title: Spring-assisted posterior skull expansion without osteotomies.
abstract: BACKGROUND
  A posterior flatness of the skull vault can be observed in infants with brachycephaly. Such posterior deformation favours the development of turricephaly which is difficult to correct. To reduce the risk of such deformation, an early posterior skull remodelling has been suggested. Translambdoid springs can be used to allow for a distraction through the patent lambdoid sutures and obtain a progressive increase of the posterior skull volume.
  
  
  METHODS
  The procedure consists in a posterior scalp elevation, the patient being on a prone position. Springs made of stainless steel wire (1.5 mm in diameter) are bent in a U-type fashion, and strategically positioned across both lambdoid sutures. No drilling is usually necessary, as the lambdoid suture can be gently forced with a subperiosteal elevator in its middle and an indentation can be created with a bony rongeur on each side of the open suture to allow for a self-retention of bayonet-shaped extremity of the spring. Careful attention is addressed to the favoured prone position during the post-operative period. After a delay of 3-6 months, the springs can be removed during a second uneventful procedure, with limited incisions, usually as a preliminary step of the subsequent frontal remodelling.
  
  
  CONCLUSIONS
  The concept of spring-assisted expansion across patent sutures under 6 months of age was confirmed in our experience (19 cases). Insertion of the springs allowed for immediate distraction across the suture. A posterior remodelling of the skull could be achieved with minimal morbidity allowing to delay safely a radical anterior surgery.
authors.affiliation: Craniofacial Unit, Department of Pediatric Neurosurgery, Hôpital Necker-Enfants Malades, 34, avenue d'Eylau, 75116, Paris, France. drericarnaud@hotmail.com
authors.forename: Eric
authors.initials: E
authors.lastname: Arnaud
authors.forename: Alexandre
authors.initials: A
authors.lastname: Marchac
authors.forename: Yassine
authors.initials: Y
authors.lastname: Jeblaoui
authors.forename: Dominique
authors.initials: D
authors.lastname: Renier
authors.forename: Federico
authors.initials: F
authors.lastname: Di Rocco
mesh_terms: D003393:Cranial Sutures / Q000000981:diagnostic imaging / Q000601:surgery*; D003398:Craniosynostoses / Q000000981:diagnostic imaging / Q000601:surgery*; D003399:Craniotomy / Q000379:methods; D004867:Equipment Design; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D009777:Occipital Bone / Q000601:surgery*; D019857:Osteogenesis, Distraction / Q000295:instrumentation* / Q000379:methods*; D014057:Tomography, X-Ray Computed