Issues for anatomic total shoulder - what do they mean for surgeons and patients?

Anatomic total shoulder arthroplasty (aTSA) is the standard surgical treatment for disabling arthritis in shoulders with an intact rotator cuff. It has an established track record of safety and effectiveness extending back over 60 years. 

Here are some of the recent publications regarding anatomic total shoulder arthroplasty.

aTSA in the younger patient and patients with prior instability

See: Why do patients under the age of 50 do less well after anatomic total shoulder arthroplasty?

In addition the authors of A history of shoulder instability is more common in young patients undergoing total shoulder arthroplasty found that patients under 50 years of age were less likely than their older counterparts to have primary osteoarthritis. They were four times more likely to have a history of shoulder instability, over twice as likely to have had prior ipsilateral shoulder surgery of any type, and six times as likely to have had prior ipsilateral shoulder stabilization surgery. Evidently, shoulder instability damages the shoulder's articular cartilage and the stabilizing soft tissues in a manner that increases the risk of secondary arthritis. This finding is consistent with Comparison of patients undergoing primary shoulder arthroplasty before and after the age of fifty which found that only 21% of the younger patients had primary osteoarthritis, whereas 66% of the older patients had that diagnosis. These studies indicate that patients <50 years of age have more complex forms of arthritis, an observation that may help explain the inferior outcomes of shoulder arthroplasty in younger individuals.

Outcomes of Total Shoulder Arthroplasty in Patients with Prior Anterior Shoulder  Instability: Minimum 5-year Follow-up presented 27 male and 9 female patients having total shoulder arthroplasty after prior anterior shoulder instability (ASI).

13 males and 2 females with instability managed non-operatively underwent TSA at an average age of 64 years
14 males and 7 females with prior instability surgery (10 open and 11 arthroscopic) underwent TSA at an average age of 50.6 years.

 

While patient reported outcomes were similar, 6 of 21 (28.6%) TSAs failed in patients with prior surgery for ASI but there were no failures in the nonoperative ASI group.

Kaplan-Meier survivorship analysis demonstrated statistically superior survivorship in patients without prior ASI surgery (100% at five years) compared to those with prior ASI surgery (79% at five years). 
The difference in survivorship between patients with prior open  (72.7%) versus arthroscopic surgery (87.5%) at 5 years was not statistically significant.

aTSA outcomes for the patient with a weak shoulder

In Clinical Outcomes of Anatomic Versus Reverse Total Shoulder Arthroplasty in Primary Osteoarthritis with Preoperative External Rotation Weakness and an Intact Rotator Cuff: A Case-Control Study  defining preoperative external rotation weakness as strength ≤7.2 pounds, the authors compared 74 weak patients having aTSA to 74 patients with normal strength having aTSA.
Despite weak aTSAs having poorer preoperative strength in FE and ER, neither of these deficits were noted postoperatively compared to the normal cohort.  Postoperative outcome scores, rates of complications and need for revision surgery did not differ between the groups. The clinical outcomes showed greater improvement for the shoulders that were weak before surgery.

aTSA outcomes for the patient with a stiff shoulder

In Clinical outcomes of anatomic vs. reverse total shoulder arthroplasty in primary osteoarthritis with preoperative rotational stiffness and an intact rotator cuff: a case control study defining preoperative stiffness as ≤0 of passive external rotation (ER), the authors matched stiff aTSAs (n 257) 1:3 to non-stiff aTSAs.  Despite stiff aTSAs having poorer preoperative range of motion and functional outcome scores for all measures assessed, postoperative outcome scores, rates of complications and need for revision surgery did not differ between the groups. The improvement in active motion was greater for the stiff group.

       

What are the risk factors for complications after aTSA? Can they be modified; if not can they be anticipated and managed?

Prior research has shown that disparities in social determinants of health may account for 80% of the variability in patient treatment outcomes, while the quality of care accounts for as little as 20%. Disparities in social determinants of health are categorized as economic (e.g. unemployment), educational (e.g. illiteracy), social (e.g. incarceration), healthcare (e.g. inability to access quality medical care), and environmental (e.g. exposure to health hazards). 

The authors of Social Determinants of Health Disparities Impact Postoperative Complications in Patients Undergoing Total Shoulder Arthroplasty used a national insurance claims database to identify patients having a primary TSA with at least two years of follow-up.

Patients were grouped in one of two cohorts: (1) patients with no history of SDHD (Control) and (2) patients with a history of SDHD (SDHD group) prior to TSA. With the application of the revised Z-codes, the number of TSA patients recognized has having SDHD is rising dramatically.

The SDHD and control groups were matched 1:1 for comorbidities and demographics prior to conducting multivariable analysis for 90-day medical complications and 2-year surgical complications. There were 8,023 patients in each group. In the SDHD group, 6,486 (80.8%) patients had an economic disparity, 1,519 (18.9%) patients had a social disparity, 354 (4.41%) patients had an environmental disparity, 54 (0.67%)  patients had an educational disparity, and 14 (0.17%) patients had a health disparity.

The SDHD group had over two times higher odds for each of the major 90-day medical complications: heart failure (OR 3.7), cerebrovascular accident (OR 2.5), renal failure (OR 2.9), deep vein thrombosis (OR 3.16), pneumonia (OR 2.8), sepsis (OR 4.9), and urinary tract infection (OR 2.6). The SDHD group had significantly higher odds (OR 1.45) for revision surgery within 2-years following TSA. 

It is evident that evaluation of potential candidates for shoulder arthroplasty should include documentation of social determinants of health (e.g. employment status, social situation, etc.). Shoulder arthroplasty is rarely an emergency. While the patient's economic, social, environmental, educational and health disparities may be difficult to modify in a timely manner, there is time to anticipate the consequences of theses disparities and make plans for managing the associated adverse effects.

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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).