Cost-effectiveness of immediate postoperative radiographs after uncomplicated total knee arthroplasty: a retrospective and prospective study of 750 patients.

We have questioned the value of postoperative radiographs after uncomplicated, primary total knee arthroplasty (TKA). A total of 750 patients were included in this 2-part study. In the first part, we retrospectively reviewed 200 consecutive, primary TKAs to determine if the immediate postoperative radiographs offered any information that altered the clinical course or if these radiographs could serve as baselines for future images. In the second part, 550 patients who underwent an uncomplicated TKA had their first postoperative radiographs taken at the initial visit. These patients were followed prospectively until the 6-week follow-up appointment to determine if any events occurred in which predischarge radiographs would have been useful as a comparison study. Of the 200 patients who underwent a primary TKA, 192 had postoperative radiographs performed before discharge. Among the 192 patients, the radiographs did not alter the postoperative management. In examining overall quality of the radiographs, only 36% were of sufficient quality to provide an accurate baseline for further studies. Total cost was approximately $36,000. In the 550 patients who had the first postoperative radiograph performed at 6 weeks, there were no instances in which radiographs taken before discharge were needed to aid in further management or legal defense. As with total hip arthroplasty, the past standard has been to obtain immediate postoperative radiographs after primary TKA. Although the information obtained in a total hip arthroplasty patient can be clinically important, the practice of obtaining routine, immediate postoperative knee radiographs in the absence of a specific clinical indication does not provide any additional clinical information and does not appear to benefit patient care.