Mixed reality with real-time navigation grants low deviations from planned inclination and version of the glenoid for...

Correct glenoid version and inclination can limit scapular notching, instability, and glenoid loosening in reverse total shoulder arthroplasty (rTSA). Traditionally, planned trajectories were displayed on a screen close to the operating table and reproduced freehand intraoperatively. Mixed reality planning has emerged, using superimposition of the scapular hologram on the patient's glenoid, with intended trajectories and real-time navigation to provide more accurate guidance. The purpose was to assess the implant version and inclination in rTSA using mixed reality with navigation.

The authors retrospectively assessed a series of 45 shoulders that underwent rTSA using mixed reality with navigation using a head-mounted display. Computed tomography scans were acquired for each shoulder and imported into Shoulder+ to plan the rTSA and define the target inclination and version. The head-mounted display was used to display an interactive hologram over the operative site to navigate the guidewire. Pre-operative and 6-month post-operative scans were performed, and version and inclination of the implant were measured.

The final cohort comprised 35 shoulders, aged 75.5 ± 7.3 years. Additional operative time was 10.1 ± 2.5 minutes. The absolute deviation between post-operative and planned version was 2.8° ± 2.0 (P < .001), and the absolute deviation between post-operative and intraoperative version was 2.9° ± 2.1 (P = .003). The absolute deviation between post-operative and planned inclination was 4.6° ± 4.6 (P = .154), and the absolute deviation between post-operative and intraoperative inclination was 4.3° ± 4.3 (P = .074).

rTSA with mixed reality navigation enables accurate glenoid implant positioning, with minimal deviations from planning. However, surgeons should be aware of the additional time required.