Eclipse stemless shoulder prosthesis vs. Univers II shoulder prosthesis: a multicenter, prospective randomized controlled trial

High revision rate of metal-backed glenoid component and impact on the overall revision rate of stemless total shoulder arthroplasty: a cohort study from the Danish Shoulder Arthroplasty Registry

BACKGROUND AND PURPOSE

There is controversy regarding the results of stemmed and stemless total shoulder arthroplasty (TSA) used for osteoarthritis. Therefore, we aimed to compare revision rates of stemmed and stemless TSA and to examine the impact of metal-backed glenoid components.

METHODS

We included all patients reported to the Danish Shoulder Arthroplasty Register from January 1, 2012 to December 31, 2022 with an anatomical TSA used for osteoarthritis. Primary outcome was revision (removal or exchange of components) for any reason.

RESULTS

3,338 arthroplasties were included. The hazard ratio for revision of stemless TSA adjusted for age and sex was 1.83 (95% confidence interval [CI] 1.21-2.78) with stemmed TSA as reference. When excluding all arthroplasties with a metal-backed glenoid component, the adjusted hazard ratio for revision of stemless TSA was 1.37 (CI 0.85-2.20). For the Eclipse stemless TSA system, the adjusted hazard ratio for revision of a metal-backed glenoid component was 8.75 (CI 2.40-31.9) with stemless Eclipse with an all-polyethylene glenoid component as reference.

CONCLUSION

We showed that the risk of revision of stemless TSAs was increased and that it was related to their combination with metal-backed glenoid components.

Evolution of Stemless Reverse Shoulder Arthroplasty: Current Indications, Outcomes, and Future Prospects

Reverse total shoulder arthroplasty (rTSA) is increasingly being used as a reliable option for various shoulder disorders with deteriorated rotator cuff and glenohumeral joints. The stemless humerus component for shoulder arthroplasties is evolving with theoretical advantages, such as preservation of the humeral bone stock and decreased risk of periprosthetic fractures, as well as clinical research demonstrating less intraoperative blood loss, reduced surgical time, a lower rate of intraoperative fractures, and improved center of rotation restoration. In particular, for anatomical total shoulder arthroplasty (aTSA), the utilization of stemless humeral implants is gaining consensus in younger patients. The current systematic review of 14 clinical studies (637 shoulders) demonstrated the clinical outcomes of stemless rTSA. Regarding shoulder function, the mean Constant-Murley Score (CS) improved from 28.3 preoperatively to 62.8 postoperatively. The pooled overall complication and revision rates were 14.3% and 6.3%, respectively. In addition, recent studies have shown satisfactory outcomes with stemless rTSA relative to stemmed rTSA. Therefore, shoulder surgeons may consider adopting stemless rTSA, especially in patients with sufficient bone quality. However, further long-term studies comparing survivorship between stemless and stemmed rTSA are required to determine the gold standard for selecting stemless rTSA.

Clinical results and computed tomography analysis of intuitive shoulder arthroplasty (ISA) stemless at a minimum follow-up of 2 years

BACKGROUND

The utilization of stemless anatomic total shoulder arthroplasty is on the rise. Epiphyseal fixation leads to radiological bone remodeling, which has been reported to exceed 40% in certain studies series. The aim of this study was to present the clinical and radiological outcomes of a stemless implant with asymmetric central epiphyseal fixation at an average follow-up of 31 months.

MATERIALS AND METHODS

This retrospective multicenter study examined prospective data of patients undergoing total anatomic arthroplasty with intuitive shoulder arthroplasty Stemless implant and followed up at least 2 years. Clinical assessment included preoperative and final follow-up measurements of active range of motion, Constant score, and Subjective Shoulder Value. Anatomical epiphyseal reconstruction and bone remodeling at the 2-year follow-up were assessed by standardized computed tomography scanner (CT scan). Statistical analysis employed unpaired Student's t-test or chi-squared test depending on the variable type, conducted using EasyMedStat software (version 3.22; www.easymedstat.com).

RESULTS

Fifty patients (mean age 68 years, 62% females) were enrolled, with an average follow-up of 31 months (24-44). Primary osteoarthritis (68%) with type A glenoid (78%) was the prevailing indication. The mean Constant score and Subjective Shoulder Value improved significantly from 38 ± 11 to 76 ± 11 (P < .001) and from 31% ± 16 to 88% ± 15 (P < .001) respectively at the last follow-up. Forward elevation, external rotation, and internal rotation range of motion increased by 39° ± 42, 28° ± 21 and 3,2 ± 2,5 points respectively, surpassing the Minimally Clinically Important Difference after total shoulder arthroplasty. No revisions were necessary. CT scans identified 30% osteolysis in the posterior-medial calcar region, devoid of clinical repercussions. No risk factors were associated with bone osteolysis.

CONCLUSIONS

At an average follow-up of 31 months, intuitive shoulder arthroplasty Stemless implant provided favorable clinical results. CT analysis revealed osteolysis-like remodeling in the posterior-medial zone of the calcar (30%), without decline in clinical outcomes and revisions. Long-term follow-up studies are mandated to evaluate whether osteolysis is associated with negative consequences.

A comparison of revision rates for stemmed and stemless primary anatomic shoulder arthroplasty with all-polyethylene glenoid components: analysis from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

We compared the rate of all-cause revision of 2 classes of primary anatomic shoulder arthroplasty, stemmed (stTSA) and stemless (slTSA), undertaken with cemented all-polyethylene glenoid components.

METHODS

A large national arthroplasty registry identified 2 cohort groups for comparison, stTSA and l undertaken for all diagnoses between January 1, 2011, and December 31, 2021. A subanalysis from January 1, 2017, allowed capturing of additional patient demographics including American Society of Anesthesiologists score, body mass index, and glenoid morphology. The cumulative percent revision (CPR) was determined using Kaplan-Meier estimates of survivorship and hazard ratios (HR) from Cox proportional hazard models adjusted for age and gender.

RESULTS

Of the 7995 stTSA procedures, the CPR at 9 years was 5.6% (95% confidence interval [CI]: 5.0, 6.4), and for 3156 slTSA procedures, the CPR was 4.4% (95% CI: 3.6, 5.5). There was no significant difference in the rate of revision between the study groups (HR = 0.76 [95% CI: 0.51, 1.14], P = .189, adjusted for age, gender, humeral head size, humeral fixation, bearing surface, glenoid design, and mean surgeon volume [MSV]). There was an increased rate of revision for stTSA and slTSA undertaken with humeral head sizes <44 mm (stTSA <44 mm vs. 44-50 mm, HR = 1.56 [CI: 1.18, 2.08], P = .001; slTSA <44 mm vs. 44-50 mm, HR = 2.08 [CI: 1.32, 3.33], P = .001). MSV as a continuous predictor was not a revision risk to stTSA vs. slTSA, but categorically, a low MSV (<10 stTSA + slTSA cases per annum) was associated with a higher revision rate for stTSA (10-20 cases/yr vs. <10 cases/yr, HR = 0.72 [CI: 0.55, 0.95], P = .019) but was not in slTSA. Revision rates were increased for stTSA with non-crosslinked polyethylene (XLPE) glenoids vs. XPLE after 2 years (HR = 2.20 [CI: 1.57, 3.08], P < .001) but did not significantly differ for slTSA. Metal/XPLE (humeral/glenoid) bearing surface of stTSA rate of revision was not different from each combination of slTSA bearing surface. Instability/dislocation was a revision risk for slTSA vs. stTSA (HR = 1.93 [CI: 1.28, 2.91], P = .001), but from 2017, neither of American Society of Anesthesiologists score, body mass index, and glenoid morphology changed the rate of revision.

CONCLUSIONS

Revision rates of stTSA and slTSA did not significantly differ and were associated with humeral head size but not patient characteristics. Surgeon inexperience of anatomic shoulder arthroplasty and non-XLPE glenoids were risk factors for stTSA revision but not slTSA. The metal/XLPE stTSA rate of revision was not found to differ significantly from slTSA regardless of polyethylene or humeral head bearing type. Revision for instability/dislocation was more common for slTSA.

Outcomes Between Stemmed and Stemless Total Shoulder Arthroplasty: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Both stemmed and stemless designs for total shoulder arthroplasty (TSA) have demonstrated efficacious outcomes for the surgical treatment of primary glenohumeral joint osteoarthritis. The purpose of this systematic review and meta-analysis was to compare the clinical outcomes of stemmed versus stemless TSA in randomized controlled trials. We hypothesized that there would be no differences in Constant Score (CS), range of motion, or adverse events, such as periprosthetic fracture and/or revision surgery.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic review of the literature was done using MEDLINE, SPORTDiscus, Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Registry of Controlled Trials, Embase, and Web of Science databases. Outcomes of interest included CS, range of motion, and adverse events (periprosthetic fracture and revision). Summary effect estimates of the mean difference between stemmed and stemless TSA for each outcome were estimated in random effects models.

RESULTS

The search yielded 301 articles with 4 appropriate for qualitative analysis, including the results of 229 stemmed and 358 stemless TSAs. No significant difference was observed in postoperative CS (P = 0.36), forward flexion (P = 0.93), abduction (P = 0.30), or external rotation (P = 0.34) between stemmed and stemless TSA. No significant difference was observed in change in CS (P = 0.27), forward flexion (P = 0.25), or external rotation (P = 0.74). A change in abduction was significantly different between stemmed and stemless TSA (standardized mean difference = -0.64; 95% confidence interval, -1.20 to -0.08) in favor of stemmed TSA (P = 0.02), attributed to preoperative differences. No significant difference was observed in periprosthetic fractures (P = 0.07) or revision (P = 0.90).

CONCLUSION

TSA with stemless versus stemmed humeral components was not associated with notable differences in functional and clinical outcomes. No difference was observed between stemmed and stemless designs in postoperative forward flexion, abduction, or external rotation. Similarly, there was no difference in change in forward flexion or external rotation. A markedly greater improvement in abduction was observed with stemmed TSA, likely due to the lower preoperative motion in the stemmed cohort in one of the studies. No differences were observed between stemmed and stemless designs in the rate of humeral fracture or risk of revision.

LEVEL OF EVIDENCE

Level II; systematic review and meta-analysis of prospective randomized controlled trials.

Early fixation of the humeral component in stemless total shoulder arthroplasty : a radiostereometric and clinical study with 24-month follow-up

AIMS

Stemless humeral implants have been developed to overcome stem-related complications in total shoulder arthroplasty (TSA). However, stemless implant designs may hypothetically result in less stable initial fixation, potentially affecting long-term survival. The aim of this study is to investigate early fixation and migration patterns of the stemless humeral component of the Simpliciti Shoulder System and to evaluate clinical outcomes.

METHODS

In this prospective cohort study, radiostereometric analysis (RSA) radiographs were obtained in 24 patients at one day, six weeks, six months, one year, and two years postoperatively. Migration was calculated using model-based RSA. Clinical outcomes were evaluated using the visual analogue scale (VAS), the Oxford Shoulder Score (OSS), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand (DASH) score.

RESULTS

At two years, median translation along the x-, y-, and z-axis was -0.12 mm (interquartile range (IQR) -0.18 to 0.02), -0.17 mm (IQR -0.27 to -0.09), and 0.09 mm (IQR 0.02 to 0.31). Median rotation around the x-, y-, and z-axis was 0.12° (IQR -0.50 to 0.57), -0.98° (IQR -1.83 to 1.23), and 0.09° (IQR -0.76 to 0.30). Overall, 20 prostheses stabilized within 12 months postoperatively. Four prostheses showed continuous migration between 12 and 24 months. At two-year follow-up, with the exception of one revised prosthesis, all clinical scores improved significantly (median VAS difference at rest: -3.0 (IQR -1.5 to -6.0); OSS 22.0 (IQR 15.0 to 25.0); CMS 29.5 (IQR 15.0 to 35.75); and DASH -30.0 (IQR -20.6 to -41.67) (all p < 0.001)) with the exception of one revised prosthesis.

CONCLUSION

In conclusion, we found that 20 out of 24 implants stabilized within 12 months postoperatively. The significance of continuous migration in four implants is unclear and future research on the predictive value of early migration for future loosening in TSA is required. Clinical results revealed a clinically relevant improvement. Cite this article: Bone Joint J 2022;104-B(1):76-82.