Measuring the Intercondylar Shelf Angle Using Radiographs: Intra- and Inter-Observer Error Tests of Reliability

• Published in: Journal of forensic sciences Vol. 52; no. 5; pp. 1020 - 1024
• Main Authors: Berg, Gregory E., Ta'ala, Sabrina C., Kontanis, Elias J., Leney, Sardiaa S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-09-2007; Wiley Subscription Services, Inc
• Subjects: Analysis of Variance; Anthropology; Bones; Continental Population Groups; distal femur; Femur - anatomy & histology; Femur - diagnostic imaging; forensic anthropology; Forensic Anthropology - methods; Forensic osteology; forensic science; Humans; intercondylar shelf angle; Medical errors; Observer Variation; racial determination; Radiography; reliability; Reproducibility of Results; Studies; Variance analysis
• ISSN: 0022-1198; 1556-4029
• DOI: 10.1111/j.1556-4029.2007.00509.x

:  This study presents a test of intra‐ and inter‐observer measurement error rates of the intercondylar shelf angle of the distal femur, as measured on lateral radiographs. This measurement is the central element of a method to determine racial affiliation from the distal femur. Four observers independently radiographed a set of 33 complete and partial femora from collections housed at the Joint POW/MIA Accounting Command, Central Identification Laboratory. Each observer then measured the intercondylar shelf angles in each radiograph, following the original method’s guidelines. A supplementary inter‐observer error test was conducted by four additional observers on one set of radiographs. Statistically significant differences were found for both intra‐ and inter‐observer error based on the results of Student’s t‐tests, paired samples t‐tests, and ANOVA analyses. The results of this study indicate that further experimentation should be undertaken in order to develop refined measurement techniques that may help improve standardization and reduce the observer error rates.