Anatomic or reverse total shoulder for posterior glenoid wear (B2) patterns?

The axillary "truth" view shown below was sent by an active 42 year old man from another state with young children and the desire to return to the gym and to play with his kids. We can agree that this film shows a posterior wear pattern. We can list a number of options for him to consider, including a ream and run, an anatomic total arthroplasty without changing glenoid version, anatomic total arthroplasty with high side (anterior) reaming, anatomic total arthroplasty with posterior bone graft, anatomic arthroplasty with a posteriorly augmented glenoid component, a reverse total shoulder without attempting to change glenoid version, a reverse total shoulder with "corrective" reaming and a reverse total shoulder with an augmented baseplate.

Is the literature helpful? A literature search found only a few articles published in the last 10 years comparing the outcomes for anatomic and reverse total shoulders in patients with posterior bone loss.

A comparative analysis of anatomic total shoulder arthroplasty versus reverse shoulder arthroplasty for posterior glenoid wear patterns. The authors reviewed thirty-eight shoulders that underwent anatomic total shoulder (TSA) and 40 shoulders that underwent reverse total shoulder (RSA) with an average followup of 2 years.  The groups were not comparable. The RSA group included 27 males and 13 females with an average age of 71 years. The TSA group included 37 males and 1 female with an average age of 61 years. The mean ASES, SANE and VAS scores were not clinically significantly different for the two groups.

Total Shoulder Arthroplasty Versus Reverse Shoulder Arthroplasty in Primary Glenohumeral Osteoarthritis With Intact Rotator Cuffs: A Meta-Analyses Two hundred and forty-two glenoids were identified as Walch type B2. The groups were not comparable. The mean ages in the B2 subgroup were 68 and 73 years for the TSA and RSA groups. The percentages of males in the B2 subgroup were 75% and 47% for the TSA and RSA groups. The ASES and SANE scores  were not clinically significantly different.

Anatomic and reverse shoulder arthroplasty for management of type B2 and B3 glenoids: a matched-cohort analysis found that in patients with Walch type B2 or B3 glenoid morphology, primary RSA yielded short-term outcomes that were largely comparable to those of TSA. 

Anatomic shoulder arthroplasty with high side reaming versus reverse shoulder arthroplasty for eccentric glenoid wear patterns with an intact rotator cuff: comparing early versus midterm outcomes with minimum 7 years of follow-up reported the results shown below. The ASES and SST scores were not clinically significantly different at two year or at final followup (i.e. the differences did not exceed the minimal clinically important difference for either score).

Anatomic vs. reverse shoulder arthroplasty for the treatment of Walch B2 glenoid morphology: a systematic review and meta-analysis reported that in the setting of Walch B2 glenoid morphology, TSA with eccentric reaming or an augmented component yielded comparable outcomes to RSA. 

Some of these studies found that the revision rate in anatomic total shoulder arthroplasty with version correction was higher than for reverse total shoulder arthroplasty. This leads us to ask the questions: "is it important to correct glenoid version?" and "what are the potential adverse effects of glenoid version correction?". Here are some slides from a forthcoming presentation on this subject.

Comment: Almost half of patients having shoulder arthroplasty have wear of their posterior glenoid - "posterior wear is not rare". As described in the first paragraph of this post, there are at least 8 different surgical techniques that have been described. The selection among them depends on the expectations of the patient, the pathoanatomy of the shoulder and the familiarity and skill of the surgeon with the different alternatives.

Considering all of these factors, our choice for patients with shoulders having a posterior wear pattern is often an anatomic total shoulder arthroplasty with a standard (non-augmented) glenoid component well-seated on glenoid bone that is conservatively reamed without attempting to change version (see below).

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link

Follow on twitter/X: https://x.com/RickMatsen

Follow on facebook: https://www.facebook.com/shoulder.arthritis

Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

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). 

Stemless or stemmed total shoulder arthroplasty?

 An active man in his mid 50s presented with pain and stiffness in his left shoulder and these x-rays. The axillary "truth" view showed the humeral head centered on an A2 glenoid.

Without preoperative CT or 3D planning, he underwent an anatomic total shoulder arthroplasty with a stemless humeral component (diameter of curvature 50, thickness 18 mm). A standard glenoid component was inserted without attempting to change glenoid version. The shoulder was stable on the "shake and bake" test.

He regained excellent comfort and function. 6 months later he presented with pain and stiffness in the right shoulder and the x-rays below. The axillary "truth" view showed the humeral head posteriorly decentered on a retroverted B2 glenoid.

 

Without preoperative CT or 3D planning, he underwent an anatomic total shoulder arthroplasty. A standard glenoid component was inserted without attempting to "correct" glenoid version. While many shoulders with this amount of posterior decentering are stable with standard humeral head components, on trialing a stemless humeral component (diameter of curvature 50, thickness 18 mm and then a diameter of curvature 50, thickness 20 mm ) this shoulder was posteriorly unstable on the "shake and bake" test. The arthroplasty was quickly and easily converted to a short stemmed implant using an anteriorly eccentric humeral head with a diameter of curvature 50, thickness 18 mm. 

 

This provided excellent posterior stability without excessively tightening the shoulder. 

For anatomic total shoulder arthroplasty, our default option is the stemless humeral implant because of the efficiency of the procedure and the ability to position the humeral head without being concerned about the stem. Our two indications for a stemmed implant are (1) the need for an eccentric humeral head component and (2) soft bone in the proximal humerus. Neither of these can be reliably determined prior to surgery. 

In performing an anatomic total shoulder, the proximal humerus is lateralized from its preoperative position by the addition of the thickness of a prosthetic glenoid component. See Seven ways to Overstuff and Anatomic Arthroplasty.

Thus, especially in shoulders that are tight preoperatively, a humeral implant with less than "anatomic" height may be needed to avoid over tightening the joint (see this link). Surgeons should be aware of the available head geometries of the implant system they are using.

That's our approach. Let's take a look at what the 2023 and 2024 literature has to say about stemless anatomic arthroplasty.

Stemless anatomic total shoulder arthroplasty is associated with less early postoperative pain "there were no differences in pain, patient-reported outcomes, range of motion or strength measures between stemless and short-stem aTSA at 2 years postoperatively."

Radiographic comparison of eccentric stemmed vs. concentric stemless prosthetic humeral head positioning after anatomic total shoulder arthroplasty "Stemless and stemmed aTSA implants have similar rates of reproducing satisfactory postoperative humeral head center of rotation (COR) with both producing COR deviation most commonly in the superomedial direction. Deviation in humeral head height above the greater tuberosity (HHH) contributes to overstuffing in both stemmed and stemless implants, COR deviation contributes to overstuffing in stemmed implants, while radius of curvature (RoC) is not associated with overstuffing."

Stemmed VS stemless total shoulder arthroplasty: a systematic review and meta-analysis "stemmed and stemless TSA provided good clinical results, with similar benefits in terms of clinical outcomes and complications."

A stemless anatomic shoulder arthroplasty design provides increased cortical medial calcar bone loading in variable bone densities compared to a short stem implant "A cortical rim-supported stemless implant maintained proximally improved dynamic bone loading compared to a press-fit short stem implant. Biomechanical time-zero implant micromotion in lower bone densities was comparable between short stem and stemless implants at rehabilitation load levels (220 N, 520 N), but there was higher cyclic stability and reduced variability for stemmed implantation at peak loads (820 N)."

Comparable low revision rates of stemmed and stemless total anatomic shoulder arthroplasties after exclusion of metal-backed glenoid components: a collaboration between the Australian and Danish national shoulder arthroplasty registries "Based on data from 2 national shoulder arthroplasty registries, we found no significant difference in risk of revision between stemmed and stemless total shoulder arthroplasties after adjusting for the type of glenoid component. We advocate that metal-backed glenoid components should be used with caution and not on a routine basis." see also High revision rate of metal-backed glenoid component and impact on the overall revision rate of stemless total shoulder arthroplasty: a cohort study from the Danish Shoulder Arthroplasty Registry. and Complications and revisions in metal-backed anatomic total shoulder arthroplasty: a comparative study of revision rates between stemless and stemmed humeral components

Stemless anatomic and reverse shoulder arthroplasty in patients under 55 years of age with primary glenohumeral osteoarthritis: an analysis of the Australian Orthopedic Association National Joint Replacement Registry at 5 years "In the predominantly male patient population below the age of 55, stemless aTSA had a lower short-term revision risk than stemmed aTSA."

Comparing optimum prosthesis combinations of total stemmed, stemless and reverse shoulder arthroplasty revision rates for men and women with glenohumeral osteoarthritis "In a subanalysis of procedures in males since 2017 with additional adjustments,stemless (slTSA) shoulder arthroplasty with cemented polyethylene glenoids had a lower revision rate than stemmed (stTSA) shoulder arthroplasty with modified central peg polyethylene glenoids" The same authors came to a slightly different set of conclusions in A comparison of revision rates for stemmed and stemless primary anatomic shoulder arthroplasty with all-polyethylene glenoid components: analysis from the Australian Orthopaedic Association National Joint Replacement Registry "Revision rates of stTSA and slTSA did not significantly differ and were associated with humeral head size but not patient characteristics. Surgeon inexperience of anatomic shoulder arthroplasty and non-XLPE glenoids were risk factors for stTSA revision but not slTSA.  Revision for instability/dislocation was more common for slTSA."

Medium-term results of stemless, short, and conventional stem humeral components in anatomic total shoulder arthroplasty: a New Zealand Joint Registry study "The medium-term survival of stemless implants for anatomic total shoulder arthroplasty appears comparable to short-stem and conventional stemmed implants."

Stemless components lead to improved radiographic restoration of humeral head anatomy compared with short-stemmed components in total shoulder arthroplasty "Stemless prostheses placed during TSA achieved improved restoration of humeral head COR and were less likely to have significant COR outliers compared with short-stem implants."

Short-term radiographic analysis of a stemless humeral component for anatomic total shoulder arthroplasty "This study demonstrates a low rate of stress shielding for a stemless design humeral implant at short-term follow-up without any revision surgery due to humeral component complications."

Preoperative metaphyseal cancellous bone density is associated with intraoperative conversion to stemmed total shoulder arthroplasty "Metaphyseal cancellous bone density can be calculated on preoperative CT scans and is associated with intraoperative conversion to a stemmed humeral component in anatomic shoulder arthroplasty. A threshold of 20 HU can be used to predict which patients are more likely to require stemmed components."

Is stemless total shoulder arthroplasty indicated in elderly patients? "Age >/=70 years does not appear to be a contraindication to stemless anatomic total shoulder arthroplasty. Postoperative improvements in outcome scores were similar between patients aged <70 yr and those aged >/=70 years. There was no difference between the groups regarding the patients who required intraoperative deviation from the preoperatively planned stemless prosthesis to a stemmed prosthesis."  

Comment: As with all of orthopedics, experience is the great teacher for stemless arthroplasty. Be ready.

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link

Follow on twitter/X: https://x.com/RickMatsen

Follow on facebook: https://www.facebook.com/shoulder.arthritis

Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

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). 

Revising the shoulder with a periprosthetic infection: how important is it to remove everything?

For most cases of shoulder periprosthetic infection, the single stage with complete implant exchange is the "go to" procedure.

However, in some patients with complex periprothetic infections in which complete implant exchange is difficult and risky, surgeons have competing priorities: 1. trying to cure the patient's infection or 2. trying to preserve the comfort and function of the patient's shoulder. The interesting thing about #1 is that no matter how hard we try, we can never be sure that we have removed every last bug from the shoulder and have eliminated the possibility of a recurrence down the line. 

Vigorous attempts to stamp out infection may involve removal of all implants and cement, but these attempts may permanently compromise the comfort and function of the patient's shoulder. Imagine an elderly person with fragile bone and a well cemented implant who has developed drainage from her shoulder, which otherwise is functional and painless. Is she better served by complete explantation or by a washout, culture-specific antibiotics and - should she continue to drain - offering her the option of retaining her implants and managing the drainage with dressings?

The authors of Does retained cement or hardware during 2-stage revision shoulder arthroplasty for infection increase the risk of recurrent infection? sought to determine if incomplete removal of cement and hardware adversely affected the results of revision for infection.

Specifically they compared the rates of repeat infection at two years after 2-stage revision for prosthetic joint infection in 37 patients who had retained cement or hardware compared to those who had complete removal.

Repeat infection was defined as either ≥2 positive cultures at the time of the second-stage with the same organism that was cultured during the first-stage or repeat surgery for infection after the two-stage revision. 

 Six patients had retained cement and 1 patient had 2 retained broken glenoid baseplate screws after first-stage revision.  30 patients had no retained hardware.

10 cases had recurrent infection:

Patient demographics were not significantly associated with recurrent infection.

Of the 10 cases of recurrent infection, 1 case had retained cement/hardware while 9 had no retained cement/hardware.

Thus 1 of 7 (14%) with retained cement/hardware had a recurrent infection while 9 of 30 (30%) with no retained cement/hardware had a recurrent infection. Retained cement or hardware was not significantly associated with a repeat risk of infection.

The authors suggested that surgeons should consider leaving cement or hardware that is difficult to remove and may lead to increased morbidity and future complications. 

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link

Follow on twitter/X: https://x.com/RickMatsen

Follow on facebook: https://www.facebook.com/shoulder.arthritis

Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

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). 

Rotator cuff tears and tendinopathy - Is platelet rich plasma (PRP) helpful? Read this important updated version.

A review of published randomized trials and meta-analyses indicates that non-operative treatment is effective for the majority of patients with conditions of the rotator cuff, including rotator cuff tears.

Local corticosteroid injections are sometimes used in non-operative treatment, however they apparently have no biologic effect in terms of regenerating or reversing the degenerative changes occurring in rotator cuff tendons and their clinical benefit usually wears off quickly.

It has been suggested that local injection of platelet-rich plasma (PRP) may promote stem and progenitor cell proliferation, modulate inflammatory responses, stimulate angiogenesis, enhance the proliferation of tenocytes, stimulate the production of extracellular matrix proteins, protect against oxidative stress, and inhibit inflammation (see Platelet-Rich Plasma in Orthopaedic Surgery: A Critical Analysis Review) and that these effects may benefit patients with rotator cuff tendinopathies before structural failure of the rotator cuff occurs. 

 The authors of Subacromial injection of platelet-rich plasma provides greater improvement in pain and functional outcomes compared to corticosteroids at 1-year follow-up: a double-blinded randomized controlled trial attempted to answer this question in a randomized clinical trial of patients between 18 and 50 years old (mean age 28 years) who had both a clinical and magnetic resonance imaging diagnosis of supraspinatus tendinopathy refractory to conservative treatment. 

A total of 50 patients received a single subacromial injection of PRP, whereas 50 patients received a single subacromial corticosteroid injection. All the patients completed 12 months of clinical follow-up. 

At 12 months, in comparison to the those receiving cortisone, patients in the PRP group showed a significantly greater improvement in 

the VAS score: 1.68 vs. 2.3

the American Shoulder and Elbow Surgeons (ASES) score, 89.8  vs. 78.0 

the Single Assessment Numeric Evaluation (SANE) score, 89.2 vs. 80.5 

and the the Pittsburgh Sleep Quality Index (PSQI) score, 2.72 vs. 4.02 

The overall failure rate was significantly higher in the corticosteroid group (30%) than in the PRP group (12%) (P < .01).

It was particularly interesting to note that the difference in the course of the two groups was not evident until 6 months after the injection. As Michael Pearl pointed out, it is possible that the PRP folks would have gotten better anyway (i.e. the PRP may not have had an effect). We'd need a saline injected control arm to examine that possibility.

It does seem that the corticosteroid injected group tended to do less well with time and their greater failure rate may be related to the adverse effects of cortisone on tendons. As Dr Pearl says "An alternative explanation could be that cortisone is deleterious and the PRP less interfered with the natural history.  " 

It is notable that the ASES score difference between 3 and 12 months (85 to 90) does not exceed the minimal clinically important difference for ASES of 15. 

Comment: This double blinded randomized clinical trial showed that young patients with rotator cuff tendinosis having subacromial injection of PRP did better than comparable patients having subacromial injection of cortisone. It does not show that patients having subacromial injection of PRP would do better than those with no treatment or with a placebo control. Keep in mind that these patients had an average age of 28, folks who have a lot of potential for recovery with time and rehab.

A possible benefit of PRP in cuff tendinosis cannot be extrapolated to the treatment of cuff tendons with structural failure, as demonstrated by the authors of Subacromial Platelet-Rich Plasma Injections Produce Significantly Worse Improvement in Functional Outcomes in Patients With Partial Supraspinatus Tears Than in Patients With Isolated Tendinopathy who found that  improvement in the ASES score was significantly greater in the group without tears than in the group with partial cuff tears (PTRCTs) at all follow-up times. 94% of the patients in the isolated tendinopathy group but less than half of patients in the PTRCTs group achieved a substantial clinical benefit at 12 months follow-up. 

Furthermore, a review of published randomized controlled trials and meta-analyses failed to demonstrate a clinically significant benefit to the patient of the use of PRP in conjunction with surgical repair of a torn rotator cuff.

You can support cutting edge shoulder research that is leading to better care for patients with shoulder problems, click on this link

Follow on twitter/X: https://x.com/RickMatsen

Follow on facebook: https://www.facebook.com/shoulder.arthritis

Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

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).