Measuring the intercondylar shelf angle using radiographs: intra- and inter-observer error tests of reliability

Area of Science:

• Forensic Anthropology
• Radiographic Analysis
• Human Osteology

Background:

• The intercondylar shelf angle of the distal femur is a key metric in methods for determining racial affiliation from skeletal remains.
• Previous studies have not comprehensively assessed the reliability of this measurement in forensic contexts.

Purpose of the Study:

• To evaluate the intra- and inter-observer measurement error rates of the intercondylar shelf angle.
• To assess the reliability of this measurement for its application in racial determination from distal femora.

Main Methods:

• Lateral radiographs of 33 femora were independently measured by four observers.
• A supplementary inter-observer error test was conducted by four additional observers.
• Statistical analyses including Student's t-tests, paired samples t-tests, and ANOVA were employed.

Main Results:

• Statistically significant differences were identified in both intra-observer and inter-observer error rates.
• The results indicate variability in measurements among different observers and by the same observer at different times.
• The current measurement technique exhibits notable error, potentially compromising its utility.

Conclusions:

• The intercondylar shelf angle measurement, as currently performed, is subject to significant observer error.
• Further research and development of standardized, refined measurement techniques are necessary.
• Improved standardization is crucial for enhancing the reliability of racial affiliation determination from distal femora in forensic science.