Clinical results and computed tomography analysis of intuitive shoulder arthroplasty (ISA) stemless at a minimum follow-up of 2 years

Background: The utilization of stemless anatomic total shoulder arthroplasty is on the rise. Epiphyseal fixation leads to radiological bone remodeling, which has been reported to exceed 40% in certain studies series. The aim of this study was to present the clinical and radiological outcomes of a stemless implant with asymmetric central epiphyseal fixation at an average follow-up of 31 months. Materials and methods: This retrospective multicenter study examined prospective data of patients undergoing total anatomic arthroplasty with intuitive shoulder arthroplasty Stemless implant and followed up at least 2 years. Clinical assessment included preoperative and final follow-up measurements of active range of motion, Constant score, and Subjective Shoulder Value. Anatomical epiphyseal reconstruction and bone remodeling at the 2-year follow-up were assessed by standardized computed tomography scanner (CT scan). Statistical analysis employed unpaired Student's t-test or chi-squared test depending on the variable type, conducted using Easy MedStat software. Results: Fifty patients (mean age 68 years, 62% females) were enrolled, with an average follow-up of 31 months (24-44). Primary osteoarthritis (68%) with type A glenoid (78%) was the prevailing indication. The mean Constant score and Subjective Shoulder Value improved significantly from 38 +/- 11 to 76 +/- 11 (P <.001) and from 31% +/- 16 to 88% +/- 15 (P < .001) respectively at the last follow-up. Forward elevation, external rotation, and internal rotation range of motion increased by 39 degrees +/- 42, 28 degrees +/- 21 and 3,2 +/- 2,5 points respectively, surpassing the Minimally Clinically Important Difference after total shoulder arthroplasty. No revisionswere necessary. CT scans identified 30% osteolysis in the posterior-medial calcar region, devoid of clinical repercussions. No risk factors were associated with bone osteolysis. Conclusions: At an average follow-up of 31 months, intuitive shoulder arthroplasty Stemless implant provided favorable clinical results. CT analysis revealed osteolysis-like remodeling in the posterior-medial zone of the calcar (30%), without decline in clinical outcomes and revisions. Long-term follow-up studies are mandated to evaluate whether osteolysis is associated with negative consequences.