Feasibility study of a robot-assisted endoscopic technique for plate osteosyntheses of the acetabulum and anterior pelvic ring.

Abstract

Background: Minimally invasive stabilization of acetabular and pelvic ring fractures using endoscopic techniques has become increasingly important. The logical advancement of conventional endoscopic techniques is a robot-assisted approach, which benefits from the advantages of robot-assistance systems (e.g., more degrees of freedom for instruments and improved visualization). The aim was therefore to investigate the feasibility of a robot-assisted endoscopic technique for plate osteosyntheses of the acetabulum and anterior pelvic ring.

Materials and methods: In this two-part feasibility study, four different plate osteosyntheses were performed endoscopically using the Hugo™ robot-assisted surgery system, first on ten synthetic pelvic models and then on ten human cadavers. During robot-assisted dissection for the preperitoneal approach, identification of ten relevant anatomical landmarks was also assessed. In both parts, the success, number of drilling errors, and time for each plate were described as learning curves and analyzed using linear regression.

Results: The infrapectineal plate could be successfully performed in 100% of synthetic models, the posterior column plate in 100%, the suprapectineal plate in 90%, and the superior pubic ramus plate in 80%. Learning curves could be observed for the number of drilling errors per plate (e.g., 0.67 to 0, p = 0.009) and the time required, but they were mostly nonsignificant. In the ten human cadavers, all ten anatomical landmarks could be identified and all four plate osteosyntheses could be performed from the third attempt on (attempt 1: 6/10 landmarks, 3/4 plates; attempt 2: 7/10 landmarks, 3/4 plates). The time decreased for the superior pubic ramus plate (98 to 15 min, p = 0.002), suprapectineal plate (55 to 25 min, p = 0.013), infrapectineal plate (50 to 10 min, p = 0.004), and nonsignificantly for the posterior acetabular column plate (31 to 21 min). The average number of drilling errors per plate decreased nonsignificantly (1 to 0.5).

Conclusions: Plate osteosynthesis for the acetabulum and anterior pelvis is feasible using a robot-assisted endoscopic technique but is more time-consuming than using a conventional endoscopic technique and is associated with technical challenges, such as screw angulation. With the development of specialized instruments for pelvic trauma surgery, endoscopic and robot-assisted techniques will likely play a significant role in the future.

Level of evidence: Level 5.