Reverse total shoulder - the value of the alternative center line for baseplate fixation

Mid-term outcomes of reverse shoulder arthroplasty using the alternative center line for glenoid baseplate fixation: a case-controlled study

These authors point out that secure glenoid baseplate fixation is essential for a successful reverse total shoulder (RSA). In cases of glenoid bone loss, use of the anatomic glenoid center line may not provide sufficient bone support for fixation. Anteversion of the baseplate and central screw fixation along the alternative center line is a described method for achieving baseplate fixation in such cases. 

The authors comparde the outcomes of RSA using the anatomic or alternative center line using a retrospective case-controlled study. 66 patients treated with the anatomic center-line technique

for baseplate fixation were matched 3:1 based on sex, indication for surgery, and age with 22 patients treated with the alternative center-line technique. The mean age was 74.2 years (range, 58-89 years) and mean follow-up period of 53 months (range, 24-130 months). 

A monoblock central-screw glenoid baseplate was used in all cases. One of the features of this design is that the preponderance of the fixation is provided by a large central compression screw.

 

 In cases in which the anatomic center line was used, the baseplate was inserted along the standard glenoid center line. Alternative center-line placement of the baseplate was used to achieve primary baseplate

fixation in cases in which it was determined preoperatively or intraoperatively that there was inadequate bone to support fixation of the center screw.

If <80% coverage of the baseplate could be obtained on host bone, structural grafting with either humeral head autograft or femoral head allograft was used to augment baseplate support as shown in the case below.

Attempts were made to achieve secondary fixation by resting the peripheral rim of the glenosphere on the host glenoid bone or bone graft to distribute the load observed through the baseplate fixation.

Often, a glenosphere with a lip extension was used to achieve this goal (glenosphere sizes of 36 mm – 4, 40 mm neutral, and 40 mm – 4). 

Postoperatively, all patients were managed with the same rehabilitation protocol consisting of wearing a shoulder immobilizer with a self-directed therapy protocol focused on only pendulum exercises for the first 6 weeks, followed by an activeassisted stretching program. Strengthening and lifting were delayed for 3 months.

At the final follow-up, they found no significant differences in patient reported measures, including the Simple Shoulder Test score, American Shoulder and Elbow Surgeons score, visual analog scale pain score, and Single Assessment Numeric Evaluation score. 

The overall improvements in these measures and all active motions and functional tasks of internal rotation were not different.

No radiographic evidence of glenoid loosening was found in either group. 

Two patients in each cohort (3% of the anatomic group and 9% of the alternative group) experienced an acromial fracture.

Low-grade scapular notching developed in 15.2% of the anatomic group and 18.2% of the alternative center line group.

Comment: This report demonstrates that - in experienced hands - placing the central screw in the thickest part of the glenoid neck can provide good fixation if coupled with bone grafting when adequate support by native bone cannot be achieved. 

We have found it useful to use a small diameter drill to confirm the orientation that will provide the maximum (ideally 3 cm) of screw fixation.

While the surgeon attempted to achieve secondary fixation by resting the peripheral rim of the glenosphere on the host glenoid bone, it is important that this contact not interfere with complete seating of the glenopshere on the baseplate.

As the authors point out, these results may not be generalizable to practitioners who have less experience or those who use other reverse shoulder devices, such as those without a central compression screw (see an example of such an implant below).

How you can support research in shoulder surgery Click on this link.

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 total shoulder arthroplasty (see this link).

The ream and run technique is shown in this link.

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

Shoulder rehabilitation exercises (see this link).

Follow on twitter: Frederick Matsen (@shoulderarth)

Reversing a failed reverse total shoulder

A man in his 60s who has Parkinson's disease had a reverse total shoulder.

After a number of falls, he presented to us with a painful, functionless shoulder and this x-ray

His reverse was reversed to a hemiarthropaslty.

He continued to have problems with falling, but in spite of these episodes his function reamained good as shown here

Comment: This case illustrates the risk of performing a reverse total shoulder for an individual with a tendency to fall. It also illustrates that a hemiarthroplasty may have been a better choice for the initial procedure.

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How you can support research in shoulder surgery Click on this link.

We have a new set of shoulder youtubes about the shoulder, check them out at this link.

Be sure to visit "Ream and Run - the state of the art" regarding this radically conservative approach to shoulder arthritis at this link and this link

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You may be interested in some of our most visited web pages  arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

Reverse Total Shoulder for Combined Shoulder Arthritis and Massive Rotator Cuff Tear and for Failed Conventional Total Shoulder Replacement - recent articles

Reverse total shoulder joint replacement is now being used in the treatment of shoulders in which stability cannot otherwise be restored: (1) rotator cuff tear arthropathy, (2) failed total shoulder arthroplasty with cuff deficiency and instability, (3) complex fractures of the shoulder in older individuals, and (4) carefully selected massive rotator tears. The reverse differs from conventional total shoulder arthroplasty in that it provides glenohumeral stability to allow function of the deltoid muscle in the absence of the normal stabilization of the joint by a functional rotator cuff. The reverse accomplishes stability though a spherical glenoid prosthesis screwed to the glenoid of the scapula along with a cup-shaped prosthesis at the upper end of the humerus. This construct creates a fixed center of rotation so that contraction of the deltoid results in elevation of the arm.

A recent article has been published by Cheung et al on the complications associated with the reverse total shoulder. The authors list nerve injury, humeral fracture, hematoma, infection, scapular notching, dislocation, prosthesis failure, and acromial fracture as the more common of these complications. The rate of these complications has approached 70% in some reports.

Nerve injury may result from difficulties during these complex surgeries; but another important cause is excessive lengthening of the arm resulting from the surgeon's attempt to achieve stability by increasing the resting tension on the deltoid. These complications may be less with prosthesis that allow tensioning in the medial-lateral as well as the proximal-distal directions.

Intraoperative fractures result from the complex pathological anatomy encountered in shoulders requiring the reverse prosthesis, especially in revision of prior joint replacement, and from poor bone quality in older individuals. These complications may be avoided by minimizing the reaming of the glenoid and humerus, by avoiding the application of torque to the humerus, and by exerting great care in removing previously placed joint replacement components.

Hematomas can result from the extensive dissection and from the 'dead space' created around the joint. Hematomas can increase the risk of infection. Care in achieving hemostasis and holding off on joint motion for several weeks after the procedure can minimize this risk.

Infections can arise after reverse total shoulder arthroplasty, especially after revision surgery. Propionibacterium acnes is recognized as a cause of infection in reverse as well as conventional shoulder arthroplasty. Infections with this organism may be difficult to recognize due to the subtle presentation and the special methods need to culture it.

Scapular notching results from the unintended contact between the medial aspect of the polyethylene of the humeral component and the lateral border of the scapula. This is particularly a concern with prosthesis designs that medialize the center of rotation of the joint as demonstrated by shoulder fellows Saltzman and Mercer. While some disregard the importance of scapular notching, we are concerned about the fact that notching is associated with polyethylene debris which may lead to osetolysis and component failure and that the unwanted contact may contribute to glenohumeral instability. Notching is best avoided by performing a reconstruction that assures the humerus can be completely adducted without contacting the scapula.

Dislocation is always a concern after reverse total shoulder, because the indication for this prosthesis in the first place is instability. Instability is best avoided by careful soft tissue management, including reconstruction of the subscapularis, avoiding unwanted scapulo-humeral contact, appropriate (but not excessive) tensioning of the soft issues, attention to component positioning, and avoiding range of motion for the first six weeks after the procedure to allow for soft tissue healing.
 Glenoid baseplate failure is a concern because of the increased and non-physiological loads placed on the fixation of the glenoid component to the scapula and because of the often poor quality of the glenoid bone. The risk of this complication can be minimized by avoiding all but minimal glenoid reaming, care in positioning of the component on the securest bone stock, secure fixation, use of supplemental bone grafting, and minimizing the loading of the joint.

Acromial fracture can result from the poor quality of the bone, from prior acromioplasty or acromial erosion and from excessive tension on the deltoid.

In conclusion, reverse total shoulder provides a method for re-establishing glenohumeral instability when other methods are insufficient. It is a technically demanding procedure with the potential for many serious complications. Nevertheless, in experienced hands it can provide a dramatic improvement in function in carefully selected cases.

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Reverse Total Shoulder for Rheumatoid Arthritis - Journal of Bone and Joint Surgery

In the Oct 19 issue of JBJS published an article on the use of the reverse total shoulder in the treatment of the shoulder with advanced rheumatoid arthritis. In this case series of 18 patients with an average age of 70 years, there was improvement in comfort and function in all but one after to to seven years of post-surgical follow-up. Four of the 18 experienced fractures, one had a transient axillary nerve palsy and 10 had scapular notching.

The authors point out that bone quality is a particular concern in this patient group. They used bone grafting in eight to enhance the glenoid bone stock and had no cases of glenoid failure.

These gratifying results are a testimony to the surgical judgment and skill of the senior author, Giles Walch, one of the pioneers of reverse shoulder arthroplasty.

It is of note that this series of reverse total shoulders was performed with a prosthesis of the original Grammont design used in the Delta and Aequalis prostheses. Shoulder fellows Saltzman and Mercer investigated the difference in the position of the center of rotation with different prosthesis designs. These positional considerations may have relevance to the tension placed on the acromion with the associated fracture risk and the propensity for notching in reverse total shoulder arthroplasty.


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Reverse Total Shoulder for Combined Shoulder Arthritis and Massive Rotator Cuff Tear and for Failed Conventional Total Shoulder Replacement

The reverse total shoulder replacement can restore comfort and function to the arthritic shoulder combined with a massive rotator cuff tear and for failed conventional total shoulder replacement.  This combination of conditions can result in major loss of stability and active motion of the shoul­der. The reverse total shoulder provides stability of the shoulder joint so that the deltoid muscle can power the shoulder through a useful range of motion. In this procedure the arthritic ball is replaced by a socket fixed to the arm bone (humerus) by a stem that fits within it. A metal ball is fixed to the bone of the arthritic socket with screws. Success requires technical excellence of the surgery and a commitment to the rehabilitation program until the desired range of motion can be achieved comfortably. The figure below left shows the humeral stem, cup, and white polyethylene cup as well as the glenosphere (ball) and screws used for fixation into the scapula (shoulder blade). The figure below right is an x-ray of this prosthesis in place.

First, a review of some basics.

What Are The Key Parts Of The Normal Shoulder Joint?

The ball (humeral head) fits in the socket (glenoid) and is held there by the rotator cuff 

What Is Shoulder Arthritis?

Shoulder arthritis is a condition in which de­generation, injury, inflammation or previous surgery destroys the normally smooth carti­lage on the ball (humeral head-below left) and socket (glenoid-below right).

How Is Shoulder Arthritis Diagnosed?

Carefully standardized X-rays reveal the loss of the space between the hu­meral head and glenoid that is normally occupied by cartilage, leaving bone on bone contact.

What Is A Conventional Total Shoulder?

In a conventional total shoulder, the arthritic surface of the ball is replaced with a metal ball with a stem that is press fit in the inside of the arm bone (humerus-below left) and the socket (glenoid) is resurfaced with a high density polyethylene component (below right).

When Will A Conventional Shoulder Not Work?

When the rotator cuff is sufficiently torn that it no longer provides the necessary stability for the joint, the humeral head slides upwards. This results in slackening of the deltoid (below left) no longer able to raise the hand to carryout nor­mal activities. A conventional shoulder cannot restore the necessary stability in this situation (below right).

What Is A Reverse Total Shoulder?

In a reverse total shoulder the ball is located on the shoulder blade (glenoid) and the socket is located on the arm bone (humerus), exactly the opposite of the situation in a conventional total shoulder. This configuration provides sta­bility because the muscles around the shoul­der compress the ball and socket together. 

How Are The Parts Of A Reverse Total Shoulder Hooked To The Bones?

The ball (glenosphere) is screwed to the bone of the shoulder blade. The cup (humeral sock­et) is fixed to a stem that is cemented down the inside of the arm bone (humerus).

What Is The Incision Like?

After a general or regional anesthetic, this procedure is performed through an incision between the deltoid and the pectoralis major muscles on the front of the shoulder. It includes release of adhesions and con­tractures and removal of bone spurs that may block range of motion. Our team of surgeons, anesthesi­ologists, and surgical assistants usually perform this procedure in less than two hours.

Who Should Consider A Reverse Total Shoulder?

Surgery for shoulder arthritis and rotator cuff deficiency should only be considered when the condition of the shoulder is limiting the quality of the patient’s life and after a trial of physical therapy and mild analgesics to determine if non-operative management is helpful.  If severe disability persists, patients may consider the reverse total shoulder – no other surgical proce­dure has the ability to restore the stability needed in the absence of a functioning rotator cuff. The ideal patient is healthy, active, motivated and committed to complying with the rehabilita­tion program.

Who Should Probably Not Consider A Reverse Total Shoulder?

This procedure is less likely to be successful in individuals with depression or obesity. Pa­tients who use narcotic medication or who use tobacco may have increased difficult recover­ing from this procedure.

What Are The Keys To Success Of A Reverse Total Shoulder?

Success requires technical excellence of the surgery and a commitment by the patient to fol­low the rehabilitation program prescribed by the surgeon.

How Does A Patient Prepare For A Reverse Total Shoulder?

As for all elective surgical procedures, the patient should be in the best possible physical and mental health at the time of the procedure. Any heart, lung, kidney, bladder, tooth, or gum problems should be managed before surgery. Any infection may be a reason to delay the operation. Any skin problem (acne, scratches, rashes, blisters, burns, etc) on the shoulder or arm should be resolved before surgery. The shoulder surgeon needs to be aware of all health issues, including allergies as well as the non-prescription and prescription medications being taken. For instance, aspirin and anti-inflammatory medication may affect the way the blood clots. Some of these may need to be modified or stopped around the time of surgery.

What Happens After Surgery?

The reverse total shoulder is a major surgical procedure that involves cutting of skin, tendons and bone. The pain from this surgery is managed by the anesthetic and by pain medications. Immediately after surgery, strong medications (such as morphine or Demerol) are often given by injection. Within a day or so, oral pain medications (such as hydrocodone or Tylenol with codeine) are usually sufficient. The shoulder rehabilitation program is started on the day of surgery. The patient is encouraged to be up and out of bed soon after surgery and to pro­gressively reduce their use of pain medications. Hospital discharge usually takes place on the second or third day after surgery. The arm is kept in a sling for six weeks after the proce­dure to allow for healing, but the patient can use the hand for eating.  Driving is not recom­mended during this time. Thus the patient needs to be prepared to have less arm function for the six weeks after surgery than immediately before surgery. For this reason, patients usually require some assistance with self-care, activities of daily living, shopping and driving.  Man­agement of these limitations requires advance planning to accomplish the activities of daily living during the period of recovery.

What About Rehabilitation?

After the six weeks in a sling, progressive use of the shoulder for usual daily activities is en­couraged. Formal physical therapy is often not needed.

When Can Ordinary Daily Activities Be Resumed?

The reverse total shoulder is not a procedure that is designed for heavy use or sports.  It is designed to help the patient regard the gentle activities of daily living.  Every precaution should be taken to avoid falls on the operated shoulder.

What Problems Can Complicate A Reverse Total Shoulder And How Can They Be Avoided?

Like all surgeries, the reverse total shoulder can be complicated by infection, nerve or blood vessel injury, fracture, instability, component loosening, and anesthetic complications. Fur­thermore, this is a technically exacting procedure and requires an experienced surgeon to optimize the bony, prosthetic and soft tissue anatomy after the procedure.  The procedure can fail if the reconstruction is too tight, too loose, improperly aligned, insecurely fixed or if unwanted bone-to-bone contact occurs. 

Conclusion

Summary reverse total shoulder replacement for the arthritic shoulder combined with a massive rotator cuff tear. 

The reverse total shoulder is a a technically challenging surgical procedure that can restore comfort and function to shoulders with arthritis and mas­sive defects in the rotator cuff or in failed conventional total shoulder replacement. In the hands of an experienced surgeon, the reverse total shoulder can be an effective method for treating shoulders arthritis and severe rotator cuff deficiency. Pre-planning and persistent rehabilitation efforts will help assure the best possible result for the patient.

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Revision surgery for failed shoulder replacement arthroplasty due to superior instability, Part 12

Loss of the integrity of the coracoacromial arch can be a major problem following shoulder arthroplasty allowing anterosuperior escape of the proximal humerus from the glenoid.  This problem is often caused by prior surgery attempting to repair a large rotator cuff tear. It most commonly seen when an acromioplasty has been performed, compromising the stabilizing effect of the coracoacromial arch.

In this situation a reverse total shoulder arthroplasty may be considered.

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Use the "Search the Blog" box to the right to find other topics of interest to you.

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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