Sacroiliac joint cut accuracy: Comparing new technologies in an idealized sawbones model.

BACKGROUND AND OBJECTIVES: The anatomical complexity of the pelvis creates challenges for orthopaedic oncologists to accurately and safely resect tumors involving the sacroiliac joint. Current technology may help overcome these obstacles. METHODS: Four fellowship-trained orthopaedic oncologists performed 22 all-posterior sacroiliac cuts using freehand, computerized navigation, and patient-specific cutting guides on a Sawbones male pelvis model. Cut accuracies to preoperative planned margins were analyzed via a high-resolution optical scanner. Soft tissue damage was determined by visually inspecting the Sawbones foam placed on the far side of the cut. RESULTS: Within 5 mm of the margins, the freehand technique resulted in 67.0% cut accuracy, the navigation technique had 71.1%, and the patient-specific cutting guide technique had 85.6% (P = .093). Within 2 mm, the techniques showed an accuracy of 25.8%, 32.5%, and 47.5%, respectively (P = .022). Regarding soft tissue damage, the freehand technique exhibited minimal penetration damage for 16.7% of the cuts, while navigation and patient-specific guide techniques exhibited 25.0% and 75.0%, respectively (P = .046). Years of surgical experience of the operator (1-7) did not influence the cut accuracy for any method. CONCLUSIONS: Under ideal conditions, patient-specific guide technology possesses the same or better accuracy as other cutting techniques as well as the circumvention of soft tissue damage.