Introduction: The quality of newborn hip screening is usually measured as the number of late detected cases of hip dysplasia. There is no consensus concernig the use of ultrasonography in hip joint screening in newborns. At our hospital the number of late detected cases was around 2/1000 births using clinical screening. In a prospective, randomised study we compared universal ultrasound screening and selective ultrasound screening. We reduced the number of late detected cases when using universal ultrasound screening to 0,13/1000, whereas the group with selective ultrasound screening had 0,65/1000, the difference was not significant. We have therefore continued selective ultrasound screening, and present the results concerning late detected cases in the 9-year period 1999–2007 with this screening model.

Materials and Methods: Newborns in our county are now offered selective ultrasound hip joint screening, in addition to the stanard clinical screening. The ultrasound examinations are performed 1–3 days after birth. The following risk factors lead to ultrasound examination: positive or doubtful Ortolani or Barlow tests, breech position, family history of hip dysplasia, foot deformities, and some syndromes. In the 9-year period 1999–2007 a total of 34000 babies where born in our county, and 13% had risk factors for hips dysplasia and were examined by ultrasound.

Our hospital is the only hospital dealing with lated detected cases in our county.

Results: In the 9-year period the primary treatment rate using the Frejka pillow was 0,9/1000 births. In the same period there were 16 children treated for lated detected hip dysplasia. There were 14 girls and 2 boys, giving an incidence of late detected cases of 0,47/1000 births. There were no common characteristics among the children with late detected hip dysplasia.

Discussion/Conclusions: It has been assumed that a good clinical hip joint screening in newborns should not give more than 0,5/1000 births of late detected cases. By using selective ultrasound screening we have achieved 0,47/1000 births of late detcted cases in our county. We therefore recommend selective ultrasound hip screening in newborns.

Introduction: Several factors of which many still are unknown may influence the mechanical strength of the impacted morsellised bone applied in revision hip surgery. To avoid initial subsidence of the prosthesis can be crucial for the survival of the revised joint. Impacted grinded bone forms a porous structure where the void space mainly is filled by liquid consisting of water and fat.

Purpose of Study: To determine the influence of moisture on the stiffness strength of impacted morsellised bone.

Material and methods: Juxtaarticular bovine bone is morsellised and experimentally impacted by standardised methods. The stiffness of the bone was recorded during bone sample construction and loading the impacted bone sample, in a brief undrained and a longer drained phase. Water and fat content were measured in loose and compressed bone material and could be altered by reproducible methods. A trial on drainage during impaction was executed. All studies were compared with a base line study. This trial was carried out as similar as possible to the routine, clinical situation.

Results: Dried bone had very high axial stiffness properties. Lowering fat content resulted in bone samples, which had significantly higher stiffness during the undrained loading period but did not diverge during drained loading. Drainage during impaction had no effect on axial strength of the bone.

Conclusion: Low water content in morsellised bone has considerable positive effect on the axial strength of impacted bone. Fat lowering may have a positive effect during initial load phase but this advantage diminishes over time. In this experimental study draining through impaction did not improve axial strength. This is probably due to the transitory effect impaction has on porous pressure.