Comparability in skeletal maturation research

Comparability is a fundamental issue in skeletal maturation research. Since the introduction of the first edition of the Greulich-Pyle Atlas and the Tanner-Whitehouse method, a number of methodologic reports have appeared regarding potential sources of error, reliability and replicability in the assessment of skeletal maturity from hand-wrist radiographs. Some of these reports are mentioned and two recent examples of methodologic studies are cited. Maximum reliability of skeletal assessments can be expected only when there is strict adherence to carefully standardized investigative procedures. Technical as well as human factors must be taken into account to insure minimal variation in findings within and between laboratories over time. Single or serial skeletal radiographs uniformly taken on properly identified subjects constitute a valuable permanent record of biologic maturation. while the film image can be considered as objective evidence of skeletal maturity, a subjective element is introduced in observing and reporting the presence or absence of particular ossification centers, or rating an ossification pattern against a standard. Intra- and interobserver skeletal maturity assessment replicability relates to such factors as motivation, training, assessment method, and quality control procedures. Suggestions are presented to facilitate comparability in skeletal maturation research, including the possibility of preparation and distribution of sets of standardized skeletal radiographs for periodic determination and improvement of assessor reliability.