Short Stems and Stemless Shoulder Arthroplasty: Current Concepts Review

Stemless reverse total shoulder arthroplasty: a systematic review and meta-analysis

Background

Stemless reverse total shoulder arthroplasty (rTSA) is one of the many modifications of the original Grammont rTSA design. Much has been made of the debate between stemless and stemmed humeral implants for anatomic reverse shoulder arthroplasty, with less attention awarded to the relatively newer variation in stemless rTSA. Proposed advantages of said design include preserving bone stock, ease of revision, reduced blood loss, and shortening surgical times.

Methods

A systematic search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines using search engines in PubMed, EMBASE, and Cochrane to retrieve all relevant studies.

Results

Initial search strategies produced 174 studies, of which 15 studies were included for full analysis in this review. This included 657 shoulders in 648 patients (9 bilateral cases). Stemless rTSA led to significant improvement in functional outcomes and range of motion (ROM) across all studies. Meta-analysis of comparative studies including stemless and stemmed rTSA showed no significant difference in ROM measurements across abduction (standardized mean difference [SMD] -0.17, 95% confidence interval [CI]: -1.05, 0.70) or forward flexion (SMD -0.36, 95% CI: -1.23, 0.50). However, there was a statistically significant difference in internal rotation in favor of stemless implants (SMD -0.79, 95% CI: -1.56, -0.03). There was no significant difference in visual analog scale (VAS) between stemmed and stemless designs (SMD -0.31, 95% CI: -2.32, 1.69). Likewise, there was no significant difference in odds ratio (OR) for revision rates (OR: 1.02, 95% CI: 0.92, 1.14) or overall complications (OR: 0.82, 95% CI: 0.2, 3.42). Across all 15 studies, comparative and noncomparative studies, overall complication rates for stemless rTSA stood at 13.4% and revision rates at 5.5%.

Conclusion

Stemless rTSA achieves similar functional outcomes to stemmed rTSA designs. Stemless designs achieved superior internal rotation in the comparative studies. Proposed advantages of stemless rTSA including reduced blood loss and lesser surgical times need further research, as does the long-term robustness of this relatively novel design.

Clinical and radiological results of the SIMPLICITI* stemless shoulder arthroplasty: a twenty five patients retrospective cohort

PURPOSE

For preserving the humeral bone stock, some surgeons proposed a stemless humeral prosthetic component. This study reports the functional and radiologic results of the stemless anatomic prosthesis Simpliciti*(Tornier, Wright, Stryker), with the hypothesis that it can achieve a good metaphyseal fixation.

METHODS

28 patients underwent 30 shoulder replacements with the Simpliciti* humeral prosthesis followed for an average of three years (2 months to 8 years). The clinical outcome used the Constant-Murley score and the Bankes resistance and force evaluation. The radiologic assessment looked after radiolucent lines, signs of implant migration, osteolysis or loosening.

RESULTS

The Constant score improved from 19.03 preoperatively to 54.03 points post operatively. Radiographic analysis showed one early component loosening, and at the longer follow-up, one radiolucent line. All the other implants appeared well fixed.

CONCLUSION

This study verified the quality of the metaphyseal fixation of this stemless implant, with achieving a significant functional improvement.

LEVEL OF EVIDENCE

Level IV, Case Series, Treatment Study.

Long-term survival of resurfacing humeral hemiarthroplasty

INTRODUCTION

The indication for shoulder resurfacing arthroplasty is controversial, and survival of these implants is somewhat inconsistent. This study aimed to evaluate the long-term survivorship of resurfacing humeral head implants (RHHIs) and determine risk factors for complications and revisions.

MATERIALS AND METHODS

This retrospective cohort study consisted of 275 cases and two types of RHHIs. The survival rate was evaluated using the Kaplan-Meier method and Cox regression for risk factor analysis. Demographic factors were studied, and the change in the humerus centre of rotation (COR) was measured.

RESULTS

The mean follow-up time was 8.7 years (SD 2.7 months, range 2.8-15.9 years). The mean age of the patients was 67.6 years (SD 9.6, range 33.5-84.9). Ten-year cumulative RHHI survival was 94.1%. The cumulative estimate without any complication was 98.9% at 5 years, 80.0% at 10 years and at 15 years it was 61.5%. The most common complication was persistent pain in 13.8% of the RHHIs. The risk factors for complications and revisions were implant type, preoperative conditions and change of COR > 5 mm.

CONCLUSIONS

RRHIs showed excellent long-term survival, but many complications were found. The most common complication was persistent pain, which seemed to be caused by a change of COR and was more related to one type of implant.

Recent Advances in the Design and Application of Shoulder Arthroplasty Implant Systems and Their Impact on Clinical Outcomes: A Comprehensive Review

Purpose of Review

This narrative review comprehensively aims to analyze recent advancements in shoulder arthroplasty, focusing on implant systems and their impact on patient outcomes. The purpose is to provide a nuanced understanding of the evolving landscape in shoulder arthroplasty, incorporating scientific, regulatory, and ethical dimensions.

Recent Findings

The review synthesizes recent literature on stemless implants, augmented glenoid components, inlay vs onlay configurations, convertible stems, and associated complications. Notable findings include improved patient-reported outcomes with stemless implants, variations in outcomes between inlay and onlay configurations, and the potential advantages of convertible stems. Additionally, the regulatory landscape, particularly the FDA's 510(k) pathway, is explored alongside ethical considerations, emphasizing the need for standardized international regulations.

Summary

Recent innovations in shoulder arthroplasty showcase promising advancements, with stemless implants demonstrating improved patient outcomes. The review underscores the necessity for ongoing research to address unresolved aspects and highlights the importance of a standardized regulatory framework to ensure patient safety globally. The synthesis of recent findings contributes to a comprehensive understanding of the current state of shoulder arthroplasty, guiding future research and clinical practices.

Trends in Shoulder Arthroplasty in Germany: A 10-Year Epidemiological Analysis of Patients with Primary Osteoarthritis of the Shoulder

Shoulder arthroplasty has significantly gained popularity in orthopedic surgery, driven by progress in prosthesis design and surgical techniques. This study explored the epidemiology of shoulder arthroplasty, analyzing healthcare data from 2012 to 2022 for primary osteoarthritis of the shoulder. The data included patient demographics and types of surgical procedures. Data analysis indicates a higher utilization rate of reverse total shoulder arthroplasty (RTSA; n = 41,251) over total- (TSA; n = 18,679) and hemiarthroplasty (HSA; n = 12,827) for primary shoulder osteoarthritis. Overall, a significant increase in RTSA procedures from n = 2237 (2012) to n = 5415 (2022) was observed, representing more than a two-fold increase of 121.1%. The relative proportion of RTSA among all types of shoulder arthroplasty increased from 39% (2012) to 68.6% (2022), while HSA decreased and TSA essentially remained constant. Age analysis identified the following peaks: RTSA, 77 ± 7 y; HSA, 68 ± 12 y; and TSA, 67 ± 10 y. Among the over 60s, significantly more women were treated with any type of prosthesis, whereas in young patients (45 to 59 y), more men received HSA or TSA. Our study confirms that RTSA has become the preferred choice for elderly patients in Germany, reflecting the prevailing preference despite varying patient ages and conditions, with a noted difference in sex in treatment prevalence.

Does the proximal humeral bone quality influence alignment after reverse total shoulder arthroplasty with short humeral stems?

PURPOSE

When compared to standard-length humeral stem in reverse total shoulder arthroplasty (RTSA), short humeral stems in RTSA require good proximal humeral metaphyseal bone quality to gain proper and secure fixation during prosthetic implantation. Shorter humeral stems potentially carry more risk of misalignment than standard or long humeral stems. The hypothesis was that misalignment of the short humeral stems is influenced by regional bone quality.

METHODS

RTSA with a short curved humeral stem with neck-shaft angle (NSA) default of 132.5° was reviewed. The study group included 35 cases at a mean age of 75.97 (± 6.23) years. Deltoid-tuberosity index (DTI) was measured to evaluate proximal humeral bone quality. The deltoid tuberosity index was measured at immediately above position of the upper end of the deltoid tuberosity. Stem alignment was given by the angle measured in degrees between the intramedullary humeral shaft axis and the axis of the humeral implant stem.

RESULTS

The patient's mean DTI was 1.37 ± 0.16 (median, 1.32; range, 1.12-1.80). 22 patients had poor bone quality (DTI < 1.4), compared to 13 patients with acceptable bone quality (DTI > 1.4). After RTSA, ten humeral components (29%) were neutrally aligned, whereas 25 humeral components (71%) were misaligned. There was no correlation between misalignment and DTI (r = 0.117; p = 0.504). But there was a strong correlation between misalignment and the patient's own NSA (r = - 0.47; p = 0.004). The postoperative stem position and stem misalignment are not associated with functional outcomes (p > 0.05).

CONCLUSION

The misalignment of the short curved humeral stem frequently occurs. Poor reginal humeral bone quality does not influence misalignment after RTSA with a short humeral stem. Postoperative stem alignment is associated with the patient's preoperative NSA and method of neck cut. The misalignment does not affect functional outcomes for midterm follow-up. Further long-term follow-up studies are needed to confirm its clinical relevance.