Intermediate to long term results of stemless metaphyseal reverse shoulder arthroplasty: A five to nine year follow-up

The radiographic and clinical outcomes of stemless reverse total shoulder arthroplasty: a minimum 2-year follow-up study

Background

The purpose of this study was to examine the radiographic and clinical outcomes of stemless reverse total shoulder arthroplasty (RTSA) after a minimum 2-year follow-up.

Methods

Between July 2018 and March 2023, 50 patients underwent 50 stemless RTSA with the Lima component. Twenty-eight patients with a follow-up of more than 2 years were reviewed. The average age was 71.9 years (range, 61-85 years), and the average follow-up period was 2.2 years (range, 2.0-5.1). Bone marrow density of the proximal humerus was measured before RTSA. We evaluated preoperative and postoperative range of motion, clinical score, radiographic change, and postoperative complications.

Results

Significant increases were observed postoperatively in forward flexion (112.0º-162.5º, P<0.01) and internal rotation (from L3 to T12 level; P<0.05). No changes were observed in external rotation (from 43.0º to 45.2º; P=0.762). The clinical scores improved for Korean Shoulder Scoring system (from 64 to 93, P<0.01) and American Shoulder and Elbow Surgeons score (from 17.5 to 27.3, P<0.01). Although radiolucent lines of less than 2 mm were observed in all cases, no osteolysis and loosening of the stemless humeral component was found. In one case, the stemless humeral component pulled out at the 1-week follow-up, and a revision was implemented to replace it with a stemmed humeral component. Scapular notching was observed in 18 cases.

Conclusions

Stemless RTSA showed good radiographic and clinical results after a minimum 2-year follow-up. Level of evidence: IV.

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.

Stemless Reverse Shoulder Arthroplasty

Since the Food and Drug Administration (FDA) approval nearly two decades ago, the indications for and utilization of reverse shoulder arthroplasty (RSA) have expanded considerably. Stemless RSA designs have been used in Europe since 2005, but have only recently been introduced in domestic Investigational Device Exemption trials. Potential advantages of stemless RSA are similar to those of stemless anatomic total shoulder arthroplasty, which may include fewer shaft-related complications, avoidance of stress shielding, bone preservation, and easier revision surgery. European data support similar outcomes between certain stemless RSA prostheses compared with that of stemmed RSA implants at early and mid-term follow-up. However, long-term outcomes remain to be seen and differences exist between the stemless RSA designs used in Europe and those being studied in domestic clinical trials. An understanding of the potential advantages and disadvantages of stemless RSA, differences between existing designs, and reported clinical outcomes is prudent for the safe and meaningful implementation of this new technology in the United States.

Outcomes of different stem sizes in shoulder arthroplasty

Background

The successive refinement in implant design and operative technique alongwith improved understanding has resulted in increased incidence of total shoulder arthroplasty (TSA). Simultaneously, the indications of TSA have widened and include a range of shoulder pathologies.

Methods

Using the keywords and relevant literature, we have described an overview of the different stem sizes used in shoulder arthroplasty. Relevant description of clinical and radiological outcome is done with regards to different stem sizes.

Discussion

There are plethora of shoulder replacement systems, based on unique philosophy and having their own advantages and disadvantages. Additionally, the rise in ageing population had increased the need for revision TSA, thereby necessitating the judicious choice of implant at primary TSA. We further present the role of cemented and uncemented humeral stems and discuss the findings of finite element analysis. The choice of humeral stem size and use of cemented or uncemented stems have been reported to affect the clinical and radiological outcomes.