Wednesday, March 15, 2023

Reverse or anatomic total shoulder for glenohumeral arthritis - does a preoperative MRI help with the decision?

Twenty years ago, the reverse total shoulder arthroplasty (RSA) was approved by the US Food and Drug Administration "in order to restore mobility in a grossly rotator cuff deficient joint with severe arthropathy" (see this link and this link).

Since that time, the use of RSA has expanded rapidly to include "off label" indications, such as primary osteoarthritis with an intact rotator cuff (see Off-label use of reverse total shoulder arthroplasty: the American Academy of Orthopedic Surgeons Shoulder and Elbow Registry).

The application of the RSA for patients having osteoarthritis with an intact cuff can be viewed in the light of several factors:

(1) The current population-based data from the Australian Orthopaedic Association, which shows better long term survivorship for the anatomic total shoulder than for the reverse total shoulder.

(2) The risk of adverse outcomes - some of which are essentially unique to the reverse total shoulder and are difficult or impossible to revise surgically, including baseplate failure, acromial and scapular spine fractures, deltoid fatigue, and limited internal rotation (see My Reverse Has Failed: Top Five Complications and How to Manage Them). Adverse outcomes managed without surgery are not captured by studies that track revision rates.

(3) The greater average selling price for the RSA in comparison to the anatomic total shoulder (the examples below are taken from Orthopaedic Network News 2021)

Because of the foregoing, the decision between anatomic and reverse total shoulder in the treatment of glenohumeral arthritis is of clinical and economic importance.

Being mindful of the original FDA approved indication for RSA - arthritis+cuff deficiency - the authors of Is Advanced Imaging to Assess Rotator Cuff Integrity Before Shoulder Arthroplasty Cost-effective? A Decision Modeling Study pointed out that for some arthritic shoulders, preoperative physical exam, radiographs, and CT scans do not adequately establish the integrity of the rotator cuff. In these shoulders there are two approaches for further elucidating the status of the cuff to inform the decision of RSA vs. anatomic TSA: (1) preoperative cuff tendon imaging (MRI or ultrasound) or (2) intraoperative assessment of the cuff, having both the RSA and anatomic TSA implants available in the operating room.

They conducted a cost-effectiveness modeling study in which all patients having shoulder arthroplasty underwent history and physical examination, radiography, and CT.  They compared the cost effectiveness of five strategies (1) no further preoperative cuff imaging, (2) selective MRI, (3) MRI for all, (4) selective ultrasound, and (5) ultrasound for all.

They used a decision model with a base-case 65-year-old patient with a 7% probability of a large-to-massive rotator cuff tear and a follow-up of 5 years. Strategies were compared using the incremental cost effectiveness ratio with a willingness to pay of both USD 50,000 and 100,000 per quality-adjusted life year. Diagnostic test sensitivity and specificity were extracted from published systematic reviews and meta-analyses, and patient utilities were obtained using the Cost-Effectiveness Analysis Registry from the Center for the Evaluation of Value and Risk in Health.

Final patient states were categorized as either inappropriate or appropriate in comparison to the actual rotator cuff integrity and type of arthroplasty performed. 

They found that MRI and MRI for all were the most cost effective additional preoperative imaging strategies. However, quality-adjusted life years gained by preoperative soft tissue imaging were minimal: 0.04 quality-adjusted life years gained for MRI for all.  The value of additional preoperative imaging increased as the age-related prevalence of cuff tear increased (rotator cuff tear prevalence greater than 12% made MRI for all cost-effective).

A secondary analysis was performed where all patients indicated for TSA underwent intraoperative rotator cuff examination to determine appropriate implant selection. This second analysis was based on the ability of the surgeon to alter the treatment plan using intraoperative rotator cuff evaluation without further preoperative imaging. This strategy was the most cost effective: least costly and achieved the greatest health utility.

They concluded that in the case of diagnostic uncertainty based on physical exam, radiographs, and CT alone, having both TSA and RSA available in the operating room would be more cost-effective than obtaining advanced soft tissue imaging preoperatively. 

However, when surgical preparedness, patient expectations, and implant availability compromise the ability to switch implants intraoperatively, performing selective MRI to assess rotator cuff integrity to indicate RSA or TSA is cost-effective 

Comment: This is an informative study, providing a clinically useful approach for considering anatomic versus reverse total shoulder for patients with arthritis based on the integrity of the rotator cuff.

A related study would be of great interest as well: comparing the cost effectiveness of anatomic versus reverse total shoulders for the treatment of glenohumeral arthritis in patients with an intact rotator cuff, considering implant cost, complications and revisions.

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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).