Total Shoulder Arthroplasty

Question 1

Indications of a TSA

Answer 1

• arthritis with intact and functional rotator cuff

Question 2

Requirements for TSA

Answer 2

• intact and functional rotator cuff

- isolated reparable supraspinatus tear without retraction is acceptable

Question 3

Humeral stem positioning in TSA

Answer 3

• retroversion (25-45 degrees)

Question 4

What is the risk of excessive humeral bone removal during humeral neck osteotomy?

Answer 4

• rotator cuff tendon injury

Question 5

Glenoid positioning in TSA

Answer 5

• neutral, avoid retroversion

Question 6

Eccentric posterior glenoid wear management in TSA

Answer 6

• from 0-15 degrees retroversion: eccentric glenoid reaming

- >15 degrees: posterior glenoid bone grafting or augmenting glenoid component; RTSA

Question 7

Rehab restrictions

Answer 7

• excessive passive ER, may cause avulsion of subscap from lesser tuberosity

Question 8

Subscap injury after TSA: presentation, dx test, tx

Answer 8

• ant shoulder instab
• US
• repair of detached subscap or augmented with pec major tendon

Question 9

Complications of TSA

Answer 9

• implant loosening 2/2 glenoid-sided failure

- infx, a/w male and young age; P. acnes and staph

Question 10

Indication of RTSA

Answer 10

• superior humeral migration with CTA

Question 11

Biomechanics of RTSA

Answer 11

• deltoid contraction rotates humerus around glenosphere = elevation
• deltoid power and efficiency improved by incr. humeral offset via medialization of center of rotation

Question 12

Requirements for RTSA

Answer 12

• intact axillary n.
• fully functional deltoid
• adequate glenoid bone stock

Question 13

How is stability achieved in RTSA?

Answer 13

• deltoid tensioning: adjust humeral offset, glenoid tilt
• head diameter: larger = more stable
• component positioning

Question 14

Component positioning in RTSA

Answer 14

• glenosphere as low as possible on glenoid: minimizes risk of scapular notching by humeral socket
• glenoid baseplate tilted inferiorly 10-15 degrees: enhances deltoid tensioning, improving implant stability
• humeral stem in 25-40 degrees retroversion

Question 15

Complications of RTSA

Answer 15

• ant. dislocation via hyperext and ER
• irreparable subscap at time of surgery
• scapular notching
• infx

Question 16

Eti of scapular notching

Answer 16

• RTSA with repeated contact b/t inf scap neck and humeral component

Question 17

Presentation of scapular notching

Answer 17

• +/- pain
• fx
• levering and dislocating

Question 18

Methods to decrease scapular notching

Answer 18

• positioning glenoid baseplate as low as possible
• optimize glenoid head length: pushes humeral socket away from scapula
• incr glenosphere size

Question 19

Infx a/w RTSA

Answer 19

• prior failed arthroplasy and <65 y/o

- NOT: DM, smoking, obesity, inflam arthropathy

Question 20

Common organisms of TSA infx

Answer 20

• P. acnes (incision of dermal sebaceous glands)

- Staph

Question 21

H and P of TSA infx

Answer 21

• pain (MC)
• persistent draining sinus (2nd MC)
• stiffness, erythema, effusion, fever, chills, pm sweats

Question 22

Dx testing for TSA infx

Answer 22

• XR: effusion, endosteal scalloping, periprosthetic radiolucent lines, bony resorption
• jt asp culture (GOLD STANDARD)
  NOT
• ESR, CRP
• bone scans

Question 23

Tx for TSA infx

Answer 23

• I and D
• revision
• fusion
• amputation
• abx per ID