The Robotic Surgical Assistant system consists of two units: one corresponds to the robotic arm and the other to the optical unit, which includes an infrared camera mounted on a separate arm.
This setup enables communication with the optical markers implanted in the patient’s humerus and coracoid. Operating in a semi-active mode, the robot assists in both humeral and glenoid preparation through three modes: automatic, collaborative, and static. In automatic mode, the robot positions the arm in the surgical area. Once in place, it switches to collaborative mode, allowing the surgeon to move the arm within the limits established in the surgical plan. After the final position is determined, the robot transitions to static mode to perform precise cuts or reaming.
Humeral head resection is performed through robotic positioning of an extramedullary cutting guide, whose final position is adjusted in collaborative mode. The robotic arm controls the cut guide along the plane of the planned resection and the guide is then secured to the humerus with pins. The robot is then placed in static mode and the humeral cut is performed through this guide at the planned version, inclination, and height. The cut surface of the humerus is then validated to confirm appropriate resection of the humeral head. Following validation the remainder of the humeral preparation including reaming and broaching is performed manually.
Glenoid preparation is performed with a conventional reamer attached to the robotic arm that is powered by a standard cordless reamer. This allows glenoid reaming, controlled by the robot with live tracking in collaborative mode, to the desired version, inclination, and depth. Bone preparation for aTSA involves two robotic controlled steps. The first reamer prepares the face of the glenoid to the correct version, inclination and depth. The second prepares the central hole for the hybrid glenoid central post. The remaining glenoid preparation for the implant performed manually. In RSA the glenoid is prepared in a single step ream for the glenoid face and central boss with the robot controlling the version, inclination and depth in collaborative mode.
The steps include
Humeral clamp placement on the proximal humerus
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
Robotic insertion of the humeral cut guide
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
The authors provided videos of this technique
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
Coracoid array tracker secured on the coracoid process using two pins.
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
Glenoid registration across various landmarks using the probe.
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
Robotic assisted glenoid reaming using an implant specific reamer mounted on the robotic arm.
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
A trial reduction is performed to assess and optimize soft tissue tension and range of motion. While robotic implantation accurately executes pre-operative planning based on the CT scan anatomy, which can assist in soft tissue balancing, intraoperative adjustments may be necessary to achieve optimal soft tissue balance.
Postoperative radiograph of a RSA with humeral and glenoid based robotic preparation.
Reproduced from Marigi et al., JSES Reviews, Reports & Techniques, 2026, under CC BY-NC-ND 4.0
The ROSA system is reported to cost between $1,000,000 and $1,500,000. As the authors point out, “The disadvantages associated with the implementation of robotic-assisted SA are not limited solely to the costs involved. This surgery will entail a steep learning curve for surgeons already accustomed to other techniques, and it could also introduce a cognitive bias in trainee surgeons. Furthermore, in centers that do not yet have the robot, it will be necessary to modify operating rooms to provide sufficient space for the installation of the robotic unit.”
Robotics is a technology to transfer a preoperative plan to the patient. Thus, this technique guide is not expected to present data on the efficacy of a robotic approach in optimizing component positioning (What Reverse Total Shoulder Geometry Will Give My Patient the Best Function and Lowest Complication Risk?)
This technique guide is not expected to present data on the value of robotics to the patient in terms of comfort, function, and reduced revision rate.
In his recent article, Robot-assisted shoulder arthroplasty Sanchez-Sotelo opined: “The main theoretical benefits of robot-assisted shoulder arthroplasty include accuracy and precision, data acquisition, and with certain robots, the promise to avoid soft-tissue injury with haptic boundaries, prepare a bone through minimally invasive or cuff-preserving exposures, and the potential for motion assessment and soft-tissue balance. The disadvantages include cost, a certain learning curve, complications related to array insertion, potential for cognitive bias, need for a larger operating room space, and the potential for malfunction. Although adoption is likely to happen in many centers, cost and space constrains may favor alternative technologies, such as mixed reality navigation, especially in ambulatory surgery centers.”
When openevidence.com was asked “does robotic-assistance improve patient reported outcomes for anatomic or reverse shoulder arthroplasty?“, it concluded “There is currently no clinical evidence that robotic arthroplasty improves patient-reported outcomes for anatomic or reverse shoulder arthroplasty”.
Let’s think on this a bit.
Great-horned Owl
Seattle
2021
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