Abstract
To assess the reliability of the pre-operative measurement methods used in the management of the hallux valgus deformity, five observers assessed 50 pre-operative standing foot radiographs on two occasions in order to assess the reliability of radiological hallux valgus assessment using the inter-metatarsal angle (IMA), hallux valgus angle (HVA) and joint congruency. Five published methods of angle measurements described by Hawkins, Venning and Hardy, Mitchell, Miller and Nestor were used.
Kappa statistics were used to assess the reliability of the diagnosis of congruency. Regarding IMA and HVA, mean values between the methods were assessed by one-way ANOVA. The differences between the methods and observers were assessed by two-way ANOVA.
Results: Diagnosis of congruency showed good agreement (k=0.608) over two occasions, although this did vary by observer.
The mean IMA and HVA measurements varied significantly between methods on both occasions (p< 0.0001). Mitchell’s method had the lowest and Miller’s the highest mean values.
Analysis of variance showed both method and observer variations were significant for IMA. But HVA measurements differed significantly only by observers.
Conclusion: The reliability of IMA and HVA measurements is poor whichever measuring method is used and these methods are not interchangeable. Study papers should state the measurement method used. For the pre- and post-operative assessment the same method should be used.
The abstracts were prepared by Mr Tim Briggs. (Editoral Secretary 2003/4) Correspondence should be addressed to him at Lane Farm, Chapel Lane, Totternhoe, Dunstable, Bedfordshire LU6 2BZ, United Kingdom
