Assessing a Limited Ultrasound Protocol in DDH

A Non-Inferiority Trial Assessing a Limited Ultrasound Protocol in the Treatment of Developmental Dysplasia of the Hip

Developmental Dysplasia of the Hip (DDH) is a common diagnosis in children that if untreated may lead to degeneration and arthritis of the hip joint at a young age. Ultrasound imaging is used to monitor progress of the developing hip joint during treatment. Initial data from our practice suggests that interim ultrasounds do not alter the course or outcome of treatment. Additionally, these ultrasounds add significant time to clinic visits and carry a substantial cost to the health care system. The goal of this study is to determine if limiting the number of ultrasounds during treatment results in the same outcomes while also evaluating the amount of time and money saved by omitting the ultrasounds.

Children in the comprehensive ultrasound protocol group will follow the current standardized treatment protocol used at the Hospital for Sick Children in Toronto, Canada. For children presenting with stable hip dysplasia, Pavlik harness (PH) treatment is initiated at the initial visit (week 0) and runs for a total of 12 weeks. Children return to clinic at weeks 2, 5, 8 and 12 for clinical and ultrasound examinations to ensure that the harness is fitting correctly, to screen for PH complications and to monitor acetabular development.

Children in the limited ultrasound protocol group will receive the same treatment as described for the comprehensive ultrasound group above, except the ultrasound imaging conducted at weeks 2, 5 and 8 will be omitted. Children will still return to clinic at 2, 5, and 8 weeks for clinical examination, which includes the assessment of the Pavlik harness fit and screening for complications.

The International Hip Dysplasia Institute (IHDI) grade will be measured from a radiograph of the pelvis. The score classifies hips into one of four groups based on the position of the proximal femoral metaphysis in relation to the acetabulum. The scores grade severity from Grade 1 as the mildest type to Grade 4 as the most severe type of hip dislocation.

Calculating time between registering at Ultrasound and registering at the Orthopaedic clinic will provide a measurement of time savings in the limited ultrasound protocol group

Inclusion Criteria: Aged 0-6 months at time of diagnosis Clinical and Ultrasound diagnosis of stable developmental dysplasia of the hip Children with dislocated/ unstable DDH will be included once the hip becomes stable Treated with Pavlik harness Assessed and treated at the SickKids Baby Hip Clinic Exclusion Criteria: Underlying neuromuscular disease Teratologic hip dysplasia Prior treatment at other institutions Non-compliance with treatment protocol