High-yield overview

The Medialized Bankart

Incidence10-20% of Instability

HealingMedialized

PeriosteumIntact

RecurrenceHigher than Bankart

Neviaser Classification

Acute (Type I)

PatternMobile, easy to reduce (less than 3 months)

Treatment

Chronic (Type II)

PatternFixed, scarred, needs release (greater than 3 months)

Treatment

Perthes

PatternVariation: Non-displaced sleeve avulsion

Treatment

GLAD

PatternVariation: Cartilage defect, stable labrum

Treatment

Critical Must-Knows

ALPSA = Anterior Labroligamentous Periosteal Sleeve Avulsion.
Unlike Bankart, the anterior scapular periosteum remains INTACT.
The labrum falls medially down the glenoid neck and heals there.
This eliminates the 'bumper' effect of the labrum.
Surgical repair requires aggressive mobilization (takedown) before fixation.

Clinical Pearls

"
Simply fixing it where it lies (in situ) leads to failure.
"
Think of it as a 'healed' dislocation in a bad position.
"
Common in chronic instability or younger patients.

Shoulder instability teaching setup with shoulder model, MR arthrogram and arthroscopy instruments — ALPSA learning frame: instability imaging, glenoid anatomy and arthroscopic repair planning need to be considered together.

The Surgical Trap

The Problem

"In Situ Repair" Because the ALPSA lesion heals, it can look like a normal (but small) labrum. If you just put anchors in and stitch it, you validatethe malposition. You have NOT restored the bumper. Recurrence is guaranteed.

The Solution

"Mobilize and Elevate" You must incise the healed tissue. Elevate the labrum off the glenoid neck. Bring it up to the articular margin (the 'face'). Only then do you fix it.

Feature	Bankart Lesion	ALPSA Lesion
Periosteum	Torn (Detached)	Intact (Stripped)
Position	Floating	Medialized on Neck
Healing	Does not heal (Gap)	Heals in bad position
Recurrence	Standard risk	Higher risk (if not mobilized)

Mnemonic

GAPVariants of Instability

G	GLAD Glenolabral Articular Disruption (Cartilage damage, stable)
A	ALPSA Anterior Labroligamentous Periosteal Sleeve Avulsion (Medialized)
P	Perthes Periosteal sleeve detached but labrum NOT displaced (undisplaced ALPSA)

G	GLAD Glenolabral Articular Disruption (Cartilage damage, stable)
A	ALPSA Anterior Labroligamentous Periosteal Sleeve Avulsion (Medialized)
P	Perthes Periosteal sleeve detached but labrum NOT displaced (undisplaced ALPSA)

Hook:Mind the GAP in the labrum.

Mnemonic

TRIPSurgical Steps

T	Takedown Release healed tissue from neck
R	Release Mobilize completely
I	Inspect Check for bone loss
P	Plicate Repair with tension (shift)

T	Takedown Release healed tissue from neck	I	Inspect Check for bone loss
R	Release Mobilize completely	P	Plicate Repair with tension (shift)

Hook:Take a TRIP to the glenoid rim.

Mnemonic

MINTPathology

M	Medialized Labrum moves medially
I	Intact Intact periosteum
N	Neck Heals on the glenoid neck
T	Tethered Becomes tethered/scarred

M	Medialized Labrum moves medially	N	Neck Heals on the glenoid neck
I	Intact Intact periosteum	T	Tethered Becomes tethered/scarred

Hook:The labrum is stuck in a MINT condition (not really).

Overview

Shoulder clinic review setup with axial shoulder MR arthrogram and anatomical shoulder model — Overview image: recurrent anterior shoulder instability requires correlation of symptoms, MR arthrography and glenoid-labral anatomy.

Definition

An ALPSA lesion (Anterior Labroligamentous Periosteal Sleeve Avulsion) involves the avulsion of the anterior labrum and IGHL from the glenoid rim. Critically, the anterior scapular periosteum remains intact but stripped, allowing the labrum to displace medially and heal inferiorly on the glenoid neck.

This "medialization" effectively shortens the anterior restraints and eliminates the glenoid depth, predisposing the joint to recurrent anterior instability even with minor trauma.

This contrasts with a Bankart lesion, where the periosteum tears, creating a distinct separation. The "sleeve" nature of the ALPSA allows the tissue to essentially slide down the neck and scar in a non-functional position.

Pathophysiology and Mechanisms

Axial shoulder joint illustration showing the humeral head, glenoid and medially displaced anterior labral tissue — Pathomechanics image: the teaching point is the loss of the anterior labral bumper when the labroligamentous sleeve scars medially on the glenoid neck.

The Labroligamentous Complex

Labrum: Fibrocartilaginous bumper. Increases glenoid depth by 50%.
IGHL: Inferior Glenohumeral Ligament. Main static restraint.
Periosteum: Thick anterior scapular periosteum.

In ALPSA, the forceful anterior dislocation strips the periosteum without rupturing it.

This creates a "sleeve" that slides medially.

Classification Systems

Four-panel shoulder instability illustration comparing anterior labral injury patterns — Instability variants: ALPSA must be distinguished from Bankart, Perthes and GLAD patterns because the operative manoeuvre changes.

Neviaser Classification

Acute (Type I): Less than 3 months. Tissue is mobile. Can be reduced easily.
Chronic (Type II): Greater than 3 months. Tissue is scarred and fixed. Requires sharp dissection/release.

This distinction is crucial for surgical planning.

Chronic lesions often require a capsular release (anterior and inferior) to gain excursion.

History

Orthopaedic clinician assessing a young athlete with recurrent shoulder instability — Clinical context: ALPSA is suspected in young patients with recurrent anterior instability, especially after repeated dislocations.

Presentation

Recurrent Instability: Often reports "loose" shoulder.
Clicking/Catching: Can occur.
Mechanism: Often a history of multiple dislocations.
Age: Common in young patients (under 25).
Symptom Duration: Chronic symptoms suggest ALPSA vs acute Bankart.
Provoking Positions: Abduction and external rotation (ABER position).

The history is identical to Bankart instability.

Red Flags

First-time dislocation over age 40 (rotator cuff tear risk).
Neurological symptoms (axillary nerve injury).
Unable to reduce (locked posterior dislocation).

These red flags warrant urgent imaging and specialist referral.

Examination

Physical Exam

Apprehension: Positive.
Relocation: Positive.
Load and Shift: Increased translation (Grade 2-3).
Sulcus Sign: May be present (multidirectional component).
Jobe Relocation Test: Relief with posterior force.
Gagey Hyperabduction Test: Assesses inferior capsular laxity.

You cannot clinically distinguish ALPSA from Bankart.

Imaging is the only differentiator.

Differential Diagnosis

Comparison diagram of an ALPSA lesion and a normal glenohumeral joint — Comparison image: the ALPSA side shows the anterior labral complex displaced medially compared with a normal glenohumeral joint.

Differential Diagnosis

Bankart Lesion: True labral detachment, floating labrum.
Perthes Lesion: Non-displaced periosteal sleeve avulsion.
GLAD Lesion: Glenolabral articular disruption (cartilage focus).
HAGL Lesion: Humeral avulsion of glenohumeral ligament.
Bony Bankart: Labrum with attached bone fragment.
Multidirectional Instability: Global capsular laxity, atraumatic.

Key Distinguishing Features

Lesion	Periosteum	Labrum Position	Stability
Bankart	Torn	Floating/Detached	Unstable
ALPSA	Intact	Medialized	Unstable
Perthes	Stripped	In situ	Unstable
GLAD	Intact	Intact	Stable

Imaging

Radiology workstation with shoulder MR arthrogram and three-dimensional glenoid reconstruction — Imaging work-up: MR arthrography identifies the medialized labrum; CT or 3D reconstruction is used when glenoid bone loss affects surgical planning.

Axial MR arthrography and diagram showing ALPSA lesion with detached labrum medially displaced to the glenoid neck — MR arthrography example: the detached labrum is medially displaced and scarred to the glenoid neck.

Cropped axial shoulder MR arthrogram showing ALPSA lesion — Cropped MR arthrogram: the labral tissue lies medial to the glenoid rim rather than restoring the anterior bumper.

MRI Features

Axial T2 / PD Fat Sat. Look for the labrum ("black triangle"). Normal: Sitting on the rim. ALPSA: Rounded, scarred bundle sitting medial to the rim on the glenoid neck. The periosteum may be visualized as a low signal line connecting the labrum to the scapula (the sleeve).

MRI Signs

Medialization: The key sign.
Synovial Stripping: Contrast tracking under the sleeve.
Bone Loss: Assess for concomitant Bony Bankart (often remodelled in chronic cases).
Hill-Sachs: Usually present due to recurrence.

Look for the "Cul-de-sac" deep to the capsule.

Management Algorithm

ALPSA treatment planning setup with shoulder MR arthrogram, glenoid model and arthroscopy instruments — Management planning image: recurrent instability, bone loss assessment and soft-tissue mobilization are considered before repair.

Decision Making

Non-Operative: High failure rate in young patients. (Not recommended for athletes).
Operative: Indicated for recurrent instability.
Approach: Arthroscopic Repair is Gold Standard. Open repair rarely needed unless massive bone loss.

The key is the technical execution of the repair.

Surgical Considerations

Arthroscopic shoulder repair monitor showing anterior labral mobilization and repair instruments — Surgical image: the key technical step is mobilizing the medialized labroligamentous sleeve before fixing it back to the glenoid rim.

Arthroscopic Repair Steps

Diagnostic Scope: Confirm diagnosis (Probe the labrum - it may feel "healed" but lacks bumper function).
Mobilization (CRITICAL):
- Use an elevator or shaver to detach the scarred labrum from the glenoid neck.
- Release anteriorly and inferiorly (around the corner).
- "Float the Labrum": It must rise to the rim effortlessly.
Preparation: Decorticate the glenoid rim (create bleeding bed).
Fixation: Suture anchors on the face (articular margin).
Shift: Tension the tissue superiorly and laterally to restore the bumper.

Failure to mobilize turns this into a non-anatomical plication.

Complications

Clinical review setup with shoulder arthroscopy and MR imaging for recurrent instability after repair — Complications image: recurrence review should check whether the labrum was restored to the rim and whether anchors or bone loss contributed to failure.

Recurrence: The most common complication. Often due to failure to mobilize the lesion fully.
Stiffness: Excessive tightening (Overtensioning).
Hardware Issues: Loose anchors, chondrolysis (if placed on face too proud).
Nerve Injury: Axillary nerve (during inferior dissection).
Infection: Rare.

Complication Pearl

Chondrolysis Risk Placing anchors on the articular face is necessary for ALPSA repair, BUT they must not be prominent. Prominent metal or hard PEEK anchors can destroy the humeral head cartilage (Chondrolysis). Use soft anchors or ensure knotless anchors are countersunk.

Rehabilitation

Phase 1 (0-6 weeks):
- Sling immobilization.
- Protect ER (usually restricted to 0 or 30 degrees).
- Pendulums.
Phase 2 (6-12 weeks):
- Regain ROM.
- Active assistive to Active.
- Scapular control.
Phase 3 (3-6 months):
- Strengthening.
- Proprioception.
- Return to sport at 6 months (contact sports).
Protocol is identical to Bankart Repair.

Return to Sport Criteria
- Full, pain-free Range of Motion.
- Symmetrical strength (ER/IR/Abduction).
- Psychological readiness (ACL-RSI or similar scale).
- Completion of sport-specific training drills.
- No apprehension in apprehension position.
Sling Removal Criteria
- No pain at rest.
- Control of scapula.
- Ability to perform ADLs waist level.
Contact Progression
- 4 months: Non-contact drills (passing, catching).
- 5 months: Controlled contact (pad work).
- 6 months: Unrestricted contact (tackling).

Prognosis

Shoulder stabilisation return-to-sport assessment with athlete and physiotherapist — Prognosis image: return to sport depends on stable repair, pain-free motion, restored strength and absence of apprehension.

Recurrence Rate: With proper mobilization, results equal Bankart repair (5-10% recurrence).
Without Mobilization: Recurrence rates are significantly higher.
Return to Sport: High (greater than 85%).
Arthritis: Long term risk exists due to initial cartilage damage (GLAD component often co-exists).

Prognostic Factors

Age: Younger patients have higher recurrence risk.
Bone Loss: Significant glenoid bone loss (greater than 20%) requires Latarjet.
Hyperlaxity: Beighton score greater than 5 increases failure risk.
Sport: Collision athletes have higher recurrence.

Evidence Base

Academic shoulder instability outcomes review with arthroscopy and imaging — Evidence frame: ALPSA outcomes are interpreted through recurrence, surgical technique and associated instability risk factors.

Original Description

Neviaser et al. • Arthroscopy (1993)

Key Findings:

Described the ALPSA lesion
Highlighted the intact periosteal sleeve
Noted medial healing and loss of bumper

Clinical Implication: Defined the pathology distinct from Bankart.

Recurrence Rates

Ozbaydar et al. • Knee Surg Sports Traumatol Arthrosc (2008)

Key Findings:

Compared Bankart vs ALPSA repair outcomes
Found no significant difference in recurrence IF ALPSA is mobilized
Emphasized technical factors

Clinical Implication: It behaves like a Bankart if you turn it back into one.

Biomechanics

Bigliani et al. • Am J Sports Med (1998)

Key Findings:

Cadaver study of capsular failure
IGHL strain properties
Showed that medialization significantly reduces restraint to anterior translation

Clinical Implication: Anatomy must be restored.

Chronic ALPSA

Habermeyer et al. • JSES (1999)

Key Findings:

Evolution of the lesion over time
Described the 'single anterior instability lesion' becoming ALPSA with recurrence
Associated with bone remodelling

Clinical Implication: Chronic instability often equals ALPSA.

Arthroscopic Technique

Burkhart and De Beer • Arthroscopy (2000)

Key Findings:

Famous paper on instability failures
Identified Bone Loss and ALPSA as risk factors
Advocated for 'Address the Tissues and the Bone'

Clinical Implication: Identify the pathology or fail.

Viva Scenarios

Use these scenarios to practise clinical reasoning and management decisions

Orthopaedic teaching station with shoulder MR arthrograms, glenoid model and revision cards — Scenario image: viva-style interpretation should link the imaging sign to the operative consequence.

CLINICAL SCENARIOStandard

Scenario 1: MRI Interpretation

CLINICAL PROMPT

"You are shown an MRI of a 19-year-old rugby player. There is a dark lump of tissue sitting on the anterior glenoid neck, medial to the rim. What is this and how does it differ from a Bankart?"

PRACTICAL APPROACH

This is an ALPSA lesion. It differs from a Bankart in that the anterior periosteum is stripped but intact, tethering the labrum medially. A Bankart is a complete detachment. This is significant because surgically, I must mobilize and take down this ALPSA lesion proper to restoring the bumper.

KEY CLINICAL POINTS

Recognition of medialized labrum

Intact periosteum concept

Surgical implication (Mobilization)

COMMON PITFALLS

Calling it a Bankart

Not mentioning mobilization

FURTHER QUESTIONS

"What happens if you just put an anchor in without moving it?"

"I would repair it in a non-anatomical position, failing to restore stability. Recurrence is high."

CLINICAL SCENARIOStandard

Scenario 2: Intra-operative Surprise

CLINICAL PROMPT

"You are scoping a 'Bankart'. You enter the joint and the labrum looks 'healed' but the shoulder is loose (Drive-through sign positive). Probe shows it is firmly attached but medial. What do you do?"

PRACTICAL APPROACH

This is a healed ALPSA (Type II). Do not leave it. I would use an elevator or radiofrequency device to peel the labrum off the neck (takedown), mobilize it fully until it floats to the rim, and then repair it with suture anchors to the articular margin.

KEY CLINICAL POINTS

Recognition of chronic ALPSA

Step-by-step takedown

Restoration of bumper

COMMON PITFALLS

Leaving it alone ('It's healed')

Plicating over the top (Insufficient)

FURTHER QUESTIONS

"Is the rehabilitation different?"

"No, standard Bankart protocol."

CLINICAL SCENARIOStandard

Scenario 3: The Revision

CLINICAL PROMPT

"A patient had a stabilisation elsewhere and re-dislocated. MRI shows the anchors are in the glenoid neck, not the face. The labrum is still medial. Why did it fail?"

PRACTICAL APPROACH

This represents a failure to mobilize an ALPSA lesion. The previous surgeon likely fixed the labrum 'in situ' on the neck. The bumper effect was never restored. I would revise this by removing/ignoring old anchors, mobilizing the tissue fully, and placing new anchors on the face.

KEY CLINICAL POINTS

Mechanism of failure

Critique of anchor placement

Revision strategy

COMMON PITFALLS

Blaming the patient or trauma

Missing the technical error

FURTHER QUESTIONS

"What if the tissue is poor?"

"I would consider a Latarjet (Coracoid transfer) if soft tissue quality is insufficient."

CLINICAL SCENARIOStandard

Scenario 4: CT Arthrography Interpretation

CLINICAL PROMPT

"You are shown a CT arthrography of a 26-year-old footballer with chronic anterior instability. Contrast tracks medially along the glenoid neck with the labrum. What is the diagnosis and how does this affect your surgical planning?"

PRACTICAL APPROACH

This is an ALPSA lesion on CT arthrography. The contrast tracking medially with the labrum indicates an intact periosteal sleeve with medialized healing. Surgical planning must include: assessment of bone loss using best-fit circle method, planning for extensive soft tissue mobilization, and determining if bone augmentation is needed.

KEY CLINICAL POINTS

CT arthrography findings of ALPSA

Bone loss quantification

Surgical planning implications

COMMON PITFALLS

Confusing with Bankart (no medial tracking)

Failing to assess bone loss

FURTHER QUESTIONS

"The CT shows 18% glenoid bone loss. What now?"

"This is in the 'grey zone' (15-25%). I would consider soft tissue repair with remplissage for engaging Hill-Sachs, or bone graft augmentation depending on patient demands."

MCQ Practice Points

Shoulder instability revision desk with MR arthrogram cases and glenoid model — Revision image: the recurring question is whether the lesion has been mobilized enough to restore the anterior labral bumper.

Pathology

Q: What structure remains intact in an ALPSA lesion that is torn in a Bankart? A: The anterior scapular periosteum.

Terminology

Q: What does ALPSA stand for? A: Anterior Labroligamentous Periosteal Sleeve Avulsion.

Surgical Technique

Q: What is the most critical step in ALPSA repair? A: Mobilization (Takedown) of the labrum.

Classification

Q: A chronic, fixed ALPSA lesion is classified as: A: Neviaser Type II.

MRI Diagnosis

Q: What MRI finding differentiates ALPSA from Bankart lesion? A: Medially displaced labrum with intact periosteal sleeve (labrum lies against glenoid neck rather than at rim).

Recurrence Risk

Q: Why do ALPSA lesions have higher recurrence rates if not properly mobilized? A: The medialized labrum heals in a non-anatomic position, failing to restore the labral bumper effect and capsular tension.

Australian Context

Contact-sport shoulder instability consultation with athlete and clinician reviewing shoulder imaging — Australian context image: recurrent anterior instability after contact sport should prompt careful imaging review for ALPSA and bone loss.

Prevalence: Highly common in the Australian contact sport population (Rugby, AFL).
Practice: ALPSA recognition is a standard of care expectation for Orthopaedic candidates. "In situ" repair is considered a technical error.

Clinical summary

Diagnosis

•History: Recurrent Instability
•MRI: Medialized Labrum
•MRI: Intact Periosteal Sleeve
•Sign: Drive-through positive

Management

•Arthroscopic Repair is Gold Standard
•CRITICAL: Mobilize/Takedown lesion
•Fix to Glenoid Face (Not neck)
•Restore Bumper Effect

Key Differentiators

•Bankart: Torn Periosteum, Floating
•ALPSA: Intact Periosteum, Medialized
•GLAD: Cartilage defect
•Perthes: Undisplaced sleeve

Feature

Bankart Lesion

ALPSA Lesion

Periosteum

Torn (Detached)

Intact (Stripped)

Position

Floating

Medialized on Neck

Healing

Does not heal (Gap)

Heals in bad position

Recurrence

Standard risk

Higher risk (if not mobilized)

Lesion

Periosteum

Labrum Position

Stability

Bankart

Torn

Floating/Detached

Unstable

ALPSA

Intact

Medialized

Unstable

Perthes

Stripped

In situ

Unstable

GLAD

Intact

Stable

MRI Features

MRI Signs

Medialization: The key sign.
Synovial Stripping: Contrast tracking under the sleeve.
Bone Loss: Assess for concomitant Bony Bankart (often remodelled in chronic cases).
Hill-Sachs: Usually present due to recurrence.

Look for the "Cul-de-sac" deep to the capsule.

ALPSA Lesions

ALPSA Lesions

Neviaser Classification

Critical Must-Knows

Clinical Pearls

The Surgical Trap

The Problem

The Solution

GAPVariants of Instability

TRIPSurgical Steps

MINTPathology

Overview

Definition

Pathophysiology and Mechanisms

The Labroligamentous Complex

The Healing Trap

Biomechanical Consequences

The Compression-Concavity Mechanism

Classification Systems

Neviaser Classification

History

Presentation

Red Flags

Examination

Physical Exam

Differential Diagnosis

Differential Diagnosis

Key Distinguishing Features

Imaging

MRI Features

MRI Signs

CT Arthrography

CTA Findings in ALPSA

Glenoid Bone Loss Assessment

Measurement Methods

Thresholds

Management Algorithm

Decision Making

Timing

Surgical Considerations

Arthroscopic Repair Steps

Surgical Pearls

Complications

Complication Pearl

Rehabilitation

Return to Sport Criteria

Sling Removal Criteria

Contact Progression

Prognosis

Prognostic Factors

Evidence Base

Original Description

Recurrence Rates

Biomechanics

Chronic ALPSA

Arthroscopic Technique

Viva Scenarios

Scenario 1: MRI Interpretation

Scenario 2: Intra-operative Surprise

Scenario 3: The Revision

Scenario 4: CT Arthrography Interpretation

MCQ Practice Points

Australian Context

Diagnosis

Management

Key Differentiators

ALPSA Lesions

ALPSA Lesions

Neviaser Classification

Critical Must-Knows

Clinical Pearls

The Surgical Trap

The Problem

The Solution

GAPVariants of Instability

TRIPSurgical Steps

MINTPathology

Overview

Definition

Pathophysiology and Mechanisms