Relationships between tibial rim alignment and joint space width measurement reproducibility in non-fluoroscopic radiographs of osteoarthritic knees

These results contradict claims that TRA to within 1 mm is essential for useful measurement of JSW. It is an arbitrary threshold, of use in quality control (QC) for protocols which explicitly require such alignment, and the choice of QC criteria for other protocols should be evaluated on a view-by-view basis. The results confirm previous studies showing the MTP view to afford highly reproducible JSW measurement.