Joint laxity and the risk of clubfoot.

BACKGROUND

Clubfoot is a relatively common and potentially disabling birth defect. The etiology of clubfoot (talipes equinovarus [TEV]) is not known. Joint laxity, or hypermobility, is a suspected risk factor for congenital hip dislocation and clubfoot.

METHODS

We conducted a case-control study of TEV in five western Washington counties. A total of 239 cases of TEV were identified from hospital and outpatient sources from 1986 to 1994. Controls (n = 356) were identified by random-digit dialing (RDD). Parents were interviewed over the telephone, and medical records were abstracted. In-person measurements of four joint laxity indices in parents and the index child were obtained.

RESULTS

Moderately elevated adjusted odds ratios (ORs) were found for extension > 90 degrees of the entire little finger, and extension of all four fingers to a position parallel to the forearm (OR = 1.6; 95% CI = 0.9-2.9; and OR = 1.7; CI = 1.1-2.5; respectively). No elevation in the OR was found for the wrist and elbow laxity measures. No consistent pattern of association between joint laxity measures in parents and an elevated OR of clubfoot among their children was found.

CONCLUSIONS

The results of this study suggest a role for joint laxity in the etiology of TEV.