Tomosynthesis Is Equivalent to Computed Tomography for Evaluating Osseous Integration After Anterior Cruciate Ligament Reconstruction

Abstract

Purpose: To compare tomosynthesis and computed tomography (CT) for evaluating bone plug integration after anterior cruciate ligament (ACL) reconstruction with a bone–patellar tendon–bone (BPTB) graft. Methods: Data of consecutive adult patients who underwent ACL reconstruction with BPTB were analyzed. Bone integration between the bone plug and bone tunnel was evaluated by tomosynthesis and CT, which were both performed 3 months postoperatively. The obtained data for both modalities were reconstructed with slice thickness of 2 mm. Evaluation of bone integration were separately performed using coronal- and sagittal-reconstructed images for the femur and tibia. The ratio of bone integration between the reconstructed slices in which bone grafting was involved, for both tomosynthesis and CT, was investigated by 2 blinded examiners. The equivalence of tomosynthesis to CT was tested by comparing the bone integration ratio for both modalities. The accuracy of diagnosing bone union using tomosynthesis and CT was also investigated. Results: The diagnostic accuracy of tomosynthesis and CT exceeded 80%. Interobserver agreement of bone integration in the sagittal plane on the femoral side was 0.92 (intraclass correlation coefficient) for CT and 0.76 (intraclass correlation coefficient) for tomosynthesis. Conclusions: Although it showed poor reliability, tomosynthesis was equivalent to CT in evaluating bone plug integration after ACL reconstruction with BPTB. Level of Evidence: Level II, diagnostic study.