Saturday, February 25, 2017

Shoulder joint replacement - is experience the great teacher?

The influence of patient- and surgeon-specific factors on operative duration and early postoperative outcomes in shoulder arthroplasty

These authors asserted that increased operative duration is associated with an increase risk of adverse outcomes and complications. They sought to determine if patient- and surgeon-specific factors correlated to operative duration in shoulder arthroplasty. They conducted a retrospective review of primary and revision total and reverse shoulder arthroplasties performed at a single institution from 2012 through 2015. Patients with postoperative readmission had a longer mean operative time (163 vs. 107.1 minutes).

They found that high surgeon volume (>30 shoulder arthroplasties/year) was associated with shorter operative duration (105.9 vs. 128.3 minutes; P < .001).

Progression through a fellowship academic year was found to be associated with decreased surgical times (100.7 vs. 116.5 minutes; P < .0001).

Reverse shoulder arthroplasty for sequelae of prior fracture, total shoulder arthroplasty for dysplastic glenoid morphology, revision surgery were also associated with increased operative times.

Comment: Increased annual surgical volume has the potential not only for shortening surgical time, but also for improving patient selection, preoperative preparation, surgical technique, postoperative rehabilitation, and justifying a consistent patient-care team around the high-volume practice - all of which can contribute to improved outcomes.

The challenges for the prospective shoulder arthroplasty patient include:
(1) 'exactly what is a 'high volume surgeon?'
(2) 'how do I find a high volume surgeon?'
(3) 'in a high volume practice, will I get personalized attention?'
(4) 'what is the trade-off between the convenience of a local lower volume surgeon and the experience of a more distant higher volume surgeon'?

Some of these questions can be informed by a recent publication:

Distribution of High-Volume Shoulder Arthroplasty Surgeons in the United States: Data from the 2014 Medicare Provider Utilization and Payment Data Release.

These authors point out that high-volume TSA surgeons are reported to have superior outcomes. They studied patient access to these surgeons using 2012 Medicare Provider Utilization and Payment Data Public Use File (MPUPD-PUF). This data base provided volume and reimbursement data for procedures performed by individual physicians participating in Medicare. They studied surgeon prevalence, surgeon distribution, and factors associated with higher or lower surgeon prevalence in metropolitan areas. Data were extracted for all physicians who performed a minimum of 11 TSA procedures for Medicare beneficiaries

The MPUPD-PUF included 774 surgeons across the United States who performed an annual minimum of 11 TSA procedures covered by Medicare, with a combined total of 19,505 TSA procedures. The median annual number of Medicare service claims for TSA was 19 (range, 11 to 163), and the mean was 25 (SE, 0.7).

Of these surgeons, 45% practiced within major metropolitan areas with a population of >1 million. Surgeons who had completed an ASES fellowship had a higher volume of procedural claims (median, 26; range, 11 to 120) compared with other surgeons (median, 17; range, 11 to 163; p < 0.001). 

The distribution among major metropolitan areas was highly unequal, and more surgeons were present in cities with an ASES fellowship program.

This study points to the challenges that patients in certain geographical areas have in accessing surgeons who perform at least 11 shoulder arthroplasties per year.

An interesting question arises from the use of an annual case volume of ≥11 as the definition of a 'high volume' surgeon. Historically, 'high volume' has been defined arbitrarily:

Surgeon Experience and Clinical and Economic Outcomes for Shoulder Arthroplasty categorized surgeons according to the total number of procedures performed within the total 6 year ( 1994 to 2000) study period  with one to five procedures considered low volume; six to thirty procedures, medium volume; and more than thirty procedures, high volume.

The relationship between surgeon and hospital volume and outcomes for shoulder arthroplasty defined a 'high volume' surgeon as one who performed 5 or more cases per year.

This study defines 'high volume' as ≥ 11 cases per year. The number is creeping up.

Last month this article was published:

Meaningful Thresholds for the Volume-Outcome Relationship in Total Knee Arthroplasty

These authors used a database of 289,976 patients undergoing primary total knee arthroplasty from an administrative database, they applied stratum-specific likelihood ratio (SSLR) analysis of a receiver operating characteristic (ROC) curve to generate sets of volume thresholds most predictive of adverse outcomes. The outcomes considered for surgeon volume included 90-day complication and 2-year revision.

They identified four volume categories: 0 to 12, 13 to 59, 60 to 145, and ≥146 total knee arthroplasties per year. 
Complication rates decreased significantly (p < 0.05) in progressively higher-volume categories without a 'bottom' in sight:

Revision rates followed a similar pattern.  This study supports the use of SSLR analysis of ROC curves for risk-based volume stratification in total knee arthroplasty volume-outcomes research. SSLR analysis established meaningful volume definitions for low, medium, high, and very high-volume total knee arthroplasty surgeons.

The question then arises, 'if a high volume knee arthroplasty surgeon is defined as one performing ≥65 cases per year, shouldn't the same threshold apply to shoulder arthroplasty surgeons?' Is there any reason to believe that the annual number of cases of shoulder arthroplasty necessary to achieve and maintain excellence should be lower than that for knee arthroplasty? Is a shoulder arthroplasty easier to learn and master than a total knee?

It is apparent that the higher the standard for 'high volume', the greater the challenge of finding a high volume surgeon.  

Never the less, there is no denying the benefits of volume. More practice

increases the chances of a good result