import { ComparisonTable, ContentSection, EvidenceCard, ExamCheatSheet, ExamPearl, ExamWarning, InfoCard, InfoCardGrid, MedicalImage, MnemonicCard, OnePagerSummary, SafetyAlert, Tab, Tabs, Timeline, TimelineItem, VivaScenario, VivaScenarioSection } from '@/components/mdx' {/* SECTION 1: ONE-PAGER SUMMARY */} {/* SECTION 2: EXAM WARNING */} **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. 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). 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). **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. {/* SECTION 3: MNEMONICS */} 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. {/* SECTION 4: OVERVIEW */} **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:** 1. **Rotator Cuff Pathology** - Rotator cuff repair (partial-thickness and full-thickness tears) - Subacromial decompression - Debridement of irreparable tears 2. **Shoulder Instability** - Labral repair (Bankart lesion, SLAP tears, posterior labral tears) - Capsular plication for multidirectional instability - Hill-Sachs remplissage 3. **Biceps Pathology** - Biceps tenodesis - Biceps tenotomy - SLAP repair 4. **Acromioclavicular Joint** - AC joint excision arthroplasty - AC joint stabilization 5. **Adhesive Capsulitis** - Arthroscopic capsular release 6. **Loose Bodies and Synovial Disease** - Loose body removal - Synovectomy (rheumatoid arthritis, PVNS) 7. **Diagnostic** - When imaging inconclusive - Evaluation of unexplained shoulder pain **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 {/* SECTION 5: ANATOMY */} **Surface anatomy landmarks:** **Intra-articular anatomy (systematic arthroscopic examination):** 1. **Biceps tendon** - long head origin from supraglenoid tubercle, runs in bicipital groove 2. **Rotator interval** - space between subscapularis and supraspinatus, contains coracohumeral ligament and superior glenohumeral ligament 3. **Subscapularis** - anterior rotator cuff, inserts on lesser tuberosity 4. **Supraspinatus** - superior rotator cuff, inserts on greater tuberosity (superior facet) 5. **Infraspinatus and teres minor** - posterior rotator cuff, insert on greater tuberosity (middle and inferior facets) 6. **Labrum** - fibrocartilaginous rim attached to glenoid, deepens socket (superior, anterior, inferior, posterior segments) 7. **Capsule and ligaments** - superior, middle, and inferior glenohumeral ligaments reinforce capsule **Structures at risk:** 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. {/* SECTION 5.5: 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. **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. **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:** 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. {/* SECTION 6: PATIENT POSITIONING */} ### Beach Chair Position (Most Common in Australia) **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:** 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. 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. 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. 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. 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. 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. ### Lateral Decubitus Position (Alternative) **Advantages:** - **Better posterior access** - gravity assists with visualization of posterior structures - **Joint distraction** - traction opens joint space, improving visualization - **Gravity assists** - fluid and debris fall away from superior and anterior structures - **No cerebral perfusion concerns** - lateral position eliminates hypotension risks - **Preferred by many arthroscopists** - especially for labral repair and complex instability procedures **Disadvantages:** - **Unfamiliar orientation** - anatomy is rotated 90 degrees from normal - **Difficult conversion to open** - requires repositioning if need to convert - **Brachial plexus traction risk** - excessive traction can cause neurapraxia - **Setup time** - more complex positioning with beanbag, traction system - **Stability assessment** - harder to test shoulder stability intraoperatively **Setup technique:** Place patient in true lateral decubitus position on beanbag. Operative side up. Non-operative shoulder supported on padded support. Axillary roll under dependent axilla to protect brachial plexus. Mold beanbag around patient and evacuate to secure position. Alternatively use posts and padding. Pelvis and thorax secured with tape or kidney rests. All bony prominences padded (fibular head, lateral malleolus, greater trochanter). Attach traction system to table. Apply arm holder/sling to operative arm. Alternative systems: overhead boom traction or lateral traction post. Ensure traction system is secure and aligned. Apply 4-5kg (10-15 pounds) of balanced traction. Arm positioned in 30-45 degrees abduction, 10-15 degrees forward flexion. Monitor for excessive traction - check radial pulse periodically. Ensure patient is in TRUE lateral position (no rotation forward or back). Operative shoulder should be perpendicular to floor. Head supported on pillow in neutral alignment. All pressure points checked and padded. **Excessive traction can cause brachial plexus neurapraxia**. Use minimum traction necessary (typically 4-5kg). Limit procedure time if possible. Check radial pulse periodically. If procedure extends beyond 90 minutes, consider releasing traction temporarily to allow reperfusion. **Traction management:** - Start with 4-5kg traction - Increase if visualization poor (up to 7kg maximum) - Release traction for stability testing if needed - Release traction if radial pulse diminishes Lateral decubitus is preferred for complex labral repairs and by arthroscopists who value posterior access and joint distraction. 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." {/* SECTION 7: SURGICAL TECHNIQUE */} ### 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 ### Complex Anatomic Variations **Vascular Variations:** - Posterior humeral circumflex artery variant courses: May affect posterior portal in 5% of cases - Anterior circumflex artery variations: Rarely affect standard anterior portal **Nerve Variations:** - Axillary nerve bifurcation pattern varies - some patients have early bifurcation closer to glenoid - Accessory suprascapular nerve (rare): May be at risk with lateral portal **Capsular Variations:** - Glenohumeral ligament variations affect capsular anatomy: - Type I: Absent IGHL (10%) - Type II: Well-developed IGHL - Type III: Cord-like MGHL with absent IGHL Know the **Buford complex** and **sublabral foramen** - these are **normal variants** that can be mistaken for pathology. The sublabral foramen is a natural labral detachment between 11-1 o'clock position. The Buford complex is absent anterosuperior labrum with a thick cord-like middle glenohumeral ligament. **Do not repair these normal variants.** ### Portal Classification Systems **Standard Portals (Used in most procedures):** **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 | ### Extended Portal Systems **Accessory Portals:** - **Posterolateral (7 o'clock portal)**: For posterior labral repair viewing - **Anteroinferior (5 o'clock portal)**: For inferior labral anchors - **Trans-subscapularis**: For subscapularis repair (controversial) - **Percutaneous portals**: For specific anchor placement **Named Portal Variants:** - **Neviaser portal**: Original description - superior portal through supraspinatus - **Port of Wilmington**: Anterosuperolateral for SLAP access - **Assassin's portal**: Posterolateral for posterior Bankart **Match portals to pathology**: The number and location of portals should be tailored to the specific procedure. Start with standard posterior viewing portal and anterior working portal, then add accessory portals as needed for the specific pathology being addressed. **All accessory portals are created under direct arthroscopic visualization.** ### 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 ### Specific Preoperative Considerations **Factors Affecting Portal Placement:** - **Body habitus**: Obesity may require longer instruments and deeper portals - **Prior surgery**: Scarring may limit capsular distension and visibility - **Contracture/stiffness**: Adhesive capsulitis requires careful portal creation with limited joint distension **Position-Specific Assessment:** **Key consent points**: (1) Nerve injury risk - particularly axillary nerve (0.1-2%), (2) Infection (less than 1%), (3) Stiffness (2-5%), (4) Failure of repair requiring revision, (5) Conversion to open surgery if needed, (6) DVT/PE (rare in shoulder surgery), (7) Procedure-specific complications (anchor failure, re-tear, etc.). ### 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 ### Advanced Imaging for Surgical Planning **CT Scan (for bone pathology):** - Glenoid bone loss quantification (critical for instability surgery) - Hill-Sachs sizing and engagement assessment - Glenoid version measurement - 3D reconstruction for bone block planning **Glenoid Bone Loss Assessment:** **Key Measurements for Surgical Planning:** - **Glenoid bone loss percentage**: Greater than 20-25% requires bone augmentation - **Hill-Sachs size**: Assess for engagement with glenoid track concept - **Glenoid version**: Retroversion greater than 15 degrees may affect anchor placement - **Rotator cuff tear size**: Dictates repair technique and prognosis **Instability**: Plain X-rays + MR arthrography (labral detail) + CT if bone loss suspected. **Rotator cuff**: Plain X-rays + MRI. **SLAP**: MR arthrography is gold standard. **Arthritis evaluation**: Plain X-rays may be sufficient if considering diagnostic scope. ### 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 | ### Complex Procedure Selection **Bone Loss Considerations:** **Decision Factors for Procedure Selection:** - **Age**: Older patients may tolerate tenotomy over tenodesis, nonoperative management - **Activity level**: Athletes require anatomic repair, may need bone block - **Bone loss**: Determines arthroscopic vs open approach - **Tissue quality**: Poor tissue may require augmentation or different technique - **Surgeon experience**: Complex procedures require appropriate training **Arthroscopic Bankart repair** is standard for primary anterior instability with less than 20% glenoid bone loss and no engaging Hill-Sachs. **Convert to open bone block** (Latarjet, Bristow, iliac crest bone block) when: (1) Greater than 20-25% glenoid bone loss, (2) Engaging Hill-Sachs not addressable with remplissage, (3) Revision instability with failed arthroscopic repair, (4) Significant humeral bone loss. ### Standard Portal Creation Sequence **Principle: Posterior portal ALWAYS first, all other portals under direct vision.** 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. 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. 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). 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. 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. 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). 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. ### Anterior Portal (Working Portal) - UNDER DIRECT VISION The anterior portal is the primary working portal for most shoulder arthroscopy procedures. **It must ALWAYS be created under direct arthroscopic visualization from the posterior viewing portal.** Ensure excellent visualization from posterior portal. Identify key landmarks: biceps tendon (superior), subscapularis (inferior), rotator interval (space between), glenoid (medial), humeral head (lateral). The anterior portal enters through the **rotator interval** - the triangular space between subscapularis (below) and supraspinatus (above). The target is just lateral to the coracoid, entering the joint near the biceps tendon. From outside, insert 18-gauge spinal needle just lateral to the coracoid (palpate coracoid first). Aim posteriorly toward the glenoid. **Watch the needle enter the joint on your arthroscopy monitor from the posterior view.** The needle should pass through the rotator interval and enter the joint superior to the subscapularis. The ideal anterior portal enters lateral to coracoid, passes through rotator interval, and enters joint near the biceps tendon origin. Adjust needle position as needed while watching on monitor. You want triangulation with the posterior portal for working instruments. Once ideal needle position confirmed under direct vision, make skin incision with 11-blade at needle entry point. The incision is typically 1-1.5cm long, longitudinal or transverse. Remove needle. Insert switching stick or cannula with blunt trocar through the incision, following the same trajectory as the needle, under direct arthroscopic visualization. Watch the cannula enter the joint on the monitor. Insert cannula into joint. The anterior portal cannula is now in place. Insert probe or other working instrument through it to confirm working access to all joint structures. The working portal should allow access to anterior labrum, glenoid, biceps, and posterior structures by triangulating with the viewing portal. **The anterior portal must ALWAYS be created under direct arthroscopic vision.** Creating this portal blind risks injury to the axillary nerve (inferiorly), musculocutaneous nerve (medially), rotator cuff (superiorly and inferiorly), and vascular structures. The spinal needle localization under direct vision ensures safe placement. **Common anterior portal placement errors:** - **Too inferior** - risks axillary nerve injury, subscapularis injury - **Too medial** - risks musculocutaneous nerve, coracoid impingement - **Too superior** - traverses supraspinatus tendon causing iatrogenic cuff damage - **Correct placement** - through rotator interval, lateral to coracoid, just superior to subscapularis The anterior portal is created under direct visualization to ensure safety and optimal working access. ### Additional Portals for Specific Procedures **Lateral Portal (Neviaser Portal)** Rotator cuff repair (supraspinatus and infraspinatus), superior labral repair (SLAP), superior capsule reconstruction, subacromial decompression. 2-3cm lateral to the lateral edge of the acromion, in line with the posterior border of the clavicle. The portal passes directly through the deltoid muscle and then through the supraspinatus tendon into the glenohumeral joint. Under direct visualization from posterior portal, insert spinal needle at planned location. Watch needle enter joint through supraspinatus. Once confirmed, make incision and insert cannula. Minimize trauma to supraspinatus by using smooth cannula insertion. **Anterosuperolateral Portal (Port of Wilmington)** SLAP repair, biceps tenodesis, superior labral pathology, some rotator cuff repairs requiring anterior-superior access. Anterolateral to the AC joint, between the standard anterior portal and lateral portal. Creates a working angle for superior structures. Created under direct vision from posterior portal. Spinal needle localization to ensure ideal trajectory for superior labrum or biceps anchor. Make incision and insert cannula once position confirmed. **Posterolateral Portal (Portal of Wilmington variant)** Posterior labral repair, posteroinferior capsular shift, posterior Bennett lesion treatment. 1-2cm lateral and 1-2cm inferior to the standard posterior portal. This creates a better working angle for posterior labrum. Created under direct vision from the standard posterior viewing portal or by switching camera to anterior portal and creating under posterior view. Spinal needle localization essential. **Subacromial Portals** For subacromial decompression, rotator cuff repair from bursal side: **ALL portals except the initial posterior portal are created under direct arthroscopic visualization.** This is non-negotiable. Spinal needle localization allows you to confirm the ideal trajectory before committing to skin incision and cannula insertion. This minimizes risk of iatrogenic injury to neurovascular structures and rotator cuff. The number and location of portals should be tailored to the specific procedure being performed. ### Systematic Arthroscopic Examination Sequence After establishing the posterior viewing portal and before creating working portals, perform a systematic diagnostic examination. **Recommended examination sequence from posterior viewing portal:** Long head of biceps tendon originating from supraglenoid tubercle. Assess for: fraying, partial tears, subluxation, SLAP lesion at the origin. Follow biceps into bicipital groove. Superior labrum from 10 o'clock to 2 o'clock position. Assess for SLAP tears (Type I-IV), detachment, fraying. Probe to assess stability of labral attachment. Space between subscapularis and supraspinatus. Assess superior glenohumeral ligament and coracohumeral ligament. Check for adhesions or synovitis. Anterior rotator cuff inserting on lesser tuberosity. Assess articular surface for tears. Note: bursal surface cannot be seen from intra-articular view. Anterior labrum from 2 o'clock to 6 o'clock (right shoulder). Assess for Bankart lesion (anterior labral detachment), ALPSA lesion, Perthes lesion. Assess inferior glenohumeral ligament complex. Inferior capsule and axillary recess. Assess for inferior labral pathology, capsular laxity. Remember axillary nerve is 5-7mm below glenoid rim here. Posterior labrum from 6 o'clock to 10 o'clock. Assess for posterior labral tears, reverse Bankart lesion, Bennett lesion (posterior labral ossification in throwers). Assess glenoid cartilage for chondral lesions, wear patterns, bipolar bone loss (in instability). Note any glenoid bone loss percentage. Assess humeral head cartilage. Look for Hill-Sachs lesion (posterolateral compression fracture from anterior dislocation), reverse Hill-Sachs (anteromedial from posterior dislocation), chondral defects. Supraspinatus, infraspinatus, and teres minor insertions on greater tuberosity. Assess for partial articular-side tears. Note: cannot assess full thickness tears or bursal-side tears from intra-articular view. **Documentation:** - Video or photo documentation of all pathology - Use clock face to describe labral lesion locations (right shoulder: anterior is 3 o'clock, inferior is 6 o'clock, posterior is 9 o'clock) - Measure glenoid bone loss if present (percentage of inferior glenoid diameter) - Classify Hill-Sachs lesions (size, engaging vs non-engaging) - Grade cartilage lesions (Outerbridge or ICRS classification) **Right shoulder**: Anterior labrum is 1-5 o'clock, Inferior is 5-7 o'clock, Posterior is 7-11 o'clock, Superior is 11-1 o'clock. **Left shoulder**: Mirror image - Anterior is 7-11 o'clock, Inferior is 5-7 o'clock, Posterior is 1-5 o'clock, Superior is 11-1 o'clock. **Alternatively**: Use anatomic terms (anterior-superior, anterior-inferior, posterior-superior, posterior-inferior) to avoid confusion. Complete systematic examination before proceeding to therapeutic procedures. {/* SECTION 8: COMPLICATIONS */} **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 {/* SECTION 9: EVIDENCE BASE */} ### 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 ### Procedure-Specific Rehabilitation **Instability Repair (Bankart):** - Weeks 0-4: Sling, pendulums, passive ER to 0 degrees only - Weeks 4-6: Progress passive ER to 30 degrees, wean sling - Weeks 6-12: Active-assisted ROM, light strengthening - Week 12+: Full strengthening, sport-specific training - Return to contact sport: 6 months minimum **Rotator Cuff Repair:** - Weeks 0-6: Sling, passive ROM only, no active elevation - Weeks 6-12: Active-assisted to active ROM - Week 12+: Strengthening program - Duration depends on tear size and tissue quality **Tissue healing dictates rehabilitation**: Labral tissue takes 6-12 weeks to heal to bone. Tendon-to-bone healing (rotator cuff) takes 8-16 weeks. Rehabilitation must respect tissue healing times while preventing stiffness. **Balance protection with mobilization** based on the specific procedure performed. ### 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% ### Factors Affecting Outcomes **Positive Prognostic Factors:** - First-time surgery (not revision) - Minimal bone loss (instability) - Small tear size (rotator cuff) - Good tissue quality - Compliant with rehabilitation - Non-smoker **Negative Prognostic Factors:** - Revision surgery - Significant bone loss requiring bone block - Large or massive tears with fatty infiltration - Workers' compensation claims - Smoking - Older age (for cuff healing) - Young age (for instability recurrence) **Comparison: Arthroscopic vs Open Outcomes:** **Arthroscopic Bankart repair** has slightly higher recurrence rates (5-15%) than open repair (2-8%), but offers better preservation of external rotation and cosmesis. For **high-risk patients** (young contact athletes, significant bone loss, revision surgery), consider open bone block procedures which have lower recurrence rates (3-5%) but higher complication rates. {/* SECTION 10: VIVA SCENARIOS */} {/* SECTION 11: MCQ PRACTICE POINTS */} **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. **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. **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. **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. **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. **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. {/* SECTION 12: 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 {/* SECTION 13: EXAM CHEAT SHEET */}

Shoulder Arthroscopy Approach

Shoulder Arthroscopy Approach