Human-Robot Collaboration (HRC) in surgery is often framed as a dyadic interaction between a surgeon and a robot. Such a focus on interactivity can narrow analytic attention, sidelining the often unseen coordination that makes robotic surgery workable across the wider surgical team. We surface the everyday practices of the Mako Product Specialist (MPS), a vendor-mandated support role embedded in Mako-assisted robotic surgeries. Drawing on ten expert interviews, supplemented by in-theatre observations, we identify three categories of specialist work: Supporting Makoplasty, Shouldering Makoplasty, and Sustaining Makoplasty. Across these categories, we show how specialist mediation sustains co-located surgical HRC through articulation work, boundary work, and translation-and-repair work that stabilises tempo, maintains legibility, and enables breakdown recovery under sterile and infrastructural constraints. These findings extend ensemble accounts of surgical HRC and motivate the design of robotic systems for ensembles rather than a single primary user.

Human-Robot Collaboration (HRC) in surgery is rarely a straightforward interaction between one human and one robot. In joint replacement surgeries performed with the Mako robot (Makoplasty), the robotic arm enhances surgical precision while also affecting how collaboration unfolds in the operating theater. Utilizing over 80 hours of hospital-based fieldwork, including observations of 15 Makoplasty surgeries and 10 interviews, we examine how the Mako robot shapes surgical HRC. We demonstrate how surgical teams coordinate via tacit cues, negotiated boundaries, and adaptive role shifts across phases of operation. Through vignettes, we highlight the pivotal role of supporting actors, such as nurses and robotic specialists, in maintaining flow and reveal how responsibility is distributed temporally among actors depending on task demands. We argue that surgical HRC is best understood as a multi-actor choreography rather than a surgeon-robot dyad, offering design implications for co-located surgical HRC systems that support distributed collaboration.

This paper presents a preliminary investigation of the human factors underpinning successful Human-Robot Collaboration (HRC) in Mako-assisted Total Knee Arthroplasty (TKA) surgeries. This investigation is critical because most prior studies on human factors in Robot-Assisted Surgeries (RAS) have focused on the da Vinci surgical robot, a teleoperated robot. It could be valuable to identify what human factors might enhance or restrict HRC in Mako-assisted surgeries. We analyzed six surgical videos demonstrating how the Mako is utilized in TKA surgeries. We performed visual and thematic analyses. The findings indicate that the Mako system improves communication through the different screens in the operation theatre. These screens promote collaboration by visually sharing relevant information with all team members. Mako-assisted surgeries also introduce several challenges related to workflow disruptions. Future work aims to compare the insights of this study with other types of Mako-assisted surgeries.