16 Total Shoulder Arthroplasty



Matthew Baker and Uma Srikumaran


Summary


Shoulder replacement has its origins in France in 1893. Since then, there have been many advances in the implant and technique for shoulder arthroplasty. It has been estimated that the demand for total shoulder replacement will increase by 755% between 2011 and 2030. 1




16 Total Shoulder Arthroplasty



I. Indications




  1. Osteoarthritis



  2. Rheumatoid arthritis



  3. Avascular necrosis



  4. Posttraumatic arthritis



  5. Postinstability arthropathy



  6. Pain that has failed to respond to conservative measures



  7. Functional decline that is unacceptable to the patient



  8. Postinfectious arthropathy. 2



II. Contraindications




  1. Absolute:




    1. Active infection.



  2. Relative:




    1. Rotator cuff (RTC)/deltoid dysfunction




      1. Irreparable tear, paralysis, and other previous injury



      2. Previous surgery involving take down/repair of the subscapularis.



    2. Neuropathic joint:




      1. Charcot and syringomyelia.



    3. Severe brachial plexopathy



    4. Approach those with prior infection cautiously



    5. Intractable instability.



III. Presentation/Evaluation




  1. Insidious onset of pain, which is slowly progressive



  2. Progressive stiffness



  3. Functional limitations:




    1. Activities of daily living (ADLs)



    2. Hobbies.



  4. Medical problems



  5. For those with avascular necrosis (AVN):




    1. Attempt to determine the cause



    2. Evaluate other joints.



IV. Physical examination (PE)




  1. Range of motion (ROM):




    1. Active and passive



    2. Osteoarthritis (OA) and AVN:




      1. Global motion loss, particularly external rotation (ER).



  2. RTC strength:




    1. Can be difficult to ascertain due to pain.



  3. Cervical examination



  4. Neurovascular examination



  5. Pain localization



  6. Evaluate for instability



  7. Scapulothoracic motion and lag signs



V. Imaging


Plain radiographs are most important:




  1. Anteroposterior (AP):




    1. Inferior osteophytes



    2. Humeral canal diameter



    3. Acromiohumeral distance:




      1. Less than 6 mm strongly suggestive of RTC tear.



  2. Axillary:




    1. Glenoid version



    2. Glenoid wear



    3. Posterior subluxation.



  3. Definitive assessment of glenoid version and bone stock:




    1. Can glenoid be resurfaced?




      1. Medialization of the glenoid past the coracoid → Don’t resurface the glenoid.



    2. Treat 15-degree posterior glenoid wear with anterior glenoid reaming 50% change of a successful correction 3



    3. Bone graft needed?



    4. Walch classification. 4



  4. Magnetic resonance imaging (MRI):




    1. Can be used if RTC tear is suspected:




      1. Uncommon with OA



      2. RTC tear of 5 to 10% at the time of total shoulder arthroplasty.



    2. May be used if acromiohumeral distance decreased or in case of prior cuff surgery



    3. Also used to stage AVN.



VI. Approach




  1. Deltopectoral:




    1. Uses the deltopectoral interval



    2. Provides excellent exposure for the proximal humerus



    3. Detach subscapularis and anterior capsule:




      1. Lesser tuberosity osteotomy (LTO) versus peel versus tenotomy



      2. No current evidence that one approach is significantly better than another.



    4. Need to do capsular releases for glenoid exposure



    5. Risks:




      1. Axillary nerve



      2. Cephalic vein.



  2. Superior:




    1. Splits the deltoid



    2. Excellent humeral exposure



    3. Using this approach may decrease instability as the subscapularis is not violated 5



    4. Risks:




      1. Glenoid component malpositioning



      2. Axillary nerve injury.



  3. Technical considerations:




    1. Glenoid component: Pegged versus keeled, cemented, metal backed:




      1. Avoid use of metal-backed glenoid components as they have high failure rate



      2. Lower incidence of radiolucent lines in pegged design



      3. It is not known if there is any clinical difference in the implant designs.



    2. Humeral stem can be cemented, cementless, or stemless:




      1. Position in 25 to 45 degrees retroversion



      2. Top of the humeral head shoulder be 5 to 8 mm above the greater tuberosity.



    3. Want to recreate anatomy:




      1. Challenges include glenoid wear, especially posterior, increased glenoid retroversion, and limited bone stock.



    4. Avoid over resection of the humeral head.



  4. Avoid iatrogenic RTC injury during humeral head osteotomy



  5. Postoperative rehabilitation should focus on minimizing tension on the subscapularis repair:




    1. Focus on passive range of motion and active assist range of motion, limiting passive external rotation.

Only gold members can continue reading. Log In or Register to continue

Feb 6, 2021 | Posted by in ORTHOPEDIC | Comments Off on 16 Total Shoulder Arthroplasty
Premium Wordpress Themes by UFO Themes