How GPS Navigation for Shoulder Arthroplasty Changed My Practice

Scott Trenhaile, MD 

As I look back on my career in orthopaedics, the journey has not been one that I would have ever predicted. I completed a sports medicine/upper extremity fellowship in orthopaedic surgery in 2002, which gave me the tools I needed at the time to better care for my patients; but, after 19 years in practice, I have found that one of the most fascinating things about time is that it changes you. Hopefully for the better. I love technology and innovation, and one of the most profound advancements in my time in practice has been GPS navigation for shoulder arthroplasty.  

In the beginning, my practice was primarily sports medicine, and therefore, I did a small number of shoulder arthroplasties. Over the years my upper extremity focus has grown to include shoulder reconstruction. And with increasing volume brings increasing complexity of cases, revisions and new challenges. As I started tackling more and more difficult cases, I started asking myself the question, “Should I be doing these cases?”; and more importantly, “Are these cases technically feasible to do intraoperatively?” 

In my opinion, the fear of the unknown sometimes drives surgeons to make the decision of whether they can help a patient with surgical intervention. I turned to technology to answer many of the technical questions I didn’t know the answer to, such as, “Can I get this implant into this patient’s bone, and will it perform as it should to accomplish the task at hand?” 

The best solution I could find to help steer through the unknown was GPS navigation for shoulder arthroplasty because it provides me with critical anatomic measurements needed to answer the question, “Can this case technically be done?” Then, I must also answer the question, “Should I do it?” My first GPS case was on a patient who I told for years ̶ reverse shoulder arthroplasty was not an option due to extensive bone loss. I was wrong. I quickly gained confidence in the system and began helping patients that otherwise wouldn’t have been helped in my practice prior to having access to GPS.  

The way I think about shoulder arthroplasty has changed as well. I have found that doing a pre-plan for patients can uncover surprises that happen preoperatively not intraoperatively. It’s such a great comfort to know that I can explore different possibilities of implants on a computer-generated model and never touch the patient. I feel more prepared and more confident in every case. I also have the ability to make minor deviations from the plan as I see fit with real-time feedback. GPS is time neutral in my hands.1-3 It also assists in cases with difficult exposure by eliminating guides and wires. 

The short-term benefits are obvious: my post-operative radiographs give me confidence that I accurately achieved my plan. Do we need to use it on everyone? At this point, it is unclear. I would argue that GPS navigation for shoulder arthroplasty has been shown to improve accuracy and minimize potential risks like cage perforation,4-6 and it gives surgeons peace of mind. You don’t know what you are missing until you try it! 


  1. Flurin, P-H., et al. Accuracy and Precision of the Use of Navigation in Shoulder Arthroplasty. International Congress on Shoulder and Elbow Surgery. Buenos Aires, Argentina: 2019. 
  2. Wang AW, et al. Computer navigation of the glenoid component in reverse total shoulder arthroplasty: a clinical trial to evaluate the learning curve. J Shoulder Elbow Surg. 2020 Mar;29(3):617-623. doi: 10.1016/j.jse.2019.08.012. Epub 2019 Oct 21.  
  3. Rosenthal Y, et al. Impact of preoperative 3-dimensional planning and intraoperative navigation of shoulder arthroplasty on implant selection and operative time: a single surgeon’s experience. J Shoulder Elbow Surg. 2020 Dec;29(12):2564-2570. doi: 10.1016/j.jse.2020.03.041. Epub 2020 Jun 9.  
  4. Nashikkar PS, et al. Role of intraoperative navigation in the fixation of the glenoid component in reverse total shoulder arthroplasty: a clinical case-control study. J Shoulder Elbow Surg. 2019 Sep;28(9):1685-1691. doi: 10.1016/j.jse.2019.03.013. Epub 2019 Jun 28.  
  5. Nashikkar PS, et al. Computer navigation re-creates planned glenoid placement and reduces correction variability in total shoulder arthroplasty: an in vivo case-control study. J Shoulder Elbow Surg. 2019 Dec;28(12):e398-e409. doi: 10.1016/j.jse.2019.04.037. Epub 2019 Jul 26. 
  6. Schoch BS, et al. Computer navigation leads to more accurate glenoid targeting during total shoulder arthroplasty compared with 3-dimensional preoperative planning alone. J Shoulder Elbow Surg. 2020 Nov;29(11):2257-2263. doi: 10.1016/j.jse.2020.03.014. Epub 2020 Jun 9.  


Scott Trenhaile, MD, practices at Rockford Orthopedic Associates. He is a faculty member at University of Illinois College of Medicine, Midwestern University and Rush University Medical Center. Dr. Trenhaile completed his internship and residency at St. Luke’s-Roosevelt Hospital Center/Columbia University and his fellowship at Mississippi Sports Medicine and Orthopaedic Center. 

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