Anatomic total shoulder arthroplasty using a stem-free ellipsoid humeral implant in patients of all ages

Abstract

Background: Stem-free shoulder arthroplasty has recently been shown to have comparable results to stemmed arthroplasty, though stemless designs are typically used in a younger patient population. Additionally, although the native humeral head is elliptical in shape, clinical results with ellipsoid implants in shoulder arthroplasty have not been reported on previously. This case series reports on the outcomes of a recently introduced anatomic total shoulder arthroplasty with an ellipsoid-shaped articular surface and unique multiplanar platform type of stemless fixation. Methods: This retrospective case series examines the initial cohort of patients who received an anatomic total shoulder arthroplasty using an ellipsoid stem-free humeral prosthesis and an all-polyethylene glenoid component from the Catalyst CSR Total Shoulder System (Catalyst OrthoScience) over a 1-year period. Inclusion criteria were patients with a diagnosis of advanced glenohumeral joint arthritis with an intact rotator cuff, regardless of patient age. Clinical outcomes including shoulder range of motion and patientreported outcome measures, as well as radiographs, were evaluated at multiple time points postoperatively, with minimum 2-year follow-up. Results: Sixty-three shoulders in 57 patients with a mean age of 73.0 years (range 60-85 years) were included in the study with a mean follow-up period of 30.5 months (range 24-41 months). Forward elevation improved from 121 to 150 (P < .0001), external rotation improved from 28 to 48 (P < .0001), and internal rotation improved from L3 to L1 (P < .001). There were statistically significant improvements exceeding the minimal clinically important difference (MCID) in the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score (37 to 94, P <.001), Single Assessment Numeric Evaluation (SANE) (40 to 93, P <.001), visual analog scale (6.3 to 0.4, P < .001), and Patient-Reported Outcomes Measurement Information System physical domain T score (44 to 57, P < .001). The improvement in the ASES score also exceeded the threshold for the substantial clinical benefit. Age, sex, and preoperative glenoid morphology did not appear to have an effect on the clinical outcome scores. There were no implant failures or evidence of radiographic loosening of the humerus component in any patients. Conclusion: At 2-year minimum follow-up, this stem-free ellipsoid humerus total shoulder arthroplasty provides very good results with high patient satisfaction, clinical improvement in all outcome measures studied, and no signs of loosening.This study was reviewed by the Western Institutional Review Board IRB Affairs Department (IRB no. 1-1231172-1) and it was found that this research met the requirements for a waiver of consent under 45 CFR x 46.104(d)(4).

Concordance of Preoperative 3D Templating in Stemless Anatomic Total Shoulder Arthroplasty

“…Finally, it is possible that noneccentricity of the humeral head implants in stemless TSA provide fewer options to adjust for variable humeral anatomy. 37,38…”

“…Finally, it is possible that noneccentricity of the humeral head implants in stemless TSA provide fewer options to adjust for variable humeral anatomy. 37,38 Of note, sex displayed a trend toward significance with both overall implant size and concordance, although a larger cohort would be needed to establish statistical significance with adequate statistical power (Table 6). Across all implants, there was a higher concordance for female patients than male patients, possibly reflecting either a wider variation in native anatomy among male patients or a bottleneck of available implant sizes.…”

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

“…The TSA system utilized in this technique has been previously shown in both clinical and cadaveric studies to result in accurate humeral head placement and sizing through the use of precision multiplanar humeral osteotomy technology [ 21 , 22 ]. More importantly, however, is the utilization of angled glenoid instruments in this system.…”

Stemless anatomic total shoulder arthroplasty: surgical technique and review of the literature

“…Most studies in the United States include mainly younger patients. However, a recent study by Goldberg et al 13 evaluates whether stemless humeral implant (CoCr ellipsoid humerus) can be safely employed in patients of more advanced age. This series included 57 patients with a mean age of 73 years and a minimum follow-up of 2 years.…”