Total Shoulder Arthroplasty Flashcards
Indications of a TSA
- arthritis with intact and functional rotator cuff
Requirements for TSA
- intact and functional rotator cuff
- isolated reparable supraspinatus tear without retraction is acceptable
Humeral stem positioning in TSA
- retroversion (25-45 degrees)
What is the risk of excessive humeral bone removal during humeral neck osteotomy?
- rotator cuff tendon injury
Glenoid positioning in TSA
- neutral, avoid retroversion
Eccentric posterior glenoid wear management in TSA
- from 0-15 degrees retroversion: eccentric glenoid reaming
- >15 degrees: posterior glenoid bone grafting or augmenting glenoid component; RTSA
Rehab restrictions
- excessive passive ER, may cause avulsion of subscap from lesser tuberosity
Subscap injury after TSA: presentation, dx test, tx
- ant shoulder instab
- US
- repair of detached subscap or augmented with pec major tendon
Complications of TSA
- implant loosening 2/2 glenoid-sided failure
- infx, a/w male and young age; P. acnes and staph
Indication of RTSA
- superior humeral migration with CTA
Biomechanics of RTSA
- deltoid contraction rotates humerus around glenosphere = elevation
- deltoid power and efficiency improved by incr. humeral offset via medialization of center of rotation
Requirements for RTSA
- intact axillary n.
- fully functional deltoid
- adequate glenoid bone stock
How is stability achieved in RTSA?
- deltoid tensioning: adjust humeral offset, glenoid tilt
- head diameter: larger = more stable
- component positioning
Component positioning in RTSA
- 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
Complications of RTSA
- ant. dislocation via hyperext and ER
- irreparable subscap at time of surgery
- scapular notching
- infx
Eti of scapular notching
- RTSA with repeated contact b/t inf scap neck and humeral component
Presentation of scapular notching
- +/- pain
- fx
- levering and dislocating
Methods to decrease scapular notching
- positioning glenoid baseplate as low as possible
- optimize glenoid head length: pushes humeral socket away from scapula
- incr glenosphere size
Infx a/w RTSA
- prior failed arthroplasy and <65 y/o
- NOT: DM, smoking, obesity, inflam arthropathy
Common organisms of TSA infx
- P. acnes (incision of dermal sebaceous glands)
- Staph
H and P of TSA infx
- pain (MC)
- persistent draining sinus (2nd MC)
- stiffness, erythema, effusion, fever, chills, pm sweats
Dx testing for TSA infx
- XR: effusion, endosteal scalloping, periprosthetic radiolucent lines, bony resorption
- jt asp culture (GOLD STANDARD)
NOT - ESR, CRP
- bone scans
Tx for TSA infx
- I and D
- revision
- fusion
- amputation
- abx per ID
