The Influence of Sex and Laterality on Clubfoot Severity.

BACKGROUND: Idiopathic clubfoot is bilateral in approximately 50% of cases and has been widely reported to affect males more frequently than females. Despite these observations, the correlation between sex and severity of the deformity has not been established. As well, the difference in severity between unilateral and bilateral clubfeet has not been extensively investigated. Therefore, the goals of the present study were to: (1) examine the relationship between sex and severity of deformity and (2) determine the relationship between laterality and severity of deformity.

METHODS: The families of infants with idiopathic clubfoot deformity treated at our institution were prospectively invited to participate in this institutional review board-approved study. Severity of the deformity was assessed by a single surgeon for each patient using the Dimeglio criteria at the first clinic visit. After evaluating the distributions, the correlations were quantified by nonparametric analyses.

RESULTS: Over 8 years, 240 infants met the inclusion criteria. There was no significant difference in the severity of deformity due to sex (P=0.61): the median Dimeglio score for males was 13 (variance 4.8) and for females, the median was 13.0 (variance of 5.1). In contrast, severity was distributed differently among unilateral versus bilateral patients. Although both unilateral and bilateral patients had a median Dimeglio score of 13, the ratio of bilateral patients was higher among those with moderate or very severe deformities compared with those with severe deformities (P<0.01).

CONCLUSIONS: Although idiopathic clubfoot is commonly considered to affect male patients disproportionately, this is the first study to document no difference in severity due to sex. Further, this study demonstrated that on average, bilateral patients did not have increased severity, but presented with a larger range of severity than those patients with unilateral deformity.

LEVEL OF EVIDENCE: Level III-prognostic.