Summary

One-leg flexion view expresses more narrowing of the tibiofemoral joint space

Abstract

Background

Osteoarthritis of the knee is one of the diseases seen in the orthopedic department. The severity of tibiofemoral joint space narrowing is used for grading the disease. Many have proposed different radiograph positions aside from knee AP radiograph to assess the degree of joint space narrowing, such as the Rosenberg view or one-leg standing AP view. So far, there has been no evaluation of the “one-leg flexion view”, which may have shown more prominent narrowing from the effect of weight bearing from standing on one-leg and 45 degrees of knee flexion.

Objective

To evaluate tibiofemoral joint space from one-leg flexion view radiograph and compared to both legs standing AP view, one-leg standing AP view, and Rosenberg view.

Study Design & Method
200 knees (100 patients) with the diagnosis of knee osteoarthritis underwent radiography of both legs standing AP, one-leg standing AP, Rosenberg view, and “one-leg flexion”. The medial (MTF) and lateral tibiofemoral joint space (LTF) of these radiographs were measured. Differences and concordance coefficient correlation have been calculated.

Results

The average MTF of one-leg flexion view, Rosenberg view, one-leg standing, and both legs standing AP are 4.32, 4.50, 4.46, and 4.78 mm respectively. The mean LTF of one-leg flexion view, Rosenberg view, one-leg standing, and both legs standing AP are 6.08, 6.17, 6.62, and 6.51 mm respectively. The MTF is significantly greater in both legs standing AP view when compared to the one-leg flexion and one-leg standing film. Both the one-leg flexion view and Rosenberg view show a statistically lower LTF when compared to one-leg standing and both legs AP view. There is a correlation between the LTF and the degree of genu varus, while there is no correlation for the one-leg flexion view.

Conclusion

The one-leg flexion view expresses better MTF and LTF narrowing when compared to other views. This view could be useful for detecting early joint space narrowing of the knee.