Background
The ring-augmented Roux-en-Y gastric bypass (raRYGB) has been reported to result in higher long-term weight loss compared to regular Roux-en-Y gastric bypass (RYGB). However, the type of ring used varied within studies, leading to heterogeneity in reported results. Therefore, this study compares the 5-year results of RYGB with and without ring augmentation using a specific prefabricated gastric ring.

Methods
All consecutive patients from a single center who received primary raRYGB between June 1, 2016, and May 31, 2018, with complete 5-year follow-up data were included and compared to a propensity score matched cohort receiving RYGB in the same period from the Dutch Audit for Treatment of Obesity. To ensure fair effect estimation of placing a ring, only RYGB procedures with alimentary and biliopancreatic limb lengths similar to those of the raRYGB were considered eligible. The primary outcome was percentage total weight loss (%TWL). Secondary outcomes included recurrent weight gain (RWG), obesity complication improvement, and complications.

Results
In total, 592 matched patients were analyzed. raRYGB was associated with higher %TWL at 5 years (31.5% versus 28.0%, β = 3.59, 95% CI [2.09–5.09], p < 0.01) and lower odds on RWG (odds ratio = 0.56, 95% CI [0.38–0.83], p < 0.01). Improvement of obesity complications and short-term complication rates were comparable in both groups. After 5 years, 13 patients (4%) had experienced ring-related complications needing reoperation.

Conclusions
At 5 years, raRYGB was associated with higher %TWL and lower odds on RWG. The occurrence of ring-related complications was limited.

Background: Quality of metabolic bariatric surgery (MBS) care is often monitored by national registries using quality indicators (QIs), but data collection takes up considerable time and costs. QIs are mostly introduced merely based on expert opinion. Therefore, the study’s aim was to systematically evaluate whether all QIs from the Dutch Audit for Treatment of Obesity (DATO) are still relevant and useful to initiate quality improvement initiatives. Methods: Twenty-four QIs were evaluated using hospital data from 2022 to 2023. To test whether QIs measured the same quality of care aspect (parsimony and relevance), correlations of QI pairs were examined using Pearson correlation coefficients. Usefulness to identify improvement opportunities was considered limited when variance is ≤ 0.001 without any outliers identified, indicating that the QI could be retired. Actionability was assessed through line graphs of hospital performance over the years. Results: Eleven QIs were highly correlated to other QIs, particularly the follow-up and weight loss indicators at 2 and 4 years, and therefore lacked added value. The weight loss QIs showed minimal variance and were adjusted by increasing the threshold to achieving ≥ 25% total weight loss. Multiple QIs showed improving trends and thereby their actionability, most pronounced for postoperative complications. The final QI set measured three constructs with good validity: Cronbach’s alpha values 0.53 (safety), 0.70 (treatment effectiveness), and 0.43 (follow-up process). Conclusion: Through a systematic evaluation of the DATO QI set, a smaller set of 13 QIs was shown to capture the same relevant information to improve MBS care.

Background and purpose — Pooling data on the performance of total knee (TK) implants across registries is only possible if the same TK implant is used across multiple registries and if used in patients with similar characteristics. We assessed to what extent specific TK implants: (i) are used across multiple registries or only in a single registry; and (ii) differ in patient characteristics between registries. Methods — All primary TK implants implanted between January 2020 and December 2021 in the Danish, Dutch, German, and Italian registries were included. We determined the number of registries using a specific TK implant (based on combined femoral-tibial component brand name and fixation/congruency/mobile bearing insert/patella usage). Patient characteristics (age/body mass index [BMI]/sex/ diagnosis osteoarthritis) were compared across registries for TK implants used in ≥ 2 registries ≥ 100 times. Results — 813 different TK implants (577,351 procedures) were used across the 4 registries, of which 53 TK implants (7%) were used in 1 registry (8,000 procedures). 760 different TK implants (569,351 procedures; 99%) were used in ≥ 2 registries of which 47 different TK implants (393,954 procedures; 68%) were used in ≥ 2 registries and ≥ 100 times. Statistically and clinically significant differences in age for the same TK implant across registries were observed for 29 TK implants (62%) and 3 TK implants (6%), respectively; for other characteristics these were for BMI 30 (64%) and 0 (0%) TK implants; for male proportion 23 (49%) and 17 (36%) TK implants; and for diagnosis of osteoarthritis 42 (89%) and 34 (72%) TK implants, respectively. Conclusion — Most specific TK implants and TK procedures were used across multiple registries, but they were often used in patients with different characteristics. This has an impact on comparing implant performances between registries.

Background and purpose — Standardized reporting on methodology and results in clinical RSA research papers facilitates evaluation of quality and interpretation of results. We aimed to assess the extent to which radiostereometric analysis (RSA) and computed tomography-based RSA (CT-RSA) studies adhered to the items of the new RSA reporting guideline from 2024. Methods — A systematic literature search was performed to identify all clinical RSA studies published between January 2012 and February 2024. Studies were eligible for inclu-sion if prosthesis migration over time was assessed. The adherence of studies to each applicable guideline item (full, partial, or no) was assessed. Results — 285 studies were included, most of which assessed prosthesis migration in the hip (n = 161) or knee (n = 99). No study reported on all guideline items. The mean (full or partial) adherence of studies to all (appli-cable) items was 61% (standard deviation [SD] 11). Large variation between the reporting of items was found, ranging from being reported in 1% of the studies to 100%. The least reported items in studies were the mean number and SD of days between surgery and baseline RSA examination (8% of studies), mean number and SD of days between surgery and primary endpoint RSA examination (1%), and consistent-or all-marker method for RSA analysis (3%). Conclusion — Current studies on average reported only 61% of the items from the updated RSA guidelines. Adherence to the guidelines in clinical RSA studies on prosthesis migration should be improved, in order to improve the quality of studies and the interpretation of outcomes on implant migration.

Following the publication of the original article [1], we were notified that the name of the 10 ^th author was incorrectly tagged in the article’s XML. <GivenName>Perla</GivenName> <GivenName>J.</GivenName> <GivenName>Marang-van</GivenName> <Particle>de</Particle> <FamilyName>Mheen</FamilyName> <GivenName>Perla</GivenName> <GivenName>J.</GivenName> <FamilyName>Marang-van de Mheen</FamilyName> The original article has now been corrected.

In recent years, the relationship between academia and the fossil fuel industry has become a focal point of intense debate. This concern arises from the fear that corporate funding might skew research activities. A significant development in this area is the adoption of policies by a Dutch university, and discussions in several others, prohibiting research funded by the fossil fuel industry. These policies aim to safeguard academic freedom and integrity. Despite this, there has been little discussion on the myriad challenges, implications, and possible unintended consequences, particularly in the realm of safety-and-security research. As such, this manuscript delves into the complex transition towards a fossil-fuel-free society, examining it through the lenses of safety science and sociotechnical systems. It emphasizes the vital importance of collective responsibility in ensuring systemic safety and security as we navigate towards achieving the sustainable development goals. This journey requires a delicate balance between the objectives of safety and sustainability, along with a deep understanding of the security implications of decreasing our dependence on the fossil fuel industry. The strategy of distancing academic research from fossil fuel industries, commonly seen as a positive step, also demands a nuanced consideration of its broader impacts, including the setting of precedents for addressing other existential and systemic risks. Instead, we argue for the establishment of robust governance structures rooted in restorative justice principles. Such frameworks can facilitate productive dialogue with underrepresented groups, motivate the fossil fuel industry towards sustainable practices, and safeguard the integrity of scholarly research. This approach not only addresses immediate concerns related to fossil fuels but also lays the groundwork for a more inclusive and equitable model of climate risk research, essential for tackling the multifaceted challenges of our era.

Randomized controlled trials (RCTs) are the cornerstone of modern evidence-based medicine. They are considered essential to establish definitive evidence of efficacy and safety for new drugs, and whenever possible they should also be the preferred method for investigating new high-risk medical devices. Well-designed studies robustly inform clinical practice guidelines and decision-making, but administrative obstacles have made it increasingly difficult to conduct informative RCTs. The obstacles are compounded for RCTs of high-risk medical devices by extra costs related to the interventional procedure that is needed to implant the device, challenges with willingness to randomize patients throughout a trial, and difficulties in ensuring proper blinding even with sham procedures. One strategy that may help is to promote the wider use of simpler and more streamlined RCTs using data that are collected routinely during healthcare delivery. Recent large simple RCTs have successfully compared the performance of drugs and of high-risk medical devices, against alternative treatments; they enrolled many patients in a short time, limited costs, and improved efficiency, while also achieving major impact. From a task conducted within the CORE-MD project, we report from our combined experience of designing and conducting large pharmaceutical trials during the COVID-19 pandemic, and of planning and coordinating large registry-based RCTs of cardiovascular devices. We summarize the essential principles and utility of large simple RCTs, likely applicable to all interventions but especially in order to promote their wider adoption to evaluate new medical devices.

Background: The Functional Resonance Analysis Method (FRAM) analyses discrepancies between written protocols (Work-as-Imagined) and real-world practice (Work-as-Done) in healthcare. Work-as-Done is created based on multiple stakeholders, leading to variability in reported functions. No guidance exists how to manage this variability. This study examines between-stakeholder variation in Work-as-Done and its impact on differences from Work-as-Imagined in FRAM visualisations. Methods: Two FRAM studies were analysed: delirium diagnosis and treatment (1) and perioperative anticoagulant management in two hospitals (2). Heatmaps visualised between-stakeholder variability of reported functions in Work-as-Done. We assessed the impact of including only functions shared by multiple stakeholders on Work-as-Imagined versus Work-as-Done comparisons. Results: In study 1, 23 of 33 functions were shared among at least two stakeholders. In study 2, stakeholders shared 30 of 33 functions in Hospital 1 and 29 of 32 functions in Hospital 2. Including or excluding functions, e.g., only mentioned by one stakeholder, influenced the observed differences between Work-as-Imagined and Work-as-Done. Conclusions: Between-stakeholder variability in both studies influenced differences between Work-as-Imagined and Work-as-Done, which often is the starting point improving the process. Showing between-stakeholder variability in FRAM studies enhances transparency in researcher decision-making. This supports more informed analysis and discussion in process improvement efforts.

Background and purpose — The amount of information publicly available from arthroplasty registries is large but could be used more effectively. This project aims to improve the knowledge concerning existing registries to facilitate access, transparency, harmonization, and reporting. Methods — Within the International Society of Arthroplasty Registries (ISAR) we aimed at developing, testing, adopting, and making publicly available a short, standardized registry description with items considered relevant for stakeholders using a cross-sectional study survey. Items were chosen based on a literature review and expert advice, selected by 9 ISAR working group members, tested iteratively in 3 registries, and commented upon by 4 external experts. All 29 ISAR member registries as of July 2023 were invited to participate in the project. Results — Included items covered general descriptive information regarding registries, information related to governance, outcomes, data quality, data access, and registry production. The template was adopted, completed, and made publicly available by 25 of the 29 registries. Of those, 2/3 were national registries. 23 captured both hip and knee arthroplasties and 10 captured shoulder arthroplasties. Most registries had public reporting of data quality, methods, and results. Data was accessible in all but 2 registries, mainly as aggregated data. Important items relevant to registry quality for researchers to consistently indicate in scientific papers include scope, inclusion criteria, outcomes definitions, coverage/completeness, and validation processes. Conclusion — This ISAR initiative implemented a short, standardized description to facilitate appropriate use of orthopedic registry data worldwide relevant for a diverse group of stakeholders including researchers, industry, public health and regulatory agencies.

For author Perla J. Marang-van de Mheen, the name tagging in the XML is incorrect. The author given name should be “Perla J.”, and the author family name should be “Marang-van de Mheen”.

Background: Orthopaedic Data Evaluation Panel (ODEP) ratings of total hip (TH) and total knee (TK) implants are informative for assessing implant performance. However, the validity of ODEP ratings across multiple registries is unknown. Therefore, we aimed to assess, across multiple registries, whether TH and TK implants with a higher ODEP rating (i.e., an A* rating) have lower cumulative revision risks (CRRs) than those with a lower ODEP rating (i.e., an A rating) and the extent to which A* and A-rated implants would be A*-rated on the basis of the pooled registries’ CRR. Methods: Implant-specific CRRs at 3, 5, and 10 years that were reported by registries were matched to ODEP ratings on the basis of the implant name. A meta-analysis with random-effects models was utilized for pooling the CRRs. ODEP benchmark criteria were utilized to classify these pooled CRRs. Results: A total of 313 TH cups (54%), 356 TH stems (58%), 218 TH cup-stem combinations (34%), and 68 TK implants (13%) with unique brand names reported by registries were matched to an ODEP rating. Given the low percentage that matched, TK implants were not further analyzed. ODEP-matched TH implants had lower CRRs than TH implants without an ODEP rating at all follow-up time points, although the difference for TH stems was not significant at 5 years. No overall differences in CRRs were found between A* and A-rated TH implants, with the exception of TH cup-stem combinations, which demonstrated a significantly lower CRR for A*A*-rated cup-stem combinations at the 3-year time point. Thirty-nine percent of A*-rated cups and 42% of A*-rated stems would receive an A* rating on the basis of the pooled registries’ CRR at 3 years; however, 24% of A-rated cups and 31% of A-rated stems would also receive an A* rating, with similar findings demonstrated at longer follow-up. Conclusions: At all follow-up time points, ODEP-matched TH implants had lower CRRs than TH implants without an ODEP rating. Given that the performance of TH implants varied across countries, registries should first validate ODEP ratings with use of country-specific revision data to better guide implant selection in their country. Data source transparency and the use of revision data from multiple registries would strengthen the ODEP benchmarks.

Background: A pectoralis major (PM) transfer is a viable treatment option for patients with scapular winging due to long thoracic nerve (LTN) palsy not responding to nonsurgical management. However, the long-term outcomes remain unknown. Therefore, the purpose of this study was to evaluate the long-term outcome of shoulder function (ie, minimum follow-up of 10 years) and quality-of-life (QoL) of patients treated for scapular winging due to LTN palsy with a PM transfer. Methods: This observational cohort study included 15 patients (16 shoulders) who underwent PM transfer, using a tendoachilles allograft, between 1995 and 2012. Shoulder forward flexion and abduction were analyzed preoperatively, 1 year after surgery and at the final follow-up. SF-36 component scores (physical component summary (PCS) and mental component summary (MCS)) were used to evaluate the QoL. Results: Shoulder forward flexion and abduction measured in degrees improved from 86 (SD 14.5) and 82 (SD 33.8) preoperatively to 140 (SD 27.3) and 138 (31.3) at 1 year postoperatively. After a median follow-up of 17 years, mean shoulder functions were slightly lower than at 1 year postoperatively, but still better than preoperative function, ie, forward flexion 121 (SD 41.9) and abduction 122 (SD 44.5). The mean PCS score at the final follow-up was 41.9 (SD 9.7), and the mean MCS score was 49.9 (SD 12.5). Better shoulder function at the final follow-up was significantly associated with higher QoL in terms of PCS scores (P = .023), but not MCS scores (P = .287). Conclusion: The results of the present study indicate that PM transfer augmented with an achilles tendon allograft for scapular winging due to LTN palsy leads to functional improvements that persist in long term. These functional improvements likely translate to better QoL based on their association.

Background and purpose — Safety notices for medical devices such as total knee arthroplasty (TKA) implants may indicate problems in their design or performance that require corrective action to prevent patient harm. Safety notices are often published on national Ministries of Health or regulatory agencies websites. It is unknown whether problems triggering safety notices identify the same implants as those identified by registries as “outlier.” We aimed to assess the extent to which safety notices and outlier identification in registries signal the same or different TKA implants. Methods — The CORE-MD tool, an automated web scraper tool, was used to collect safety notices related to TKA implants on 13 national Ministries of Health websites and regulatory agencies. Safety notices were defined accord-ing to the Medical Device Regulation (MDR) as “a com-munication sent by a manufacturer to users or customers in relation to a field safety corrective action.” Identified TKA outliers, defined as having a significantly higher revision risk than other comparable TKA implants, were extracted from registry reports. Results — 787 safety notices for 38 TKA implants and 35 TKA outliers were identified, together identifying 47 unique TKA implants. 26 (55%) TKA implants had safety notices and were also outliers, 12 (26%) TKA implants had only safety notices, and 9 (19%) were outliers only. TKA implants with safety notices only had similar types of problems to TKA outliers with safety notices, with “Manufac-turing/Packaging/Shipping” problems being most frequent (44%). Cumulative revision risks (1/5/10 years) were lower for TKA implants with safety notices only than for TKA out-liers with safety notices. Conclusion — 55% of the TKA with a safety notice were identified as outliers in the registry, whereas around 25% of TKA outliers are not the subject of publicly released safety notices, with safety notices pointing to TKA implants not identified by registries as potentially having a higher risk of failure. This suggests that safety notices and registry outlier data measure different aspects of safety and performance.

Introduction
Different limb lengths are used in Roux-en-Y gastric bypass (RYGB) surgery, as there is no consensus which limb length strategy has the best outcomes. The biliopancreatic limb (BPL) is thought to play an important role in achieving weight loss and associated comorbidity resolution. The objective of this study was to assess the impact of a longer BPL on weight loss and comorbidity improvement at 5 years after primary RYGB.

Methods
All patients aged ≥ 18 years undergoing primary RYGB between 2014–2017 with registered follow-up 5 years after surgery were included. Long BPL was defined as BPL ≥ 100 cm and short BPL as BPL < 100 cm. The primary outcome was achieving at least 25% total weight loss (TWL) at 5 years. Secondary outcomes included absolute %TWL and improvement of comorbidities. A propensity score matched logistic and linear regression was used to estimate the difference in outcomes between patients with long and short BPL.

Results
At 5 years, long BPL had higher odds to achieve ≥ 25% TWL (odds ratio (OR) 1.19, 95% confidence interval (CI) [1.01 – 1.41]) and was associated with 1.26% higher absolute TWL (β = 1.26, 95% CI [0.53 – 1.99]). Furthermore, long BPL was more likely to result in improved diabetes mellitus (OR = 2.17, 95% CI [1.31 – 3.60]) and hypertension (OR = 1.45, 95% CI [1.06 – 1.99]).

Conclusion
Patients undergoing RYGB with longer BPL achieved higher weight loss and were more likely to achieve improvement of comorbidities at 5 years.

Background: Loosening is a major cause for failure of total hip and total knee arthroplasties (THAs/TKAs). Preemptive diagnostics of asymptomatic loosening could open strategies to prevent gross loosening. A multitude of biomarkers may discriminate between loosened and stable implants, but it is unknown which have the best performance. The present systematic review aimed to assess which biomarkers have shown the most promising results in discriminating between stable and aseptic loosened THAs and TKAs.

Methods: PubMed, Embase, Web of Science, Cochrane Library, and Academic Search Premier were systematically searched up to January 2020 for studies including THA/TKA and biomarkers to assess loosening. Two reviewers independently screened records, extracted data, and assessed the risk of bias using the ICROMS tool to classify the quality of the studies.

Results: Twenty-eight (three high-quality) studies were included, reporting on a median of 48 patients (interquartile range 28–69). Serum and urine markers were evaluated in 22 and 10 studies, respectively. Tumor necrosis factor α and osteocalcin were significantly higher in loosened compared with stable implants. Urinary N-terminal telopeptide had significantly elevated levels in loosened prostheses.

Conclusion: Several serum and urine markers were promising in discriminating between loosened and stable implants. We recommend future studies to evaluate these biomarkers in a longitudinal fashion to assess whether progression of loosening is associated with a change in these biomarkers. In particular, high-quality studies assessing the usability of these biomarkers are needed.

Background:Radiostereometric analysis (RSA) provides highly accurate data about the migration of a total knee arthroplasty (TKA) component. However, patient-reported outcome measures (PROMs) reflect the patients' perspective of their functional status, pain, and overall health after TKA. The aim of this study was to evaluate the association between tibial implant migration and change in postoperative PROMs and clinical scores, using data pooled from long-Term follow-up RSA studies.Methods:Individual implant migration data were collected from 5 randomized RSA studies, including a total of 300 patients with 6 distinct TKA implant designs (all Stryker). Tibial implant migration (maximum total point motion [MTPM]) was evaluated with RSA at 3 months, 1 year, and 2, 5, 7, and 10 years postoperatively. The Knee Society Score (KSS)-Knee and KSS-Function and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales were collected in all studies at the same follow-up times. Linear mixed-effects models, with adjustment for TKA implant design and patient characteristics, were used to analyze the data. The 3-month follow-up visit was used as the baseline to assess the association between implant migration and PROMs across the 10-year follow-up.Results:No association between tibial implant migration and change in KSS-Knee (p = 0.384), KSS-Function (p = 0.737), KOOS-Symptoms (p = 0.398), KOOS-Pain (p = 0.699), KOOS-Activities of Daily Living (p = 0.205), KOOS-Sport and Recreation (p = 0.702), or KOOS-Quality of Life (p = 0.368) was found across the entire follow-up. Similar results were found when using the 2-year follow-up as the baseline, after which both cemented and uncemented implants are expected to have stabilized.Conclusions:Tibial baseplate migration was not associated with postoperative worsening in PROMs or clinical scores in patients who underwent TKA. These findings suggest that implant migration, as measured with RSA, measures a different parameter (i.e., implant-bone fixation) than PROMs (i.e., patient perception) and clinical scores. Therefore, to assess the performance and safety of TKA implant designs, RSA and PROMs cannot be used interchangeably during the postoperative follow-up of patients and evaluation of the fixation of knee implants.Level of Evidence:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background: The purpose of the study was to gain insight into how clinically relevant improvement in patient-reported outcome measure scores after total hip arthroplasty (THA) and total knee arthroplasty (TKA) may be underestimated or overestimated, we compared patient-reported outcome measure respondents and nonrespondents on their adverse event rates and assessed whether adverse event occurrence was associated with clinically relevant patient-reported outcome measure improvement from those without adverse events. Methods: All primary THAs and TKAs performed in 19 Dutch hospitals between January 2017 and December 2019 were included. The hip disability and osteoarthritis outcome score-physical function short form (HOOS-PS) and knee injury and osteoarthritis outcome score-physical function short form (KOOS-PS) were used to assess the physical function after THA and TKA, respectively. Adverse events included 1-year revision, 30-day readmission, 30-day complications, and long (ie, >75th percentile) length of stay. A clinically relevant improvement was defined as at least a 10-point decrease in HOOS-PS and 9 points in KOOS-PS scores. Associations between adverse events and clinically relevant HOOS-PS and KOOS-PS improvement were assessed using binary logistic regression models adjusted for patient characteristics and clustering of patients within hospitals. Results: There were 20,338 THA and 18,082 TKA procedures included. Adverse events occurred more frequently in HOOS-PS and KOOS-PS nonrespondents than in respondents. The THA patients experiencing revision, complications, or long length of stay were less likely to experience clinically relevant HOOS-PS improvements (odds ratios of 0.11 [0.06 to 0.20], 0.44 [0.30 to 0.63], and 0.66 [0.50 to 0.88], respectively). The TKA patients experiencing revision or long length of stay were less likely to experience clinically relevant KOOS-PS improvements (odds ratios of 0.26 [0.12 to 0.55] and 0.63 [0.50 to 0.80], respectively). Conclusions: Clinically relevant HOOS-PS and KOOS-PS improvements are likely overestimated, as nonrespondents had higher adverse event rates which were associated with lower likelihood to achieve clinically relevant HOOS-PS and KOOS-PS improvements.

Aims The objective of this study was to compare the two-year migration and clinical outcomes of a new cementless hydroxyapatite (HA)-coated titanium acetabular shell with its previous version, which shared the same geometrical design but a different manufacturing process for applying the titanium surface. Methods Overall, 87 patients undergoing total hip arthroplasty (THA) were randomized to either a Trident II HA or Trident HA shell, each cementless with clusterholes and HA-coating. All components were used in combination with a cemented Exeter V40 femoral stem. Implant migration was measured using radiostereometric analysis (RSA), with radiographs taken within two days of surgery (baseline), and at three, 12, and 24 months postoperatively. Proximal acetabular component migration was the primary outcome measure. Clinical scores and patient-reported outcome measures (PROMs) were collected at each follow-up. Results Mean proximal migrations at three, 12, and 24 months were 0.08 mm (95% confidence interval (CI) 0.03 to 0.14), 0.11 mm (95% CI 0.06 to 0.16), and 0.14 mm (95% CI 0.09 to 0.20), respectively, in the Trident II HA group, versus 0.11 mm (95% CI 0.06 to 0.16), 0.12 mm (95% CI 0.07 to 0.17), and 0.14 mm (95% CI 0.09 to 0.19) in the Trident HA group (p = 0.875). No significant differences in translations or rotations between the two designs were found in any other direction. Clinical scores and PROMs were comparable between groups, except for an initially greater postoperative improvement in Hip disability and Osteoarthritis Outcome Symptoms score in the Trident HA group (p = 0.033). Conclusion The Trident II clusterhole HA shell has comparable migration with its predecessor, the Trident hemispherical HA cluster shell, suggesting a similar risk of long-term aseptic loosening. Cite this article: Bone Joint J 2024;106-B(2):136–143.