Multiple birth hip dysplasia screening questioned

By Lynda Williams, Senior medwireNews Reporter

Ultrasound screening for developmental dysplasia of the hip (DDH) is unnecessary in twins and triplets without signs of the condition, say UK researchers.

Contrary to the belief that multiple birth infants are at increased risk for DDH, especially after breech presentations, the team found no significant difference in the rate of DDH between infants from multiple and singleton births, at rates of 3.0 and 2.3 cases per 1000 births.

The study collated information on DDH diagnoses in 990 multiple and 24,246 singleton births at Addenbrooke's Hospital in Cambridge between 2004 and 2008.

In total, 267 twins or triplets were referred for neonatal ultrasound scanning owing to breech presentation, being twin of a breech presentation infant, or for being a twin.

One girl was diagnosed with DDH and treated successfully with a Pavlik harness, report Andreas Rehm and co-authors from the hospital in the US edition of the Journal of Bone and Joint Surgery.

A further two multiple birth children had late presentation of DDH at 8 and 14 months and underwent open reduction with femoral osteotomy. The researchers note: "Both were female with no risk factors and a normal neonatal examination and had therefore not been referred for ultrasound scan."

None of the three multiple birth DDH cases had breech presentation, emphasize Rehm et al.

The researchers note that singleton breech presentation has been shown to increase the risk for DDH, possibly owing to hamstring tension displacing the femur head when in the extended leg position. However, twin breech often occurs shortly before birth and with the knees flexed and the feet parallel, reducing the risk for DDH.

Fifty-eight singleton children were diagnosed with DDH after referral for ultrasound following neonatal examination or owing to the presence of risk factors, such as family history of the condition or abnormal presentation. Fifty-three of the patients were female, including five infants with delayed DDH presentation. One late presentation occurred in a child who did not undergo ultrasound screening despite having a family history of the condition.

Overall, late presentations occurred in 0.27 children per 1000 live births.

"Whereas selective ultrasound scanning of multiple births would have led to earlier detection and treatment of the late-presenting cases, they did not have a significantly higher incidence of DDH compared with single births," the researchers write.

They therefore conclude that "being a twin or triplet in itself is not a risk factor for DDH and that selective ultrasound scanning is not indicated for this population."

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.