Exploring Stemless Implants for RSA: A Conversation with Dr. Peter Johnston
Editor’s note: During the upcoming Critical Concepts in Shoulder & Elbow Surgery course, Dr. Peter Johnston will discuss Stemless Reverse Considerations. We asked Dr. Johnston to preview the key points of this talk.
FORE, the Foundation for Orthopaedic Research and Education: One of your presentations will address the use of stemless implants in reverse shoulder arthroplasty. Why is this an important topic to include in the agenda for Critical Concepts in Shoulder & Elbow Surgery?
Peter S. Johnston, MD: Stemless reverse shoulder arthroplasty is an evolving technology that is not currently approved by the US Food and Drug Administration (FDA). Investigational device exemption (IDE) studies are in process to evaluate both the safety and efficacy of these implants and their potential role in treating patients in the US who are candidates for a reverse procedure.
Several arthroplasty platforms offer the ability to convert a stemless hemiarthroplasty or anatomic arthroplasty to a stemless reverse in the setting of failed arthroplasty. The exact indications for stemless reverse shoulder arthroplasty are yet to be elucidated; however, given the comprehensive nature of the Critical Concepts in Shoulder & Elbow Surgery course, this topic fits really well into the agenda and dialogue.
FORE: What are your indications for using a stemless implant? How about contraindications?
Dr. Johnston: I will preface this response by again stating that the use of a stemless implant in reverse total shoulder arthroplasty is not currently approved by the FDA.
My preferred arthroplasty system has the option to convert to a stemless reverse, with my indications including malunion from fracture sequelae, other post-traumatic or genetic deformity, and extensive avascular necrosis preventing the use of a short or traditional long-stemmed implant.
Contraindications in these scenarios include poor bone quality unsuited to support a stemless implant and severe osteonecrosis not amenable to bony ingrowth onto the implant.
FORE: What are some of the advantages of using a stemless implant versus a stemmed implant in a reverse procedure? And the drawbacks? How do outcomes compare?
Dr. Johnston: My current indications for stemless reverse shoulder arthroplasty are very specific and demonstrate the real advantages of a stemless implant in this small subset of patients. The advantages are similar to those of a stemless anatomic arthroplasty, in that it provides bony preservation and decreased surgical preparation time, with theoretic advantages including decreased blood loss and reduced risk of periprosthetic humeral fracture.
Drawbacks at this point are being defined in IDE studies but include implant migration, frank loosening, and calcar fracture requiring conversion to a stemmed implant.
Short-term outcomes are largely comparable to stemmed implants, although longer-term data will guide us on the indications and technique for stemless reverse shoulder arthroplasty.
FORE: What are the key points you want attendees to take away from your presentation?
Dr. Johnston: Attendees need to keep these 5 points in mind:
- Stemless reverse shoulder arthroplasty is not currently approved by the FDA.
- Surgeons need to identify specific indications for use in their practice; this is not for every patient.
- Identify an arthroplasty platform that supports convertibility to a stemless reverse implant.
- Surgical technique is key.
- Longer-term data are necessary.
ABOUT THE EXPERT
Peter S. Johnston, MD, is a board-certified shoulder and elbow specialist at the Centers for Advanced Orthopaedics, Southern Maryland Orthopaedics and Sports Medicine, in Leonardtown, Maryland. He is also an Assistant Clinical Professor of Orthopaedic Surgery at Georgetown University Department of Orthopaedic Surgery in Washington, DC, and he is on the faculty of the Medstar Union Memorial Shoulder and Elbow Fellowship. His research interests include the management of proximal humerus and clavicle fractures, treatment of massive rotator cuff tears, shoulder replacement with glenoid bone loss, and the management of shoulder arthritis in younger patients.
ABOUT THE COURSE
Dr. Johnston is among the 29 faculty members of the completely redesigned Critical Concepts in Shoulder & Elbow Surgery, taking place November 14-16, 2024, at FIVE Labs Las Vegas.
This is the only course where you’ll learn how to do shoulder and elbow procedures by actually doing them. We aren’t going to tell you how to address a rotator cuff tear, or tackle shoulder instability, or expose the glenoid and humerus for anatomic shoulder replacement. We’re going to show you, and then we’re going to coach you as you perform the techniques on anatomic specimens in our brand-new, state-of-the-art bioskills lab.
Click here for more information and to register for the course.