Patients considering orthopaedic surgery want their surgeon to predict the long-term outcomes for the procedure they are being offered: how long will it last? what are the chances of complications? how likely is it that a revision will be necessary? As pointed out in Objective ignorance - a problem in predicting outcomes in climbing and in orthopaedic surgery, average data from long-term followup studies of similar procedures performed in the past can be presented to the patient, but these averages do not predict the outcome for that individual.
There is another problem with using long-term followup studies in an attempt to predict future patient outcomes: this can be referred to as "diminishing returns".
By this I mean that the longer the period of followup:
(1) the percentage of the initial patient cohort that is lost to followup increases progressively (perhaps because the patients were dissatisfied and transferred their care to another surgeon, or because they had a revision that truncated the followup of their initial surgery, or because they could not afford to return for followup or because they got tired of returning questionnaires or because they became ill or expired).
(2) the procedures performed a while back become progressively less representative of what is being performed currently (the patient selection, surgical techniques and implants, and surgeons evolve progressively over the time interval)
(3) the measures of patient comfort and function are inconsistent.
(4) patients having complications and revisions have a tendency to get lost or omitted for one reason or another.
(5) the number of patients included in long term followup studies is a very small (non-representative) sample of the total number of the patients currently having the procedure
To see these factors in action, let's look at a recent article, Long-Term Outcomes Following Reverse Total Shoulder Arthroplasty A Systematic Review with a Minimum Follow-Up of 10 Years.
The means of followup were inconsistent: Four studies conducted all follow-ups in a clinical setting, while 3 used either outpatient visits (20 to 41%) or phone/mail interviews. The absolute Constant score (CS) was used 5 studies. The relative CS was used in 3 studies. The Subjective Shoulder Value was used in 2 studies. The American Shoulder and Elbow Surgeons Score was used in 1 study. The Single Assessment Numeric Evaluation was used in 1 study.
The weighted mean reported revision-free implant survivorship reported in 5 studies was 88% at 10 years; the complication rate was 36% with need for further revision in 23% of patients. However, because almost two thirds (63%) of the patients were lost to follow-up, we must suspect that the 37% of patients with followup were not representative of the total group.
Note that this study reviewed 469 rTSA procedures in 460 patients. Compare that number to the data in The incidence of shoulder arthroplasty: rise and future projections compared with hip and knee arthroplasty which found that 63,845 rTSAs were performed in 2017 with projected volume increases by the linear and Poisson models of 87.9% and 353.0%, to an estimated 119,994 and 289,193 procedures in 2025. Thus the total number of rTSAs in the entire Systematic Review was less than 0.25% of the estimated current annual volume of rTSAs - we must ask whether this is a representative sample.
The authors concluded that "rTSA appears to provide substantial long-term improvements in shoulder function, clinical outcomes, and pain relief, albeit with significant complication and revision rates. However, caution is warranted when interpreting the data due to high lost-to-follow-up rates and limited data quality in the contemporary literature".
In a salute to all mothers on Mothers' Day (May 11), here is my photo of a mother hummingbird feeding her chicks.
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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link)
Shoulder rehabilitation exercises (see this link).