Two-year follow-up of a novel fully 3D-printed off-the-shelf humeral total shoulder arthroplasty prosthesis

Background: The purpose of this study was to provide 2-year post-operative clinical outcomes and survivorship of a novel, fully 3D-printed humeral prosthesis. Methods: This is a prospective case series of 34 patients who underwent anatomic total shoulder arthroplasty (TSA) with a fully 3D-printed humeral prosthesis. Minimum post-operative follow-up was two years. Patient demographics, clinical outcomes, and radiographic outcomes were collected. X-rays were examined for radiolucent lines surrounding the implant. The primary outcome was TSA survivorship. Secondary outcomes were patient-reported outcome measure (PROM) scores and radiographic findings. The rate of any periprosthetic radiolucent line on X-ray was 2 of 34 (6%). All identified radiolucent lines were <0.5 mm. Discussion: The results of early clinical follow-up of this fully 3D-printed, off-the-shelf humeral prosthetic are encouraging. Post-operative radiolucent lines appear to be minimal in thickness, infrequent, and of unclear clinical significance given 100% survivorship and reassuring PROMs. Further clinical follow-up of this and other 3D-printed systems is necessary to confirm that additive manufacturing is a mechanically durable and viable method for off-the-shelf TSA manufacturing.