Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Dec 5 2024

Total Shoulder Arthroplasty

Images
https://upload.orthobullets.com/topic/3075/images/total shoulder arthroplasty.jpg
https://upload.orthobullets.com/topic/3075/images/7c7fa9f1-0201-434d-b3e8-0c2c8d04fd5c_tsa2..jpg
https://upload.orthobullets.com/topic/3075/images/982f0f63-cedb-447d-bf78-de5f2a190843_tsa..jpg
  • Introduction
    • Replacement of humeral head and glenoid resurfacing
      • cemented all-polyethylene glenoid resurfacing is standard of care
    • Total shoulder arthroplasty unique from THA and TKA in that
      • greater range of motion in the shoulder
      • success depends on proper functioning of the soft tissues
      • glenoid is less constrained
        • leads to greater shear stresses and is more susceptible to mechanical loosening
    • Factors required for success of TSA
      • rotator cuff intact and functional
        • if rotator cuff is deficient and proximal migration of humerus is seen on x-rays (rotator cuff arthropathy) then glenoid resurfacing is contraindicated
        • if there is an irreparable rotator cuff deficiency then proceed with hemiarthroplasty or a reverse ball prosthesis
        • an isolated supraspinatus tear without retraction can proceed with TSA
          • incidence of full thickness rotator cuff tears in patients getting a TSA is 5% to 10%
          • if positive impingement signs on exam, order a pre-operative MRI
      • glenoid bone stock and version
        • if glenoid is eroded down to coracoid process then glenoid resurfacing is contraindicated
        • see Walch classification below
    • Outcomes
      • pain relief most predictive benefit (more predictable than hemiarthroplasty)
      • reliable range of motion with preserved internal and external rotation
      • good survival at 10 years (93%)
      • good longevity with cemented and press-fit humeral components
      • worse results for post-capsulorrhaphy arthropathy
  • Classification
      • Walch Classification of Glenoid Wear
      • Type A
      • Concentric wear, no subluxation of HH, well centered
      • A1: no or minor central erosion
      • A2: deeper central erosion, line connects anterior/posterior glenoid rims and transects humeral head (HH)
      • Type B
      • Biconcave glenoid, asymmetric glenoid wear and head subluxated posteriorly
      • B0: pre-osteoarthritic posterior subluxation of HH
      • B1: posterior joint narrowing (no posterior bone loss), osteophytes, subchondral sclerosis
      • B2: posterior rim erosion, retroverted glenoid
      • The highest degrees of glenoid erosion in B2 glenoids is typically seen between the 7- and 8-o'clock positions (posteroinferior)
      • B3: mono-concave, posterior wear, at least HH subluxation >70% OR retroversion >15%
      • Type C
      •  C1: Glenoid retroversion >25 degrees, regardless of erosion
      • C2: Biconcave, posterior bone loss, posterior translation of HH
      • Type D
      • Glenoid anteversion or anterior HH subluxation (HH subluxation <40%)
  • Indications
    • Indications
      • pain (anterior to posterior), especially at night, and inability to perform activities of daily living
      • glenoid chondral wear to bone
        • preferred over hemiarthroplasty for osteoarthritis and inflammatory arthritis
      • posterior humeral head subluxation
    • Contraindications
      • insufficient glenoid bone stock
      • rotator cuff arthropathy
      • deltoid dysfunction
      • irreparable rotator cuff (hemiarthroplasty or reverse total shoulder are preferable)
        • risk of loosening of the glenoid prosthesis is high ("rocking horse" phenomenon)
      • active infection
      • brachial plexus palsy
  • Preoperative Imaging
    • Radiographs
      • true AP
        • determine extent of arthritis and look for superior migration of humerus
      • axillary view
        • look for posterior wear of glenoid
    • CT scan
      • obtain CT scan to determine glenoid version and glenoid bone stock
    • MRI
      • evaluate rotator cuff condition
  • Approach
    • Deltopectoral
      • detach the subscapularis and capsule from anterior humerus
      • dislocate shoulder anteriorly
      • tight shoulders may require release of the upper half of the pectoralis tendon to increase exposure and dislocation
        • pectoralis major tendon passes on top of the biceps tendon to attach to the humerus
    • Complications
      • axillary nerve damage is the most common complication
        • axillary nerve and posterior humeral circumflex artery pass beneath the glenohumeral joint in the quadrilateral space
  • Technical considerations
    • Capsule
      • anterior capsule contracture (passive ER < 40°)
        • treatment
          • anterior release and Z-lengthening
      • posterior capsule stretching
        • treatment
          • volume-reducing procedure (plication of posterior capsule)
    • Subscapularis
      • no differences in outcomes between subscapularis peel, lesser tuberosity osteotomy, subscapularis tenotomy, partial tenotomy 
    • Glenoid deficiency and retroversion
      • glenoid deficiency
        • treatment
          • build up with iliac crest autograft or part of the resected humerus
          • do not use cement to build up the deficiency
      • retroverted glenoid
        • degree of retroversion determines treatment type
        • treatment
          • for retroversion > 15 degrees
            • build up posterior glenoid with allograft
          • for retroversion < 15 degrees
            • eccentrically ream anterior glenoid
    • Glenoid component
      • convex backside superior to flat
      • recreate neutral version
      • peg design is biomechanically superior to keel design
      • polyethylene-backed components superior to metal-backed components
        • glenoid not large enough to accommodate both metal and PE
      • cemented glenoid has a lower rate of loosening
      • conforming vs. nonconforming
        • both have advantages and neither is superior
        • conforming is more stable but leads to rim stress and radiolucencies
        • nonconforming leads to increased polyethylene wear
    • Humeral stem fixation
      • cemented stem or uncemented porous-coated implants
      • position of humeral stem should be 25-45° of retroversion
        • if position of glenoid retroversion is required, then the humeral stem should be less retroverted to avoid posterior dislocation
      • avoid valgus positioning of humeral stem
      • avoid overstuffing the humeral head
        • increases joint reaction forces and tension on the rotator cuff
        • the top of the humeral head should be 5 to 8 mm superior to the top of the greater tuberosity
      • intraoperative humerus fracture
        • greater tuberosity fracture
          • treatment
            • if minimally displaced, insert a standard humeral prosthesis with suture fixation and autogenous cancellous bone grafting of the greater tuberosity fracture
        • humeral shaft fracture
          • treatment
            • remove prosthesis and add longer stem with cement and reinforce with cerclage wiring
      • platform stem components allow for modular conversion to reverse total shoulder arthroplasty
        • reduce risk of humeral bone loss, overall operative time, and blood loss
  • Rehabilitation
    • Passive or active-assisted motion only during early rehab
      • limiting factor in early postoperative rehabilitation is risk of injury to the subscapularis tendon repair
    • Progress to ER isometrics
    • Limit passive external rotation
      • risk of tear and pull-off of subscapularis tendon from anterior humerus
        • tear leads to anterior shoulder instability (most common form of instability after TSA)
        • treatment of subscapularis pull-off is early exploration and repair of tendon
        • test for pull-off of subscapularis
          • weak belly-press test
          • inability to put hand in back pants pockets or tuck shirt behind the back
        • avoid pushing out of chair during acute rehab
    • IR eccentric and isometric
    • Post-operative pain control
      • Preoperative narcotic associated with increased post-operative narcotic use
      • Increasing age associated with decreased post-operative narcotic use
  • Complications
    • Glenoid loosening
      • common cause of TSA failure and revision
        • historically, more common complication than rotator cuff failure
        • newer evidence suggests rotator cuff tear/failure may be more common than glenoid loosening
      • risk factors
        • insufficient glenoid bone stock (posterior glenoid wear associated with glenoid loosening)
        • rotator cuff deficiency
      • 2.9% reoperation rate for loosening (28% with revision)
      • radiographic lines
        • presence of radiographic lines does not correlate with symptoms
        • progression of a radiographic line does correlate with symptoms
          • progression present in 50% of patients as early as 3 to 4 years after TSA
        • radiolucency around the glenoid does not always correlate with clinical failure
          • at 3- and 7-year follow-up did not correlate with poor functional outcomes or pain
    • Vascular injury
      • Arcuate artery, branch off the anterior humeral circumflex artery, can be damaged during biceps tendon elevation
    • Humeral stem loosening
      • more common in RA and osteonecrosis
      • rule out infection
    • Malposition of components
    • Improper soft tissue balancing
      • failure due to undiagnosed presence of rotator cuff tears
    • Iatrogenic rotator cuff injury/attritional rotator cuff tear
      • common cause of TSA failure (more common than glenoid loosening in some studies)
      • can occur if humeral neck osteotomy is inferior to level of rotator cuff insertion
      • overstuffing glenohumeral joint leading to attritional supraspinatus and subscapularis tears
      • common reason for conversion to reverse total shoulder arthroplasty 
    • Stiffness
    • Infection 
      • may have normal aspiration results
      • culture
        • arthroscopic tissue culture more sensitive (100% sensitive and specific) than fluoroscopically guided aspiration (17% sensitivity, 100% specific)
      • Propionibacterium acnes (P. acnes), 
        • now referred to as Cutibacterium acnes (c. acnes)
        • most common cause of indolent infections and implant failures
          • infection rate 1-2% after primary TSA
        • characteristics
          • gram positive, facultative, aerotolerant, anaerobic rod that ferments lactose to propionic acid
          • has high bacterial burden around the shoulder
          • forms biofilm within 18-90h (found on implant surface and on synovial tissue) >> planktonic (explains why aspiration is only 17% sensitive)
          • P. acnes PJI more common in males
        • presentation
          • initial pain & stiffness
          • later swelling & redness
        • diagnosis
          • use anaerobic culture bottles, keep for 10-14days (mean time to detection 6 days)
          • 16s rRNA PCR
          • imaging (XR, CT, ultrasound) positive for subluxation/loosening in 24% of cases
          • if implant is removed, sonicate implant (to dislodge bacteria from surface) for sonication culture
        • treatment
          • early infection (<6 weeks) can be treated with open irrigation and debridement
          • late infection (>6 weeks) should be treated by explant and 2-stage reimplantation after IV antibiotic (penicillin G, ceftriaxone, clindamycin, vanco) x 6wk, followed by 2-6mths of PO antibiotic
    • Neurologic injury
      • axillary nerve is most commonly injured
        • inferior border of subscapularis tendon can be used as a landmark to identify axillary nerve as it courses from anterior to posterior
      • musculocutaneous nerve can be injured by retractor placement under conjoint tendon
    • Periprosthetic fracture
      • acceptable fragment alignment ≤ 20° flexion/extension, ≤ 30° varus/valgus, ≤ 20° rotation malalignment
      • see table below
      • Wright & Cofield Classification of Periprosthetic fracture
      • Type
      • Characteristics
      • Treatment of Intraoperative Fracture
      • Treatment of Postop Fracture
      • Type A
      • Centered near the tip of the stem and extends proximally
      • Span fracture with standard length prosthesis (2-3 cortical diameters) or long-stem prosthesis.  Transosseous sutures for tuberosity fractures
      • Usually min displaced/angulated (treat nonop).
      • If significant overlap between prox-distal fragments, treat as if stem loose and revise to long stem prosthesis.
      • Type B
      • Centered at the tip of the stem and extends distally.
      • Span fracture with standard length prosthesis (2-3 cortical diameters) or long-stem prosthesis.
      • Cement in distal canal to engage prosthesis (do NOT let cement escape from fracture site).
      • Cortical strut allograft + cerclage.
      • Revise to long-stem prosthesis.
      • Cement in distal canal to engage prosthesis
      • Type C
      • Located distal to the tip of the stem.
      • Long-stem prosthesis, or if close to olecranon fossa, plate+screws± cerclage wire, strut allograft
      • ORIF (plate overlap prosthesis by 2 cortical diameters to avoid stress riser)
Card
1 of 42
Question
1 of 51
Private Note