Use of standard and anatomic-tilt lateral X-rays to determine distal radius volar angulation.

PURPOSE: To determine the reliability of measurements of distal radius volar tilt using either standard lateral or anatomic tilt lateral (ATL) radiographs, and to compare the mean values obtained using each radiographic method.

METHODS

We obtained standard and 23° ATL plain radiographs of the distal radii of 20 patients with a distal radius fracture treated with a volar locking plate, and of 20 healthy individuals without a history of fracture of the wrist. Three orthopedic surgeons measured volar tilt twice with an interval of 4 weeks. We analyzed intraobserver and interobserver reliability and compared intraobserver means of volar tilts obtained using standard and ATL radiographs.

RESULTS

The volar tilts measured using ATL radiographs in patients and healthy controls showed moderate to excellent intraobserver and interobserver reliability, whereas those determined using standard lateral radiographs showed poor to moderate intraobserver and interobserver reliability in patients and controls. However, the mean values of volar tilts measured in standard lateral radiographs and in ATL radiographs were similar in patients and not significantly different in healthy controls.

CONCLUSIONS

Volar tilt measurements obtained using anatomic tilt lateral radiographs provided moderate to excellent reliability. However, we found no statistically significant difference between volar tilts determined using ATL and standard lateral radiographs. Accordingly, standard lateral and ATL radiographs are interchangeable with respect to volar tilt measurements.

TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.