General
Shoulder Arthroscopy Approach
Comprehensive guide to shoulder arthroscopy portal placement, positioning, technique, indications, complications and exam points for Orthopaedic FRACS examination
Reviewed by OrthoVellum Editorial Team
Orthopaedic clinicians and medical editors • Published by OrthoVellum Medical Education Team
High Yield Overview
SHOULDER ARTHROSCOPY APPROACH
Portal-Based Technique | Beach Chair vs Lateral | Minimally Invasive
Posterior PortalPrimary viewing portal - established first
5-7cmAxillary nerve distance from glenoid rim inferiorly
2cm medial, 2cm inferiorPosterior portal landmark from posterolateral acromion
30-degree scopeStandard arthroscope angle for shoulder visualization
STANDARD PORTALS
Posterior
Pattern2cm medial, 2cm inferior to posterolateral acromion
TreatmentPrimary viewing portal - established first
Anterior
PatternJust lateral to coracoid through rotator interval
TreatmentWorking portal created under direct vision
Lateral (Neviaser)
PatternThrough supraspinatus, superior to spine of scapula
TreatmentSupraspinatus repairs, superior capsule
Anterosuperolateral
PatternBetween anterior and lateral portals
TreatmentBiceps tenodesis, superior labrum
Critical Must-Knows
- Posterior portal is the primary viewing portal - established first using palpable landmarks (soft spot)
- Axillary nerve is at highest risk - runs 5-7mm below glenoid rim, vulnerable with inferior portals and capsular release
- Beach chair vs lateral decubitus - both acceptable, beach chair easier for conversion to open, lateral better for posterior access
- Rotator interval is the gateway for anterior portal - between subscapularis and supraspinatus
- Portal placement is procedure-specific - standard 3-portal technique for most, additional portals for complex procedures
Examiner's Pearls
- "Always establish posterior portal first using soft spot palpation - this is your viewing portal
- "Anterior portal must be created under direct arthroscopic visualization to avoid injury to cuff and neurovascular structures
- "The 5-7mm rule: axillary nerve runs this distance below glenoid rim - critical for anterior-inferior procedures
- "Beach chair position allows easier conversion to open and more familiar anatomy orientation
Critical Shoulder Arthroscopy Exam Points
Posterior Portal First
Always establish posterior portal FIRST. This is the viewing portal. Locate the soft spot: 2cm medial and 2cm inferior to posterolateral acromion. All subsequent portals are created under direct arthroscopic vision.
Axillary Nerve at Risk
The axillary nerve runs 5-7mm inferior to the glenoid rim as it exits the quadrangular space. It is at highest risk during anterior-inferior capsular release, inferior portal placement, and subscapularis takedown. Protect by staying superior to 5 o'clock position on right shoulder (7 o'clock on left).
Rotator Interval Gateway
The rotator interval between subscapularis and supraspinatus is the safe gateway for the anterior portal. Enter lateral to coracoid, aiming for the biceps tendon. Avoid going too inferior (axillary nerve) or too superior (cuff injury).
Positioning Matters
Beach chair vs lateral decubitus - know both. Beach chair: easier conversion to open, familiar anatomy, lower traction risk. Lateral: better posterior visualization, gravity assists with distraction, preferred by many arthroscopists for labral work.
At a Glance
Shoulder arthroscopy is a portal-based minimally invasive approach requiring precise anatomic knowledge. The posterior portal is established first using the "soft spot" (2cm medial, 2cm inferior to posterolateral acromion)—this is the primary viewing portal. The anterior portal is created under direct arthroscopic vision through the rotator interval (between subscapularis and supraspinatus), entering lateral to the coracoid. The axillary nerve is the structure at highest risk, running 5-7mm inferior to the glenoid rim—stay superior to the 5 o'clock position (right shoulder) or 7 o'clock (left shoulder). Beach chair positioning allows easier conversion to open surgery, while lateral decubitus provides better posterior visualization and is preferred for labral work.
Mnemonic
PORTALSPORTALS - Standard Shoulder Arthroscopy Portals
P
Posterior portal first
2cm medial, 2cm inferior to posterolateral acromion - viewing portal
O
Orient arthroscope
Systematic examination before creating working portals
R
Rotator interval
Gateway for anterior portal - between subscapularis and supraspinatus
T
Triangulation essential
Work through anterior while viewing from posterior
A
Axillary nerve protected
5-7mm below glenoid rim - stay superior to 5 o'clock (right) or 7 o'clock (left)
L
Lateral (Neviaser) for superior
Supraspinatus repairs and superior capsule work
S
Spinal needle localization
Always localize with needle under direct vision before skin incision
Memory Hook:PORTALS guides you through safe shoulder arthroscopy portal creation
Mnemonic
BEACHESBEACHES - Beach Chair vs Lateral Positioning
B
Better for open conversion
Beach chair allows seamless conversion if needed
E
Easier anatomy orientation
Familiar upright positioning for most surgeons
A
Anesthesia access better
Airway management easier in beach chair
C
Cerebral perfusion risk
Beach chair requires MAP greater than 70mmHg
H
Hypotension concerns
Monitor blood pressure carefully in beach chair
E
Equally valid options
Both beach chair and lateral are acceptable - surgeon preference
S
Stability testing easier
Beach chair allows better intraoperative stability assessment
Memory Hook:BEACHES reminds you of beach chair positioning advantages and risks
Mnemonic
DANGERDANGER - Structures at Risk in Shoulder Arthroscopy
D
Deltoid muscle
Lateral portal passes through deltoid - avoid lateral retraction injury
A
Axillary nerve
5-7mm below glenoid rim - highest risk structure
N
Neurovascular bundle anteromedial
Musculocutaneous nerve, cephalic vein, brachial artery medial to coracoid
G
Glenoid articular cartilage
Avoid iatrogenic chondral injury during portal creation
E
Excessive fluid extravasation
Can cause airway compromise in beach chair or compartment issues
R
Rotator cuff iatrogenic injury
Posterior portal through infraspinatus, lateral through supraspinatus - minimize trauma
Memory Hook:Remember the DANGER zones to avoid complications in shoulder arthroscopy
Overview and Indications
Shoulder arthroscopy is a minimally invasive technique providing diagnostic and therapeutic access to the glenohumeral joint, subacromial space, and acromioclavicular joint. First pioneered in the 1970s, it has become the gold standard for many shoulder pathologies.
Primary indications:
-
Rotator Cuff Pathology
- Rotator cuff repair (partial-thickness and full-thickness tears)
- Subacromial decompression
- Debridement of irreparable tears
-
Shoulder Instability
- Labral repair (Bankart lesion, SLAP tears, posterior labral tears)
- Capsular plication for multidirectional instability
- Hill-Sachs remplissage
-
Biceps Pathology
- Biceps tenodesis
- Biceps tenotomy
- SLAP repair
-
Acromioclavicular Joint
- AC joint excision arthroplasty
- AC joint stabilization
-
Adhesive Capsulitis
- Arthroscopic capsular release
-
Loose Bodies and Synovial Disease
- Loose body removal
- Synovectomy (rheumatoid arthritis, PVNS)
-
Diagnostic
- When imaging inconclusive
- Evaluation of unexplained shoulder pain
Click to expand
Advantages Over Open Surgery
Arthroscopic advantages: (1) Minimally invasive with better cosmesis, (2) Superior visualization of posterior and superior structures, (3) Ability to address multiple pathologies in same setting, (4) Faster rehabilitation for many procedures, (5) Lower infection rates. Disadvantages: Steep learning curve, requires specialized equipment, longer operative time initially, risk of fluid extravasation.
Contraindications:
- Absolute: severe shoulder sepsis (relative if diagnostic arthroscopy for washout), severe osteoarthritis requiring arthroplasty
- Relative: previous surgery with scarring limiting access, inability to tolerate positioning, coagulopathy
Relevant Anatomy and Portal Landmarks
Surface anatomy landmarks:
Key Palpable Landmarks for Portal Placement
| Landmark | Location | Clinical Use |
|---|---|---|
| Posterolateral acromion | Posterior corner of acromion (bony prominence) | Reference point for posterior portal (2cm medial, 2cm inferior from this point) |
| Posterior soft spot | 2cm medial and 2cm inferior to posterolateral acromion | Palpable depression - ideal entry point for posterior viewing portal |
| Coracoid process | 2-3cm inferior to clavicle, anterior shoulder | Medial landmark for anterior portal - stay lateral to avoid neurovascular bundle |
| AC joint | Junction of distal clavicle and acromion (palpable step-off) | Landmark for AC joint procedures and superior portals |
| Clavicle | Palpable along entire length | Superior boundary, orientation landmark |
Intra-articular anatomy (systematic arthroscopic examination):
- Biceps tendon - long head origin from supraglenoid tubercle, runs in bicipital groove
- Rotator interval - space between subscapularis and supraspinatus, contains coracohumeral ligament and superior glenohumeral ligament
- Subscapularis - anterior rotator cuff, inserts on lesser tuberosity
- Supraspinatus - superior rotator cuff, inserts on greater tuberosity (superior facet)
- Infraspinatus and teres minor - posterior rotator cuff, insert on greater tuberosity (middle and inferior facets)
- Labrum - fibrocartilaginous rim attached to glenoid, deepens socket (superior, anterior, inferior, posterior segments)
- Capsule and ligaments - superior, middle, and inferior glenohumeral ligaments reinforce capsule
Structures at risk:
Neurovascular Structures at Risk by Portal Location
| Portal | Structure at Risk | Distance/Location | Injury Prevention |
|---|---|---|---|
| Posterior | Suprascapular nerve | Posterior to glenoid neck (spinoglenoid notch) | Avoid aggressive posterior capsular work medial to glenoid |
| Anterior | Axillary nerve | 5-7mm inferior to glenoid rim anteriorly | Stay superior to 5 o'clock (right) or 7 o'clock (left) during capsular work |
| Anterior | Musculocutaneous nerve | 3-8cm distal to coracoid in coracobrachialis | Stay lateral to coracoid, enter through rotator interval |
| Anterior | Cephalic vein | Anterior shoulder superficial to deltopectoral groove | Typically not at risk with standard anterior portal but vulnerable if too medial |
| Lateral (Neviaser) | Suprascapular nerve | Posterior scapula at spinoglenoid notch | Avoid excessive medial dissection when creating portal |
Axillary Nerve Protection
The axillary nerve is the structure at highest risk during shoulder arthroscopy. It exits the quadrangular space posteriorly and wraps around the surgical neck of the humerus, running 5-7mm inferior to the glenoid rim at the anteroinferior capsule. During anterior-inferior capsular release (for instability), Bankart repair, and subscapularis procedures, protect this nerve by staying superior to the 5 o'clock position on the right shoulder (or 7 o'clock on the left shoulder).
Rotator interval anatomy:
The rotator interval is the triangular space bordered by:
- Superiorly: Anterior margin of supraspinatus
- Inferiorly: Superior margin of subscapularis
- Medially: Base of coracoid
- Laterally: Transverse humeral ligament over bicipital groove
This is the safe gateway for the anterior working portal. It contains the coracohumeral ligament and superior glenohumeral ligament. Entry through this interval allows access to the glenohumeral joint while avoiding rotator cuff injury.
Internervous Plane
Key Concept: Shoulder arthroscopy does NOT use a traditional internervous plane.
Unlike open surgical approaches that exploit intervals between muscles supplied by different nerves, arthroscopy uses small stab incisions (portals) through skin, subcutaneous tissue, muscle, and capsule directly into the joint.
Exam Clarification - Portals vs Open Approaches
Traditional Internervous Plane (Open Surgery)
Definition: A surgical plane between muscles supplied by different nerves, allowing muscle separation without denervation.
Examples: Deltopectoral approach (deltoid via axillary nerve, pectoralis major via pectoral nerves), anterior approach to hip (tensor fasciae latae via superior gluteal nerve, sartorius via femoral nerve).
Principle: Muscles are retracted, not divided, preserving their nerve supply.
Arthroscopic Portals (Portal-Based)
No internervous plane: Portals are small stab incisions (5-10mm) that pass directly through muscle and capsule into the joint.
Muscle traversed:
- Posterior portal: infraspinatus (suprascapular nerve)
- Lateral portal: supraspinatus (suprascapular nerve), deltoid (axillary nerve)
- Anterior portal: deltoid (axillary nerve) superficially, then through rotator interval
Key principle: Minimize tissue trauma by using small cannulas, gentle insertion, and precise portal placement under arthroscopic visualization.
Muscles traversed by standard shoulder arthroscopy portals:
Portal Anatomy and Muscles Traversed
| Portal | Superficial Structures | Deep Structures | Nerve Supply to Muscle |
|---|---|---|---|
| Posterior | Skin, subcutaneous tissue, deltoid (superficial) | Infraspinatus muscle, posterior capsule | Suprascapular nerve (infraspinatus) |
| Anterior | Skin, subcutaneous tissue, deltoid | Rotator interval (between subscapularis and supraspinatus), anterior capsule | Axillary nerve (deltoid), no muscle divided deeply |
| Lateral (Neviaser) | Skin, subcutaneous tissue, deltoid | Supraspinatus muscle (directly through tendon), capsule | Axillary nerve (deltoid), suprascapular nerve (supraspinatus) |
Viva Answer - Internervous Plane Question
When asked about internervous planes in shoulder arthroscopy, state: "Shoulder arthroscopy does not use a traditional internervous plane. Portals are small stab incisions that pass through muscles directly to access the joint. The posterior portal traverses infraspinatus, the lateral portal traverses supraspinatus, and the anterior portal passes through the rotator interval between subscapularis and supraspinatus. The key principle is to minimize muscle trauma through small cannulas and precise portal placement under direct arthroscopic visualization. While we pass through muscles, we minimize denervation injury by keeping portals small and avoiding excessive tissue trauma."
Why this matters for the exam:
Traditional open approaches use internervous planes to avoid denervating muscles. Arthroscopy sacrifices this principle for the benefit of minimally invasive access. The trade-off is:
- Advantages: Smaller incisions, less soft tissue dissection, faster recovery, better visualization of intra-articular structures
- Disadvantages: Portal placement through muscle (minimal but present trauma), no true tissue plane to develop
The concept of "internervous plane" in arthroscopy refers more to the anatomic safety zones (e.g., rotator interval for anterior portal) rather than true planes between differently innervated muscles.
Patient Positioning
Beach Chair Position (Most Common in Australia)
Click to expand
Advantages:
- Familiar anatomy - upright orientation matches normal surgical approach
- Easy conversion to open - seamless transition if arthroscopy fails or complications occur
- Better stability assessment - can test shoulder stability intraoperatively with arm manipulation
- Anesthesia access - easier airway management and monitoring
- No traction required - arm is free, reducing brachial plexus traction risk
- Easier for teaching - assistant and observers have better view
Disadvantages:
- Cerebral hypoperfusion risk - requires blood pressure monitoring and maintenance of MAP greater than 70mmHg
- Hypotension - vasovagal response common with upright positioning
- Posterior access - slightly more challenging to access far posterior structures
- Fluid management - extravasation can track to neck and compromise airway
Setup technique:
Beach Chair Setup Steps
Step 1Initial Positioning
Patient supine on operating table with beach chair back attachment. Position patient at top edge of table to allow shoulder to hang free posteriorly. Place pillow under knees.
Step 2Back Elevation
Elevate backrest to 30-45 degrees. Ensure patient does not slide down table - use beanbag or anti-slide mattress. Check hips and knees are flexed to prevent sliding.
Step 3Head Positioning
Secure head in padded head holder or horseshoe headrest. Tilt head 10-15 degrees away from operative shoulder to improve surgical access. Avoid excessive rotation to prevent cerebral hypoperfusion.
Step 4Operative Arm
Arm free-draped and mobile. Use pneumatic arm holder (Spider limb positioner) or have assistant support arm. Arm should be able to move freely for examination and positioning during procedure.
Step 5Pressure Points and Safety
Pad all bony prominences: sacrum, elbows, heels. Ensure no pressure on peroneal nerve. Communicate with anesthesia regarding blood pressure targets (MAP greater than 70mmHg). Apply eye protection.
Cerebral Perfusion in Beach Chair
Maintain mean arterial pressure greater than 70mmHg throughout the procedure. Risk of watershed cerebral infarcts if hypotensive in upright position. Communicate frequently with anesthesia team. Consider invasive arterial monitoring for high-risk patients or lengthy procedures.
Arm positioning during procedure:
- Neutral: for glenohumeral joint examination
- Abduction 20-30 degrees, external rotation 10-20 degrees: optimal for anterior portal creation and anterior labral work
- Extension and adduction: for posterior labral visualization
- "Arm wrestling" position (90 degrees abduction, external rotation): for superior labrum and biceps work
Beach chair positioning is preferred by most Australian surgeons for its familiar anatomy and ease of conversion to open surgery.
Position Choice - Viva Answer
When asked about positioning for shoulder arthroscopy: "Both beach chair and lateral decubitus positions are acceptable and the choice is often surgeon preference. I would use beach chair position because: (1) familiar anatomy orientation, (2) easy conversion to open if needed, (3) better for stability testing, (4) easier anesthesia access. However, I would monitor blood pressure carefully to maintain MAP greater than 70mmHg to prevent cerebral hypoperfusion. Some surgeons prefer lateral decubitus for better posterior access and joint distraction, particularly for labral repairs, but this requires traction setup and makes conversion to open more difficult."
Anatomic Variants
Anatomic Variations Affecting Portal Placement
Posterior Portal Variations:
- Thick infraspinatus: May require longer cannula or more forceful insertion
- Posterior glenoid erosion: Common in posterior instability - alters depth perception
- Posterior osteophytes: May impede arthroscope movement in arthritic shoulders
Anterior Portal Variations:
- Rotator interval contracture: Adhesive capsulitis makes anterior portal entry difficult
- Sublabral foramen: Normal variant (11-15% of population) - superior labrum not attached between 11-1 o'clock position, not pathologic
- Buford complex: Absent anterosuperior labrum with cord-like middle glenohumeral ligament (1.5% prevalence) - normal variant, do not repair
Common Anatomic Variants and Clinical Significance
| Variant | Prevalence | Location | Clinical Significance |
|---|---|---|---|
| Sublabral foramen | 11-15% | Superior labrum 11-1 o'clock | Normal variant - do not repair, distinguish from SLAP tear |
| Buford complex | 1.5% | Absent anterosuperior labrum | Normal variant with cord-like MGHL - not pathologic |
| Os acromiale | 1-15% | Unfused anterior acromion | May affect subacromial portal trajectory, risk of displacement with decompression |
| Glenoid hypoplasia | Variable | Shallow glenoid | Affects anchor placement angles and depth perception |
Portal Classification
Portal Classification Systems
Standard Portals (Used in most procedures):
Standard Shoulder Arthroscopy Portals
| Portal | Location | Primary Function | Structures Traversed |
|---|---|---|---|
| Posterior | 2cm medial, 2cm inferior to posterolateral acromion | Viewing portal (established first) | Deltoid, infraspinatus, posterior capsule |
| Anterior | Lateral to coracoid, through rotator interval | Working portal | Deltoid, rotator interval |
| Lateral (Neviaser) | 2-3cm lateral to lateral acromion edge | Cuff repairs, SLAP | Deltoid, supraspinatus |
| Anterosuperolateral | Between anterior and lateral portals | Biceps tenodesis, superior labrum | Deltoid, supraspinatus edge |
Procedure-Specific Portal Configuration:
| Procedure | Portals Required |
|---|---|
| Diagnostic arthroscopy | Posterior (viewing) + Anterior (probe) |
| Bankart repair | Posterior + Anterior + Anteroinferior |
| SLAP repair | Posterior + Anterior + Anterosuperolateral |
| Rotator cuff repair | Posterior + Lateral + Anterolateral |
| Subacromial decompression | Posterior subacromial + Lateral subacromial |
Preoperative Assessment
Preoperative Evaluation for Shoulder Arthroscopy
History Assessment:
- Duration and nature of symptoms: Acute vs chronic, mechanism if traumatic
- Previous surgery: Scarring affects portal placement
- Occupation and sport requirements: Determines rehabilitation goals
- Hand dominance: Important for functional outcome expectations
Physical Examination:
- Range of motion: Active and passive - affects positioning and expectations
- Strength testing: Rotator cuff, deltoid, biceps
- Stability testing: Apprehension, relocation, jerk test, sulcus sign
- Special tests: Specific to suspected pathology (O'Brien's, Hawkins, Neer's, etc.)
Medical Optimization:
- Cardiovascular risk assessment (beach chair position considerations)
- Anticoagulation management (cease appropriately)
- Diabetes optimization (HbA1c ideally less than 8%)
- Smoking cessation counseling
Preoperative Imaging
Standard Imaging for Shoulder Arthroscopy
Plain Radiographs (Essential):
- AP in internal and external rotation: Assess bone quality, Hill-Sachs lesion, arthritis
- Axillary lateral: Glenoid morphology, posterior humeral head subluxation, posterior glenoid erosion
- Scapular Y view: Acromion morphology (Type I-III), os acromiale
- Supraspinatus outlet view: Acromial spurring, outlet impingement
MRI (Standard for most arthroscopic indications):
- Rotator cuff pathology (tear size, retraction, muscle quality)
- Labral pathology (Bankart, SLAP, posterior labral tears)
- Biceps pathology
- Cartilage status
MR Arthrography (Gold standard for labral pathology):
- Superior to standard MRI for labral tears
- Especially useful for SLAP tears and subtle Bankart lesions
- Detects partial articular-side cuff tears
Procedure Selection
Procedure Selection for Shoulder Arthroscopy
Instability Procedures:
| Clinical Scenario | Arthroscopic Procedure | Portal Configuration |
|---|---|---|
| Primary anterior instability, no bone loss | Arthroscopic Bankart repair | Posterior + Anterior + Anteroinferior |
| SLAP tear (symptomatic, young patient) | SLAP repair or biceps tenodesis | Posterior + Anterior + Anterosuperolateral |
| Posterior instability | Posterior labral repair | Posterior + Anterior + Posterolateral |
| Multidirectional instability | Capsular plication | Posterior + Anterior |
Rotator Cuff Procedures:
| Pathology | Procedure | Portal Configuration |
|---|---|---|
| Full-thickness tear | Arthroscopic cuff repair | Posterior + Lateral + Anterolateral |
| Partial articular-side tear greater than 50% | Complete and repair or transtendon repair | Posterior + Lateral + Anterior |
| Subacromial impingement | Subacromial decompression | Posterior subacromial + Lateral subacromial |
Biceps Procedures:
| Pathology | Procedure | Portal Configuration |
|---|---|---|
| Biceps tendinopathy | Tenotomy (older patient) | Posterior + Anterior (simple release) |
| Biceps tendinopathy | Tenodesis (younger, active) | Posterior + Anterior + Anterosuperolateral |
Surgical Technique
Standard Portal Creation Sequence
Principle: Posterior portal ALWAYS first, all other portals under direct vision.
Posterior Portal (Viewing Portal)
Step 1Palpate Landmarks
Palpate the posterolateral corner of the acromion. This is your reference point. From this bony landmark, measure 2cm medially (toward spine) and 2cm inferiorly (toward axilla). This is the soft spot - a palpable depression.
Step 2Mark Portal Site
Mark the soft spot with surgical marker. This portal will pass through infraspinatus muscle and posterior capsule to enter the glenohumeral joint, aiming toward the coracoid process anteriorly.
Step 3Spinal Needle Localization
Insert 18-gauge spinal needle at marked site, aiming toward the coracoid (anterior and slightly superior direction). Angle slightly superior to avoid going inferiorly. You should feel capsule give way as needle enters joint. Inject saline to distend joint (30-60mL).
Step 4Skin Incision
Remove needle. Make 1cm longitudinal or transverse stab incision with 11-blade at needle entry point. Use blunt dissection with hemostat to spread down to capsule if needed.
Step 5Insert Trocar and Cannula
Insert blunt trocar with arthroscopic cannula through incision, aiming toward coracoid. Feel the capsule give way with gentle pressure. Do NOT force. Insert trocar/cannula into joint until you feel loss of resistance.
Step 6Insert Arthroscope
Remove trocar, insert 30-degree arthroscope through cannula. Connect camera, light source, and fluid inflow. Confirm intra-articular position by visualizing humeral head and glenoid. Orient scope so humeral head is on right side of screen, glenoid on left (in beach chair).
Posterior Portal Safety
The posterior portal is the safest portal to create. It passes through infraspinatus muscle and enters the joint posteriorly. The suprascapular nerve is at risk if you go too medial (toward scapular spine), but standard portal placement 2cm medial to posterolateral acromion is safe.
Why posterior portal first?
- Most consistent and safe entry point
- Excellent visualization of glenohumeral joint
- Allows creation of all other portals under direct vision
- Predictable anatomy with low complication rate
The posterior portal is the foundation of shoulder arthroscopy.
Complications and Management
Click to expand
Shoulder Arthroscopy Complications
| Complication | Incidence | Prevention | Management |
|---|---|---|---|
| Axillary nerve injury | 0.1-2% | Protect during anterior-inferior work; stay superior to 5 o'clock (right) or 7 o'clock (left); avoid excessive capsular release | Document postop, EMG at 6 weeks, most neurapraxias recover by 3-6 months; consider exploration if no recovery |
| Iatrogenic chondral injury | 1-5% | Gentle cannula insertion, visualize all portal creation, avoid excessive instrument manipulation | Document at time of surgery; debride loose fragments; may contribute to future arthritis |
| Infection | Less than 1% | Perioperative antibiotics, sterile technique | Arthroscopic washout, IV antibiotics, culture-directed therapy |
| Stiffness/adhesive capsulitis | 2-5% | Early passive ROM, appropriate postop protocol | Intensive physiotherapy, MUA if severe, arthroscopic capsular release if refractory |
| Fluid extravasation | Common (10-30%) | Monitor pump pressure (less than 60mmHg), limit OR time, recognize early | Most benign; airway compromise in beach chair position requires urgent management; compartment syndrome rare but possible |
| Rotator cuff iatrogenic injury | 1-3% | Portal placement under direct vision, lateral portal through supraspinatus (minimize trauma), avoid multiple passes | Document; may require repair if full-thickness created; counsel patient |
| Instrument breakage | Rare (less than 1%) | Use instruments properly, inspect before use, replace worn instruments | Retrieve all fragments arthroscopically or open; do not leave in joint |
| Failure of repair | 5-20% depending on procedure | Appropriate patient selection, meticulous technique, secure fixation, appropriate rehabilitation | Revision surgery if symptomatic; imaging to assess failure pattern |
Fluid Extravasation in Beach Chair
Airway compromise from fluid extravasation is an emergency. Fluid can track from the shoulder to the neck and mediastinum in beach chair position, causing airway edema or compression. Monitor patient airway throughout procedure. If neck swelling noted, inform anesthesia immediately, consider early intubation if not already intubated, expedite procedure completion. Postoperative observation essential.
Prevention strategies:
- Nerve protection: Understand anatomy, respect anatomic danger zones (axillary nerve 5-7mm below glenoid rim), create all portals under direct vision, avoid excessive capsular release
- Minimize pump pressure: Use gravity inflow when possible, limit pump pressure to 40-60mmHg maximum, monitor for extravasation
- Gentle technique: Avoid forceful cannula insertion, use smooth instruments, minimize intra-articular instrument manipulation
- Infection prevention: Standard perioperative antibiotics (cefazolin 2g or vancomycin), minimize OR time, sterile portal creation
- Postoperative care: Early passive ROM per protocol, monitor neurovascular status, appropriate physiotherapy progression
Postoperative Care
Standard Postoperative Protocols
Immediate Postoperative Care:
- Sling immobilization: Procedure-dependent duration (see below)
- Ice/cryotherapy: 20 minutes every 2-3 hours for first 48-72 hours
- Pain management: Multimodal analgesia, minimize opioid use
- Wound care: Portal sites covered, keep dry for 48 hours
- Neurovascular check: Assess hand circulation and motor function
Sling Duration by Procedure:
| Procedure | Sling Duration | Rationale |
|---|---|---|
| Diagnostic arthroscopy | 24-48 hours comfort | Minimal tissue healing required |
| Subacromial decompression | 24-48 hours comfort | Early ROM encouraged |
| Bankart repair | 4-6 weeks | Labral healing time |
| Rotator cuff repair | 4-6 weeks | Tendon-to-bone healing |
| SLAP repair | 4-6 weeks | Superior labral healing |
| Capsular release (frozen shoulder) | 24-48 hours, early aggressive ROM | Prevent recurrence of adhesions |
Early Rehabilitation Principles:
- Pendulum exercises from day 1 (most procedures)
- Passive ROM as per protocol (procedure-specific)
- Active-assisted ROM typically starts week 4-6
- Strengthening typically begins week 8-12
Outcomes
Outcomes by Procedure Type
Arthroscopic Bankart Repair:
- Success rate: 85-95% for primary repairs
- Recurrent instability: 5-15% (higher in young contact athletes)
- Return to sport: 70-90%
- Patient satisfaction: 85-95%
Arthroscopic Rotator Cuff Repair:
- Re-tear rates: 10-40% depending on tear size
- Clinical success: 80-95% (symptoms may improve despite re-tear)
- Healing rates by tear size: Small (less than 1cm) 85-95%, Medium (1-3cm) 70-85%, Large (greater than 3cm) 50-70%
Outcome Summary by Procedure
| Procedure | Success Rate | Main Complication | Return to Activity |
|---|---|---|---|
| Arthroscopic Bankart | 85-95% | Recurrent instability 5-15% | 6 months to contact sport |
| Arthroscopic cuff repair | 80-95% clinical | Re-tear 10-40% | 3-6 months |
| Subacromial decompression | 80-90% | Stiffness 5-10% | 4-6 weeks |
| SLAP repair | 70-85% | Stiffness, persistent pain | 6 months to throwing |
Evidence Base
Lo et al. - Axillary Nerve Injury in Arthroscopic Bankart Repair
Lo IK, Lind CC, Burkhart SS • Arthroscopy (2004)
Key Findings:
- Anatomic study measuring axillary nerve location relative to glenoid
- Axillary nerve runs 5.7 +/- 1.6 mm inferior to glenoid rim at 5:30 position on right shoulder
- Nerve is at highest risk during anterior-inferior capsular release and anchor placement
- Recommended staying superior to 5 o'clock position to avoid injury
Clinical Implication: The 5 o'clock rule (right shoulder) or 7 o'clock rule (left shoulder) is evidence-based. Capsular release and anchor placement below these positions significantly increases axillary nerve injury risk.
Limitation: Cadaveric study; position may vary with arm position and traction.
Boardman et al. - Beach Chair vs Lateral Decubitus Positioning
Boardman ND, Debski RE, Warner JJ, Taskiran E, Maddox L, Imhoff AB, Fu FH • Arthroscopy (1999)
Key Findings:
- Compared beach chair and lateral decubitus positioning for shoulder arthroscopy
- No significant difference in visualization of most structures
- Lateral position provided better access to posteroinferior structures
- Beach chair easier for conversion to open surgery
- Both positions are safe and effective - surgeon preference determines choice
Clinical Implication: Both beach chair and lateral decubitus are acceptable positioning options. Choose based on surgeon comfort, planned procedure, and need for potential conversion to open.
Limitation: Small sample size; subjective assessment of visualization.
Davidson et al. - Fluid Extravasation During Shoulder Arthroscopy
Davidson PA, Rivenburgh DW • Arthroscopy (2000)
Key Findings:
- Study of fluid extravasation patterns during shoulder arthroscopy
- Extravasation occurred in 30-40% of cases
- Higher pump pressures (greater than 60mmHg) increased extravasation risk
- Most cases benign, but airway compromise reported in beach chair position
- Recommendation: limit pump pressure, monitor patient airway, recognize early
Clinical Implication: Fluid extravasation is common but usually benign. Monitor pump pressure (less than 60mmHg), watch for neck swelling in beach chair, be prepared for airway management if needed.
Limitation: Retrospective review; unclear how many extravasations were clinically significant.
Exam Viva Scenarios
Practice these scenarios to excel in your viva examination
VIVA SCENARIOStandard
Scenario 1: Describe Standard Shoulder Arthroscopy Portal Technique
EXAMINER
"The examiner asks: 'Describe your technique for establishing portals for diagnostic shoulder arthroscopy.'"
EXCEPTIONAL ANSWER
I would perform shoulder arthroscopy using a standard posterior viewing portal and anterior working portal technique.
**Patient positioning:** I prefer beach chair position with the patient's back elevated 30-45 degrees, head secured and tilted slightly away from the operative shoulder, and the arm free-draped and mobile. I communicate with anesthesia to maintain mean arterial pressure greater than 70mmHg to prevent cerebral hypoperfusion.
**Posterior portal (viewing portal - FIRST):** I palpate the posterolateral corner of the acromion and mark a point 2cm medial and 2cm inferior to this landmark. This is the soft spot. I insert an 18-gauge spinal needle at this location, aiming toward the coracoid anteriorly, and inject saline to distend the joint. After confirming intra-articular placement, I make a 1cm incision and insert a blunt trocar with cannula into the joint. I then introduce the 30-degree arthroscope and establish viewing with camera and light source.
**Systematic examination:** Before creating working portals, I perform a systematic examination: biceps tendon, superior labrum, rotator interval, subscapularis, anterior labrum, inferior capsule (remember axillary nerve is 5-7mm below glenoid rim here), posterior labrum, glenoid and humeral head cartilage, and articular-side rotator cuff.
**Anterior portal (working portal - UNDER DIRECT VISION):** With the arthroscope viewing from the posterior portal, I create the anterior portal under direct visualization. I insert a spinal needle from outside just lateral to the coracoid, aiming to pass through the rotator interval (between subscapularis and supraspinatus) and enter the joint near the biceps tendon. **I watch the needle enter the joint on my monitor.** Once I confirm ideal position, I make a skin incision and insert a cannula following the same trajectory as the needle, again under direct visualization.
**Additional portals:** If needed for specific procedures, I create lateral portals, anterosuperolateral portals, or posterolateral portals, all under direct arthroscopic vision using spinal needle localization first.
The key principle is that the posterior portal is created first as the viewing portal, and all subsequent portals are created under direct arthroscopic visualization to ensure safety and optimal positioning.
KEY POINTS TO SCORE
Beach chair position preferred - maintain MAP greater than 70mmHg
Posterior portal FIRST: 2cm medial, 2cm inferior to posterolateral acromion (soft spot)
Posterior portal is viewing portal - aim toward coracoid
Systematic examination before creating working portals
Anterior portal UNDER DIRECT VISION through rotator interval
Spinal needle localization for all portals under direct visualization
All working portals created watching on monitor - never blind
COMMON TRAPS
✗Creating anterior portal blind (must be under direct vision)
✗Not mentioning systematic examination sequence
✗Not knowing the 2-2 rule for posterior portal (2cm medial, 2cm inferior)
✗Forgetting to mention cerebral perfusion concerns in beach chair
LIKELY FOLLOW-UPS
"Where exactly does the axillary nerve run and how do you protect it?"
"What are the advantages of lateral decubitus over beach chair position?"
"How would you manage fluid extravasation causing neck swelling?"
VIVA SCENARIOModerate
Scenario 2: Intraoperative Complication - Cannot Visualize Glenoid
EXAMINER
"During shoulder arthroscopy for anterior instability, after establishing the posterior portal you have poor visualization of the anterior glenoid due to bleeding and cannot see clearly to create your anterior working portal. How do you proceed?"
EXCEPTIONAL ANSWER
Poor visualization during shoulder arthroscopy is a common challenge that requires systematic troubleshooting.
**Immediate assessment:**
First, I would assess the cause of poor visualization:
- Is there active bleeding (need to identify source and control)?
- Is there inadequate joint distension?
- Is the arthroscope in the correct position?
- Is the pump pressure adequate?
- Is there fluid extravasation?
**Systematic approach to improve visualization:**
**Step 1: Optimize fluid flow**
- Increase pump pressure incrementally (start at 40mmHg, can increase to 60mmHg maximum)
- Ensure adequate inflow through the arthroscope sheath
- Consider switching to pump if using gravity inflow
- Check outflow is not obstructed
**Step 2: Control bleeding**
- Identify bleeding source using arthroscope
- If bleeding from portal site: adjust cannula position, use larger diameter cannula to tamponade
- If bleeding from synovium or capsule: increase pump pressure temporarily to tamponade, consider use of epinephrine in irrigation fluid (1:1000 concentration, 1mL per 3L bag if permitted)
- If bleeding from larger vessel: may need bipolar radiofrequency probe through additional portal to cauterize
**Step 3: Ensure adequate joint distension**
- Inject additional saline to distend capsule
- In some cases, joint is too tight - may need to release some capsular adhesions first
**Step 4: Verify arthroscope position**
- Ensure arthroscope is truly intra-articular (should see humeral head and glenoid)
- If in soft tissue, reposition scope
- Withdraw scope slightly if too close to structures (can create red-out from proximity to capsule)
**Step 5: Create anterior portal for outflow**
- If visualization improves enough to see rotator interval, consider creating anterior portal for outflow even with suboptimal view
- Insert spinal needle through rotator interval under limited vision, then use switching stick technique
- Insert outflow cannula through anterior portal
- This creates flow-through (inflow posterior, outflow anterior) which dramatically improves visualization
**If visualization remains inadequate:**
- Consider converting to mini-open approach
- Consider aborting procedure and rescheduling after addressing underlying issue (may be acute synovitis, acute trauma with hemarthrosis)
**For this specific case (anterior instability):**
Given this is instability surgery (likely has good capsular space), I would:
1. Increase pump pressure to 50-60mmHg to tamponade bleeding
2. Inject additional saline through a separate anterior portal using spinal needle to further distend joint
3. Once visualization improves, create formal anterior working portal under better vision
4. If bleeding is from acute trauma, may need to proceed quickly or consider staging procedure
**Prevention:**
- Minimize portal trauma during creation
- Use smooth cannulas
- Adequate distension before creating portals
- Control pump pressure appropriately from the start
The key is systematic troubleshooting and not forcing ahead with poor visualization, as this increases risk of iatrogenic injury.
KEY POINTS TO SCORE
Systematic approach: assess cause of poor visualization
Optimize fluid flow: increase pump pressure (up to 60mmHg), ensure adequate inflow/outflow
Control bleeding: identify source, increase pressure to tamponade, consider epinephrine in irrigation
Create outflow portal: anterior portal for flow-through improves visualization dramatically
Do not proceed with poor visualization - high risk of iatrogenic injury
Consider conversion to mini-open or abort if unable to improve
Prevention: gentle portal creation, adequate distension, appropriate pump pressure from start
COMMON TRAPS
✗Proceeding with poor visualization (high injury risk)
✗Not increasing pump pressure to tamponade bleeding
✗Not creating outflow portal to improve flow-through
✗Not considering conversion or aborting procedure if unsafe
LIKELY FOLLOW-UPS
"What pump pressure would you use and what is the maximum safe pressure?"
"How would you create an anterior portal if you can barely see the rotator interval?"
"What are the risks of excessive pump pressure?"
VIVA SCENARIOStandard
Scenario 3: Beach Chair vs Lateral Decubitus - Justify Your Choice
EXAMINER
"You are planning an arthroscopic Bankart repair for recurrent anterior shoulder instability. The examiner asks: 'Would you use beach chair or lateral decubitus positioning and why?'"
EXCEPTIONAL ANSWER
Both beach chair and lateral decubitus positions are acceptable for arthroscopic Bankart repair, and the choice often comes down to surgeon preference and training. However, I would use **beach chair position** for this case and I will explain my reasoning.
**My choice: Beach Chair Position**
**Advantages for this case:**
1. **Familiar anatomy orientation** - The shoulder is in an upright position which matches my mental model from open surgery. This makes navigation easier, especially if I need to convert to open if the arthroscopic repair is not adequate or if I encounter unexpected findings (e.g., significant glenoid bone loss requiring bone block procedure).
2. **Easy conversion to open** - If I need to convert to open Bankart repair or if I discover bone loss requiring Latarjet or bone block procedure, I can seamlessly convert without repositioning. This is important for instability cases where bone loss may not be fully appreciated until arthroscopy.
3. **Intraoperative stability testing** - At the end of the repair, I can easily test shoulder stability by manipulating the arm in various positions to ensure the repair is secure and there is no persistent instability. This is more difficult in lateral position with traction applied.
4. **Anesthesia access** - The anesthesia team has better access to the airway, which is important if there is fluid extravasation to the neck (although this is rare).
5. **No traction required** - I avoid brachial plexus traction injury risk that exists with lateral position and traction setup.
**Disadvantages I acknowledge:**
1. **Cerebral hypoperfusion risk** - I must communicate with anesthesia to maintain mean arterial pressure greater than 70mmHg throughout the case to prevent watershed cerebral infarcts in the upright position. This requires close monitoring.
2. **Posterior access** - Visualization of far posterior structures is slightly more challenging compared to lateral position, but for anterior Bankart repair this is not a major limitation.
**Alternative: Lateral Decubitus Position**
I recognize that many high-volume shoulder arthroscopists prefer lateral decubitus position for instability surgery because:
- **Better posterior access** - Gravity helps visualize posterior structures
- **Joint distraction** - Traction opens the joint which can improve visualization and working space
- **No cerebral perfusion concerns** - Eliminates hypotension risks
- **Gravity assists with fluid flow** - Debris and blood fall away from superior structures
However, the disadvantages for instability cases are:
- **Difficult conversion to open** - Requires complete repositioning if bone block needed
- **Brachial plexus traction risk** - Requires careful monitoring and traction limitation (4-5kg maximum)
- **Unfamiliar orientation** - Anatomy is rotated 90 degrees which has a learning curve
**Conclusion:**
For arthroscopic Bankart repair, I would use **beach chair position** because of ease of conversion to open (in case bone loss requires bone block), better stability testing at case completion, familiar anatomy orientation, and elimination of traction injury risk. I would ensure close communication with anesthesia regarding blood pressure management and monitor for fluid extravasation.
Both positions are valid and the surgeon should use whichever position they are most comfortable and experienced with, as outcomes are similar with either approach when performed by experienced surgeons.
KEY POINTS TO SCORE
Both beach chair and lateral are acceptable - surgeon preference
Beach chair advantages: easy conversion to open, familiar anatomy, better stability testing, no traction risk
Beach chair disadvantages: cerebral hypoperfusion risk (need MAP greater than 70), slightly harder posterior access
Lateral advantages: better posterior access, joint distraction, no cerebral perfusion concerns
Lateral disadvantages: difficult conversion to open, brachial plexus traction risk, unfamiliar orientation
For instability (Bankart), beach chair preferred due to potential need for conversion to open bone block if bone loss found
Communication with anesthesia essential in beach chair for blood pressure management
COMMON TRAPS
✗Saying one position is universally better (both are valid)
✗Not knowing cerebral perfusion concerns with beach chair
✗Not knowing traction risks with lateral
✗Not mentioning conversion to open as a key consideration for instability cases
LIKELY FOLLOW-UPS
"How much traction would you use in lateral position and what is the maximum safe amount?"
"What blood pressure target would you communicate to anesthesia in beach chair?"
"If you found 30% glenoid bone loss during arthroscopy, how would you proceed?"
MCQ Practice Points
Posterior Portal Landmarks
Q: What are the correct landmarks for the posterior viewing portal in shoulder arthroscopy?
A: 2cm medial and 2cm inferior to the posterolateral corner of the acromion. This is the "soft spot" and represents the safest and most consistent entry point. The portal passes through infraspinatus muscle and posterior capsule to enter the glenohumeral joint, aiming toward the coracoid process anteriorly.
Axillary Nerve Protection
Q: Where does the axillary nerve run in relation to the glenoid and how do you protect it during shoulder arthroscopy?
A: The axillary nerve runs 5-7mm inferior to the glenoid rim at the anteroinferior capsule. To protect it during arthroscopic Bankart repair and anterior-inferior capsular work, stay superior to the 5 o'clock position on the right shoulder (or 7 o'clock on the left shoulder). Avoid excessive capsular release inferiorly and place anchors superior to this position.
Anterior Portal Gateway
Q: What is the safe anatomic gateway for the anterior working portal and what are its boundaries?
A: The rotator interval is the safe gateway. Boundaries are: superior border of subscapularis (inferior), anterior border of supraspinatus (superior), coracoid base (medial), and transverse humeral ligament over bicipital groove (lateral). The portal enters just lateral to the coracoid, passes through the rotator interval, and enters the joint near the biceps tendon origin.
Beach Chair Cerebral Perfusion
Q: What is the target blood pressure for shoulder arthroscopy in beach chair position and why?
A: Mean arterial pressure should be maintained greater than 70mmHg to prevent cerebral hypoperfusion and watershed infarcts in the upright position. This requires communication with anesthesia and blood pressure monitoring throughout the procedure. Hypotension in beach chair can lead to cerebral ischemia.
Portal Creation Sequence
Q: What is the correct sequence for shoulder arthroscopy portal creation and why?
A: Posterior portal is ALWAYS created first. This is the primary viewing portal and is created using palpable landmarks (2cm medial, 2cm inferior to posterolateral acromion). All subsequent portals (anterior, lateral, etc.) are created under direct arthroscopic visualization from the posterior portal using spinal needle localization. This minimizes risk of iatrogenic injury to neurovascular structures and rotator cuff.
Lateral Portal Anatomy
Q: The lateral (Neviaser) portal passes through which structure and what is the risk?
A: The lateral portal passes directly through the supraspinatus tendon to enter the glenohumeral joint. The risk is iatrogenic injury to the supraspinatus. This is minimized by: (1) creating the portal under direct visualization, (2) using smooth cannula insertion, (3) minimizing the number of passes through the tendon. The lateral portal is primarily used for rotator cuff repairs and superior labral work where access to the cuff tendon is already needed.
Australian Context
Epidemiology:
Shoulder arthroscopy is one of the most commonly performed orthopedic procedures in Australia, with over 40,000 procedures performed annually. The most common indications are rotator cuff repair, subacromial decompression, and anterior shoulder stabilization for instability.
Practice patterns:
- Beach chair positioning is most common in Australian practice (approximately 70% of surgeons), though lateral decubitus has significant representation particularly among high-volume shoulder arthroscopists
- Standard perioperative antibiotics: Cefazolin 2g IV (or vancomycin 15mg/kg if penicillin allergic) within 60 minutes of incision
- Thromboprophylaxis: Generally not required for isolated shoulder arthroscopy unless patient has additional risk factors
Training requirements:
Shoulder arthroscopy is a core skill for Australian orthopedic trainees. Competence in:
- Beach chair and lateral positioning
- Standard portal creation (posterior, anterior)
- Systematic arthroscopic examination
- Diagnostic arthroscopy
These skills are expected for FRACS examination and independent practice.
Medicolegal considerations:
- Obtain informed consent discussing: nerve injury risk (particularly axillary nerve), infection, stiffness, failure of repair, conversion to open surgery
- Document systematic arthroscopic examination findings
- Document all portals created and structures at risk
- Early postoperative assessment of neurovascular function
- Clear documentation if conversion to open required
Australian guidelines:
- RACS guidelines for perioperative antibiotics and VTE prophylaxis
- Australian Orthopaedic Association practice standards
SHOULDER ARTHROSCOPY APPROACH
High-Yield Exam Summary
Key Positioning
- •Beach chair: 30-45° back elevation, maintain MAP greater than 70mmHg, arm free-draped, easy conversion to open
- •Lateral decubitus: true lateral, 4-5kg traction, 30-45° abduction, better posterior access, brachial plexus risk
- •Both positions acceptable - surgeon preference, beach chair easier for conversion to open
Standard Portals
- •Posterior (FIRST): 2cm medial, 2cm inferior to posterolateral acromion - viewing portal, aim toward coracoid
- •Anterior (UNDER VISION): lateral to coracoid through rotator interval - working portal, watch needle enter on monitor
- •Lateral (Neviaser): 2-3cm lateral to acromion, through supraspinatus - for cuff repairs and SLAP
- •Anterosuperolateral: between anterior and lateral - for biceps, superior labrum
- •ALL portals except posterior created UNDER DIRECT VISION with spinal needle localization
Structures at Risk
- •Axillary nerve: 5-7mm inferior to glenoid rim - stay superior to 5 o'clock (right) or 7 o'clock (left)
- •Musculocutaneous nerve: 3-8cm from coracoid in coracobrachialis - stay lateral to coracoid for anterior portal
- •Suprascapular nerve: posterior scapula at spinoglenoid notch - avoid excessive posterior medial dissection
- •Rotator cuff: posterior portal through infraspinatus, lateral through supraspinatus - minimize trauma
Systematic Examination Sequence
- •1. Biceps tendon - fraying, tears, SLAP at origin
- •2. Superior labrum - 10-2 o'clock, SLAP tears
- •3. Rotator interval - subscapularis/supraspinatus interval
- •4. Subscapularis - articular side only from intra-articular view
- •5. Anterior labrum - 2-6 o'clock, Bankart lesion
- •6. Inferior capsule - axillary nerve 5-7mm below rim here
- •7. Posterior labrum - 6-10 o'clock, reverse Bankart
- •8. Glenoid cartilage - bone loss percentage in instability
- •9. Humeral head - Hill-Sachs lesion, cartilage
- •10. Rotator cuff - articular side partial tears
Technical Pearls
- •Posterior portal ALWAYS first using soft spot (2-2 rule)
- •Spinal needle localization for ALL portals under direct vision
- •Rotator interval is gateway for anterior portal
- •Pump pressure: 40-60mmHg maximum (lower reduces extravasation)
- •30-degree arthroscope standard for shoulder
- •Clock face: right shoulder anterior is 1-5 o'clock, left shoulder anterior is 7-11 o'clock
Complications and Prevention
- •Axillary nerve injury (0.1-2%): protect by staying superior to 5/7 o'clock, avoid excessive inferior capsular release
- •Iatrogenic chondral injury (1-5%): gentle cannula insertion, visualize all portals, minimize instrument passes
- •Fluid extravasation (10-30%): limit pump pressure less than 60mmHg, monitor neck in beach chair (airway risk)
- •Infection (less than 1%): perioperative antibiotics (cefazolin 2g), sterile technique
- •Stiffness (2-5%): early passive ROM per protocol, appropriate physiotherapy