Related Experiment Videos
The validity of sacral ratios to identify sacral abnormalities.
S A Warne1, M L Godley, C M Owens
1Department of Paediatric Urology, Guy's Hospital, London, UK. WarneS@gosh.nhs.uk
BJU International
|March 27, 2003
Summary
The sacral ratio measurement shows good repeatability for detecting sacral abnormalities. However, its wide variability limits its effectiveness in distinguishing normal from abnormal sacra.
Area of Science:
- Radiology
- Orthopedics
- Pediatric Surgery
Background:
- Sacral abnormalities are linked to neuropathic bladder, but diagnosing subtle anomalies is often delayed.
- The sacral ratio is a previously described measurement for assessing sacral abnormalities.
Purpose of the Study:
- To evaluate the repeatability and validity of the sacral ratio measurement for detecting sacral abnormalities.
- To assess the diagnostic utility of the sacral ratio in differentiating normal and abnormal sacra.
Main Methods:
- Fifty sacral radiographs from children (30 with anorectal anomalies, 20 normal) were analyzed.
- Four investigators measured sacral ratios (anteroposterior and lateral), assessing inter- and intra-observer variability.
- Validity was determined by comparing sacral ratio values to expert radiological diagnosis using Pena's criteria.
Main Results:
- Sacral ratio measurements were feasible in 48 of 50 radiographs, demonstrating good repeatability and moderate inter-observer variability.
- Mean AP sacral ratios differed significantly across normal, abnormal, and anorectal anomaly groups (P < 0.02).
- However, wide individual variability and overlap in sacral ratio values between normal and abnormal sacra were observed, leading to poor agreement with radiological diagnosis.
Conclusions:
- The sacral ratio measurement exhibits good inter- and intra-observer repeatability.
- While the mean normal AP sacral ratio aligns with previous findings, significant variability limits its clinical value for discriminating normal from abnormal sacra.