Between 1992 and 1997, we undertook a prospective, targeted clinical and ultrasonographic hip screening programme to assess the relationship between ultrasonographic abnormalities of the hip and clinical limitation of hip abduction. A total of 5.9% (2 of 34) of neonatal dislocatable hips and 87.5% (7 of 8) of ‘late’ dislocated hips seen after the age of six months, presented with unilateral limitation of hip abduction. All major (Graf type III) and 44.5% of minor (Graf type II) dysplastic hips presented with this sign.

Statistically, bilateral limitation of hip abduction was not a useful clinical indicator of underlying hip abnormality because of its poor sensitivity, but unilateral limitation of abduction of the hip was a highly specific (90%) and reasonably sensitive sign (70%). It was more sensitive than the neonatal Ortolani manoeuvre, which has been considered to be the method of choice. It was, however, not sensitive enough to be of value as a routine screening test in developmental dysplasia of the hip.

We consider unilateral limitation of hip abduction to be an important clinical sign and its presence in an infant over the age of three to four months makes further investigation essential.

Between May 1992 and April 1997, there were 20 452 births in the Blackburn District. In the same period 1107 infants with hip ‘at-risk’ factors were screened prospectively by ultrasound. We recorded the presence of dislocation and dysplasia detected under the age of six months using Graf’s alpha angle. Early dislocation was present in 36 hips (34 dislocatable and 2 irreducible). Of the 36 unstable hips, 30 (83%) were referred as being Ortolani-positive or unstable; 25 (69%) of these had at least one of the risk factors. Only 11 (31%) were identified from the ‘at-risk’ screening programme alone (0.54 per 1000 live births). Eight cases of ‘late’ dislocation presented after the age of six months (0.39 per 1000 live births). The overall rate of dislocation was 2.2 per 1000 live births.

Only 31% of the dislocated hips belonged to a major ‘at-risk’ group. Statistical analysis confirmed that the risk factors had a relatively poor predictive value if used as a screening test for dislocation. In infants referred for doubtful clinical instability, one dislocation was detected for every 11 infants screened (95% confidence interval (CI) 8 to 17) whereas in infants referred because of the presence of any of the major ‘at-risk’ factors the rate was one in 75 (95% CI 42 to 149).

Routine ultrasound screening of the ‘at-risk’ groups on their own is of little value in significantly reducing the rate of ‘late’ dislocation in DDH, but screening clinically unstable hips alone or associated with ‘at-risk’ factors has a high rate of detection.