Stemless anatomic total shoulder arthroplasty (aTSA) is a promising option for the treatment of degenerative disease in patients. This novel technique avoids the stem-related complications associated with the traditional stemmed aTSA. Stemless aTSA offers additional benefits such as decreased operative time, preservation of bone stock, improved radiographic outcomes, and easier revision. Moreover, loading of the metaphyseal region rather than the diaphysial region with traditional stemmed implants can decrease stress shielding. When compared to stemmed-implants, stemless aTSA has demonstrated similar outcomes and complication rates. The purpose of this article is to analyze published outcomes and complications following the utilization of stemless aTSA. Additionally, key aspects of the surgical technique that may promote optimal results in stemless aTSA implantation are presented.

BACKGROUND: Stemless reverse total shoulder arthroplasty is used to treat rotator cuff deficient arthropathies, rheumatoid arthritis, and osteoarthritis. It has several advantages over the stemmed implant including preservation of bone stock, reduced surgical time, and easier revision.
METHODS: A systematic search was conducted in MEDLINE, EMBASE, PubMed, and CENTRAL to retrieve all relevant studies evaluating stemless reverse total shoulder arthroplasty.
RESULTS: The literature search identified 1993 studies out of which 7 studies were included in this review; 324 patients underwent stemless reverse total shoulder arthroplasty with a weighted mean age of 74.1 (SD = 8.6, range = 38 to 93) years and a weighted mean follow-up time of 44 (SD = 6.6, range = 3 to 95) months. The included studies reported significant improvements in range of motion and functional scores comparable to stemmed reverse total shoulder arthroplasty. The weight mean flexion and abduction was (135 ± 12)° and (131 ± 12)° post-operatively, respectively. The weighted mean constant score increased from (26.7 ± 5.2) Patients (pts) to (63.0 ± 8.0) pts post-operatively. Overall complication and revision rate were 12.3% and 5.2%.
CONCLUSIONS: Early and mid-term results indicate stemless reverse total shoulder arthroplasty has similar clinical outcomes to stemmed reverse total shoulder arthroplasty. There was no radiological evidence of humeral loosening at the latest follow-up.

OBJECTIVE: Reverse shoulder prostheses are increasingly used for treatment of rotator cuff tear arthropathy and other degenerative shoulder diseases. In recent years, aiming for bone stock preservation has led to the design of metaphyseal humeral components without a stem. The aims of this study were to evaluate the complication and reintervention rates, as well as the clinical and radiographic outcomes in patients who underwent reverse shoulder arthroplasty (RSA) with stemless implants.
METHODS: A systematic review of the literature was completed until May 2020 using PubMed, EMBASE, CINAHL and Cochrane databases, according to PRISMA guidelines.
RESULTS: The literature search revealed 2942 studies, of which 13 were included in this review, with a total of 517 patients and a mean follow-up between 6.4 and 101.6 months. The total complication rate was 6.5%, while 3.3% were humeral associated complications. Finally, the rate of shoulders that underwent a reintervention was 6.7%, with 1.4% relating to a humeral component reason. Stemless RSA led to substantial improvements in patient reported outcome measures and range of motion across all studies. Scapular notching was reported in 15.2%, and lucencies around humeral component were reported in 0.8% of shoulders.
CONCLUSIONS: Stemless RSA resulted in low complication and reintervention rates at the mid-term follow-up. The reported clinical and radiological outcomes showed that these prostheses have at least equivalent outcomes with their stemmed counterparts. Further studies are required to investigate the long-term longevity and performance of the stemless humeral implants.
METHODS: Level IV; Systematic Review.

UNASSIGNED: The number of anatomic total shoulder (TSA), hemiarthroplasty (HA), and reverse total shoulder arthroplasties (RTSA) is rapidly increasing in the United States. Stemless shoulder arthroplasty has numerous theoretical advantages, including preserved bone stock, decreased operating time, reduced rate of intraoperative humerus fracture, and flexibility of anatomic reconstruction. Only recently studies with more than 5 years of mean follow-up have become available.
UNASSIGNED: The MEDLINE database was systematically queried to identify all studies reporting outcomes regarding anatomic or reverse stemless shoulder arthroplasty. Studies were categorized according to mean reported follow-up. Outcome scores and range of motion measurements were compiled. Complication and revision rates due to failure of the humeral or glenoid components were summarized.
UNASSIGNED: Nineteen TSA and HA studies with a total of 1115 patients were identified, with 4 studies and 162 patients with a mean follow-up between 60 and 120 months. Six RTSA studies with a total of 346 patients were identified, all with a mean follow-up between 18 and 60 months. There was a reliable improvement in outcomes compared with preoperative scores across studies. A cumulative 0.7% (8 of 1115) humeral component complication rate was found for TSA and HA components. There was a cumulative 1.7% (6 of 346) humeral complication rate for RTSA prostheses.
UNASSIGNED: In the studies reporting similar outcome measures, there were reliable improvements on par with stemmed counterparts. Aggregate complication rates appear similar to those published in the literature for stemmed components. Evidence supporting the utility and safety of stemless designs would be strengthened by longer-term follow-up and additional prospective comparative studies.

Uncemented press-fit humeral stems were developed with the goal of decreasing operative time, preserving bone stock, and easing revision. In recent years, short stems and stemless humeral implants have also become available. These press-fit humeral implants have varying designs that can lead to changes in stress distribution in the proximal humerus. Such stress shielding manifests as bony adaptations and may affect long-term functional outcome and the ability to perform revision. However, current studies of humeral fixation during total shoulder arthroplasty are complicated because a variety of classification systems have been used to report findings. The purpose of this report is to review the current literature on press-fit fixation of the humeral component during total shoulder arthroplasty and propose minimum requirements for radiographic descriptions of stress shielding.

The latest generation of shoulder arthroplasty includes canal-sparing respectively stemless designs that have been developed to allow restoration of the glenohumeral center of rotation independently from the shaft, and to avoid stem-related complications. The stemless prosthesis design has also recently been introduced for use in reverse arthroplasty systems.
We systematically reviewed the literature for studies of currently available canal-sparing respectively stemless shoulder arthroplasty systems. From the identified series, we recorded the indications, outcome measures, and humeral-sided complications.
We identified 11 studies of canal-sparing respectively stemless anatomic shoulder arthroplasty implants, published between 2010 and 2016. These studies included 929 cases, and had a mean follow-up of 26 months (range, 6 to 72 months). The rates of humeral component-related complications ranged between 0 and 7.9 %. The studies reported only a few isolated cases of complications of the humeral component. Some arthroplasty systems are associated with radiological changes, but without any clinical relevance.
All of the published studies of canal-sparing respectively stemless shoulder arthroplasty reported promising clinical and radiological outcomes in short to midterm follow-up. Long-term studies are needed to demonstrate the long-term value of these kind of implants.

The design of humeral implants for shoulder arthroplasty has evolved over the years. The new-generation modular shoulder prostheses have an anatomical humeral stem that replicates the three-dimensional parameters of the proximal humerus. An anatomical reconstruction is the best way to restore stability and mobility of the prosthetic shoulder and improve implant durability. However, a perfect anatomical match is not always possible in, for example, patients with post-traumatic osteoarthritis of the shoulder and deformities in the metaphyseal region. To avoid stem-related complications while retaining the advantages of the fourth generation of shoulder implants, different stemless implants have been developed. The stemless shoulder prosthesis is a new concept in shoulder arthroplasty. The authors review the indications, surgical technique, clinical and radiological midterm results, and complications of these humeral implants.