Ian Byram, MD
The authors of this study present a series of 47 total shoulder arthroplasties performed with trabecular metal-backed glenoid components, reporting radiographic and clinical outcomes at an average follow-up of 41 months. The operative technique described involved placement of a trabecular metal peg-keel construct, with the vast majority placed in an uncemented, press-fit fashion. The authors noted that this method of implantation is not approved by the FDA, but this technique is “acceptable practice.” Patients were placed into a sling for four weeks and external rotation was limited for six weeks.
Five of the 47 patients (11%) underwent revision to reverse TSA for rotator cuff failure at an average of 12 months postoperative and were not included in the radiographic analysis. Despite excluding these patients, the authors still report an alarming rate of metal debris and osteolysis (25%) with one catastrophic failure at a minimum of two years follow-up. Notably, the majority of patients with radiographic changes were asymptomatic. For all revisions in this series, the authors note the “substantial central bone loss” in the glenoid vault, requiring bone grafting for reverse baseplate implantation. As a result of the high rate of metallic debris and osteolysis, the authors have discontinued the use of the trabecular metal glenoid.
“The authors still report an alarming rate of metal debris and osteolysis (25%) with one catastrophic failure at a minimum of two years follow-up.
For a short period of time in my practice, I utilized this same trabecular metal backed glenoid. Preparation for this implant requires perpendicular glenoid exposure and removal of bone from the central glenoid vault in a cross shape with a series of drill holes and punches. In my experience revising this implant, I also have noted severe central bone loss requiring bone grafting and occasional staged reconstruction.
Similar to the authors of this study, I had one catastrophic failure in a 50 year old male with normal bone density and no comorbidities. Continue reading