Saturday, September 18, 2021

Total shoulder arthroplasty - how long will it last?

Survival of the Aequalis total shoulder replacement at a minimum 20-year follow-up: a clinical and radiographic study

These authors reported the survival and clinical outcome at a minimum of 20-yr follow-up for 44  shoulder replacements in 40 patients (age at surgery 68.5 years, 82.5% female).


The original indication for surgery was rheumatoid arthritis in 14 patients (35%) and osteoarthritis in

26 (65%).


The implants were a cemented keeled ultrahigh-molecular-weight all-polyethylene, flat-backed Aequalis glenoid component.



Of the 40 patients, 29 (72%) were deceased at the time of the latest review. Of the 11 remaining patients (12 arthroplasties), 3 had undergone revision surgery and 2 had severe dementia, leaving 6 patients (7 arthroplasties) who completed the clinical review.  


The average age at surgery was 68.5 years (range 36.9-86.7); of the surviving patients, the average age at review was 81.5 years (range 60.0-90.6), and of the deceased patients, the average age at death was 84.4 years (range 60.0- 102.5). 


The average time to follow-up in the surviving cohort was 22.1 years (range 20.0-23.6). The average time the arthroplasty was in situ in the deceased cohort was 12.5 years (range 4.9-21.7).


Survival with all-cause revision as an endpoint was 84.1% at 20 years; glenoid loosening was seen in all patients who survived to the 20-year follow-up. Survival of rotator cuff integrity was 16.8% at 20 years. 



Survival with all-cause revision as an endpoint was 94.6% at 10 years, 90.1% at 15 years, and 84.1% at 20 years 


Radiographic loosening of components was found in 20 of 39 glenoid implants (51.2%). Glenoid loosening was first identified on radiographs at an average of 11.4 years postsurgery. The radiographically defined survival of glenoid implants was 70.0% at 10 years, 26% at 15 years, and 19.9% at 18.9 years.




No patients survived to, or beyond, 20 years without showing radiographic evidence of an ‘‘at-risk’’ glenoid.


Radiographic evidence of superior humeral head migration as a proxy for rotator cuff failure was identified in 23 of 39 arthroplasties (59.0%). Superior migration was identified on radiographs at an average of 8.8 years postsurgery. The survival of the rotator cuff integrity was 59.6% at 10 years, 25.2%

at 15 years, and 16.8% at 20 years.




VAS pain scores demonstrated improvement at 10 years but not at 20 years.


At 20 years, 72% of patients had died with the prosthesis in situ.



Comment: Patients want and deserve to know "how will a joint replacement last?" 


While this series is small, it presents some useful information:

(1) Radiographic failure of the glenoid component was not noted until an average of >10 years after surgery. Thus the value of new glenoid component innovations need to be determined a full decade after implantation; claims of added value cannot be made with shorter terms of followup.

(2) Radiographic "failure" occurs much earlier and more frequently than revision; thus revision rates may not be the most sensitive indicator of the quality of the result.

(3) Many of the factors affecting outcome change over a decade or so:

    (a) Indications for anatomic arthroplasty change (rheumatoid arthritis has become a less common indication as medical management of this disease improves; patients with deficient rotator cuffs are now offered reverse total shoulders)

    (b) Implants change (flat backed glenoids as used in this study are less commonly used after being recognized as having inferior outcomes (see this link)).

    (c) Techniques of surgery and rehabilitation change

    (d) Limited patient survivorship limits the ability to evaluate prosthesis survivorship

    (e) Patients are having arthroplasty at a younger age; data on survivorship from older patients may not apply to younger patients.



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How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link)
The smooth and move for irreparable cuff tears (see this link)
The total shoulder arthroplasty (see this link).
The ream and run technique is shown in this link.
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).

Shoulder rehabilitation exercises (see this link).