Intraoperative fluoroscopy improves surgical precision in conventional TKA

PURPOSE: The purpose of this study was to assess whether intraoperative fluoroscopy assists in the restoration of the coronal limb alignment target in conventional total knee arthroplasty (TKA). METHODS: One hundred and six patients undergoing conventional cemented TKA were randomly assigned to be operated on with or without intraoperative fluoroscopy. The image intensifier, together with customized manual instrumentation, was used for separately measuring the frontal alignment of the femoral and tibial resection surfaces. The surgeon adjusted the resection surfaces when a mechanical axis deviation error angle of ≥0.5° was observed on the fluoroscopic image. Coronal alignment was measured on standing long-leg digital radiographs. RESULTS: Patients operated with fluoroscopy assistance had (1) a lower risk of malalignment at the threshold of >3° (risk ratio, 0.7; 95 % CI, 0.13–1.2), (2) a mean fluoroscopic time of 3 s, and (3) a longer operative time (69 vs. 60 min, p < 0.001). The American Knee Society Score was not different between the two groups at 1-year follow-up. CONCLUSION: This new surgical intervention appears to offer an effective means for improving the precision of TKA alignment in the coronal plane. LEVEL OF EVIDENCE: Randomized clinical study, therapeutic study, Level I.