aTSA vs RSA for cuff intact arthritis: what is the evidence that informs the choice for each patient?

Both anatomic total shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (RSA) are considerations for patients with cuff-intact glenohumeral osteoarthritis. Currently many, if not most shoulder surgeons are trending toward RSA. In fact many surgeons have little working experience in performing aTSA. For example, per the Australian registry, the share of primary total shoulder replacements that is anatomic has collapsed from roughly 57% in 2008 to about 4% by 2024, while stemmed reverse has risen to nearly 90% (see figure below) [1]. In some circles the pro RSA argument is based on the contentions that (1) the RSA is easier to perform by less experienced-as well as experienced-surgeons and (2) the RSA as a lower rate of revision.

A look at the published evidence may inform the choice for patients and surgeons:

1. Patient-reported outcomes

With commonly used scores, the two types of arthroplasty seem similar for cuff-intact arthritis. A 2026 meta-analysis of 1,716 patients aged ≥70 with a competent cuff found no significant differences in ASES, Constant, or SST scores [2]. A meta-analysis of 14 studies (4,819 cases) found similar ASES, Constant, SST, SSV, and VAS pain scores [3], as did an earlier systematic review [4] and a propensity score–matched JBJS analysis [5]. 

However, in the UK National Joint Registry, roughly a quarter of 21,918 RSA patients had an “unsatisfactory” Oxford Shoulder Score (<29) [6]. Single-center series using patient-acceptable-symptom-state (PASS) thresholds put the figure higher — 25–40% of RSA patients failed to reach PASS for ASES or SANE at two years [7], and 34–35% still failed at minimum five years [8], with pain the primary factor in these adverse outcomes. 

With the Shoulder Arthroplasty Smart score, aTSA achieved higher absolute postoperative scores even though the improvement from baseline was similar [9]. Among patients who reached a “new normal” (defined as a SANE score  ≥95), aTSA significantly outperformed RSA on higher-demand tasks, motion, and return to sport and work [10]. 

2. Motion 

Across the comparative meta-analyses, aTSA delivered better external and internal rotation, with differences that exceed the MCID and reached 10–11° of external rotation in pooled estimates [2,3,4] as well as  better overall motion in matched cohorts [5]. Rotation enables the patient to perform basic activities of daily living: dressing, toileting, perineal care, and reaching behind the back.

3. Complications

In pooled comparative data, RSA carried a lower overall complication rate than aTSA in the cuff-intact population [2,3]. But the complications the two implants produced differed in kind. Historically, primary stemmed anatomic shoulders done for osteoarthritis using legacy techniques and implants have been revised chiefly for glenoid component loosening (29.1%), rotator cuff insufficiency (27.6%), and instability/dislocation (23.1%), with loosening being predominant [1]. Stemmed reverse shoulders have been revised chiefly for instability/dislocation, infection, loosening, and fracture [1]. 

4. Revision 

At ten years, cumulative percent revision (all diagnoses, modern prostheses) was 5.5% for stemmed reverse, 5.2% for stemless aTSA, and 7.9% for stemmed aTSA (Figure 2 below) [1]. 

It is worthwhile noting that the 7.9% ten-year revision rate for stemmed aTSA includes decades of older, non-crosslinked polyethylene. When the glenoid is crosslinked, aTSA durability improves markedly: in a dedicated AOANJRR study of 10,102 stemmed aTSAs done for osteoarthritis, non-crosslinked polyethylene had more than double the revision risk of crosslinked polyethylene after 18 months (HR 2.3; 95% CI 1.6–3.1), with 12-year cumulative revision of 9% versus 5% [22]. Considering only crosslinked anatomic glenoids, the revision rate for stemmed aTSAs (5%) was comparable to stemmed RSA (5.5%) and stemless aTSA (5.2%). 

Vitamin E–stabilized polyethylene is a type of crosslinked polyethylene, and registries tend to pool the two.  Vitamin E reduces wear and osteolytic particle debris on the bench [23], but no study has yet demonstrated a vitamin-E–versus–plain-crosslinked revision difference in shoulder arthroplasty.

The revision rates for stemless aTSA match those for the RSA; the reasons for this are not clear - perhaps more experienced surgeons, greater ability to achieve the desired humeral component position,  a higher rate of use of modern glenoid components, and/or preferential selection of healthier shoulders with better quality bone. 

Comparative meta-analyses report RSA revision rates about four-fold lower than aTSA in the cuff-intact analysis, OR 0.43; 95% CI 0.29–0.65; p<0.001) [3], although an earlier meta-analysis found no mid-term difference (OR 0.33; p=0.16) [4]. A 2026 propensity-matched study showed a lower early revision rate for aTSAs, but at midterm followup the revision rate increased [12].

However, it is critical to recognize that revision is a poor proxy for clinical failure in RSA. A National Joint Registry analysis concluded that low RSA revision rates may not signify implant success. Instead, patients with poor outcomes and their surgeons may be reluctant to undertake complex RSA revisions which have unpredictable results.[6]. The point is apparent for the most common mode of RSA failure — a painful, poorly functioning but radiographically satisfactory RSA. Such an outcome is experienced by about a quarter of RSA patients [6,7,8], yet RSAs are rarely revised for this indication. A failure that is not revised never appears in the revision rate.

[Complication frequencies were drawn from indexed systematic reviews [26–29] (e.g., PJI 2.4%, acromial/scapular fracture 2.5%, primary-RSA instability 2.5%); the revisability column reflects their reported management — acromial fractures are predominantly treated non-operatively, instability usually presents within 90 days and is treated by component revision, and infection is nearly always surgical. The registry anchor for pain/PROM failure is O’Malley [6].]

The different failure types are not equally salvageable. If an anatomic shoulder fails, it can usually be converted to a RSA with outcomes that approach those of primary RSA.  Primary stemmed anatomic shoulders done for osteoarthritis are revised to a reverse in 89% of cases, keeping the original humeral stem 58% of the time [1]; 93.8% of failed stemless aTSAs are converted to RSAs. On the other hand, revision of a failed reverse to another reverse often fails to yield the desired improvement in comfort and function.

5. Durability

Durability matters most for the patient with decades of active use ahead. At minimum ten-year follow-up, aTSAs sustain their functional gains for primary osteoarthritis [13], the large concurrent aTSA experience supports this option in the high-demand patient who wishes to avoid a RSA [14]. The Australian registry shows modern stemless anatomic matching reverse on revision out to ten years, and crosslinked stemmed-anatomic glenoids more than halve the revision risk of older non-crosslinked ones [1,22].

6. Return to sport 

Return-to-sport rates are high after both implants and highest after aTSA in pooled data [15]. A recent large weightlifting series reported high self-rated comfort, yet its endpoint is a single ordinal “difficulty” item — capturing neither the amount of load nor performance. [16]. When actual one-repetition-max recovery is measured, returners perform below their presymptomatic level, with the largest decrement in bench press [17]. 

7. Surgeon capability. It is often said that a good aTSA outperforms a good RSA, which outperforms a bad aTSA, which outperforms a bad RSA [18].  Some say it is technically easier to do a good RSA than an aTSA (not my view). However it is for sure that as aTSA volume falls, fewer surgeons will be able to reliably provide a good anatomic to their patients with cuff intact arthritis. While some hold that navigation, patient-specific instrumentation, and robotics may improve component positioning; none has been shown to improve patient-reported outcomes or reduce complications for any type of arthroplasty [19,20,21]. It appears that the surgeon is sill the method.

So, in rough summary

Bottom line: 

The patient and the surgeon considering arthroplasty for cuff intact shoulder arthritis should discuss the available evidence on aTSA and RSA.

An aTSA - when performed by a surgeon who can deliver a reliable aTSA -  may be attractive when function and salvageability matter most —  particularly in the more active patient with a reconstructable glenoid.

A RSA may be more attractive in the less active patient, or one whose glenoid morphology or bone quality makes a durable aTSA less certain or when the shoulder surgeon is not comfortable performing an anatomic shoulder arthroplasty.

Two cautions bear on the consideration: the revision rate understates RSA failure, because its most common failure — a painful but intact shoulder — is rarely revised [6]; and roughly a quarter of RSA patients do not reach a satisfactory outcome at all [6,7,8]. 

A choice

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References

[1]Lewis PL, Gill DR, McAuliffe MJ, et al. Hip, Knee and Shoulder Arthroplasty: 2025 Annual Report. Australian Orthopaedic Association National Joint Replacement Registry. AOA: Adelaide; 2025. doi:10.25310/MXFR3061. (Figures ST1, ST2; Tables ST6, ST39, ST46–47, ST76.)

[2]Gupta MS, Krishan A, Rashid A, et al. Reverse versus anatomic total shoulder arthroplasty in patients over 70 with a competent rotator cuff and glenohumeral osteoarthritis: a meta-analysis. J Shoulder Elbow Surg. 2026 (online 2025). PMID: 41276069.

[3]Thamrongskulsiri N, Limskul D, Tanpowpong T, et al. Comparison of revision rates and clinical outcomes between anatomic and reverse total shoulder arthroplasty for rotator cuff-intact osteoarthritis: a systematic review and meta-analysis. Clin Orthop Surg. 2025;17(6):907–921. doi:10.4055/cios25012.

[4]Kim H, Kim CH, Kim M, et al. Is reverse total shoulder arthroplasty more advantageous than anatomic TSA for osteoarthritis with intact cuff tendon? A systematic review and meta-analysis. J Orthop Traumatol. 2022;23(1):3. PMID: 34993646.

[5]Kirsch JM, Puzzitiello RN, Swanson D, et al. Outcomes after anatomic and reverse shoulder arthroplasty for glenohumeral osteoarthritis: a propensity score-matched analysis. J Bone Joint Surg Am. 2022. PMID: 35867705.

[6]O’Malley O, Davies A, Sabharwal S, et al. Is there a difference in thresholds for revision between shoulder arthroplasty types? A National Joint Registry study. PLoS One. 2025. doi:10.1371/journal.pone.0330975.

[7]Werner BC, Lederman E, Gobezie R, et al. Understanding the variables associated with failure to achieve an acceptable symptom state after reverse shoulder arthroplasty. Semin Arthroplasty JSES. 2021.

[8]Ardebol J, et al. Defining the MCID and PASS following reverse shoulder arthroplasty for glenohumeral arthritis or cuff tear arthropathy at minimum 5-year follow-up. JSES Int. 2025.

[9]Marigi EM, Hao KA, Friedman RJ, et al. Exactech Equinoxe anatomic versus reverse total shoulder arthroplasty for primary osteoarthritis: case-controlled comparisons using the machine learning-derived Shoulder Arthroplasty Smart score. J Shoulder Elbow Surg. 2023. PMID: 39292145.

[10]Beleckas CM, Schodlbauer DF, Mousad AD, et al. Evaluation of new normal after shoulder arthroplasty: comparison of anatomic vs. reverse total shoulder arthroplasty. J Shoulder Elbow Surg. 2025;34:S43–S49. doi:10.1016/j.jse.2025.02.010. PMID: 40074195.

[11]Barco R, Savvidou OD, Sperling JW, et al. Complications in reverse shoulder arthroplasty. EFORT Open Rev. 2016;1:72–80. doi:10.1302/2058-5241.1.160003.

[12]Leinweber KA, Bowler AR, Diestel DR, et al. Reverse and anatomic total shoulder arthroplasty for glenohumeral osteoarthritis: a propensity-matched comparison at early and midterm follow-up. J Shoulder Elbow Surg. 2026. PMID: 41564999.

[13]Sharareh B, Whitson AJ, Matsen FA III, et al. Minimum 10-year follow-up of anatomic total shoulder arthroplasty and ream-and-run arthroplasty for primary glenohumeral osteoarthritis. J Shoulder Elbow Surg. 2024;33(6):1276–1284. PMID: 37777045.

[14]Matsen FA III, Whitson A, Jackins SE, et al. Ream and run and total shoulder: patient and shoulder characteristics in five hundred forty-four concurrent cases. Int Orthop. 2019;43(9):2105–2115. PMID: 31240359.

[15]Liu JN, Steinhaus ME, Garcia GH, et al. Return to sport after shoulder arthroplasty: a systematic review and meta-analysis. Knee Surg Sports Traumatol Arthrosc. 2018;26(1):100–112. PMID: 28409200.

[16]Abdelshaheed J, Chatterji R, Levy J, et al. Return to weightlifting following anatomic and reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2026;35:1660–1666. doi:10.1016/j.jse.2026.02.002.

[17]Ames A, Shah SS, Pettit R, et al. Against surgeons’ advice: the return to sport in high-demand weightlifters following anatomic total shoulder arthroplasty at average 3.6 years’ follow-up. J Shoulder Elbow Surg. 2023;32(4):e153–e159. doi:10.1016/j.jse.2022.09.027.

[18]Menendez ME, Garrigues GE, Jawa A. Clinical Faceoff: anatomic versus reverse total shoulder arthroplasty for primary glenohumeral osteoarthritis. Clin Orthop Relat Res. 2022;480(11):2095–2100.

[19]Daher M, Fares MY, Boufadel P, et al. Patient-specific instrumentation in primary total shoulder arthroplasty: a meta-analysis of clinical outcomes. Clin Shoulder Elb. 2025;28(2):129–136. doi:10.5397/cise.2024.01095.

[20]Patient-specific instrumentation in shoulder arthroplasty: high tech, low yield? [editorial]. Clin Shoulder Elb. 2025;28(2). doi:10.5397/cise.2025.00423.

[21]Gaj E, Pagnotta SM, Berlinberg EJ, et al. Intraoperative navigation system use increases accuracy of glenoid component inclination but not functional outcomes in reverse total shoulder arthroplasty. Arch Orthop Trauma Surg. 2024;144(1):91–102. doi:10.1007/s00402-023-05038-y.

[22]Page RS, Alder-Price AC, Rainbird S, et al. Reduced revision rates in total shoulder arthroplasty with crosslinked polyethylene: results from the Australian Orthopaedic Association National Joint Replacement Registry. Clin Orthop Relat Res. 2022;480(10):1940–1949. doi:10.1097/CORR.0000000000002293. PMID: 35901440.

[23]Khan AZ, Maxwell MJ, Parrott RM, et al. Effect of vitamin E–enhanced highly cross-linked polyethylene on wear rate and particle debris in anatomic total shoulder arthroplasty: a biomechanical comparison to ultrahigh-molecular-weight polyethylene. J Shoulder Elbow Surg. 2024. PMID: 38182025.

[24]Gowd AK, Liu JN, Cabarcas BC, et al. Single Assessment Numeric Evaluation and patient acceptable symptom state thresholds following shoulder arthroplasty. J Shoulder Elbow Surg. 2021. (PASS: ASES 81.9, SANE 75.5; n=207, mixed TSA/RSA.)

[25]DeVito P, Damodar D, Berglund DD, et al. Predicting outstanding results after reverse shoulder arthroplasty using percentage of maximal outcome improvement. J Shoulder Elbow Surg. 2019;28(6):1223–1231. PMID: 30910258. (SST threshold 61.3% MPI; n=198.)

[26]Shah SS, Gaal BT, Roche AM, et al. The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part I. JSES Int. 2020;4(4):929–943. (Periprosthetic joint infection 2.4% for primary RSA.)

[27]Shah SS, Roche AM, Sullivan SW, et al. The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part II. JSES Int. 2020;5(1):121–137. doi:10.1016/j.jseint.2020.07.018. PMID: 33554177. (Instability, humerus/glenoid fracture, acromial/scapular-spine fracture.)

[28]Zumstein MA, Pinedo M, Old J, et al. Problems, complications, reoperations, and revisions in reverse total shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg. 2011;20(1):146–157.

[29]Lau SC, Large R. Acromial fracture after reverse total shoulder arthroplasty: a systematic review. Shoulder Elbow. 2020;12(6):375–389. doi:10.1177/1758573219876486. PMID: 33281942.

Pyrocarbon Section 4: clinical data

In this post we take a bit of a deeper dive into the clinical information available regarding pyrocarbon humeral arthroplasty - looking at evidence from the Australian and New Zealand registries alongside the currently available reports on specific cohorts.

Please note that this is a "best effort" attempt to put together what's out there. If the reader finds any of this to be in error, please do let me know.

Newspaper-style, the post starts with a summary

and then presents data that may support the points presented in the summary.

1. There is no single “pyrocarbon shoulder” — there are at least three. Resurfacing (PyroTITAN, not FDA-cleared in the U.S.), the U.S. FDA-cleared stemmed pyrocarbon hemiarthroplasty, and the European stemmed hemiarthroplasty with systematic head-downsizing. Each uses different implants or different techniques; a finding for one may not transfer to another, and pooling them is a common error in this literature.

2. Registries present data on revision rate, not function. McBride 2026, the AOANJRR 2025 special clinical assessment, and the New Zealand registry agree that pyrocarbon is revised about as often as a good anatomic TSA. However revision is a surrogate endpoint: the observation that a patient's implant was not revised does not necessarily mean that the patient had good shoulder comfort and function (we know this from reverse total shoulders where patients living with poor postoperative comfort and function often do not have revision surgery).  What matters most to the patient and to us is the degree to which the arthroplasty improved the patient's quality of life.

3. The currently available data often do not relate to implants and techniques currently in use. Most series are based heavily on approaches no longer in play today.

4. Where patient-reported outcomes exist, they show - like just about every other type of shoulder arthroplasty - clinically significant improvement over the preoperative state that lasts 5–10 years. Appropriately controlled studies that compare clinical outcomes for pyrocarbon humeral arthroplasty to other surgical options for managing glenohumeral arthritis are, however, uncommon.

5. The one head-to-head functional comparison still favors total over hemiarthroplasty early on. In the New Zealand registry, anatomic TSA surpassed pyrocarbon hemi on the Oxford score at both 6 months and 5 years. Notably, the functional advantage of total over hemi is not eliminated by changing the use of pyrocarbon bearing surface.

6. Royalties or research funding from pyrocarbon implant manufacturers are disclosed in many of the cohort series.  That does not invalidate the data, but it is recognized that industrial support can affect study design, data analysis and conclusions.

7. The bearing surface is not the most important aspect of the reconstruction. As is the case for all other types of shoulder arthroplasty, the outcome of pyrocarbon arthroplasty is critically dependent on patient selection, component size, component positioning, glenoid management, soft tissue balancing, and rehabilitation.

Future clinical research will hopefully define the indications, the appropriate implants, the surgical technique, and the clinical outcomes for pyrocarbon humeral arthroplasty.

Now for the details

Two Australian Orthopaedic Association (AOANJRR) analyses: two different pyrocarbon devices. Both draw on the AOA registry, but they study different pyrocarbon configurations. Both presen revision/survivorship endpoints with no patient-reported outcomes.

1. McBride presents the pyrocarbon humeral hemi-resurfacing (PHR/PyroTITAN — a resurfacing cap, no head excision, the Australian research-restricted device that is not FDA-cleared for use in the U.S.), comparing PHR in patients <65 versus the five lowest-CPR (cumulative percent revision) aTSA combinations.

2. The AOA Annual Report also presents data on a hemi stemmed pyrocarbon implant. That stemmed configuration is basically the same as the U.S.-cleared device and the European (Boileau) stemmed construct.

To complement these registry studies, cohort reports concern the three pyrocarbon devices in current use: (1) resurfacing (PHR/PyroTITAN); (2) the U.S. stemmed hemiarthroplasty (FDA-cleared Tornier/Stryker); and (3) the Boileau/European stemmed hemiarthroplasty. Devices 2 and 3 share the same hardware (Aequalis Ascend Flex stem + pyrocarbon head) but have separate literature, study designs, and technique: the Boileau approach systematically downsized the component.

In the table above, each cell carries a generation/technique caveat: the long-term numbers may not describe the devices and techniques commonly used today.

AOANJRR 2025

The AOANJRR 2025 “hemi stemmed anatomic — pyrocarbon head” class does not differentiate U.S. vs Boileau technique.  This Annual Report compares four shoulder arthroplasty classes in patients under 60 with OA, restricted to prostheses still implanted in 2024 (the “modern prostheses” filter), with data to 31 December 2024. 

Note that the confidence intervals for all four classes overlap. Adjusted for age and sex, no comparison to the pyrocarbon hemi reached significance. The executive summary states it plainly: “a hemi stemmed anatomic with a pyrocarbon head was not different to traditional total shoulder replacement options in this age group.” The report contains no patient reported outcome data.

New Zealand National Joint Registry

Gao and colleagues reported the 159 stemmed pyrocarbon hemiarthroplasties (PyCHAs (Tornier Flex stem, pyrocarbon head) against 1,280 conventional metal HAs and 4,285 aTSAs. Importantly, average follow-up was shorter for PyCHA (3.3 yr vs 12.7 and 8.3). With this caveat, PyCHA retention (96.9%) was comparable to aTSA in patients under 60 and better than conventional metal HA on both retention and Oxford Shoulder Score. aTSA had numerically better Oxford scores than PyCHA at 6 months and 5 years.

Clinical outcomes and revision rates by device — the cohort series

The cohort series add what the registries omit — but they are single-arm, small, and almost all industry-linked. The registry analyses above report revision only; none measures a patient-reported outcome. The published cohort series below supply PROs, range of motion, and graded glenoid erosion — but each one is a single-arm case series (Level IV, no comparator), the largest is ~100 shoulders; follow-up is short-to-intermediate. They establish that each device improves shoulder scores against the patient’s own baseline; however, they do not establish superiority over aTSA or any other glenoid-sparing alternative. 

Resurfacing (PHR):  the contemporary third-generation resurfacing implant specifically has neither long-term revision nor any PRO follow-up. 

Hemiarthroplasty — US: the U.S. experience with the currently available implant is anchored by Griswold 2025 (JBJS), drawn from the Stryker pyrocarbon IDE cohort plus a subsequent prospective follow-up: 45 patients at a mean 73 months. Every PRO improved past MCID (ASES 47->96, Constant 48->88, SANE 39->94, VAS pain 5.0->0.2), satisfaction was 97.8%, and 7-year revision-free survival was 95.7% — both revisions for infection, none for glenoid erosion or breakage. 

Hemiarthroplasty — Boileau / European: the largest, longest evidence. The European stemmed device is the same Ascend Flex + pyrocarbon-head hardware as the U.S. implant, but placed with systematic head downsizing, anchored by the Boileau (Nice) and Garret/Godenèche (Lyon) groups, and corroborated by two independent European centers.

Cointat 2022 (64 shoulders, 92% survival at 3 yr), Garret 2024 (45 patients, 4.4% revision, scores maintained at 5–9 yr), and Boileau 2026 (103 shoulders, revision-free 94% at 5 yr and 89% at 10 yr) consistently show Constant rising from the mid-30s to ~80, SSV from ~35 to ~84, and return to work and sport above 90%. Mathon 2023 (Marseille; 41 shoulders, Constant 34->80 at 3 yr, 100% return to work, glenoid wear <0.6 mm on CT 3D modeling, no revisions) and Kleim 2024 (Munich/Agatharied; 31 shoulders, Constant 45->79 sustained to 5.5 yr, MCID surpassed in every diagnosis, medial glenoid erosion only ~0.3 mm/yr after a biphasic first year, 100% survival).  Kleim independently reproduced Boileau’s finding that glenoid reaming does not drive more erosion. 

The dominant, reproducible failure mechanism across the series was humeral-head oversizing: the pyrocarbon head sits ~2 mm proud of a metal head of equal diameter (a 1.5-mm support tray plus a 0.5-mm taper gap), nonanatomic reconstruction occurred in 24–29% of cases, and in Boileau’s series nonanatomic reconstruction carried a roughly 19-fold higher revision rate (25% vs 1.3%) along with worse erosion and function — which is why the group now downsizes the head by one size as routine. 

What the cohort series add — and still cannot settle. 

These series add to the registries: all three devices produce within-patient PRO gains exceeding MCID, durable to 5–10 years, with infrequent revision. However, there is still no well-controlled comparison against aTSA or any other glenoid-sparing alternative.

Summary

What the evidence supports:

• Resurfacing PHR (McBride): no detectable difference in revision risk versus best-in-class aTSA in patients <65 with OA — on a research-restricted device that is not available in the U.S., with shorter followup and thinner data, adjusted for age and sex only.

• AOA Annual Report: Stemmed pyrocarbon hemiarthroplasty not different from anatomic TSA with respect to revision rate at up to 7 years in patients <60 with OA. 

• New Zealand registry: In comparison to conventional metal hemiarthroplasty, both pyrocarbon configurations are at least non-inferior; pyrocarbon may outperform metal hemi with respect to implant retention.

• Cohort series: For each device-and-technique combination studied, patient-reported and clinician scores rise from baseline by margins exceeding MCID and hold to 5–10 years — across the resurfacing device (Caughey), the U.S. stemmed implant (Griswold), and the European stemmed implant at five centers (Cointat, Garret, Boileau, Mathon, Kleim). 

What the current evidence does not support:

• Any comparative effectiveness with respect to patient reported outcomes. The registries do not report PROs; the cohort series report PROs with clinically significant preoperative to postoperative gains, but lack well-controlled studies comparing clinical benefit relative of pyrocarbon to aTSA or other glenoid-sparing alternatives.

Conclusion

Future clinical research is needed define the indications, the appropriate implants, the surgical technique, and the clinical outcomes for pyrocarbon humeral arthroplasty relative to other methods for managing glenohumeral arthritis.

While the gold standard for comparing surgical treatments is a prospective randomized controlled trial, this is difficult to accomplish with meaningful numbers in a procedure performed on relatively few, highly selected patients. Authors therefore turn to propensity matching to compare separately collected series. The approach carries two challenges. The first is deciding which characteristics to match on — diagnosis? Walch type? how the glenoid was managed? length of follow-up? age? sex? The variables that most influence the result, such as Walch type and glenoid management, are often the very ones not recorded in the comparison series, so they cannot be matched even in principle. The second is attrition: cases are lost both because stricter matching discards more unmatched cases and because missing data remove others, so the compared groups end up a fraction of the original cohorts — sometimes a small one — and no longer fully representative of them. The commentary by Sanchez-Sotelo is required reading on this point (Pyrocarbon Shoulder Hemiarthroplasty Seems to Outperform Metallic Hemiarthroplasty at a Short-Term Follow-up. JBJS Am2026;108(8):529–530. DOI: 10.2106/JBJS.25.01142)

There is work to be done

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References

1. McBride A, Hurley R, Gill D, Du P, Duke P, Taylor F, Hoy G, Page R, Ross M. Outcomes of pyrolytic carbon humeral resurfacing hemiarthroplasty compared to best-in-class total shoulder arthroplasty in young patients with osteoarthritis: analysis from the Australian Orthopaedic Association National Joint Replacement Registry. J Shoulder Elbow Surg. 2026;35(5):1209–1218. doi:10.1016/j.jse.2025.09.007.

2. Australian Orthopaedic Association National Joint Replacement Registry. Hip, Knee and Shoulder Arthroplasty: 2025 Annual Report. Adelaide: AOA; 2025. Special Clinical Assessment: Shoulder Implant Choice — patients aged <60 years with OA (Table ST110, Figure ST77); data to 31 December 2024.

3. Gao R, Viswanath A, Frampton CM, Poon PC. Short-term outcomes following 159 stemmed pyrolytic carbon shoulder hemiarthroplasties and how they compare with conventional hemiarthroplasties and total shoulder arthroplasties in patients younger than 60 years with osteoarthritis: results from the New Zealand National Joint Registry. J Shoulder Elbow Surg. 2023;32(8):1594–1600. doi:10.1016/j.jse.2023.01.020.

4. Caughey MA, Penny I, Frampton CM. Medium-term results of the Ascension Pyrotitan surface replacement and Pyrocarbon hemiarthroplasty in the shoulder. Semin Arthroplasty JSES. 2024;34(1):1–10. doi:10.1053/j.sart.2023.01.005.

5. Griswold BG, Berger JM, Davis BP, Mauter L, Boyd M, Schuette HB, Johnston PS, Sears BW, Hatzidakis AM. Five-year radiographic and clinical outcomes of pyrocarbon hemiarthroplasty for glenohumeral arthritis and osteonecrosis. J Bone Joint Surg Am. 2025;107(24):2751–2762. doi:10.2106/JBJS.25.00163.

6. Cointat C, Raynier JL, Vasseur H, Lareyre F, Raffort J, Gauci MO, Boileau P. Short-term outcomes and survival of pyrocarbon hemiarthroplasty in the young arthritic shoulder. J Shoulder Elbow Surg. 2022;31(1):113–122. doi:10.1016/j.jse.2021.06.002.

7. Garret J, Cuinet T, Ducharne L, ReSurg, Godenèche A. Pyrocarbon humeral heads for hemishoulder arthroplasty grant satisfactory clinical scores with minimal glenoid erosion at 5-9 years of follow-up. J Shoulder Elbow Surg. 2024;33(2):328–334. doi:10.1016/j.jse.2023.06.021.

8. Boileau P, Cointat C, Raynier JL, Schippers P, Ranieri R. Pyrocarbon hemiarthroplasty for the treatment of shoulder osteoarthritis in young, active patients: survival and risk factors for revision. J Shoulder Elbow Surg. 2026;35(2):421–437. doi:10.1016/j.jse.2025.06.021.

9. Mathon P, Chivot M, Galland A, Airaudi S, Gravier R. Pyrolytic carbon head shoulder arthroplasty: CT scan glenoid bone modeling assessment and clinical results at 3-year follow-up. JSES Int. 2023;7:2476–2485. doi:10.1016/j.jseint.2023.06.028.

10. Kleim BD, Zolotar A, Hinz M, Nadjar R, Siebenlist S, Brunner UH. Pyrocarbon hemiprostheses show little glenoid erosion and good clinical function at 5.5 years of follow-up. J Shoulder Elbow Surg. 2024;33(1):55–64. doi:10.1016/j.jse.2023.05.027.

11. Lajoinie L, Garret J, van Rooij F, Saffarini M, Godenèche A. Pyrocarbon hemi-shoulder arthroplasty provides satisfactory outcomes following prior open Latarjet. J Shoulder Elb Arthroplast. 2024;8:24715492241292857. doi:10.1177/24715492241292857.

12. Barret H, Garret J, Favard L, Bonnevialle N, Collin P, Gauci MO, Boileau P. Long-term (minimum 10 years) survival and outcomes of pyrocarbon interposition shoulder arthroplasty. J Shoulder Elbow Surg. 2025;34:739–749. doi:10.1016/j.jse.2024.05.026.

13. U.S. Food and Drug Administration, Center for Devices and Radiological Health. De Novo Classification Request for Tornier Pyrocarbon Humeral Head — Decision Summary. DEN220012. Silver Spring, MD: FDA; granted December 16, 2022. (Regulatory decision file for IDE G140202; documents the propensity-subclassified historical cobalt-chrome control [Tornier Flex CoCr, n=169] from the Aequalis Post-Market Outcomes Registry. The composite-clinical-success analysis was subsequently published as Hatzidakis 2026, ref 14.)

14. Hatzidakis AM, Garrigues GE, Mauter LA, de Gast A, Venegoni MR, Yang Y, Johnston PS. Clinical Outcomes of Pyrocarbon Hemiarthroplasty: A Short-Term, Multicenter Study. J Bone Joint Surg Am. 2026;108(8):572–583. doi:10.2106/JBJS.25.00054. 

15. Sanchez-Sotelo J. Pyrocarbon Shoulder Hemiarthroplasty Seems to Outperform Metallic Hemiarthroplasty at a Short-Term Follow-up. Commentary on Hatzidakis et al. J Bone Joint Surg Am. 2026;108(8):529–530. doi:10.2106/JBJS.25.01142. (Independent JBJS commentary flagging the 43% missing control data as substantially weakening the study, the 2-year follow-up as very limited, the absence of radiographic assessment of humeral-head reconstruction, and the need to compare pyrocarbon HA with contemporary anatomic TSA using modern polyethylene.)

Pyrocarbon - the material rationale for its use in humeral arthroplasty - Section 3

3. The material rationale

A substantial part of the support for the clinical use of a pyrocarbon bearing surface in humeral arthroplasty rests on material properties demonstrated in laboratory studies. It is worth separating these properties from the possible clinical benefits inferred from them. Let's look at some of these studies.

Pyrolytic carbon is a graphite–carbon composite — the low-temperature isotropic (LTI) carbon that Bokros and colleagues developed at General Atomic in the 1960s and that has been the dominant bearing material for mechanical heart valves for roughly half a century.¹ Three of its properties are often used to justify its use as a shoulder bearing surface.

Elastic modulus close to bone. Pyrolytic carbon has a Young's modulus on the order of 20 GPa, within range of cortical bone (~15–20 GPa) and roughly an order of magnitude below cobalt-chromium (~210 GPa).² The argument is that a bearing surface whose stiffness approximates the bone it articulates against — rather than one ten times stiffer — transmits contact stress more physiologically and should therefore abrade subchondral bone less aggressively than metal.

Surface chemistry favorable to boundary lubrication. The load-bearing boundary lubricant of both native and prosthetic synovial joints is widely held to be surface-active phospholipid (SAPL), adsorbed as a film on the articular surface.³ Pyrolytic carbon's hydrophobic surface is hypothesized to adsorb these phospholipids and sustain the same boundary-lubrication film, lowering friction against bone. This is a frequently cited mechanism, but the pyrocarbon-specific link remains an inference from the general SAPL literature rather than a property directly demonstrated on the implant surface in vivo.

Reduced wear and favorable cell and tissue response, in vitro and in animals. In a shoulder wear simulator, the linearized bone-penetration rate, bone-volume-loss rate, and surface roughness for cobalt-chromium were roughly 30 times those for pyrocarbon; cobalt-chromium testing was halted at about 320,000 cycles because the bone interface had been consumed, whereas pyrocarbon ran to five million cycles.² In cultured chondrocytes, pyrocarbon supported cell growth without cytotoxicity and promoted type II collagen expression, generating a more cartilage-like matrix than either cobalt-chromium or plastic controls.⁴ An in vivo canine hip study found that cartilage articulating against LTI pyrocarbon showed significantly less gross wear, fibrillation, eburnation, glycosaminoglycan loss, and subchondral bone change than cartilage articulating against cobalt-chromium-molybdenum or titanium; survival analysis showed a 92% probability of cartilage survival against pyrocarbon at 18 months versus only 20% against either metal alloy.⁵ In a canine full-thickness-defect model, fibrocartilage regenerated at 86% of carbon-articulating defects versus 25% of metal, with surface cracking in 14% of carbon specimens versus 100% of metal.⁶

The clinical case built on these data is that pyrocarbon should generate less glenoid erosion than a metal hemiarthroplasty.

Two cautions should be considered. First, each finding presented above is preclinical — bench modulus, in vitro wear and cell culture, animal histology. None of it is, by itself, evidence of a potential patient-reported-outcome benefit exceeding the minimal clinically important difference relative to other bearing surfaces. Second, the material rationale describes the bearing surface only and does not necessarily predict the clinical performance of the implant itself.

Black Turnstone

Lopez Island

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References

1. Bokros JC. Carbon biomedical devices. Carbon. 1977;15(6):353–371.
2. Klawitter JJ, Patton J, More R, Peter N, Podnos E, Ross M. In vitro comparison of wear characteristics of PyroCarbon and metal on bone: shoulder hemiarthroplasty. Shoulder Elbow. 2020;12(1 Suppl):11–22. doi:10.1177/1758573218796837. (Authors employed by / holding stock in the implant manufacturer.)
3. Hills BA. Boundary lubrication in vivo. Proc Inst Mech Eng H. 2000;214(1):83–94. doi:10.1243/0954411001535264.
4. Hannoun A, Ouenzerfi G, Brizuela L, Mebarek S, Bougault C, Hassler M, Berthier Y, Trunfio-Sfarghiu AM. Pyrocarbon versus cobalt-chromium in the context of spherical interposition implants: an in vitro study on cultured chondrocytes. Eur Cell Mater. 2019;37:1–15. doi:10.22203/eCM.v037a01.
5. Cook SD, Thomas KA, Kester MA. Wear characteristics of the canine acetabulum against different femoral prostheses. J Bone Joint Surg Br. 1989;71(2):189–197.
6. Kawalec JS, Hetherington VJ, Melillo TC, Corbin N. Evaluation of fibrocartilage regeneration and bone response at full-thickness cartilage defects in articulation with pyrolytic carbon or cobalt-chromium alloy hemiarthroplasties. J Biomed Mater Res. 1998;41(4):534–540.

Pyrocarbon in the Shoulder: what we think we know. Section 2

As a sequel to the prior post (Section 1), here is a look at the literature on clinical results for the pyrocarbon shoulder implants. Results can be expressed as (a) revision rate and (b) patient-reported outcomes (PRO). At the outset we recognize that lack of a revision is not the same as a clinically significant improvement (i.e., improvement in PRO that exceeds the minimal clinically important difference, MCID). Lack of a revision may result from patient unwillingness to undergo another procedure, patient lost to follow-up, poor patient health, or patient death — none of which indicate a clinically significant improvement.

An issue confounding the available clinical results for pyrocarbon implants is that reports often combine legacy devices, revised versions, and current instantiations.

PYRO TYPE 1: PROXIMAL HUMERAL RESURFACING (PHR/PYROTITAN)

This implant has been through at least three significant design iterations and three commercial sponsors. None of the published papers isolates the current implant configuration. Every survivorship figure in the literature pools generations. The lineage, reconstructed from the McBride 2026 paper [1], the Hoy 2026 paper [2], the Therapeutic Goods Administration hazard alert [3], and contemporaneous trade press, is summarized in the following table.

The McBride 2026 registry cohort (n = 403, enrolled 2004–2022) spans all three iterations; and the reported 35%-of-revisions-from-breakage figure averages performance across known-fracture-prone implants and the current design.[1] The Hoy 2026 cohort (n = 119, enrolled January 2013–November 2023) starts at about the time of the TGA hazard alert; the earliest patients received the first-redesign implant; mid-cohort patients received the second-redesign implant, and late patients received the current implant.[2] Thus, the result for the current commercially available PHR/PyroTITAN implant is unknown. It cannot be extracted from the existing literature because every published series pools at least two device generations.

Here is what relates to the post-2017 third design:

Survivorship:  cumulative percent revision (CPR) 7.7% at 10 yr (McBride 2026 [1]); 5-year Kaplan–Meier survivorship 97.5% (mean follow-up 34.6 months) (Hoy 2026 [2]). Manufacturer filings (not peer-reviewed): Kaplan–Meier survival ~86% up to ~117 mo as posted to ClinicalTrials.gov (NCT02405208 [9]). The primary endpoint of NCT02983292 [8] is device survival, not patient-reported outcomes; results are not yet published.

Effectiveness:  WOOS 38→83 and ASES 49→87, all exceeding MCID (Hoy 2026 [2]).

PYRO TYPE 2: THE U.S. STEMMED PYROCARBON HEMIARTHROPLASTY (HA-PYC)

The FDA Investigational Device Exemption study [4] enrolled patients between December 2015 and April 2017, before the final round of design changes. The De Novo clearance was granted in 2022, and U.S. commercial use of the pyrocarbon humeral head began only in March 2023. The Griswold 2025 JBJS paper [5] reports the IDE patients at 5 years, not the post-clearance commercial cohort.

Survivorship:  3 of 157 revised before 24 mo, mean follow-up 24.4 mo; 3-year Kaplan–Meier revision-free survival 96.6% (Hatzidakis 2026 [4]). In the same IDE lineage followed forward (n = 45, mean follow-up 73 mo), 7-year revision-free survival 95.7% and failure-free survival 93.4% — the 2 revisions were both for infection (Griswold 2025 [5]).

Effectiveness:  Composite Clinical Success 82.7%, defined as a ≥17-point Constant-score improvement without revision or device-related adverse event; ASES 44→88, adjusted Constant 51→91, SANE 36→85 (Hatzidakis 2026 [4]). At ≥5 years (mean 73 mo): ASES 47→96, SANE 39→94, Constant 48→88, all exceeding MCID, with glenoid morphology stable between the 2-year and final imaging (Griswold 2025 [5]).

PYRO TYPE 3: THE EUROPEAN STEMMED PYROCARBON HEMIARTHROPLASTY

The European cohort, followed a mean of 5.6 years [6], pools shoulders implanted before and after the systematic head-downsizing maneuver that became standard once Cointat reported that nonanatomic reconstruction (center of rotation > 3 mm off the anatomic center) occurred in 29% of cases and was strongly associated with glenoid erosion and revision [7].

With the current downsizing technique (Boileau 2026 [6]):

Survivorship:  revision-free survival 94% at 5 yr and 89% at 10 yr.

Effectiveness:  Constant 29→77, SSV 25%→84%, 91% return to work, 88% return to sport.

SUMMARY

Pyrocarbon shoulder arthroplasty is an exciting technology that is rapidly evolving. While evolution to address clinical issues (fracture, overstuffing, component malposition) is critical, it does confound the study of clinical outcomes: the implants on which follow-up data are available are often not the ones in current use. Once the designs and techniques have stabilized, data on revision rates and patient-reported outcomes for them will be of great interest.

Black vulture

San Antonio

2025

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REFERENCES

1. McBride A, Hurley R, Gill D, Du P, Duke P, Taylor F, Hoy G, Page R, Ross M. Outcomes of pyrolytic carbon humeral resurfacing hemiarthroplasty compared to best-in-class total shoulder arthroplasty in young patients with osteoarthritis: analysis from the Australian Orthopaedic Association National Joint Replacement Registry. J Shoulder Elbow Surg. 2026;35(5):1209–1218. doi:10.1016/j.jse.2025.09.007.

2. Hoy G, Burrows K, McBride A, Ross M, Davis K, Warby S. PyroTITAN Pyrocarbon Shoulder Hemiarthroplasty: Clinical and Radiographic Outcomes with Medium-Term Follow-up. J Bone Joint Surg Am. Epub 2026 May 13. doi:10.2106/JBJS.25.00779.

3. Therapeutic Goods Administration. PyroTitan humeral resurfacing arthroplasty — hazard alert. Canberra, Australia: Australian Government Department of Health; August 2013. Available at: https://www.tga.gov.au/safety/recalls-and-other-market-actions/market-actions/pyrotitan-humeral-resurfacing-arthroplasty (LMT Surgical, 3% worldwide implant breakage rate, sub-surface fractures identified).

4. Hatzidakis AM, Garrigues GE, Mauter LA, de Gast A, Venegoni MR, Yang Y, Johnston PS. Clinical Outcomes of Pyrocarbon Hemiarthroplasty: A Short-Term, Multicenter Study. J Bone Joint Surg Am. 2026;108(8):572–583. doi:10.2106/JBJS.25.00054.

5. Griswold BG, Berger JM, Davis BP, Mauter L, Boyd M, Schuette HB, Johnston PS, Sears BW, Hatzidakis AM. Five-Year Radiographic and Clinical Outcomes of Pyrocarbon Hemiarthroplasty for Glenohumeral Arthritis and Osteonecrosis. J Bone Joint Surg Am. 2025;107(24):2751–2762. doi:10.2106/JBJS.25.00163.

6. Boileau P, Cointat C, Raynier JL, Schippers P, Ranieri R. Pyrocarbon hemiarthroplasty for the treatment of shoulder osteoarthritis in young, active patients: survival and risk factors for revision. J Shoulder Elbow Surg. 2026;35(2):421–437. doi:10.1016/j.jse.2025.06.021.

7. Cointat C, Raynier JL, Vasseur H, Lareyre F, Raffort J, Gauci MO, Boileau P. Short-term outcomes and survival of pyrocarbon hemiarthroplasty in the young arthritic shoulder. J Shoulder Elbow Surg. 2022;31(1):113–122. doi:10.1016/j.jse.2021.06.002.

8. ClinicalTrials.gov. A Clinical and Radiological Study to Evaluate the Safety and Efficacy of the PyroTITAN Humeral Resurfacing Arthroplasty (HRA) Device in a New Cohort of Patients After Product Re-Release (T-HRA-003). NCT02983292. Sponsor: Smith & Nephew. Completed February 2023; results posted to ClinicalTrials.gov 2024 (not peer-reviewed). https://clinicaltrials.gov/study/NCT02983292.

9. ClinicalTrials.gov. A Multi-center Outcomes Clinical Study of the PyroTITAN HRA Shoulder Implant in Humeral Head Resurfacing (CP-HRA-002). NCT02405208. Sponsor: Smith & Nephew. Enrollment 156; completed September 2023; results posted to ClinicalTrials.gov 2025 (not peer-reviewed). https://clinicaltrials.gov/study/NCT02405208.

Pyrocarbon in the Shoulder: what we think we know. Section 1 (more to come)

There have been some publications in the past eighteen months that have attracted attention: the FDA De Novo clearance for the stemmed Tornier pyrocarbon humeral head [1], the Hatzidakis IDE multicenter study [2], the McBride AOANJRR comparison of pyrocarbon humeral resurfacing against best-in-class anatomic total shoulder arthroplasty (aTSA) [3], the Griswold 5-year U.S. radiographic study with prospective Walch typing [4], and the Hoy PyroTITAN single-surgeon prospective cohort with disease-specific PROMs and Walch typing on every patient [5]. Together with the Boileau group’s HA-PYC survival and risk-factor analysis [6] and the Barret/Boileau 10-year interposition cohort [7], the evidence base is now sufficient to make some statements about these implants. With the help of Claude AI and Open Evidence I’ve tried to put together what we can glean from the literature.

Disclosure: I have not used a pyrocarbon implant in my 50+ years of practice (no first-hand experience). I have no relationship with any orthopaedic company. While I try to refrain from using proprietary names in my posts, I have done so here to clarify which implant is under discussion. My summary may contain errors and I would welcome corrections and comments. You may wish to compare this information to that in the prior post regarding the ream and run.

At least three different implant configurations

It seems that three distinct configurations of “pyrocarbon shoulder arthroplasty” have entered clinical practice:

• Pyrocarbon humeral resurfacing (PHR) / PyroTITAN: a stemless pyrocarbon resurfacing cap stabilized by a short central post seated on the prepared humeral head. The resurfacing cap is intended to solve two of the problems of the classic hemiarthroplasty technique: there is no metal collar/disc beneath the head that can oversize the construct, and there is no humeral stem that can malposition the bearing surface in height, version or inclination. The trade-off is the intrinsic risk of implant fracture— a failure mode identified during early device development that prompted design refinement and proof-testing after product re-release, and subject to a 2013 Therapeutic Goods Administration hazard alert [8]. This is the implant in the McBride 2022 [9], McBride 2026 [3], and Hoy 2026 [5] papers — the AOANJRR “PHR” label and the commercial “PyroTITAN” name refer to the same device class, which has undergone several design iterations under three sponsors (Ascension, Integra/LMT Surgical, Smith+Nephew). The implant is not FDA-cleared in the United States.

• Stemmed pyrocarbon hemiarthroplasty (HA-PYC / PyCHA). A conventional press-fit humeral stem (e.g. the Aequalis Ascend Flex) carrying a pyrocarbon head mounted on a metal Morse-taper tray. Humeral head excision and metaphyseal broaching are identical to other stemmed hemiarthroplasties; only the bearing surface differs. This construct retains the two technique vulnerabilities that resurfacing eliminates: the 1.5–2 mm metal disc beneath the pyrocarbon head effectively oversizes the construct (unless the surgeon systematically downsizes), and stem positioning errors in height, version or inclination can compound the oversizing. This is the implant in the European literature (Boileau, Cointat, Garret, Kleim, Ranieri) [6,10–13], the New Zealand registry [14], the Griswold U.S. five-year study [4], and the U.S. IDE study published in JBJS in April 2026 [2]. It is also the only configuration FDA-cleared in the U.S., via De Novo DEN220012 in late 2022 [1].

• Pyrocarbon interposition (PISA / InSpyre). A pyrocarbon spheroid with no humeral fixation. Largely supplanted by the stemmed head construct, but the Barret/Boileau 10-year PISA cohort [7] remains the only true long-term human data on any pyrocarbon shoulder implant.

The distinction matters for several reasons. First, the metaphyseal-preservation contention — that PHR may protect the rotator cuff blood supply because the arcuate artery is not violated [3] — applies to PHR/PyroTITAN and does not transfer to stemmed HA-PYC, where the head is excised. Second, the European mid-term PROM data (Constant, ASES, SSV, return-to-work, return-to-sport) come predominantly from stemmed HA-PYC series [6,10–13]. The Australian registry papers (McBride 2022, McBride 2026) report PHR survivorship without PROMs [3,9]. The Hoy 2026 paper is the only mid-term study with disease-specific PROMs (WOOS) and prospective Walch typing on every patient in the PHR/PyroTITAN configuration [5]. Third, the radiographic erosion data come from different measurement methods that are not directly comparable. Hoy reported mean medial glenoid erosion of 2.0 mm at 3 years following PHR (glenoid–medial spinoglenoid notch distance on Grashey radiographs) [5]; Griswold reported 2.9 mm at 2 years and 4.0 mm at 5+ years following stemmed HA-PYC (center-of-rotation to acromion–glenoid reference, with magnification correction) [4]. The absolute numbers cannot be compared across the two studies, but both constructs show most erosion in the first 1–2 years and substantial slowing thereafter [5,13]. Fourth, the FDA-cleared U.S. indication applies only to the stemmed construct and excludes inflammatory arthritis and total shoulder arthroplasty configurations [1] — a label restriction that would, for example, exclude the 4.2% inflammatory-arthritis cases in the Hoy PHR cohort [5]. Fifth, the implant-fracture history is specific to the PHR/PyroTITAN construct and is documented even in the contemporary design — Hoy reported one spontaneous fracture in 119 shoulders at 3 years (0.8%) [5], and the AOANJRR has tracked fracture-related revisions through three design iterations [3,9].

To summarize, the resurfacing-vs-stemmed decision can be thought of as a deliberate trade between two different failure modes. The stemmed construct carries a design-mediated, technique-modifiable failure mode: oversizing from the metal disc, plus stem malposition in height, version or inclination. Both drive nonanatomic reconstruction. Boileau and colleagues reported nonanatomic humeral reconstruction with oversizing of the pyrocarbon head in 24% of cases even in expert hands, and this single technical error was associated with roughly a 19-fold increase in revision risk (25% revision rate in the oversized subgroup vs. ~1.3% in the anatomic subgroup) and a 3.46-fold odds of progressive glenoid erosion (95% CI 1.13–10.55, P = .0295) [6]. The AOANJRR registry analyses align with this: the main reasons for revision in pyrocarbon HA were ongoing pain and implant fracture, in contrast to metal HA, where revisions were mostly for glenoid erosion [3,9,15]. The resurfacing construct eliminates the disc and the stem — and with them the oversizing and malposition problems — but introduces an implant-mediated failure mode: pyrocarbon head fracture, which the AOANJRR PHR cohort has tracked through three design iterations and which Hoy still observed in 0.8% of his contemporary series [5]. Both failure modes may be partly modifiable: the stemmed problem has been addressed by systematic downsizing — a surgeon-borne correction for a geometric perturbation introduced by the design itself; the resurfacing problem has been addressed by progressive design refinement and proof-testing improvements [5,8]. The jury is still out.

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Black Oystercatcher

References

1. U.S. Food and Drug Administration. De Novo classification request for Tornier Pyrocarbon Humeral Head. DEN220012. Silver Spring (MD): Center for Devices and Radiological Health; 2022. https://www.accessdata.fda.gov/cdrh_docs/reviews/DEN220012.pdf

2. Hatzidakis AM, Garrigues GE, Mauter LA, de Gast A, Venegoni MR, Yang Y, Johnston PS. Clinical Outcomes of Pyrocarbon Hemiarthroplasty: A Short-Term, Multicenter Study. J Bone Joint Surg Am. 2026;108(8):572–583. doi:10.2106/JBJS.25.00054.

3. McBride A, Hurley R, Gill D, Du P, Duke P, Taylor F, Hoy G, Page R, Ross M. Outcomes of pyrolytic carbon humeral resurfacing hemiarthroplasty compared to best-in-class total shoulder arthroplasty in young patients with osteoarthritis: analysis from the Australian Orthopaedic Association National Joint Replacement Registry. J Shoulder Elbow Surg. 2026;35(5):1209–1218. doi:10.1016/j.jse.2025.09.007.

4. Griswold BG, Berger JM, Davis BP, Mauter L, Boyd M, Schuette HB, Johnston PS, Sears BW, Hatzidakis AM. Five-Year Radiographic and Clinical Outcomes of Pyrocarbon Hemiarthroplasty for Glenohumeral Arthritis and Osteonecrosis. J Bone Joint Surg Am. 2025;107(24):2751–2762. doi:10.2106/JBJS.25.00163.

5. Hoy G, Burrows K, McBride A, Ross M, Davis K, Warby S. PyroTITAN Pyrocarbon Shoulder Hemiarthroplasty: Clinical and Radiographic Outcomes with Medium-Term Follow-up. J Bone Joint Surg Am. Epub 2026 May 13. doi:10.2106/JBJS.25.00779.

6. Boileau P, Cointat C, Raynier JL, Schippers P, Ranieri R. Pyrocarbon hemiarthroplasty for the treatment of shoulder osteoarthritis in young, active patients: survival and risk factors for revision. J Shoulder Elbow Surg. 2026;35(2):421–437. doi:10.1016/j.jse.2025.06.021.

7. Barret H, Garret J, Favard L, Bonnevialle N, Collin P, Gauci MO, Boileau P. Long-term (minimum 10 years) survival and outcomes of pyrocarbon interposition shoulder arthroplasty. J Shoulder Elbow Surg. 2025;34(3):739–749. doi:10.1016/j.jse.2024.05.040.

8. Therapeutic Goods Administration. PyroTitan humeral resurfacing arthroplasty – hazard alert. Canberra, Australia: Australian Government Department of Health; 2013.

9. McBride AP, Ross M, Hoy G, Duke P, Page R, Peng Y, Taylor F. Mid-term outcomes of pyrolytic carbon humeral resurfacing hemiarthroplasty compared with metal humeral resurfacing and metal stemmed hemiarthroplasty for osteoarthritis in young patients: analysis from the Australian Orthopaedic Association National Joint Replacement Registry. J Shoulder Elbow Surg. 2022;31(4):755–762. doi:10.1016/j.jse.2021.08.017.

10. Cointat C, Raynier JL, Vasseur H, Lareyre F, Raffort J, Gauci MO, Boileau P. Short-term outcomes and survival of pyrocarbon hemiarthroplasty in the young arthritic shoulder. J Shoulder Elbow Surg. 2022;31(1):113–122. doi:10.1016/j.jse.2021.06.002.

11. Garret J, Cuinet T, Ducharne L, ReSurg, Godèneche A. Pyrocarbon humeral heads for hemishoulder arthroplasty grant satisfactory clinical scores with minimal glenoid erosion at 5–9 years of follow-up. J Shoulder Elbow Surg. 2024;33(2):328–334. doi:10.1016/j.jse.2023.06.021.

12. Kleim BD, Zolotar A, Hinz M, Nadjar R, Siebenlist S, Brunner UH. Pyrocarbon hemiprostheses show little glenoid erosion and good clinical function at 5.5 years of follow-up. J Shoulder Elbow Surg. 2024;33(1):55–64. doi:10.1016/j.jse.2023.05.027.

13. Ranieri R, Cointat C, Lacouture-Suarez JD, Boileau P. B2 and B3 glenoid osteoarthritis: outcomes of corrective and concentric (C2) reaming of the glenoid combined with pyrocarbon hemiarthroplasty. J Shoulder Elbow Surg. 2025;34(3):726–738. doi:10.1016/j.jse.2024.06.028.

14. Gao R, Viswanath A, Frampton CM, Poon PC. Short-term outcomes following 159 stemmed pyrolytic carbon shoulder hemiarthroplasties and how they compare with conventional hemiarthroplasties and total shoulder arthroplasties in patients younger than 60 years with osteoarthritis: results from the New Zealand National Joint Registry. J Shoulder Elbow Surg. 2023;32(8):1594–1600. doi:10.1016/j.jse.2023.01.020.

15. Khoriati AA, McBride AP, Ross M, Duke P, Hoy G, Page R, Holder C, Taylor F. Survivorship of shoulder arthroplasty in young patients with osteoarthritis: an analysis of the Australian Orthopaedic Association National Joint Replacement Registry. J Shoulder Elbow Surg. 2023;32(10):2105–2114.