High Yield Overview

SHOULDER HEMIARTHROPLASTY - DELTOPECTORAL APPROACH

Deltopectoral approach | advanced

Critical Danger Structures - MUST KNOW

Axillary Nerve

Location: Exits quadrangular space, runs 5-7cm inferior to lateral acromion edge, winds around surgical neck of humerus with posterior circumflex humeral artery

Protection: Avoid dissection >5cm below acromion inferior edge, gentle inferior capsular release only, identify and protect during humeral preparation

Musculocutaneous Nerve

Location: Penetrates conjoint tendon (coracobrachialis) 5-8cm distal to coracoid tip, variable anatomy (3-10cm range)

Protection: Avoid aggressive medial retraction of conjoint tendon, minimal dissection medial to conjoint, gentle retractor placement

Anterior Circumflex Vessels

Location: "Three sisters" - run horizontally along inferior border of subscapularis tendon, 3 small arteries typically present

Protection: Identify and ligate/cauterize before subscapularis release to prevent bleeding that obscures surgical field

Cephalic Vein

Location: Runs in deltopectoral groove, marks the interval between deltoid and pectoralis major, lateral tributaries from deltoid, medial from pectoralis

Protection: Retract LATERAL with deltoid (preserves lateral tributaries), do not ligate (risk of DVT), gentle handling

Posterior Circumflex Vessels

Location: Travel with axillary nerve through quadrangular space, wind around surgical neck posteriorly

Protection: Gentle humeral manipulation, avoid aggressive circumferential dissection around neck, bleeding indicates nerve proximity

Mnemonic

Three SISTERS at Subscapularis Inferior borderSISTERS

Mnemonic

VERSION determines stabilityVERSION

Primary Indications

Trauma Indications

Acute 3-4 part proximal humerus fracture in elderly patients (>65-70 years)
- Head split pattern or severe comminution
- Concern for AVN risk with ORIF
- NOTE: Trend toward reverse TSA over hemiarthroplasty in most elderly fracture cases
Failed ORIF of proximal humerus fracture with:
- Humeral head collapse/AVN
- Articular incongruity
- Symptomatic malunion/nonunion

Elective Indications

Primary glenohumeral osteoarthritis with:
- Intact rotator cuff
- Glenoid bone loss or erosion (insufficient for anatomic TSA)
- Patient preference to avoid glenoid component
Avascular necrosis of humeral head:
- Preserved glenoid cartilage
- Humeral head collapse (Ficat stage 3-4)
Rheumatoid arthritis (selected cases):
- Intact rotator cuff
- Severe humeral head destruction, glenoid relatively preserved

Contraindications

Absolute:

Active infection (shoulder or systemic)
Neurologic dysfunction (axillary nerve, complete brachial plexopathy)
Insufficient bone stock for component fixation
Medical comorbidities precluding surgery

Relative:

Rotator cuff deficiency (consider reverse TSA instead)
Young active patient with high demands (reverse TSA may be better long-term)
Severe glenoid wear (will progress, consider anatomic or reverse TSA)
Non-compliance with rehabilitation protocol

Preoperative Planning

Critical Yield Data

Imaging Assessment

Templating

Surgical Decision

Equipment Required

Implants

Shoulder hemiarthroplasty system (cemented or uncemented stem options)
Modular humeral heads (range 40-56mm diameter, various eccentricities)
Bone cement (PMMA) if cementing
Cement restrictor

Instruments

Shoulder arthroplasty instrument set
Humeral canal reamers and broaches
Head resection guide/cutting blocks
Stem insertion instruments
Trial components (stems and heads)

Fixation Materials

Heavy non-absorbable sutures: #5 Ethibond (tuberosity-to-tuberosity)
#2 FiberWire or Ethibond (subscapularis, cerclage)
18-gauge wire (cerclage, if preferred)
Small fragment plates/screws (if greater tuberosity plate augmentation planned)

Positioning and Preparation

Patient position: Beach chair position (70-80° head elevation)

Entire shoulder, chest wall, arm to hand exposed
Arm free-draped (allows manipulation, extension for canal preparation)
Head secured in head holder
Ensure ability to extend and externally rotate arm

Anesthesia: General with regional block (interscalene typically)

Antibiotics: IV cefazolin (or vancomycin if MRSA risk) within 60 minutes

Positioning pearls:

Table break at level of scapula allows extension
Ensure adequate medial exposure (avoid table obstruction)
Arm holder may be useful but free arm preferred by many

Operative Steps - Complete Sequence

Step 1: Skin Incision and Superficial Dissection

Incision:

Start at coracoid process
Extend 12-15cm distally along deltopectoral groove
Aim toward lateral border of deltoid insertion
Can palpate groove as depression between muscle masses

Technique:

Incise skin, subcutaneous tissue
Identify cephalic vein in deltopectoral groove
KEY DECISION: Retract vein LATERAL with deltoid
- Preserves lateral tributaries (more robust than medial)
- Reduces risk of thrombosis
- Alternative: take vein medially (less common) or ligate (avoid if possible)

Exam Pearl

Exam Answer: "I make a deltopectoral incision from the coracoid extending 12-15cm distally. I identify the cephalic vein marking the interval. I retract it LATERAL with the deltoid - this preserves the lateral tributaries and reduces thrombosis risk. I develop the deltopectoral interval bluntly."

Dangers - Step 1

Incision too lateral = through deltoid muscle (damage to muscle, axillary nerve risk)
Incision too medial = poor exposure, conjoint tendon injury
Cephalic vein injury = bleeding, DVT risk if ligated
Inadequate skin exposure = poor visualization, increased retraction force

Step 2: Deep Dissection - Expose Rotator Cuff

Technique:

Incise clavipectoral fascia lateral to conjoint tendon
Place self-retaining retractors:
- Deltoid retracted LATERALLY
- Conjoint tendon (coracobrachialis + short head biceps) retracted MEDIALLY
Identify subscapularis tendon (large tendon extending to lesser tuberosity)
Identify rotator interval (superior - between subscapularis and supraspinatus)
Identify long head biceps tendon in bicipital groove (if intact)

Anatomic orientation:

Subscapularis is large anterior cuff tendon
Biceps tendon marks lateral border of rotator interval
Feel for coracoid medially (protect musculocutaneous nerve)

Exam Pearl

Exam Answer: "I incise the clavipectoral fascia and place retractors - deltoid lateral, conjoint medial. I protect the musculocutaneous nerve which enters the conjoint 5-8cm from the coracoid. I identify subscapularis - the large anterior cuff tendon. The rotator interval is superior, and I can see the biceps tendon in its groove."

Dangers - Step 2

Musculocutaneous nerve injury - avoid aggressive medial retraction of conjoint tendon
Axillary nerve - lies 5-7cm below acromion, avoid inferior dissection at this stage
Anterior circumflex vessels - at inferior subscapularis border (not yet exposed)
Biceps tendon injury - if tenodesing, do so deliberately (don't avulse accidentally)

Step 3: Subscapularis Management

For TRAUMA cases:

Subscapularis often torn/avulsed with lesser tuberosity fragment
Identify lesser tuberosity fragment and tag with strong suture (#2 FiberWire)
Preserve all soft tissue attachments to fragments
Identify greater tuberosity fragment and tag similarly

For ELECTIVE cases - two options:

Option A - Subscapularis tenotomy:

Release subscapularis tendon 1cm from insertion on lesser tuberosity
Tag with two #2 FiberWire sutures (medial-lateral mattress)
Easier repair, less bone healing required
Risk: tendon retraction, repair failure

Option B - Lesser tuberosity osteotomy:

Osteotomize lesser tuberosity with thin collar of bone (5mm)
Tag with two #2 FiberWire sutures through bone
Preserves tendon insertion, better healing potential
Risk: fracture, nonunion of osteotomy

Critical step - "Three Sisters":

Identify anterior circumflex humeral vessels at inferior border of subscapularis
Ligate or cauterize BEFORE completing subscapularis release
Prevents obscuring bleeding

Exam Pearl

Exam Answer: "For fracture cases, the subscapularis is often torn with the lesser tuberosity fragment - I identify and tag it with strong sutures. For elective cases, I perform either subscapularis tenotomy 1cm from insertion or lesser tuberosity osteotomy with a thin collar of bone - both tagged with #2 FiberWire. I ligate the three sisters - the anterior circumflex vessels at the inferior subscapularis border."

Dangers - Step 3

Subscapularis repair failure = anterior instability (main cause of dislocation)
Three sisters bleeding = obscured field (ligate FIRST)
Axillary nerve lies just below inferior subscapularis border
Excessive release = external rotation contracture risk
Inadequate release = difficulty exposing joint

Step 4: Capsular Release and Joint Exposure

Technique:

Release anterior capsule from glenoid rim
Place stay sutures in capsule for later repair
Release superiorly in rotator interval (to supraspinatus)
Release inferiorly (GENTLY - axillary nerve)
Apply gentle external rotation, extension, adduction to deliver head

For TRAUMA cases:

Assess fracture pattern (identify head, shaft, GT, LT fragments)
Assess head viability - look for soft tissue attachments (if none = AVN risk)
Document fracture configuration

For ELECTIVE cases:

Assess humeral head articular cartilage
Assess glenoid cartilage quality
Confirm diagnosis (OA vs AVN vs other)

Exam Pearl

Exam Answer: "I release the anterior capsule from the glenoid and place stay sutures. I release the rotator interval superiorly and gently release inferiorly - protecting the axillary nerve which is 5-7cm below the acromion. I deliver the head with external rotation, extension, and adduction. For fractures, I identify all four fragments and assess head viability."

Dangers - Step 4

Iatrogenic humeral shaft fracture - especially in osteoporotic bone, gentle manipulation
Axillary nerve injury - inferior capsular release most dangerous
Rotator cuff tear - aggressive manipulation can extend fracture lines
Glenoid fracture - from retractor or excessive force

Step 5: Humeral Head Resection and Canal Preparation

For TRAUMA:

Remove comminuted head fragments
Save greater and lesser tuberosity fragments (preserve soft tissue)
Clear canal of debris and blood clot

For ELECTIVE:

Osteotomy at anatomic neck (resection guide typically used)
Remove at 130-135° to shaft axis, 30-40° retroversion
Measure resected head for sizing

Canal preparation:

Insert canal finder/reamer
Sequential reaming (start small, increase size)
Ream until cortical chatter (avoid over-reaming)
Sequential broaching
Broach until cortical contact (avoid over-sizing)

Critical assessments with trial stem:

HEIGHT: Restore normal offset (compare to native or opposite shoulder)
VERSION: 30-40° retroversion to epicondylar axis (palpate epicondyles with elbow flexed)
SIZE: Cortical contact without over-sizing (fracture risk in osteoporotic bone)

Exam Pearl

Exam Answer: "I remove the damaged head, preserving tuberosity fragments with soft tissue in fracture cases. I ream and broach the canal sequentially, avoiding over-sizing which risks fracture in osteoporotic bone. With the trial stem I assess three critical parameters: HEIGHT to restore offset, VERSION 30-40° retroversion to the epicondyles, and SIZE for cortical contact without fracture risk."

Dangers - Step 5

IATROGENIC SHAFT FRACTURE - most common with over-sizing broach/stem in osteoporotic bone
Malversion - difficult to correct after cementing (check version repeatedly)
Incorrect height - overstuffing causes stiffness, understuffing causes instability
Humeral perforation - anterior cortex at risk with eccentric reaming

Step 6: Trialing and Soft Tissue Balancing

Head sizing:

Match native head diameter (measure resected head or templating)
Typical range 42-50mm diameter
Various eccentricities available (standard vs offset)

Trialing sequence:

Insert trial stem at correct height, version, size
Attach trial humeral head
Reduce glenohumeral joint
Assess STABILITY:
- Inferior translation with axial traction
- Anterior-posterior translation
- Should be stable, not excessive laxity
Assess ROM:
- Passive forward elevation (goal 90-120° at this stage)
- External rotation (30-40°)
- Internal rotation
Assess TENSION:
- Should feel "snug" but not overstuffed
- Too tight = stiffness, glenoid wear
- Too loose = instability, poor function

Adjustments:

Change head size if too tight/loose
Change head eccentricity if needed
Adjust stem height (up/down)
Confirm version again

Exam Pearl

Exam Answer: "I select a head size matching the native anatomy - typically 42-50mm. With trials reduced I perform three assessments: STABILITY with translation testing in all directions, ROM checking passive elevation and rotation, and TENSION - should feel snug but not overstuffed. Overstuffing causes stiffness and glenoid erosion, understuffing causes instability."

Dangers - Step 6

Overstuffing (head too large/tall) = stiffness, increased glenoid contact stress → erosion
Understuffing (head too small/short) = instability, poor rotator cuff function
Missing instability at this stage = postoperative dislocation
Eccentric head malposition affects center of rotation

Step 7: Final Component Implantation

Cemented vs uncemented decision:

TRAUMA/osteoporotic: Usually cemented (poor bone quality, immediate fixation)
ELECTIVE/good bone: Press-fit often suitable (bone preservation, biologic fixation)

Cementing technique (if used):

Place cement restrictor 2cm beyond stem tip
Clean and dry canal
Mix cement (low viscosity for mantle penetration vs high viscosity for pressurization - system dependent)
Retrograde fill canal with cement gun
Pressurize cement with distal plug or finger
Insert stem at correct version and depth
Hold version stable until cement hardens (8-10 minutes)
Remove excess cement

Press-fit technique (if used):

Clean canal
Insert stem with gradual impaction
Achieve metaphyseal fill and stability
Confirm version and depth

Final head attachment:

Attach modular humeral head to Morse taper
Impact firmly
Check head seating and rotation

Exam Pearl

Exam Answer: "I use cement for osteoporotic trauma cases and press-fit for good bone in elective cases. For cementing, I place a restrictor, clean the canal, and retrograde fill with cement. I insert the stem at 30-40° retroversion - this is critical as version cannot change after cement hardens. I attach the modular head and confirm seating."

Dangers - Step 7

MALVERSION on final component - cannot correct after cement hardens (disaster)
Cement extrusion into joint = third body wear
Air in cement = weak fixation, fracture risk
Stem prominent/recessed = offset wrong, affects function
Cement burns to soft tissue

Step 8: Tuberosity Repair (Trauma) / Soft Tissue Balancing (Elective)

For TRAUMA - Tuberosity repair (CRITICAL for outcome):

Principles:

Anatomic reduction of greater and lesser tuberosities
Restore normal anatomy and rotator cable
Multiplanar fixation
Tuberosities 5-10mm below head level

Technique:

Reduce greater tuberosity anatomically (lateral and posterior)
Reduce lesser tuberosity anatomically (anterior and medial)
GT-to-GT sutures: #5 Ethibond, horizontal mattress, restores rotator cable
Vertical cerclage: GT and LT to shaft, proximal to prosthesis, #5 Ethibond or wire
Tuberosity-to-prosthesis: Sutures through prosthesis fins/holes to tuberosities
Confirm tuberosities 5-10mm below head articular surface
Check ROM - tuberosities should not displace

For ELECTIVE:

Check rotator cuff integrity
Assess balance with trials
Repair any iatrogenic cuff injury

Exam Pearl

Exam Answer: "For fractures, tuberosity repair is THE critical determinant of functional outcome. I reduce the GT and LT anatomically around the prosthesis. I use three fixation planes: GT-to-GT with #5 Ethibond restores the rotator cable, vertical cerclage from tuberosities to shaft, and sutures from tuberosities to the prosthesis fins. Goal is tuberosities 5-10mm below the head level. I check ROM to confirm no displacement."

Dangers - Step 8

Tuberosity malunion/nonunion/resorption = POOR FUNCTION (most common cause of failure in fracture hemiarthroplasty)
Superior migration GT = subacromial impingement, cuff dysfunction
Inadequate fixation = early displacement
Sutures cut through osteoporotic bone - use large bites, consider plate augmentation
Overtensioning = fracture

Step 9: Subscapularis Repair

Technique for tenotomy:

Mobilize subscapularis (should reach lesser tuberosity without tension)
Drill 3-4 holes in lesser tuberosity (transosseous tunnels)
Pass #2 FiberWire sutures through bone tunnels
Pass sutures through subscapularis tendon (mattress configuration)
Tie with arm in neutral to 20° internal rotation
Test repair strength manually

Technique for LT osteotomy:

Reduce LT fragment anatomically
Secure with screws (if fragment large enough) or heavy sutures
Ensure stable fixation

Critical assessment:

Subscapularis should be snug but not over-tight
Test with passive external rotation - should achieve 30-40°
Too tight = rupture, external rotation loss
Too loose = anterior instability

Exam Pearl

Exam Answer: "Subscapularis repair is critical for anterior stability. I use transosseous sutures through drill holes in the lesser tuberosity with #2 FiberWire in mattress configuration. I tie with the arm in neutral to slight internal rotation. The repair should be snug but allow 30-40° external rotation. Too tight risks rupture, too loose risks anterior instability."

Dangers - Step 9

Subscapularis failure = anterior instability, dislocation (main cause of instability)
Repair too tight = rupture, external rotation loss
Repair too loose = anterior subluxation/dislocation
Sutures pull through if bone quality poor

Step 10: Capsular Repair and Closure

Capsule:

Repair anterior capsule using stay sutures placed earlier
Absorbable sutures (0 or 2-0 Vicryl)
Snug but not over-tight

Final ROM assessment:

Passive forward elevation (goal 90-120° immediate post-op)
External rotation (30-40°)
Internal rotation
Check stability - no subluxation with translation

Irrigation and hemostasis:

Copious irrigation with 6-9 liters normal saline
Achieve meticulous hemostasis
Anterior circumflex should already be controlled
Cauterize any venous ooze

Deltopectoral interval:

Close loosely or leave open (allows drainage, prevents hematoma)
If closing, use interrupted absorbable sutures

Subcutaneous and skin:

Subcutaneous 2-0 Vicryl
Skin: staples or subcuticular suture

Immobilization:

Shoulder immobilizer with arm in INTERNAL ROTATION (protects subscapularis repair)
Abduction pillow if used (some surgeons prefer for tuberosity healing)

Exam Pearl

Exam Answer: "I repair the capsule, then perform final ROM and stability checks - passive elevation 90-120°, ER 30-40°, and confirm no subluxation. I irrigate copiously with 6-9 liters. I close the deltopectoral interval loosely to allow drainage and prevent hematoma. I apply a sling in INTERNAL ROTATION - this protects the subscapularis and tuberosity repairs for 4-6 weeks."

Dangers - Step 10

Hematoma if inadequate hemostasis = infection risk, stiffness
Arm positioned in external rotation = subscapularis repair rupture
Missing instability at closure = postoperative dislocation
Wound closure under tension = dehiscence risk

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

EXAMINER

"A 72-year-old woman presents 3 days after a fall with a 4-part proximal humerus fracture. She lives alone and was previously independent. Walk me through your decision-making between hemiarthroplasty and reverse total shoulder replacement."

EXCEPTIONAL ANSWER

This is a classic scenario where management has evolved. Let me outline my approach systematically. PATIENT ASSESSMENT: 72 years old, previously independent - functional demands matter. Need to assess bone quality (DEXA if available, cortical thickness on radiographs), rotator cuff status (MRI may show pre-existing tears, although acute trauma limits assessment), comorbidities (diabetes, smoking affect healing), and social support for rehabilitation. FRACTURE ASSESSMENT: 4-part fracture means head, shaft, greater tuberosity, and lesser tuberosity all displaced. CT scan essential - assess head split, head ischemia risk (soft tissue attachments), tuberosity comminution, bone quality. HISTORICAL CONTEXT: Hemiarthroplasty was traditional treatment for 3-4 part fractures. CURRENT EVIDENCE: Multiple meta-analyses and RCTs now show reverse TSA superior to hemiarthroplasty for elderly fracture patients - better functional outcomes (forward elevation, ASES scores), lower revision rates, outcomes NOT dependent on tuberosity healing. DECISION FACTORS: AGE - at 72, she's in the reverse TSA age range. BONE QUALITY - if osteoporotic, tuberosity healing with hemi uncertain (supports reverse). CUFF STATUS - unknown acutely, but reverse doesn't require intact cuff. FUNCTIONAL DEMANDS - independent living requires good function (reverse provides more predictable outcome). MY RECOMMENDATION: I would recommend reverse TSA for this patient because: (1) Better functional outcomes in her age group, (2) Does not rely on tuberosity healing - more predictable result, (3) Lower revision rate, (4) She needs reliable function to maintain independence. ALTERNATIVES: Hemiarthroplasty might be considered if: younger (<65-70), excellent bone quality with high likelihood of tuberosity healing, or inadequate glenoid bone stock for reverse baseplate. ORIF could be considered if: much younger, good bone quality, simple fracture patterns, but at 72 with 4-part fracture, high risk of AVN, malunion, poor function.

VIVA SCENARIOStandard

EXAMINER

"You're performing a hemiarthroplasty via deltopectoral approach. Describe the critical neurovascular structures at risk and how you protect each one."

EXCEPTIONAL ANSWER

The deltopectoral approach has several critical neurovascular structures that must be protected. Let me describe each systematically with their anatomy and protection strategies. STRUCTURE 1 - AXILLARY NERVE: ANATOMY - Terminal branch of posterior cord (C5, C6), exits quadrangular space with posterior circumflex humeral artery, winds around surgical neck of humerus posteriorly, runs 5-7cm inferior to lateral acromion edge (range 3-9cm - variable). Anterior and posterior branches supply deltoid and teres minor. AT-RISK DURING - Inferior capsular release, humeral neck osteotomy, inferior retractor placement, circumferential neck dissection. PROTECTION - Avoid dissection >5cm below acromion, gentle inferior capsular release (blunt, minimal), identify if doing extensive inferior release, palpate with finger posteriorly to assess location. INJURY CONSEQUENCE - Deltoid paralysis, cannot abduct arm, regimental badge sensory loss, very poor functional outcome. STRUCTURE 2 - MUSCULOCUTANEOUS NERVE: ANATOMY - Terminal branch of lateral cord (C5, C6, C7), penetrates conjoint tendon (coracobrachialis) 5-8cm from coracoid tip but highly variable (3-10cm range). Continues between biceps and brachialis. AT-RISK DURING - Aggressive medial retraction of conjoint tendon, medial dissection beyond conjoint, deep medial retractor placement. PROTECTION - Identify conjoint tendon and retract gently, avoid dissection medial to conjoint, place retractors carefully, remember nerve enters conjoint 5-8cm distal to coracoid. INJURY CONSEQUENCE - Weak elbow flexion (biceps and brachialis), sensory loss lateral forearm. STRUCTURE 3 - CEPHALIC VEIN: ANATOMY - Superficial vein in deltopectoral groove, lateral tributaries from deltoid (robust), medial tributaries from pectoralis (smaller), drains to axillary vein. AT-RISK DURING - Superficial dissection, interval development. PROTECTION - Retract LATERAL with deltoid (preserves lateral tributaries, less thrombosis risk). Alternative is retract medial or ligate, but lateral preferred. INJURY CONSEQUENCE - Bleeding (controllable), potential arm DVT if ligated. STRUCTURE 4 - ANTERIOR CIRCUMFLEX HUMERAL VESSELS: ANATOMY - 'Three sisters' - branch from axillary artery (third part), run horizontally along inferior border of subscapularis, typically 3 small arteries, anastomose with posterior circumflex. AT-RISK DURING - Subscapularis release, inferior exposure. PROTECTION - Identify and ligate or cauterize BEFORE subscapularis release. This prevents obscuring bleeding. Landmark for axillary nerve (just below). INJURY CONSEQUENCE - Obscuring bleeding, difficult visualization. STRUCTURE 5 - POSTERIOR CIRCUMFLEX HUMERAL VESSELS: ANATOMY - Travel with axillary nerve through quadrangular space, wind around surgical neck posteriorly. AT-RISK DURING - Humeral manipulation, circumferential dissection. PROTECTION - Gentle manipulation, avoid aggressive circumferential dissection. If bleeding encountered, indicates nerve proximity. STRUCTURE 6 - BRACHIAL PLEXUS CORDS: ANATOMY - Lie medial in axilla, posterior cord gives axillary and radial nerves, lateral cord gives musculocutaneous nerve, medial cord gives ulnar and median nerves. AT-RISK DURING - Excessive medial retraction. PROTECTION - Respect tissue planes, avoid pulling medially on neurovascular bundle. SUMMARY OF PROTECTION STRATEGY: Gentle tissue handling, respect danger zones (5-7cm below acromion for axillary, 5-8cm from coracoid for musculocutaneous), ligate three sisters first, careful retractor placement, and identify structures if extensive dissection needed.

VIVA SCENARIOStandard

EXAMINER

"What are the key technical factors that determine the outcome of hemiarthroplasty, and what are the long-term problems you counsel patients about?"

EXCEPTIONAL ANSWER

Excellent question that tests both surgical technique and long-term understanding. Let me address both parts systematically. PART 1 - KEY TECHNICAL FACTORS DETERMINING OUTCOME: FACTOR 1 - COMPONENT VERSION: Target 30-40° retroversion relative to epicondylar/forearm axis. HOW I ASSESS - With trial or final stem inserted, elbow flexed 90°, palpate epicondyles, check version. IMPORTANCE - Incorrect version causes instability (excessive anteversion → anterior instability, excessive retroversion → posterior subluxation) and rotator cuff dysfunction. CRITICAL - Must check BEFORE cement hardens, cannot adjust after. FACTOR 2 - COMPONENT HEIGHT: Goal is restore normal offset (humeral head center relative to shaft). HOW I ASSESS - Compare to preoperative templating or opposite shoulder, check tuberosity position (5-10mm below head if fracture), assess soft tissue tension with trials. IMPORTANCE - Overstuffing (too tall) causes stiffness, increased glenoid contact stress → erosion. Understuffing (too short) causes instability, rotator cuff dysfunction, weakness. FACTOR 3 - COMPONENT SIZE: Stem should achieve cortical contact without over-sizing (fracture risk). Head should match native size (42-50mm typically). HOW I ASSESS - Sequential broaching until cortical chatter, measure resected head, templating. IMPORTANCE - Over-sized stem → iatrogenic fracture (especially osteoporotic bone). Under-sized → loosening. Wrong head size → instability or overstuffing. FACTOR 4 - TUBEROSITY HEALING (TRAUMA CASES): This is THE determinant of outcome in fracture hemiarthroplasty. TECHNIQUE - Anatomic reduction of GT and LT, multiplanar fixation (GT-to-GT with #5 Ethibond restores rotator cable, vertical cerclage to shaft, sutures to prosthesis fins), tuberosities 5-10mm below head. IMPORTANCE - Malunion/nonunion/resorption → poor function, weakness, limited ROM (most common cause of failure in trauma). Superior GT migration → impingement. FACTOR 5 - SUBSCAPULARIS REPAIR: Critical for anterior stability. TECHNIQUE - Transosseous sutures through lesser tuberosity, #2 FiberWire, arm in neutral to slight IR, test strength. IMPORTANCE - Repair failure → anterior instability/dislocation (most common cause of instability post-op). Too tight → rupture, ER loss. Too loose → instability. FACTOR 6 - SOFT TISSUE BALANCING: Assess with trials - stability (translation test), ROM, tension. Adjust head size/height/eccentricity to optimize. IMPORTANCE - Unbalanced = instability or stiffness. PART 2 - LONG-TERM PROBLEMS TO COUNSEL PATIENTS: PROBLEM 1 - GLENOID EROSION: INCIDENCE - Up to 50% by 5-10 years on radiographs (not all symptomatic). MECHANISM - Prosthetic humeral head (metal/ceramic) harder than glenoid cartilage → accelerated wear, especially with eccentric loading, imbalanced cuff, or malpositioned component. PRESENTATION - Progressive pain (anterior/superior glenoid), radiographic wear, subchondral sclerosis, cysts. MANAGEMENT - Activity modification, NSAIDs if mild. If symptomatic, conversion to anatomic TSA (if cuff intact and adequate bone) or reverse TSA (if cuff deficient or inadequate bone - more common). COUNSELING - 'Hemiarthroplasty is a temporizing solution in young patients. The metal head will gradually wear the glenoid cartilage over years. If painful, we can convert to a total shoulder replacement, but that's a bigger operation.' PROBLEM 2 - ROTATOR CUFF FAILURE: INCIDENCE - 20-30% develop cuff tears over time (higher in trauma). MECHANISM - Age-related degeneration, trauma, component malposition (overstuffing increases cuff stress). PRESENTATION - Weakness, limited active ROM (passive preserved), positive lag signs. MANAGEMENT - PT for compensation, reverse TSA if symptomatic and cuff irreparable. COUNSELING - 'The rotator cuff can weaken or tear over time, especially after fracture. If this causes significant weakness, we may need to convert to a reverse shoulder replacement.' PROBLEM 3 - INSTABILITY: INCIDENCE - 5-10% (higher in trauma, revision cases). MECHANISM - Subscapularis failure, malversion, overstuffing/understuffing, component loosening. PRESENTATION - Anterior dislocation most common, pain, inability to move arm. MANAGEMENT - Closed reduction, assess cause. Recurrent → repair subscapularis or revision (correct version, consider reverse TSA). COUNSELING - 'There is a risk of shoulder dislocation, especially in the first few months. We protect against this with the sling and activity restrictions.' PROBLEM 4 - STIFFNESS: INCIDENCE - 30-40% in trauma cases (less in elective). MECHANISM - Overstuffing, capsular scarring, heterotopic ossification, subscapularis over-tightening, inadequate rehabilitation. PRESENTATION - Limited passive and active ROM. MANAGEMENT - PT, manipulation under anesthesia if <6 months, capsular release if >6 months. COUNSELING - 'Stiffness is common, especially after fractures. Therapy is critical to maintain motion. Most patients don't get back to completely normal motion.' PROBLEM 5 - REVISION SURGERY: INCIDENCE - 10-15% at 10 years. INDICATIONS - Glenoid erosion, tuberosity failure, instability, infection, component loosening, periprosthetic fracture. REVISION OPTIONS - Conversion to reverse TSA (most common - more forgiving), anatomic TSA (if cuff intact and adequate bone), revision hemiarthroplasty (rarely). COUNSELING - 'There's a 10-15% chance you may need another operation within 10 years. This is usually to convert to a reverse total shoulder replacement if you develop problems.' SUMMARY OF COUNSELING: 'Hemiarthroplasty can provide good pain relief and function, but it's not a perfect solution. For fractures, the outcome depends on bone healing. Long-term, the main concern is wearing of the glenoid cartilage over 5-10 years, which may require a bigger operation to convert to a total shoulder replacement. Younger, more active patients are at higher risk of this problem. Realistic expectations are important - you won't get back to completely normal strength and motion, especially after a fracture.'