Do non-weight-bearing knee radiographs for chronic knee pain result in increased follow-up imaging?

Abstract

While weight-bearing radiographs are considered the optimal method for evaluation of joint spaces in osteoarthritis, non-weight-bearing radiographs are often performed. The purpose of this study is to evaluate the rate of follow-up radiographs in patients receiving non-weight-bearing radiographs for chronic knee pain in the outpatient setting, compared with patients receiving weight-bearing radiographs. Consecutive patients who received non-weight-bearing knee radiographs for chronic knee pain between January 1, 2018, and June 15, 2019, were included. Exclusion criteria included trauma, concern for infection or tumor, and post-surgical radiographs. An age- and sex-matched control group of 100 patients who received weight-bearing knee radiographs was compiled. The proportion of follow-up radiographs within 1 year was compared between the study and control groups with chi-squared tests. Four hundred non-weight-bearing knee radiographic examinations were included. There were 74/400 (18.5%) follow-up radiographs within 12 months. All follow-up radiographs were weight-bearing. In the control group, 4/100 (4%) had follow-up weight-bearing radiographs within 1 year (p < 0.001). Outpatients who underwent non-weight-bearing knee radiographs for chronic pain had a higher frequency of repeat imaging than those who initially underwent weight-bearing knee radiographs. These results suggest that non-weight-bearing knee radiographs are of lower clinical utility compared with weight-bearing radiographs.