Mixed reality guidance enhances and levels the accuracy of glenoid preparation pin positioning in shoulder arthroplasty between experienced and junior surgeons.

Purpose: The potential of mixed reality to improve the accuracy of glenoid preparation pin positioning in shoulder arthroplasty has been previously reported. Another benefit of mixed reality may be its ability to assist junior surgeons in enhancing their precision during prosthetic procedures. The aim of this study was to evaluate and compare the accuracy of glenoid preparation pin positioning between a senior surgeon and a junior surgeon utilizing mixed reality guidance. The hypothesis of this study was that mixed reality would equalize surgical accuracy between operators of different experience levels.

Methods: An experienced senior surgeon and a novice junior surgeon each aimed to position a glenoid preparation pin, first freehand and then using a mixed reality guidance solution (Blue Mixed Reality Guidance™, Stryker), on 15 and 30 3D-printed scapula specimens, respectively (10 Type A and 10 Type B according to Walch, and 10 Type E according to Favard), which were pre-planned with dedicated software (Blueprint Planning™, Stryker). The accuracy of the entry point and orientation of the glenoid pin post-surgery, without and with mixed reality guidance, was evaluated and compared between the two operators.

Results: Without mixed reality, there was no significant difference between the two surgeons regarding entry point accuracy (p = 0.8) and pin orientation (p > 0.05). However, there was an important median positional discrepancy for version and inclination, measuring 17 ± 12° and 20 ± 13° for the junior surgeon, compared to 9 ± 8° for version and inclination for the senior surgeon. With mixed reality guidance, no significant differences were observed in inclination, version, or positioning along the antero-posterior and supero-inferior axes of the pin between the two surgeons. Nevertheless, the junior surgeon demonstrated greater accuracy for the overall entry point of the pin, with a median positional discrepancy of 1.39 ± 1.04 mm versus 2.10 ± 0.86 mm (p = 0.02). There were no significant differences in accuracy between the two surgeons based on glenoid type, except for the overall entry point of Type A glenoids, where the junior surgeon was more precise (p = 0.02), as well as for the antero-superior axis (p = 0.01).

Conclusion: The use of mixed reality improves and levels the accuracy of positioning and orientation of a glenoid guide pin in arthritic glenoids between two surgeons of different experience levels.

Level of evidence: III; experimental non-randomized comparative study.