Showing posts with label anatomic total shoulder. Show all posts

Sunday, March 29, 2026

Glenoid component version in anatomic total shoulder arthroplasty- does it matter?

Almost 30 years ago Gilles Walch called our attention to arthritic glenoid retroversion. Morphologic study of the glenoid in primary glenohumeral osteoarthritis

From that point on, there has been great interest in the version of the arthritic glenoid: what is it?, how should it be measured?.

And in the execution of an anatomic total shoulder (aTSA), should the version of the glenoid component be "corrected" to some particular value?, if so what value?, how should this correction be achieved? and does changing the preoperative version affect the clinical outcome of aTSA?

It goes without saying that a lot of time and money can go into the evaluation and management of arthritic glenoid retroversion. Perhaps it's time to see how much glenoid component matters to the patient.

About 15 years ago, Patterns of loosening of polyethylene keeled glenoid components after shoulder arthroplasty for primary osteoarthritis: results of a multicenter study with more than five years of follow-up pointed out that posterior tilting of the glenoid component was associated with preoperative posterior decentering and with excessive reaming. The authors suggested that preserving subchondral bone may be important for long-term longevity of the glenoid component.

Glenoid component retroversion is associated with osteolysis found that osteolysis around the center peg of a glenoid component was correlated with component retroversion of ≥15°, the paper clearly stated that "the presence of osteolysis around the center peg was not correlated with a worse clinical outcome defined by shoulder scores or a reoperation due to glenoid loosening".

Nevertheless, achieving component retroversion of <15° has become a goal for many surgeons and an opportunity for orthopaedic companies who have made substantial investments in three-dimensional planning platforms, patient specific instrumentation, navigation, augmented / virtual reality and robotic assisted glenoid preparation.

A recent paper, Does postoperative glenoid component retroversion following anatomic total shoulder arthroplasty affect clinical outcomes? A systematic review and meta-analysis assessed the clinical importance of implanting the glenoid component in <15° of retroversion. After screening 2,457 articles, 15 studies comprising 1,190 shoulders met inclusion criteria. Patients were stratified by whether postoperative glenoid component retroversion was <15° or ≥15°. The principal finding was that no clinically significant differences were observed between the two groups in patient-reported outcome scores, range of motion, or complications.

An unexpected and important finding in this meta-analysis was that shoulders with ≥15° of postoperative retroversion were actually more likely to have no radiolucency (a Lazarus grade 0 radiographic score) than those with <15° retroversion (76.9% vs. 55.6%; P = .00021). This finding argues against the presumption that retroversion promotes loosening.

Does Postoperative Glenoid Retroversion Affect the 2-Year Clinical and Radiographic Outcomes for Total Shoulder Arthroplasty? directly addressed the question in a case-control study. At 2-year follow-up, patients with glenoid components implanted in ≥15° retroversion had similar improvement in Simple Shoulder Test (SST) scores, similar final outcome scores, and similar radiographic findings compared to those with <15° retroversion. Notably, none of the patients with retroverted glenoid components underwent revision surgery, compared to 3 of 50 patients in the non-retroverted group.

Anatomic Total Shoulder Arthroplasty with All-Polyethylene Glenoid Component for Primary Osteoarthritis with Glenoid Deficiencies reported outcomes of aTSA with conservative, noncorrective reaming in shoulders with glenoid deficiencies, including those with significant retroversion. Mean postoperative retroversion in this series was 16°, yet mean postoperative SST was 9 out of 12, consistent with the excellent results achieved in shoulders without glenoid deformity. The revision rate was zero in 143 shoulders at mean follow-up of 34 months.

Anatomic total shoulder arthroplasty for posteriorly eccentric and concentric osteoarthritis: a comparison at a minimum 5-year follow-up compared outcomes of aTSA for posteriorly eccentric (Walch B) versus concentric osteoarthritis at minimum 5-year follow-up, finding no significant difference in ASES scores, revision rates, or radiographic loosening between groups. These durable results were achieved without attempting retroversion correction.

Does glenoid version and its correction affect outcomes in anatomic shoulder arthroplasty? A systematic review analyzed 16 studies and 1,211 shoulders finding that 8 of 11 reports found no significant association between pre- or postoperative glenoid retroversion and clinical results, including patient-reported outcomes, range of motion, and revision rates.

Total shoulder arthroplasty outcomes after noncorrective, concentric reaming of B2 glenoids reported a 95% implant survivorship at a mean of 4.9 years in a series treated with noncorrective reaming with a mean postoperative retroversion of 19°.

The Effect of Version Correction Techniques

If clinical outcomes are equivalent regardless of postoperative retroversion, the question becomes whether correction efforts add value without adding risk. Does postoperative glenoid component retroversion following anatomic total shoulder arthroplasty affect clinical outcomes? A systematic review and meta-analysis compared three correction strategies: posteriorly augmented glenoids, eccentric (“high-side”) reaming, and conservative noncorrective reaming. Eccentric reaming was associated with a significantly higher complication rate than noncorrective reaming (9.3% vs. 3.1%; P = .043, OR 3.22) and a significantly higher revision rate (7.4% vs. 1.2%; P = .015, OR 6.18).

Loss of the dense subchondral bone layer from corrective reaming may result in reduced glenoid component support, increased micromotion, and greater loosening risk over time.

Implications for 3D CT Planning and Technology Transfer

CT-based three-dimensional preoperative planning, patient specific instrumentation, intraoperative navigation, augmented/virtual reality, and robotic glenoid preparation are all predicated on the same clinical logic: that achieving a glenoid component position closer to neutral version will improve patient outcomes. As reviewed above, the available evidence indicates that differences in postoperative glenoid component retroversion do not produce clinically detectable differences in pain relief, function, or implant survival at the follow-up intervals studied.

Use of Preoperative CT Scans and Patient-Specific Instrumentation May Not Improve Short-Term Adverse Events After Shoulder Arthroplasty: Results from a Large Integrated Health-Care System compared aTSA with and without preoperative CT scanning and PSI. These technologies expose patients to additional radiation from CT scanning and incur substantially greater costs of care. Use of CT scans and PSI did not reduce the rate of short-term adverse events following shoulder arthroplasty. Patients receiving PSI may be at greater risk of deep vein thrombosis or deep infection, possibly reflecting the additional operative time this technology requires.

Three-dimensional computed tomography analysis of pathologic correction in total shoulder arthroplasty based on severity of preoperative pathology analyzed 152 shoulders with 3D CT postoperatively and found that while glenoid component shift occurred in 51% of patients, neither component shift nor central peg osteolysis was associated with worse clinical outcomes at minimum 2-year follow-up.

What the Evidence Does Suggest About Optimizing aTSA outcomes?

The available evidence points to factors other than retroversion that drive aTSA results.

See: Below left-poor glenoid seating with cement interposed between the glenoid component and the bone.

Below right-posterior decentering due to poor glenoid preparation and ill-advised use of a posteriorly eccentric humeral head component.

Surgeons may wish to consider 6 aspects of aTSA that are relevant to the glenoid side of the arthroplasty.

(1) conservative reaming to retain the maximal amount of quality host bone

(2) rather than "correcting" glenoid retroversion (A, below), consider "accepting" it (B, below)

(3) component seating — good carpentry with complete backside contact of the glenoid implant against prepared bone; no cement between the component and the bone.

(4) humeral head centering on the glenoid achieved through soft tissue balancing and the possible us of an anteriorly eccentric humeral component.

(5) awareness that technologies can lead surgeons to prioritize postoperative glenoid component retroversion <15° retroversion (without acknowledging the potential risks)

(6) recognition that specialized (e.g. augmented) glenoid components may have downstream risks (see chart below from the 2025 AOANJRR)

Here is a thought provoking case in which substantial glenoid retroversion was accepted

Function at 14 years

Conclusion:

Glenoid component version may not be as critical to the outcome of aTSA as secure seating of the glenoid component on quality host bone and centering of the humeral head on the prosthetic glenoid.

Rather than improving outcomes, there is evidence that "corrective reaming" can be associated with a significantly higher complication rate than noncorrective reaming (9.3% vs. 3.1% ) and a significantly higher revision rate (7.4% vs. 1.2%).

Seating and balance

Yellow-headed blackbird

Malheur

2024

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/rickmatsenmd

Saturday, January 10, 2026

How I perform a kinematic anatomic shoulder arthroplasty : what is the appropriate amount of stuffing?

Overstuffing in anatomic shoulder athroplasty is simply defined as putting too much volume in the limited space of the glenohumeral joint. The capacity of the joint is limited by its soft tissue envelope. While a tight capsule can be surgically released, the excursion of the rotator cuff and subscapularis remain limiting. Sort of like what Lewis Carroll described in his 1865 children's novel, Alice in Wonderland. After Alice drinks from the bottle labeled "DRINK ME" she expands to where she cannot move.

The authors of a recent article, Humeral Head Reconstruction in Anatomic Shoulder Arthroplasty: How to Assess It, How to Avoid Overstuffing, and Whether It Matters provide an excellent review of factors that can influence overstuffing.

When we perform an anatomic arthroplasty, we add volume: the humeral and the glenoid components. When we replace a flattened humeral head with a round one, we add volume. When we add a glenoid component to a joint that had no preoperative articular cartilage, we add volume.

Other factors influence the change in volume in shoulder arthroplasty: osteophyte resection, location of the humeral head cut and extent of glenoid reaming.

Since the goal of shoulder arthroplasty is restoration of mobility and stability, the optimal amount of stuffing for a particular shoulder cannot be determined by preoperative planning but only by intraoperative examination with the trial components in place. For example a shoulder with severe preoperative stiffness may need to be understuffed (i.e. putting in less volume than that suggested by preoperative imaging). Recall that our goal is not "restoring pre-morbid anatomy", but restoring optimal shoulder kinematics for the patient.

Here are some steps that have proven useful in optimizing anatomic shoulder arthroplasty outcomes for the patient while being mindful of stuffing.

(1) Preoperatively, have an in-depth discussion with patient regarding the procedure, emphasizing the importance of adhering to the postoperative rehabilitation. program, precautions, and contacting the surgical team with questions or concerns during the recovery period,

(2) Assess preoperative glenohumeral motion and write it on the white board in the OR.

(3) Review preoperative Grashey and axillary "truth" views to determine the degree of joint space loss, humeral flattening, and humeral centering. Display these images in the OR.

(4) Display the tentative plan on the Grashey view, recognizing that this plan does not consider the thickness of the glenoid component or the preoperative glenohumeral tightness.

(5) Perform a 360 release of the subscapularis to achieve maximal excursion.

(6) Resect osteophytes to reveal the inferior capsular reflection and identify the "hinge point"( the superior-lateral extent of the humeral articular surface) and place baby Hohmann retractor there to assure a complete head resection.

(7) Make humeral head cut at 45 degrees with the long axis of the shaft and in 30 degrees of retroversion, being careful to avoid the cuff insertion posteriorly.

(8) Conservatively ream the glenoid to a single concavity.

(9) Insert glenoid component making sure it is perfectly seated on the prepared bone without cement between its backside and the glenoid bone.

(10) Insert trial humeral component, making sure that its superior margin is just below the berm.

(11) Verify the desired range of flexion, internal rotation with the arm in 90 degrees of abduction, and external rotation with the subscapularis approximated to its repair site.

(12) If the range of motion is limited, especially if tight preoperatively, downsize the humeral component thickness.

(13) Examine stability: optimally shoot for 50% translation on posterior loading. If excessive posterior translation, consider anteriorly eccentric humeral head to avoid stiffness from overstuffing by upsizing humeral head thickness.

(14) Securely repair subscapularis and re-examine motion.

(15) Verify range of flexion with a "parting shot" photograph to be included in the operative note along with documentation of final range of motion measurements.

(16) Tailor post operative rehabilitation program, considering early assisted range of motion for shoulders at risk for stiffness. Document plan in operative note.

(17) Share a copy of the operative note with the patient.

(18) Stay in close communication with patient after surgery, inviting them to email photos of their progress in range of motion

until their rehabilitation is complete.

(19) If the outcome is not what was expected, ask the counterfactual : "what could I have done differently for this patient?

(20) Note that this is a Bayesian approach (see How to make good decisions in shoulder (and other) surgery : Bayesian Thinking) in which at each step the "prior" (starting with the preoperative images and the physical exam) is progressively informed by new information to generate a new "posterior" resulting in a kinematic arthroplasty (rather than an attempt at restoring "premorbid anatomy". Furthermore, the outcomes from each case refine the surgeon's priors for future similar patients, creating a continuous learning cycle that improves a surgeon's judgment over time - something that algorithmic or robotic approaches cannot replicate.

Be self-critical

Barred owl

Seattle Arboretum

2024

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).

Friday, October 24, 2025

When should we consider anatomic total shoulder arthroplasty in patients under 50 years of age?

It is well recognized that patients under the age of 50 often have risk factors for inferior clinical outcomes from shoulder arthroplasty:

(1) more complex arthritis (avascular necrosis, capsulorrhaphy arthropathy, chondrolysis, rheumatoid arhritis, anchor arthropathy, post traumatic arthritis, failed non-arthroplasty surgery, post infectious arthritis, etc.),

(2) higher activity levels,

(3) higher expectations,

(4) increased longevity,

(5) increased risk of cutibacterium periprosthetic infection.

The arthroplasty options for managing arthritis in younger patients include: hemiarthroplasty, ream and run, total shoulder arthroplasty and reverse total shoulder arthroplasty. The choice among these options needs to be made by shared patient-surgeon decision making. Because of the many factors that weigh on this decision, it is unlikely that randomized controlled trials or propensity matching will yield patient-specific guidelines on "the best" approach for young patients with arthritis. Because the surgeon is the method, different surgeons will lean toward certain options based on their experience and training.

The authors of Anatomic Total Shoulder Arthroplasty Indications, Outcomes, and Survivorship in Patients Younger Than 50 Years of Age: A Systematic Review reviewed articles published in last 44 years and found 9 that met their inclusion criteria representing 184 shoulders in 173 patients with a mean age ranging from 33 to 44 years of age. As indicated above, a minority (38%) had primary osteoarthritis, while 35% had rheumatoid arthritis, 9% post-traumatic arthritis, 7% chondrolysis, 6% avascular necrosis, and 5% other. This spectrum is quite different from that of patients over the age of 50.

While patient reported outcomes were improved on average, the improvements were substantially less than those reported by older patients having primary osteoarthritis.

Implant survivorship ranged from 95 to 100% at 0 to 10yrs, 71% to 84% at 11 to 15yrs, and 61% to 84% at > 15yrs postoperatively. These data suggest that over one-third of patients having had an anatomic TSA at the age of 40 years of age had a revision for failure by the time they were over 55 years of age.

Revision rates and followup durations varied widely: 1/26 at 2.3yrs to 7/17 at 14.5yrs. The indications for revision are shown in this table below drawn from the data in the paper.

Comment: As is the case in all reviews and longer term followup studies, it is likely that the implants and techniques used in these papers do not represent current practice. Longer term data on what is being done today will become available a decade from now, but at that time techniques and implants will be different than those used in current practice. As pointed out in Objective ignorance - a problem in predicting outcomes in climbing and in orthopaedic surgery we can't predict future outcomes from past data.
The one element that we do not expect to change is that, as pointed out by the authors of Comparison of patients undergoing primary shoulder arthroplasty before and after the age of fifty, younger patients have more complex pathological conditions, such as capsulorrhaphy arthropathy, rheumatoid arthritis, and posttraumatic arthritis. Only 21% of the younger patients had primary degenerative joint disease, whereas 66% of the older patients had that diagnosis.
With some of these diagnoses, such as rheumatoid and other inflammatory arthropathies, a glenoid component is commonly indicated. However when a glenoid component fails it typically leaves a large, difficult to manage defect in the glenoid bone.

Therefore, for diagnoses such as capsulorrhapy arthropathy, secondary arthritis, AVN and primary osteoarthritis in patients with increased longevity and higher desired activity levels, there is a rise in interest in bone-preserving procedures that do not involve insertion of a glenoid component. Such procedures include a hemiarthroplasty alone or a ream and run (hemiarthroplasty with non-prosthetic glenoid arthroplasty).

Sometimes simpler is better

American Avocet

Malheur

May 2025

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).

Wednesday, October 1, 2025

Anatomic total shoulder - my approach

There are many different approaches to anatomic total shoulder. Here's the one I use. My approach to planning has been presented previously (see this link).