss causing instability.
Stability mechanisms:
- Bony congruity: glenoid provides 50% of stability
- Labrum: deepens socket by 50%
- Capsule and ligaments: static restraints
- Rotator cuff: dynamic stabilizers
Bone loss effects:
Effect of Glenoid Bone Loss
| Bone Loss | Stability Effect | Surgical Implication |
|---|---|---|
| Under 15% | Minimal effect on stability | Soft tissue repair adequate |
| 15-20% | Increased recurrence risk | Consider bone augmentation in athletes |
| Over 20-25% | High recurrence with soft tissue repair | Bone augmentation required |
Glenoid track concept:
- Glenoid track = 0.83 x inferior glenoid width - bone loss
- Hill-Sachs interval = medial to lateral width of Hill-Sachs
- If Hill-Sachs interval is greater than glenoid track, it is off-track (will engage)
- Off-track lesions need to be addressed (remplissage, bone graft, arthroplasty)
Classification Systems
Ideberg Classification (1984) - Glenoid fossa fractures
| Type | Description | Fracture Line |
|---|---|---|
| Ia | Anterior rim fracture | Avulsion anteroinferior |
| Ib | Posterior rim fracture | Avulsion posterior |
| II | Transverse through glenoid | Exits lateral scapula border |
| III | Oblique through superior glenoid | Exits suprascapular notch area |
| IV | Horizontal through body | Exits medial scapula border |
| V | Combination Type I + Type IV | Combined rim and body |
| VI | Comminuted (added later) | Severe comminution |
Type I vs Others
Type I (rim fractures) are fundamentally about instability - treat based on bone loss. Types II-V are about articular congruity - treat based on displacement and joint surface.
Clinical Assessment
History
- Mechanism: dislocation, direct trauma, sport
- Number of prior dislocations
- Hand dominance and sport level
- Prior shoulder surgery
- Occupation and functional demands
Examination
- Inspection: contour, swelling, bruising
- Palpation: bony landmarks
- ROM: usually limited acutely
- Instability tests: apprehension, load-and-shift
- Neurovascular: axillary nerve
Axillary Nerve Assessment
The axillary nerve is at risk with anterior dislocations and glenoid fractures. Test:
- Sensation: regimental badge area (lateral shoulder)
- Motor: deltoid function (when pain allows) Document neurovascular status clearly before and after any manipulation.
Key examination findings:
- Apprehension test positive with anterior instability
- Load-and-shift test may demonstrate increased translation
- Palpable bony defect sometimes possible
- Associated rotator cuff weakness (especially over age 40)
Differential Diagnosis
Differential Diagnosis of Post-Dislocation / Acute Shoulder Pain
| Diagnosis | Distinguishing Features | Key Investigation |
|---|---|---|
| Bony Bankart (glenoid rim fracture) | Anteroinferior rim defect, instability after dislocation | 3D CT with humeral subtraction (quantify bone loss) |
| Soft-tissue Bankart (no fracture) | Labral avulsion without bony fragment | MR arthrogram |
| Glenoid body fracture (Ideberg II-VI) | High-energy, articular step, often scapular involvement | CT (articular gap/step, fracture pattern) |
| Hill-Sachs / engaging lesion | Humeral head impaction, may engage in abduction-ER | CT (Hill-Sachs interval) + glenoid track |
| Rotator cuff tear (older patient) | Weakness, night pain, age over 40 after dislocation | MRI / ultrasound |
| Proximal humerus / greater tuberosity fracture | Tuberosity tenderness, fracture line on plain film | AP and axillary radiographs, CT if displaced |
| Posterior dislocation / reverse bony Bankart | Locked internal rotation, seizure/electrocution history | Axillary view / CT |
Investigations
Imaging Protocol
InitialPlain Radiographs
- AP in internal rotation: Hill-Sachs
- Axillary view: glenoid rim, anterior bone loss
- West Point view: anteroinferior glenoid
- Stryker notch view: Hill-Sachs
EssentialCT Scan
- 3D reconstruction: gold standard for bone loss
- En-face glenoid view: bone loss quantification
- Humeral subtraction: removes overlap
- Axial cuts: fracture pattern, displacement
Soft TissueMRI
- Labral pathology: Bankart lesion
- Rotator cuff: tears, especially older patients
- Capsular damage: HAGL, ALPSA lesions
- Bone marrow edema: confirms injury location
CT is Essential
Plain X-rays underestimate glenoid bone loss by up to 50%. Always obtain CT with 3D reconstruction and humeral head subtraction for accurate bone loss measurement. This determines whether soft tissue repair or bone augmentation is needed.
Management Algorithm
Algorithm
Management based on bone loss:
Algorithm by Bone Loss
Low RiskUnder 15% Bone Loss
- Arthroscopic Bankart repair
- May incorporate fragment with anchors
- Good outcomes with soft tissue repair
Intermediate15-20% Bone Loss
- Individualized decision
- Young contact athlete: consider bone augmentation
- Recreational: may try soft tissue repair first
- Counsel on recurrence risk
High RiskOver 20-25% Bone Loss
- Bone augmentation required
- Latarjet (coracoid transfer)
- Eden-Hybinette (iliac crest graft)
- Soft tissue alone will fail
Why Latarjet Works
Latarjet provides triple benefit: bone block effect, sling effect (conjoint tendon), and capsular repair. It extends the glenoid track by the width of the coracoid (approximately 10mm), converting many off-track lesions to on-track.
Surgical Technique
Indications:
- First-time dislocation with bony Bankart under 15% bone loss
- Recurrent instability with minimal bone loss
Setup:
- Beach chair or lateral decubitus
- Standard posterior and anterior portals
- May need accessory 5 o'clock portal
Steps:
- Diagnostic arthroscopy - assess bone loss, labrum
- Prepare glenoid rim (decorticate)
- Place anchors at 5, 4, 3 o'clock positions
- Pass sutures through labrum
- Tie knots to restore labral bumper
- May incorporate small bony fragment
Anchor Placement
Anchors should be placed on the glenoid face, not the neck. This restores the labral bumper effect. At least 3 anchors typically needed for adequate repair.
Complications
Complications by Treatment
| Complication | Incidence | Risk Factors | Management |
|---|---|---|---|
| Recurrent instability | 5-25% | Bone loss over 25%, soft tissue repair | Revision with bone augmentation |
| Glenoid arthritis | 10-30% | Malreduction, excessive lateralization | Activity modification, arthroplasty |
| Stiffness | 5-15% | Prolonged immobilization, capsular repair | Physiotherapy, manipulation, arthroscopy |
| Nerve injury (axillary/suprascapular) | Less than 5% | Surgical approach, retraction | Observation, exploration if no recovery |
| Graft/coracoid nonunion (Latarjet) | 5-10% | Poor technique, smoking | Observation if stable, revision if unstable |
| Hardware failure | Less than 5% | Poor bone quality, early motion | Revision fixation |
Recurrence Risk Factors
Factors increasing recurrence after instability surgery:
- Bone loss over 25% not addressed
- Off-track Hill-Sachs not addressed
- Young age (under 20)
- Contact sport athlete
- Connective tissue disorder
Postoperative Care
Rehabilitation Protocol - Instability Surgery
0-3 weeksPhase 1: Protection
- Sling immobilization
- Pendulum exercises only
- No external rotation beyond neutral
- Elbow, wrist, hand ROM
3-6 weeksPhase 2: Early Motion
- Passive to active-assisted ROM
- Begin external rotation to 30°
- Forward flexion to 120°
- Wean from sling
6-12 weeksPhase 3: Strengthening
- Full ROM goal
- Isometric then isotonic strengthening
- Rotator cuff program
- Scapular stabilization
3-6 monthsPhase 4: Return to Sport
- Sport-specific training
- Plyometrics
- Contact sports at 6 months
- Full clearance after strength testing
ORIF-specific considerations:
- Weight-bearing restrictions until union
- ROM based on fixation stability
- Earlier motion if stable fixation
Outcomes and Prognosis
Outcome by procedure:
Procedure Outcomes
| Procedure | Recurrence | Return to Sport | Arthritis Risk |
|---|---|---|---|
| Arthroscopic Bankart | 5-15% (higher with bone loss) | 85-95% | Low |
| Open Bankart | 5-10% | 85-90% | Low |
| Latarjet | 2-5% | 90-95% | 10-30% (long-term) |
| ORIF body fracture | N/A | 80-90% | Depends on reduction |
Evidence Base
Redefining Critical Bone Loss (Subcritical Loss)
Shaha JS, Cook JB, Song DJ, Rowles DJ, Bottoni CR, Shaha SH, Tokish JM • Am J Sports Med (2015)
Key Findings:
- Cohort of 72 patients (73 shoulders) after isolated arthroscopic Bankart repair, mean follow-up 48 months
- WOSI and SANE scores worsened progressively with each quartile of increasing bone loss
- Bone loss above 13.5% led to clinically unacceptable WOSI scores even without recurrence
- Overall failure 12.3%; bone loss higher in failures (24.7% vs 12.8%, p less than 0.01)
Clinical Implication: 'Critical' bone loss may be lower than the classic 20-25% threshold; subcritical loss above ~13.5% degrades function and should lower the threshold for bone augmentation in high-demand patients.
Glenoid Track Concept (On-Track / Off-Track)
Di Giacomo G, Itoi E, Burkhart SS • Arthroscopy (2014)
Key Findings:
- Introduced on-track/off-track paradigm for bipolar (glenoid plus humeral) bone loss
- Off-track Hill-Sachs engages the anterior rim and risks recurrence
- For glenoid loss of 25% or more (inverted-pear), glenoid bone grafting is recommended
- Provided a quantitative treatment paradigm for all anterior instability patterns
Clinical Implication: Calculate the glenoid track and compare to the Hill-Sachs interval; off-track lesions require the Hill-Sachs to be addressed (remplissage) or the track widened (Latarjet/graft).
3D CT Glenoid Index for Bone Loss
Chuang TY, Adams CR, Burkhart SS • Arthroscopy (2007)
Key Findings:
- 25 instability patients had bilateral 3D CT with humeral subtraction vs arthroscopic measurement
- Glenoid index = injured/uninjured inferior diameter; cut-off 0.75 (about 25% loss)
- 3D CT predicted the arthroscopic decision (Bankart vs open Latarjet) in 24/25 (96%)
- Glenoid index of 0.75 or less predicted need for bone grafting
Clinical Implication: Preoperative 3D CT with humeral subtraction reliably quantifies glenoid bone loss and predicts the need for a bone-block procedure, supporting CT as the planning standard.
Exam Viva Scenarios
Use these scenarios to practise clinical reasoning and management decisions
CLINICAL SCENARIOStandard
Scenario 1: Recurrent Instability with Bone Loss
CLINICAL PROMPT
"A 24-year-old rugby player has had 5 anterior dislocations over 2 years. MRI shows Bankart lesion. CT shows 22% anteroinferior glenoid bone loss. How would you manage this patient?"
PRACTICAL APPROACH
Thank you. This patient has recurrent anterior shoulder instability with significant glenoid bone loss. Let me approach this systematically. **Assessment:** The key factors here are: young age, contact sport athlete, 5 dislocations, and 22% glenoid bone loss. The CT finding of 22% bone loss is at the critical threshold where soft tissue repair alone is likely to fail. **Bone loss significance:** At 22% bone loss, we are approaching the "inverted pear" configuration. The literature shows that soft tissue Bankart repair alone has unacceptably high recurrence rates (up to 70%) when bone loss exceeds 20-25%. **Glenoid track assessment:** I would also assess the Hill-Sachs lesion to determine if this is an on-track or off-track lesion. With 22% glenoid bone loss, the glenoid track is reduced, making engagement more likely. **Management:** My recommendation would be bone augmentation via **Latarjet procedure**. This addresses the bone deficit directly, extends the glenoid track, and provides the sling effect of the conjoint tendon. In a contact sport athlete with this degree of bone loss, I would not attempt arthroscopic soft tissue repair. **Procedure overview:** I would use a deltopectoral approach, transfer the coracoid to the anterior glenoid flush with the articular surface, fix with two screws, and repair the capsule. Post-operatively, he would be in a sling for 3 weeks with return to rugby at 6 months. I would counsel him on the expected success rate of 95% and the small risk of complications including graft nonunion and long-term arthritis.
KEY CLINICAL POINTS
Recognize 20-25% as critical bone loss threshold
Soft tissue repair inadequate for significant bone loss
Latarjet addresses bone deficit and extends glenoid track
Contact athlete with bone loss needs bone augmentation
COMMON PITFALLS
Attempting arthroscopic Bankart for significant bone loss
Not measuring bone loss on CT before planning surgery
Ignoring the Hill-Sachs lesion (glenoid track concept)
FURTHER QUESTIONS
"How do you position the coracoid?"
"What are the complications of Latarjet?"
"What if he had 15% bone loss instead?"
CLINICAL SCENARIOChallenging
Scenario 2: Acute Glenoid Body Fracture
CLINICAL PROMPT
"A 45-year-old woman presents after motor vehicle accident with severe shoulder pain. X-rays show a glenoid fracture. CT reveals an Ideberg Type III fracture with 5mm articular step. How would you manage this?"
PRACTICAL APPROACH
Thank you. This patient has an acute Ideberg Type III glenoid body fracture with significant articular displacement. **Classification:** An Ideberg Type III fracture is an oblique fracture line that exits through the superior glenoid toward the suprascapular notch. With 5mm of articular step, this requires surgical intervention. **Assessment:** I would complete my assessment looking for: - Associated injuries (high-energy mechanism) - Neurovascular status (axillary, suprascapular nerves) - Associated scapula or clavicle fractures (floating shoulder pattern) - Rotator cuff status **Imaging:** The CT scan is essential and has shown the fracture pattern. I would review the 3D reconstruction to plan the surgical approach and fixation. **Management:** With 5mm articular step, operative management is indicated. The surgical threshold is generally 2-5mm displacement. Nonoperative treatment would result in articular incongruity and early arthritis. **Surgical approach:** For an Ideberg Type III, I would use a **posterior Judet approach**: - Lateral decubitus position - Incision along scapula spine extending to lateral border - Develop infraspinatus-teres minor interval - Protect the suprascapular nerve at the spinoglenoid notch - Direct visualization of the glenoid neck and body **Fixation:** I would achieve anatomic reduction of the articular surface, fix with lag screws through the fracture, and apply a neutralization plate along the lateral scapular border. **Post-operative:** She would be in a sling for 2-4 weeks with early passive motion, progressing to active motion as the fracture heals. I would expect union at 8-12 weeks.
KEY CLINICAL POINTS
Ideberg Type III is oblique through superior glenoid
5mm step exceeds threshold for surgical intervention
Posterior Judet approach for most body fractures
Anatomic reduction is critical for good outcome
COMMON PITFALLS
Not recognizing the surgical threshold for displacement
Using anterior approach for posterior/superior fracture
Forgetting to protect suprascapular nerve posteriorly
FURTHER QUESTIONS
"How would you protect the suprascapular nerve?"
"What if this was an Ideberg Type Ia instead?"
"What is the long-term prognosis?"
CLINICAL SCENARIOCritical
Scenario 3: Bipolar Bone Loss
CLINICAL PROMPT
"A 28-year-old presents after first-time dislocation. CT shows 18% glenoid bone loss and a large Hill-Sachs lesion measuring 25mm (medial to lateral). How do you decide on treatment?"
PRACTICAL APPROACH
Thank you. This is a bipolar bone loss situation requiring careful analysis using the glenoid track concept. **Glenoid track calculation:** First, I need to calculate the glenoid track. Assuming a normal inferior glenoid width of 25mm: - Glenoid track = 0.83 x 25mm - bone loss - Glenoid track = 20.75mm - (18% of 25mm) - Glenoid track = 20.75mm - 4.5mm = approximately 16mm **Hill-Sachs assessment:** The Hill-Sachs interval (medial to lateral width) is 25mm. **On-track vs Off-track:** Since the Hill-Sachs interval (25mm) is GREATER than the glenoid track (16mm), this is an **off-track** lesion. This means the Hill-Sachs will engage with the glenoid rim during external rotation, causing instability. **Treatment implications:** In an off-track situation, I cannot simply do an isolated soft tissue Bankart repair. I need to either: 1. Address the Hill-Sachs directly (remplissage, bone graft) 2. Increase the glenoid track (Latarjet adds approximately 10mm) 3. Or both **My recommendation:** Given 18% bone loss and an off-track lesion, I would recommend a **Latarjet procedure**. This will: - Add approximately 10mm bone to the glenoid (increased track to approximately 26mm) - Convert the off-track lesion to on-track - Provide the conjoint tendon sling effect - Be more reliable than isolated remplissage **Alternative:** If I were to attempt arthroscopic management, I would need to combine Bankart repair with remplissage (infraspinatus tenodesis into the Hill-Sachs). However, with 18% bone loss approaching threshold and an off-track lesion, Latarjet is more predictable. I would discuss both options with the patient, acknowledging Latarjet has slightly higher complication risk but lower recurrence.
KEY CLINICAL POINTS
Calculate glenoid track: 0.83 x width - bone loss
Compare to Hill-Sachs interval to determine on/off-track
Off-track lesions need Hill-Sachs addressed or track increased
Latarjet adds approximately 10mm to glenoid track
COMMON PITFALLS
Ignoring the Hill-Sachs in decision-making
Not calculating glenoid track for bipolar lesions
Treating off-track lesion with isolated soft tissue repair
FURTHER QUESTIONS
"What is remplissage and when would you use it?"
"What if this was an on-track lesion?"
"How does Latarjet increase the glenoid track?"
MCQ Practice Points
Q1: Bone Loss Threshold
Q: What percentage of glenoid bone loss is the threshold above which bone augmentation is recommended?
- A) 10-15%
- B) 20-25%
- C) 30-35%
- D) 40-45%
A: B - 20-25% bone loss is the critical threshold. Above this, soft tissue repair alone has unacceptably high recurrence rates.
Q2: Ideberg Classification
Q: An Ideberg Type III glenoid fracture is:
- A) Anterior rim avulsion
- B) Transverse fracture exiting lateral border
- C) Oblique fracture exiting superiorly
- D) Horizontal fracture exiting medially
A: C - Type III is an oblique fracture through the superior glenoid exiting near the suprascapular notch.
Q3: Glenoid Track
Q: The glenoid track is calculated as:
- A) 0.5 x glenoid width + bone loss
- B) 0.83 x glenoid width - bone loss
- C) 1.0 x glenoid width - bone loss
- D) 0.83 x glenoid width + Hill-Sachs interval
A: B - Glenoid track = 0.83 x inferior glenoid width - glenoid bone loss (d).
Q4: Latarjet Mechanism
Q: What does Latarjet provide stability through all EXCEPT?
- A) Bone block effect
- B) Sling effect of conjoint tendon
- C) Capsular repair
- D) Rotator cuff augmentation
A: D - Latarjet provides bone block, sling effect (conjoint tendon), and capsular repair. It does not augment the rotator cuff.
Inverted Pear Question
Q: What does an inverted pear glenoid indicate? A: Significant anterior-inferior bone loss (greater than 25%). Normal glenoid is pear-shaped with wider inferior portion. An inverted pear indicates loss of inferior width, causing recurrent instability.
CT Imaging Question
Q: Why is CT with 3D reconstruction essential for glenoid fractures? A: Plain X-rays underestimate bone loss by up to 50%. CT with humeral head subtraction and en-face glenoid view allows accurate quantification of bone loss for surgical planning.
Guidelines, Registries & Global Practice
Global epidemiology:
- Anterior shoulder dislocation incidence is highest in young males (peak in the second to third decades) and in contact/collision athletes (rugby, American football, ice hockey).
- A bony Bankart (anteroinferior rim fracture) is present in a substantial minority of first-time dislocations; some degree of glenoid bone loss accumulates with recurrent dislocations.
- Isolated glenoid body (Ideberg II-VI) fractures are uncommon, usually high-energy, and frequently associated with scapular and chest-wall injury.
Side-by-side society/expert guidance:
Guideline & Society Positions
| Source | Bone Loss / Imaging | Procedure Emphasis |
|---|---|---|
| AAOS (US) | 3D CT for bone loss; quantify before stabilisation | Individualised; bone augmentation for significant loss |
| BOA / BESS (UK) | Risk stratification (e.g. ISIS); CT if bone loss suspected | Arthroscopic Bankart for low-risk; Latarjet for bone loss/high-risk |
| AO Foundation | CT mandatory for articular fractures; assess displacement/step | ORIF for displaced (4mm or more) body fractures, congruity-driven |
| EFORT / European consensus | Glenoid track and bipolar loss assessment routine | Track-based: remplissage vs Latarjet for off-track lesions |
Registry and outcome notes:
- Instability and stabilisation procedures are not as systematically captured as arthroplasty in joint registries; most evidence is from institutional series and meta-analyses (e.g. An 2016).
- Where shoulder instability registries exist (e.g. regional and national instability databases in Europe), they reinforce that recurrence rises with glenoid bone loss, younger age, and contact sport — mirroring the ISIS risk factors.
High- vs limited-resource practice variation:
- Where 3D CT is readily available, bone loss is quantified preoperatively and the glenoid track guides surgery.
- In limited-resource settings, plain radiographs (West Point, Stryker notch) and intra-operative arthroscopic assessment of the bare-spot/inverted-pear may substitute, accepting that plain films underestimate bone loss.
- Open Bankart and open Latarjet remain reliable, equipment-light options where advanced arthroscopic capability is limited.
Controversies & Areas of Uncertainty
What is truly 'critical' bone loss?
The classic 20-25% threshold is challenged by 'subcritical' data (Shaha 2015) showing functional decline above ~13.5%. The exact cut-off, and how it interacts with the glenoid track, remains debated.
Latarjet vs Bankart + remplissage
For off-track lesions with subcritical glenoid loss, arthroscopic Bankart plus remplissage competes with Latarjet. Comparative trials are ongoing and the optimal indication boundary is unsettled.
Arthroscopic vs open Latarjet
Arthroscopic Latarjet offers visualisation advantages but a steep learning curve and graft-positioning concerns. Whether it matches open results in routine practice is not established.
Fragment fixation vs excision/repair
For a bony Bankart, whether to incorporate and fix the fragment versus excise it and repair soft tissue (and the size threshold for doing so) varies by surgeon and remains an area of practice variation.
GLENOID FRACTURES
Clinical summary
Classification
- •Type I = rim avulsion (bony Bankart)
- •Type II = transverse (exits laterally)
- •Type III = oblique (exits superiorly)
- •Type IV = horizontal (exits medially)
- •Type V = combined I + IV
- •Type VI = comminuted
Bone Loss Thresholds
- •Under 15% = soft tissue repair adequate
- •15-20% = individualize (consider bone block in athletes)
- •Over 20-25% = bone augmentation required
- •Over 25% = inverted pear glenoid appearance
Glenoid Track
- •Track = 0.83 x glenoid width - bone loss
- •Compare to Hill-Sachs interval (HSI)
- •HSI greater than Track = off-track = will engage
- •Off-track needs Hill-Sachs addressed or track increased
- •Latarjet adds approximately 10mm to track
Surgical Options
- •Arthroscopic Bankart: under 15% bone loss
- •Latarjet: over 20-25% bone loss or off-track
- •ORIF: displaced body fractures (Ideberg II-V)
- •Remplissage: address Hill-Sachs arthroscopically
Complications
- •Recurrence 5-15% (higher with bone loss)
- •Arthritis 10-30% (especially post-Latarjet)
- •Stiffness 5-15%
- •Nerve injury under 5%