Intraoperative O-arm-navigated resection in musculoskeletal tumors

Background: Although emerging evidence has suggested that computer-assisted navigation allows surgeons to plan the optimal level of resection without compromising the surgical margins, the precise accuracy of the procedures has been unclear. The aim of this study was to investigate the accuracy and safety of the musculoskeletal tumor resection using O-arm/Stealth intraoperative navigation assistance. Methods: A retrospective study of six patients with bone and soft tissue tumors who underwent surgical resection using O-arm/Stealth navigation system was performed. The histological diagnosis was osteosarcoma, metastatic bone tumor, leiomyosarcoma, undifferentiated sarcoma, and synovial sarcoma, respectively. Tumor resection was performed according to planned osteotomy planes determined on O-arm/Stealth three-dimensional intraoperative images. The resection accuracy, length of time for the procedures, surgical margins, and perioperative complications were evaluated. Results: The distances between the entry and exit points for the planned and actual cuts were 1.5 ± 0.3 mm and 2.3 ± 0.3 mm, respectively, and the mean discrepancy of the osteotomy angle was 2.8 ± 1.2°. The mean length of time required for navigation was 14 min. A histological examination revealed clear margins in all patients. There were no complications related to navigation, and no patients developed local recurrence during a mean follow-up of 30.6 months. Conclusions: The O-arm/Stealth intraoperative CT navigation system provides safe and accurate osteotomy in musculoskeletal tumor resections. However, surgeons should keep in mind and be careful of minimal errors during osteotomy, which are around 2 mm from the planned line.