Lateral tilt wrist radiograph using the contralateral hand to position the wrist after volar plating of distal radius fractures.

摘要

PURPOSE: Lateral tilt (radially inclined) radiographs are useful after volar locked plate fixation of distal radius fractures to assess the radiocarpal joint, subchondral bone congruity, and volar tilt. The purpose of our study was to define the reliability of our positioning method using the patient's opposite hand to position the injured wrist to obtain an inclined lateral radiograph with good visualization of the subchondral bone. METHODS: A retrospective review identified adult patients who had a unilateral distal radius fracture treated with a volar locked plate and who had an initial postoperative lateral tilt radiograph using the contralateral hand to position the injured wrist. Intraoperative fluoroscopic images were reviewed to confirm the ability to see the extra-articular placement of all hardware. The inclined lateral wrist radiograph was obtained by positioning the injured wrist at a height determined by the contralateral hand being placed under the ulnar wrist crease. The wrist was then supported there with firm blocks in all cases. The radiographic beam was directed perpendicular to the horizontal cassette. Two reviewers (authors) then blindly reviewed postoperative radiographs to determine whether the radiocarpal joint and subchondral bone were visualized and whether any screws or pegs appeared to cross the radiocarpal joint. An acceptable lateral tilt radiograph was defined as good visualization of the subchondral bone while allowing only the most radial peg to appear to cross the joint. We also placed 15 normal volunteers into the lateral tilt position, using their opposite hand, to measure the inclined forearm angle. RESULTS: A total of 24 wrists (24 patients) were identified and 23 patients had lateral tilt radiographs with acceptable visualization of the subchondral bone. The concordance of the subchondral bone visualization was 100% (95% confidence interval, 85.5% to 100%). The mean angle with lateral tilt positioning was 18 degrees from horizontal (range, 15 degrees to 23 degrees; standard deviation, 2.4 degrees). CONCLUSIONS: Using the contralateral hand to position the lateral inclined view, our lateral tilt position produced radiographs with reliable visualization of the distal radius subchondral bone in 96% of our cases. Visualization of the subchondral bone in the region of the radial aspect of the scaphoid fossa requires more tilt than is achieved with this technique.