Unlinked total elbow arthroplasty

For more than 60 years, total elbow arthroplasty (TEA) has been successfully used to treat a variety of elbow conditions. Although first designed to treat older patients with rheumatoid arthritis, the indications have expanded to include younger, higher-demand patients with a broad range of elbow pathology. Two groups of TEA currently exist. The first group includes linked or semiconstrained elbows with a mechanical connection between the humeral and ulnar components that prevents disassociation. These implants do not rely on muscular or ligamentous tissues for stability. The second group includes unlinked implants that have no physical connection between the humeral and ulnar components. They rely on bearing surface architecture as well as soft-tissue integrity for elbow stability. Critical to the success of unlinked implants is a thorough preoperative evaluation of elbow stability, including bone stock, collateral ligament integrity, and periarticular muscle function. Unlinked implants should apply less strain to the bone-cement-implant interfaces, which may theoretically decrease rates of bearing wear and aseptic loosening. For this reason, some surgeons prefer unlinked implants for younger, higher-demand patients. To date, unlinked implants have not been clinically shown to improve survivorship compared with linked devices. No prospective randomized trials comparing linked and unlinked TEAs are currently available. Historically, unlinked implants have had higher revision rates, mostly caused by instability and early design flaws. More recent series have shown no significant differences in outcomes compared with linked devices. Unlinked TEA provides reliable pain relief and improved range of motion for patients with a variety of elbow disorders. Diligent patient selection and careful surgical technique are of utmost importance when considering an unlinked TEA as a treatment option. The recent development of convertible implants now allows surgeons to make intraoperative decisions regarding elbow stability and convert to a linked implant without revising the stems.