Total Shoulder Replacement -

Aims

Relieve pain
Restore anatomy
Stable ROM
Durability

Indications

Painful osteoarthritis
AVN
Rheumatoid arthritis
Traumatic arthritis
Capsulorrhaphy arthritis

Contraindications

Cuff arthropathy
Fracture
Sepsis
Uncooperative patient
Combined palsy of deltoid & rotator cuff muscles
Youth
Do not use Glenoid Component with Rotator Cuff Tear
- Edge loading
- Rocking horse phenomenon
- early loosening

Consent | Preop Planning

Xrays
- Views
  - Scapular AP view with humerus internally rotated
  - Scapular AP view with humerus externally rotated
  - Scapular Lateral View
  - Supine Axillary View
- Assessment
  - Humeral head
    - head flattening
    - extensive osteophyte formation
  - Acromiohumeral interval
    - rotator cuff tear
  - Glenoid
    - posterior glenoid erosion (axillary view) – osteoarthritis
    - anterior glenoid erosion – inflammatory arthritis
Template

Lima SMR (105%)
make sure Xray inclueds enought of humeral shaft to template stem properly
establish
- stem size
- humeral head resection level
CT scan
- if presence of glenoid defect or bone loss

Position

Place an appropriately prepared patient, under general (preferred) or regional anaesthesia on the operating table in a 30-40° beach chair position
- arm must protrude out of surgical table to allow good mobility in all planes
  - test that full adduction, extension can be achieved
  - determine amount of pre-operative external rotation
- or use shoulder table
- knees flexed
Fix head rigidly
IV antibiotics
Prepare & drape the patient, with the upper limb free & the elbow mobile
Small sandbag under the back, medial to the scapular border to assist in accessing the glenoid

Landmarks

Acromion, Coracoid process, AC joint
Mark with Surgical Marker

Incision

Anterior Deltopectoral approach
- Option 1 Extensile Recommended
  - Start: above the AC joint
  - Path: curving distally over the coracoid to the deltopectoral groove
    - about 10-15cm in length
  - End: humeral insertion of deltoid
- Option 2 NonExtensile
  - Anterior axillary incision

Internervous Plane

Deltoid | Axillary Nerve
Pectoral | Medial and Lateral Pectoral Nerves

Superficial Dissection

Identify Cephalic Vein
- vein is retracted either laterally or medially
  - laterally: to damage the least possible number of braches
  - medially: less traction on vein & less chance of damage
- if difficult to find
  1. ER arm places pectoralis major under tension
  2. Identify interval more proximally at anterior edge of lateral clavicle
Incise Clavipectoral fascia
Palpate Coracoid process
Identify conjoined tendon (short head of biceps and coracobrachialis)
- retract medially
Preserve coracoacromial ligament
- if difficult exposure – may divide few millimeters to help exposure

Deep Dissection

Divide superior 1cm of Pectoralis Major insertion
- improves exposure
Subacromial space
- Deltopectoral interval is opened to gain access to the subacromial space
- Consider any cuff pathology, & plan its repair now
- Using blunt (fingertip) dissection, clear the SA space of adhesions
Biceps Tenodesis
- No 2 nonabsorbable sutures
- then divide
Subscapularis
- ER the humerus, & identify the tendon of subscapularis
  - Identify Anterior Circumflex humeral Artery adn tis venae comitantes (3 sisters)
  - isolate and cauterize
- Option 1
  - Place No 1 nonabsorbable sutures in subscapularis near its insertion
  - divide its tendon 1 cm medial to the bicipital groove with a vertical incision
- Option 2
  - removed subperiosteally
- Option 3
  - Osteotomy
- Dangers: Axillary Nerve
  - Be careful to identify & protect the axillary nerve during this step
  - Perform Subcapularis release with arm in ER
    - increases distance between axillary nerve and subscapularis
- NOTE: when reattaching, each cm of medialization = 20° of ↑ER
Releases
- Divide Rotator Interval
  - follow line of biceps
- Capsular attachment to humeral neck
  - Humerus in ER
  - Release capsule directly off bone
    - anteroinferior aspect of humeral neck to posteroinferior aspect
    - release capsule off bone

Dangers

Nerves

Axillary nerve
Musculocutaneous nerve
- enters Conjoint Tendon 5cm distal to the tip of coracoid process

Vessels

Cephalic Vein

Procedure

Humeral Preparation

Dislocate the joint
- by external rotation 90° & extension of the humerus
  - should be able to visualise whole humeral head
- being careful to avoid excessive, humeral fracturing force
  - especially in osteoporotic bone
Osteophytes
- Clear the humeral articular joint margins of osteophytes to ID anatomic neck
- Beware the osteophytes that may overhang the axillary nerve inferiorly
Further Exposure
- release subscapularis off anterior glenoid margin
- partial excision of anterior capsule
- release off base of coracoid
Shaft Preparation
- Perforate humerus proximally with pointed instrument
- Insert reamer with rotary motion until reamer cutting edges are no longer visible
- Fit
  - humeral head resection device
  - alignment rod (determines retroversion)
    - elbow flexed to 90°
    - aligment rod and forearm are parallel
    - gives 30° retroversion
Head resection
- Insert reamer until the Humeral Head resection device is at desired level
  - eg. anatomic neck level
  - humeral head should now be osteotomised, in approximately 35° of retroversion (20-45°),
  - preserving length of neck
  - Use the arm &/or the bicipital groove as references
- Fix the guide with 2.5mm Kirschner wire
- Start cutting head with thin blade oscillating saw
- Stop half way
- Remove K wires, reamer and guide
- Complete the cut
- Screw the stem impactor onto the conical trial stem with 45° stop guide
  - recut the nect again if necessary to obtain nice fit
- Prepare the shaft by reaming sequentially to the desired size & canal fill
- Place a trial stem in situ, & leave it while the glenoid is prepared

Glenoid preparation

Retract the humeral head by placing an angled retractor to displace it posteriorly
- Fukuda retractor on posterior rim of glenoid neck
Further soft tissue release may be required
Small Hohman to superior glenoid
Excise remain biceps tendon
Spiked retractor anteriorly
Reposition arm | table
- rest arm on Mayo Stand
- raise table to allow humerus to displace posteriorly

Expose glenoid
Remove remaining labral tissue
Release capsule from inferior glenoid with diathery or bristow 1cm beyond rim of glenoid
Another retractor inferiorly
Inspect the glenoid for bone loss, which is usually posteriorly located.
- Deal with bone loss as follows;
  - 1-2mm
    - burr down the high side to match
  - 3-5mm
    - burr down the high side, but accept some retroversion of glenoid
  - >5mm
    - build up the glenoid with bone graft harvested from the humeral head, or use an augment
Remove osetophytes
Marking with diathermy
- 2 cross orthogonal lines to mark the centre
Guide wire (15cm x 2.5 mm) into cm for depth of 3cm
- check of version of guide wire as it determines version of glenoid component
- IF abnormal glenoid – do CT scan to assess deformations of articular surface
- Position is central and pendicular to glenoid surface before any bone erosion occurred
Glenoid Reamer
- Small or Standard (depending on size of glenoid)
- expose subchondral bone
Glenoid Core Reamer
- until stop position
Dealing posterior glenoid wear
- change version of glenoid by 10°
- eccentric reaming
- downsizing glenoid component
- posterior bone graft from humeral head
- No more than 25% of glenoid should be left unsupported
Final Implant
- Cemented
  - Pressurise cement into the glenoid
  - A sponge with adrenaline or fibrin can be used for haemostasis
  - Cement in the all-poly component
- Uncemented
  - Impact implant
  - Drill screws with 3.5 mm drill
  - Best to not to initially tighten screws too much, wait till both screws are in to tighten
- Liner

Humeral Stem

Shaft Preparation
- unscrew to stem impactor
- insert the trial humeral body
- use aligment rod to obtain correct retroversion
- tighten screw of tiral humeral body with allen wrench
Trial head and adaptors
- options
  - Adaptors
    - Standard
      - neutral or eccentric
    - Long
      - neutral or eccentric
- Trial the stem now, checking that the soft tissue tension is correct;
  - 1/2 head diameter translation anteriorly & posteriorly
  - head sitting above the level of the tuberosity
Trial reduction
- Reference the best position of the trials with a diathermy
Retrial the humeral component & select desired components
Predrill the proximal humeral shaft for repair of subscapularis tendon
Place the component with, or without, cement as desired (note better results with proximal cement)
- Insertion of Definitive Stem
  - Uncemented Finned Stem
  - Cemented
    - use a stem with smaller diameter than trial stem
Be sure to consider the possibility of future revision &/or elbow surgery, in choosing to use a cement restrictor

Reduction & Closure

Reduce the joint & carry out ROM testing, noting range for reference during rehabilitation
Repair subscapularis tendon to proximal shaft, usually not in the same location from whence it came, to allow ER
Perform limited closure of the rotator interval, to avoid IR contracture
Close the deltopectoral fascia loosely, over a suction drain, with interrupted sutures
Close the skin & place the arm in a shoulder immobiliser

Postop / Rehab

Passive ROM day one post-op
active assisted begin in fourth week
resisted exercises begin at 6 weeks
full activities at 8-10 weeks

Results

Complications / Dangers

Perioperative

General

Bleeding
- higher with TSR than hemiarthroplasty

Local

Humeral fracture
- usually diaphysis
Nerve palsy
- 1. Axillary
- 2. Radial
Malpositioned components

Postoperative

Early

Instability
Rotator cuff tear, ~2%
Infection,
- usually staph aureus or other gram positives
Heterotopic ossification
Stiffness
Periprosthetic fracture

Late

Component failure, usually glenoid
Implant loosening, 1-5% loosening of glenoid