To The Editor: In their very detailed study, "The Effect of the Orientation of the Acetabular and Femoral Components on the Range of Motion of the Hip at Different Head-Neck Ratios" (82-A: 315-321, March 2000), D'Lima et al. have missed one important point. The introduction of high-nitrogen stainless steel and the cold forming process has resulted in a much stronger Charnley stem, the Ortron (Johnson and Johnson, Leeds, United Kingdom). The diameter of the neck is reduced from 12.5 millimeters to ten millimeters without loss of strength. Use of this …