Type of Brace for the Unstable Hip
Limited evidence supports use of the von Rosen splint over Pavlik, Craig, or Frejka splints for initial treatment of an unstable hip.

Rationale
There are no high quality comparative effectiveness studies between different types of braces for the treatment of DDH.  Limited evidence suggests that rigid braces may have higher rates of resolution of hip dysplasia than non-rigid braces. Two low strength studies compared rigid bracing to soft bracing for initial treatment of unstable hips in infants. 29, 30 Heikkila compared the Frejka pillow with the von Rosen splint.29There were 920 patients treated with Frejka pillow and 180 patients treated with von Rosen splint. Fifty-five of 920 from the Frejka pillow group had treatment failure, while 1 out of 180 from the von Rosen splint group failed treatment. These differences were significant. A limitation of this study is that it was a historical comparative study of two cohorts over two time periods. AVN rates were inadequately reported. The authors did not differentiate between dislocated and dislocatable hips.

Three splints were compared in the Wilkinson study: Craig, Pavlik, and von Rosen.30 Four of 28 in the Craig splint group, 13 of 43 in the Pavlik group, and 0 of 26 in the von Rosen group required further treatment in the form of plaster or operation.

This recommendation is based on the braces that were studied, but other similar fixed-position braces may or may not work as well as the braces mentioned in the evidence.

Risks and Harms
Nineteen percent of the patients in the rigid brace group experienced skin irritation29. There is a potential risk of AVN with all bracing; the relative risk is unknown between rigid and soft bracing.