Incidental findings on preoperative computed tomography for the planning of robotic arthroplasty: retrospective cohort study.

BACKGROUND: The use of robotically assisted arthroplasty has increased substantially in recent years. Some robotic platforms require preoperative computed tomography for surgical planning. These scans frequently include anatomical regions beyond the primary operative field, creating potential for incidental findings. Planning computed tomography is not formally reported routinely, raising the possibility that clinically relevant incidental findings may be overlooked. METHODS: The reports of all computed tomography performed for preoperative planning of robotically assisted arthroplasty at the authors' institution between October 2019 and February 2024 were reviewed retrospectively. Incidental findings were noted, and their clinical significance assessed. The notes of patients with significant findings were reviewed to ascertain the final diagnosis and management. RESULTS: A total of 1602 patients (mean age 66.8 years, median 68 (range 16-98) years; 847 women) were identified within the study period. Some 447 patients (27.9%) demonstrated incidental findings, 136 (8.5%) of which were significant, requiring further investigation or management. Eighty-six significant findings (5.4%) were suspicious for malignancy and, of these, five (0.3%) resulted in a new cancer diagnosis. CONCLUSION: In this study, the rate of significant incidental findings was 8.5% and the risk of discovery of previously undiagnosed malignancy was 0.3%. A new significant finding was demonstrated in 1 in every 12 patients, and a new cancer diagnosis in 1 in every 320 patients. Planning imaging for robotic arthroplasty should be reported by a radiologist to prevent significant findings and malignancy being missed.