Rosendahl 2010.

Study characteristics
Methods	Design: parallel RCT Unit of randomization: baby
Participants	Location/Setting: single (maternity unit); Norway Sample size: 128 Number of withdrawals/dropouts: 0 Sex: 97 female (76%) Mean age: not stated Graf: not reported Inclusion criteria: newborns (aged 1‐3 days old); with mild dysplasia in 1 or both hips, identified on hip ultrasound Exclusion criteria: dislocated/dislocatable or severe dysplastic hips; and < 2500 grams at birth or major congential abnormalities
Interventions	Intervention (sample size): immediate abduction splinting with Frejka pillow splint and sonographic follow‐up for at least 6 weeks (n = 64) Control (sample size): active sonographic surveillance but no treatment for 6 weeks (n = 64). " Abduction splinting was initiated for 12 infants in whom the angle was 50° (6 weeks), for an additional 12 infants in whom the angle as 55° at the 3‐month review, and for 1 infant who was seen at 10 weeks. At 6 months, treatment was initiated for the first time in 5 infants in whom the acetabular index was 2 standard deviations above the mean."
Outcomes	Primary outcome(s): measurement of acetabular index Secondary outcome(s): complications Timing of outcome assessment: 1 year
Notes	Study start date: 1998 Study end date: 2003 Funding source: not stated Conflicts of interest: no financial relationships Comment(s): none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Judgement comment: a statistician performed the randomization as 1 single block by using a computerized random‐number generator.
Allocation concealment (selection bias)	Low risk	Judgement comment: group assignments were put in opaque, sealed, and numbered envelopes. With the parent present but the radiologist absent, a senior nurse opened the envelopes in numerical sequence for each baby at the outpatient clinic.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Judgement comment: with the parent present but the radiologist absent, a senior nurse opened the envelopes in numerical sequence for each baby at the outpatient clinic.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Judgement comment: with the parent present but the radiologist absent, a senior nurse opened the envelopes in numerical sequence for each baby at the outpatient clinic. The same paediatric radiologist performed the majority (80%) of follow‐up ultrasound examinations, and 2 other paediatric radiologists performed the remainder. All treated babies had their abduction splinting device removed before entering the radiology department for imaging. In addition, parents were instructed not to discuss their child’s treatment with the radiologists to ensure that the radiologists were blinded to the intervention assigned.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: all those randomized were analyzed.
Selective reporting (reporting bias)	Unclear risk	Judgement comment: outcomes stated in the trial registry were fully reported in the journal article. However, the trial registration is dated February 2009 and the study was conducted from 1998 to 2003. The study was published in 2010. Therefore, the trial does not appear to have been registered prior to the study starting.