Short-term clinical outcome of an anatomic short-stem humeral component in total shoulder arthroplasty

Abstract

Short-stem press-fit humeral components have recently been developed in an effort to preserve bone in total shoulder arthroplasty (TSA), but few studies have reported outcomes of these devices. The purpose of this study was to evaluate the short-term clinical outcomes of an anatomic short-stem humeral component in TSA. We hypothesized that the implant would lead to significant functional improvement with low rates of radiographic loosening. A multicenter retrospective review was performed of TSAs using an anatomic short-stem humeral component (Apex; Arthrex, Inc., Naples, FL, USA). The minimum follow-up was 2 years. Functional outcome was evaluated according to the American Shoulder and Elbow Surgeons score, Visual Analog Scale for pain, Single Assessment Numeric Evaluation, Simple Shoulder Test, and range of motion. A radiographic analysis was performed to evaluate component loosening. Sixty-four patients with a mean age of 64.1 years were available for follow-up at a mean of 25 months postoperatively. There were significant improvements in the Visual Analog Scale (6 to 2; P < .001), Simple Shoulder Test (4 to 10; P < .001), Single Assessment Numeric Evaluation (32 to 84; P < .001), and American Shoulder and Elbow Surgeons (37 to 80; P < .001) scores. Forward flexion improved from 116° to 148° (P < .001), external rotation improved from 30° to 57° (P < .001), and internal rotation improved from an average spinal level of S1 to L2 (P < .001). On radiographic examination, 9% of stems were deemed at risk for loosening, but there was no gross loosening in any patient. TSA with an anatomic press-fit short-stem humeral component is associated with significant improvements in clinical outcomes, without evidence of component loosening at short-term follow-up.