Low reliability of the Risser sign in consecutive radiographs: a case series

Conclusions and discussion At this stage, the following explanatory hypotheses can be drawn: Technical radiological differences (exposure, machine) Variation of pelvis positioning Postural changes influencing the pelvis Brace compression on the pelvis According to our study results, all of the hypotheses include data both in favor and against the reliability of the Risser sign. Since the Risser sign is a 2D evaluation of a 3D phenomenon, pelvis repositioning could perhaps be the most plausible explanation. This case series is open to the possibility that the Risser sign is even less reliable than originally considered. Unfortunately, this result cannot be checked experimentally due to ethical reasons. Nevertheless, observational designs could be considered in the future.