PURPOSE:

Recent trends in craniofacial surgery focus on developing less invasive techniques that achieve lasting results.  Spring assisted surgery (SAS), first introduced by Claes Lauritzen in 1998, has demonstrated promising outcomes for the treatment of craniosynostosis.  The purpose of this study was to assess outcome of this treatment modality in our first 75 cases, in comparison to both historical controls and patients treated during the same time interval with standard cranial expansion techniques.

METHOD: Children with scaphocephaly were considered for this IRB approved study.  Seventy-five children, 20 females and 55 males, have completed this study protocol to date.  All study patients underwent cranial surgery with removal of a 1cm strip of the sagittal suture followed by the insertion of two 1.2 mm stainless steel springs.  Each spring exerted a mean force of 7.5 Newtons at initial placement.  All patients had preoperative and postoperative skull films to measure cranial expansion and cephalic index. Clinical outcome assessment included analysis of changes in cephalometric measurements and shape and volumes calculated from 3D laser scans.  These were compared to control patients treated for scaphocephaly using cranial expansion techniques during the same time interval as well as historic controls. Additionally, perioperative variables including OR time, blood loss, transfusion requirements, ICU stay, hospital stay, and hospital costs were compared between the two groups.

RESULTS: All of the study patients successfully underwent spring assisted surgery without significant complications with a mean follow up of 46 months.  Four children underwent a secondary surgery for skin infection (1), spring malposition (1), and scars (2). The mean age at the initial operation for the spring cranioplasty group was 5.7 months and 9.8 months for the cranial expansion group. Perioperative variables including OR time, blood loss, transfusion requirements, ICU stay, hospital stay, and hospital costs were significantly different between treatment groups with improved morbidity with SAS.  Serial follow-up skull films showed a mean maximal spring expansion of 6.4 cm.  The mean cephalic index preoperatively was 64.3 and postoperatively was 75.1, which compares favorably to historical controls treated with cranial expansion techniques.  Frontal bossing, measured as the ratio of anterior to total cranial volume calculated from the laser 3D scans, decreased after treatment by SAS.

CONCLUSION:

This data supports that spring assisted surgery is a safe and effective, minimally invasive treatment for scaphocephaly.  It combines the low morbidity and operative time of a strip craniectomy with cranial expansion techniques using an implanted spring to gradually distract the skull, achieving an improved head shape. Our 7 years of experience with more than 75 children has shown spring assisted surgery is able to effectively correct cranial shape abnormalities including frontal bossing, and maintain cephalic index.