Anatomic and reverse total shoulder arthroplasties for cuff-intact glenohumeral arthritis: rotations and revisions

The authors of Comparison of Reverse and Anatomic Total Shoulder Arthroplasty in Patients With an Intact Rotator Cuff and No Previous Surgery compared the clinical and radiographic outcomes of the Equinoxe primary anatomic total shoulder arthroplasty (aTSA) and the Equinoxe primary reverse total shoulder arthroplasty (rTSA) in patients with osteoarthritis (OA), an intact rotator cuff, and no previous history of shoulder surgery at a minimum follow-up of 2 years. The procedure performed, either aTSA or rTSA, was decided by the surgeon. The authors have strived to standardize practices across 30 different surgeons.

They matched 370 aTSA patients and 370 rTSA patients from an international multi-institutional registry for age, sex, and length of follow-up . 

Internal rotation was scored as the posterior segment reached: hip = 1, buttocks = 2, sacrum = 3, L4-5 = 4, L1 to L3 = 5, T8 to T12 = 6, T7 =7

Preoperatively, the rTSA patients had lower outcome metrics and less motion.

Postoperatively, aTSA and rTSA patients had similar clinical outcomes, motion, and function. 

Patients having aTSA had significantly greater postoperative internal and external rotation and greater improvement in these motions than those receiving rTSA. 

94% of patients having aTSA rated their shoulder arthroplasty as much better or better, compared with 93% for rTSA patients.

Adverse events in rTSA patients included three periprosthetic joint infections (all 3 revised), one dislocation, one broken baseplate screw, one humeral liner disassociation (revised), one humeral fracture (revised) and one patient with unexplained pain. 

Adverse events in aTSA patients included four glenoid loosenings (3 revised), two humeral loosenings (1 revised), four rotator cuff tears (all 4 revised), three periprosthetic joint infections (all 3 revised), and four patients with unexplained pain.

Comment: This study found that in comparison to the rTSA, the aTSA provided significantly better external and internal rotation (see this link on how to achieve internal rotation), but was subject to the risk of rotator cuff tears. A few patients with each type of arthroplasty experienced infections, hardware related problems, and unexplained pain. The rate of patient satisfaction was high for both types of implants.

It will be of interest to continue to follow this series as longer term followup becomes available and to compare revision rates with other long term studies, such as Total shoulder replacement stems in osteoarthritis-short, long, or reverse? An analysis of the impact of crosslinked polyethylene that compared the long term revision rates in a large series of 28,467 different primary arthroplasties performed for osteoarthritis. Of note is that the lowest revision rates were seen with all-polyethylene glenoid components made of cross linked poly (XLPE). It is also noteworthy that that the cumulative revision rates for all arthroplasty types continued to increase with increasing time of followup, especially for the reverse total shoulders and for anatomic total shoulders performed with non-cross linked polyethylene. 

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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).

Reverse total shoulder - scapular motion

How does scapula motion change after reverse total shoulder arthroplasty? - a preliminary report

This report examines changes in scapular position after reverse total shoulder arthroplasty in seven patients having reverse total shoulder arthroplasty for cuff tear arthropathy from July 2007 to October 2008. The distance between the long axis of the thoracic spine and the inferior pole of the scapula (lateralization of the scapula) was measured on shoulder A-P radiographs at 0 degrees (the neutral position) and at 30, 60, 90, and 120 degrees of shoulder abduction. In addition, the angle between the long axis of the thoracic spine and medial border of the scapula was measured and compared with the patients' contralateral shoulder.

Of interest is that the authors tracked the change in position and orientation of the scapula without the use of elaborate sensors attached to the bone, but rather with plain radiographs. While the authors concluded "The pattern of scapular position after RTSA, was found to differ from that of the contralateral shoulder, and showed a more scapular upward rotation," when I replotted their data from their Table II, I was impressed at how similar the motion patterns were, with somewhat greater ST motion in the reverse than in the contralateral shoulder:

It is always of interest to view radiographs of reverse total shoulders.

Here's one showing notching and some heterotopic bone formation. We're fortunate that shoulders forgive these happenings.

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You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty,  and rotator cuff surgery.

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On the hypotheses that determine the definitions of glenohumeral joint motion: with resolution of Codman’s pivotal paradox JSES

On the hypotheses that determine the definitions of glenohumeral joint motion: with resolution of Codman’s pivotal paradox JSES

In this article the authors provide a highly mathematical method for describing shoulder motion.

In a previous post we have pointed to the value of global diagrams for accomplishing the same goal.

With respect to Codman's paradox (and the similar paradox of Rowe), the diagrams below from our book, Practical Evaluation and Management of the Shoulder (available free here) make it easy for us to understand. In order to determine the acquired rotation of the humerus, all we need to know is the fraction of the globe circumscribed by the motion of the arm.

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Revision surgery for stiff shoulder replacement arthroplasty - our approach, Part 3

Before embarking on a surgical revision to regain motion, it is important to determine the cause of the residual stiffness.  Previous operative notes are reviewed to discover if the joint was intentionally tightened and if so how this was carried out.  Particular note is made of whether the subscapularis was advanced lateral to the bicipital groove and whether thermal or laser capsular cauterization was carried out.  Excellent anteroposterior and axillary radiographs are needed to exclude bony or articular causes of shoulder stiffness.  The location of hardware and other implants is determined.

Prior to prepping and draping the shoulder, the ranges of flexion, cross body adduction, internal and external rotation in 90 degrees of abduction, and external rotation at the side as well as the excursion on posterior drawer testing are recorded for both shoulders.

The surgical procedure is performed sequentially, with the range of motion being reexamined after each step of the release.  When the desired range is achieved, the procedure may be concluded. The initial step is to completely free the humeroscapular motion interface.

Any prominent suture, suture anchors, hardware, bone or soft tissue is resected from the proximal humerus to assure smooth passage within the coracoacromial arch.  A nerve-to-nerve release is performed.

The second step is to incise the coracohumeral ligament from around the coracoid process.

Next the subscapularis is identified. and incised from its humeral attachment, preserving maximal length.  A 360-degree release of the subscapularis and anterior capsule is carried out, assuring that the subscapularis moves freely with respect to the coracoid, the glenoid lip, the inferior capsule and the axillary nerve.

In this release the anterior capsule is incised just lateral to the labrum, leaving the labrum on the bony glenoid to maintain the glenoid concavity.  After the release, the subscapularis should have a nice ‘bounce’ when traction is applied to it.  Recall that if the subscapularis is to allow a range of rotation of 115 degrees (two radians) it must have an excursion of twice the radius of the humeral head.  Thus, if a humeral head has a radius of 25 mm, a subscapularis excursion of 50 mm will allow a 115-degree range of internal and external rotation.

After this complete release, additional subscapularis lengthening is rarely needed.  However, if additional lengthening of the subscapularis tendon is needed, an inside-out coronal plane Z-plasty is considered if there is adequate thickness of the capsule and tendon. Sometimes a hamstring autograft is used to robustly connect the subscapularis to the lesser tuberosity with additional tendon length.  It must be noted, however, that adding tendon length does not increase the functional excursion of the muscle.

If the long head tendon of the biceps does not slide freely in the bicipital groove, the adhesions in the groove are released.  If freedom cannot be achieved, the tendon is incised at its insertion to the supraglenoid tubercle and tenodesed to the proximal humerus in its groove.

The next step is, while protecting the axillary nerve with the non-dominant index finger, to release the inferior capsule from the inferior glenoid labrum.

Inserting a humeral head retractor into the joint and rotating its inferior aspect away from the glenoid puts the inferior capsule under tension, facilitating this release.  The anterior and posterior bands of the inferior glenohumeral ligament are released.  Exposure of the origin of the long head of the triceps signals a complete release.

The articular aspect of the joint is inspected and any bony prominences that potentially block motion are resected.  Note is made of the condition of the glenoid and humeral joint surfaces.

Finally, the posterior capsule is released from the posterior glenoid labrum. The capsule is placed under tension by rotating the humeral head retractor away from the glenoid, first inferiorly and then superiorly.

At the conclusion of the procedure, the shoulder is put through a full range of motion.  The subscapularis tendon is closed robustly to the lesser tuberosity so that immediate, postoperative motion maintaining exercises can be implemented.

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You may be interested in some of our most visited web pages including: shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery.

See the countries from which our readers come on this post.