Mid-term outcomes of a stemless ceramic head anatomic total shoulder replacement

Background In an anatomic shoulder replacement (aTSR) good results have been reported with the use of a stemless humeral prosthesis. In vitro a ceramic articulation with polyethylene has been shown to produce less polyethylene wear particles than with metal. This study aims to evaluate clinical and radiographic results of a stemless aTSR with a ceramic head articulating with a polyethylene glenoid component, with mid-term follow-up. Methods All patients (n = 92) in this prospective study had an aTSR utilizing a stemless humeral component with a ceramic head and a cemented double pegged cemented polyethylene glenoid component for glenohumeral osteoarthritis. Pre- and postoperative clinical evaluations at 2 years were performed using the ASES score, Constant score, SPADI score, DASH score, VAS pain score, patient satisfaction and range of motion. There was a 5-year evaluation of SPADI, ASES, pain, and satisfaction, plus radiographic assessment of glenoid component radiolucent lines and humeral osteolysis. Results Seventy-four cases (68.1 ± 7.1 years) had a five-year follow-up and demonstrated active elevation improvement from 91.3° preoperatively to 151.1° (p < 0.001). Further improvement was identified with the ASES from 41.6 to 94.3, the SPADI from 62.9 to 4.3, VAS pain from 5.6 to 0.4 (0–10), and satisfaction levels were at 96%. Sixty-two cases had no glenoid radiolucent lines with a maximum Lazarus score of 2 in one patient. Constant scores, available up to 2 years, improved significantly from 30.3 to 77.9 (p < 0.001). There was one case that required revision for glenoid loosening. Conclusions Overall, the 5-year results of this ceramic head prosthesis demonstrated good radiographic and clinical outcomes. Trial registration ACTRN12613001183774. Registered: 29 October 2013 - Retrospectively registered. Australian New Zealand Clinical Trials Registry (ANZCTR).

Technical note: subscapularis-sparing approach to perform anatomic total shoulder arthroplasty using a multiplanar humeral osteotomy and angled glenoid instruments

Background Anatomic total shoulder arthroplasty is typically performed through the deltopectoral approach followed by either a subscapularis tenotomy, tendon peel, or lesser tuberosity osteotomy to provide adequate exposure. These subscapularis-takedown methods have been associated with incomplete subscapularis healing, however, and as a result often lead to functional deficits and complications. Subscapularis-sparing approaches have been introduced to mitigate these complications, but thus far have either been limited to hemiarthroplasty or resulted in residual inferior humeral head osteophytes and humeral component size mismatch. The present technique demonstrates the possibility for surgeons to capitalize on the improved patient outcomes that are afforded by subscapularis-sparing approaches, while still utilizing the deltopectoral interval to perform a total glenohumeral joint arthroplasty. Methods This article describes in detail the placement of a stemless anatomic TSA with the use of angled glenoid instruments through a subscapularis-sparing deltopectoral approach. Postoperatively, patients are placed in a sling but are instructed to remove as tolerated, as early as the 1st postoperative week. Physical therapy is started at week 1 with a 4-phase progression. Conclusions This technique using a TSA system with a polyaxial glenoid reamer and angled pegs on the backside of the glenoid allows the potential for maintenance of the strong postoperative radiographic and patient-reported outcomes that are achieved using traditional TSA approaches, with the advantage of accelerated rehabilitation protocols and decreased risk of subscapularis insufficiency that result from the use of subscapularis-sparing approaches.

Early fixation of the humeral component in stemless total shoulder arthroplasty

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.

Onlay versus inlay humeral components in reverse shoulder arthroplasty: A systematic review and meta-analysis

Background Advances have been made to the traditional inlay Grammont Reverse Shoulder Arthroplasty (RSA) design such as the onlay humeral component prosthesis. Currently, there is no agreement in the literature regarding the best option for the humeral component when comparing inlay and onlay designs. This review compares the outcomes and complications between onlay versus inlay humeral components for RSA. Methods A literature search was conducted using PubMed and Embase. Only studies reporting outcomes comparing onlay versus inlay RSA humeral components were included. Results Four studies with 298 patients (306 shoulders) were included. Onlay humeral components were associated with better external rotation (ER) ( p < 0.0001). No significant difference in forward flexion (FF) or abduction was found. Constant scores (CS) and VAS scores did not differ. Increased scapular notching was found in the inlay group (23.18%) versus the onlay group (7.74%) ( p = 0.02). Postoperative scapular fractures and acromial fractures did not differ. Conclusion Onlay and inlay RSA designs are associated with improved postoperative range of motion (ROM). Onlay humeral designs may be associated with greater ER and lower rate of scapular notching; however, no difference was found in Constant and VAS scores, so further studies are required to assess the clinical significance of these differences.

Medialized versus Lateralized Center of Rotation in Reverse Total Shoulder Arthroplasty: A Systematic Review and Meta-Analysis

One of the original biomechanical principles of reverse total shoulder arthroplasty (RTSA) is medialization of the center of rotation (COR) relative to the native level of the glenoid. Several authors have proposed the lateralized center of rotation, which is characterized by a lateralized (L) glenoid and medialized (M) humeral component. The aim of this review is to compare the clinical and functional outcomes of COR in medialized (M-RTSA) and lateralized (L-RTSA) RTSA in patients with uniform indications and treatment through a meta-analysis. A PRISMA-guided literature search of PubMed, Medline, Embase, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Cochrane Clinical Answers was conducted from April to May 2021. Twenty-four studies were included in the qualitative synthesis, and 19 studies were included in the meta-analysis. Treatment with RTSA resulted in positive post-operative outcomes and low complication rates for both groups. Statistically relevant differences between L-RTSA group and M-RTSA group were found in post-operative improvement in external rotation with arm-at-side (20.4° and 8.3°, respectively), scapular notching rates (6.6% and 47.7%) and post-operative infection rates (1% and 7.7%). Both lateralized and medialized designs were shown to improve the postoperative outcomes. Nevertheless, a lateralized COR resulted in greater post-operative external rotation.

Current Concepts in Humeral Component Design for Anatomic and Reverse Shoulder Arthroplasty

The history of humeral component design has evolved from prostheses with relatively long stems and limited anatomic head options to a contemporary platform with short stems and stemless implants with shared instrumentation and the ability to provide optimal shoulder reconstruction for both anatomic and reverse configurations. Contemporary humeral components aim to preserve the bone, but they are potentially subject to malalignment. Modern components are expected to favorably load the humerus and minimize adverse bone reactions. Although there will likely continue to be further refinements in humeral component design, the next frontiers in primary shoulder arthroplasty will revolve around designing an optimal plan, including adequate soft tissue tension and providing computer-assisted tools for the accurate execution of the preoperative plan in the operating room.