Browsing by Subject "Craniosynostosis"

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  • Leikola, Junnu; Heliövaara, Arja; Koivikko, Mika; Koljonen, Virve (2019)
    PurposeTo evaluate the incidence of squamosal suture synostosis (SQS) in children with non-syndromic sagittal synostosis and to evaluate whether the additional SQS affects the intracranial volume (ICV).MethodsThirty-four consecutive patients (23 boys) who had been operated by cranial vault remodelling because of sagittal synostosis were compared retrospectively from 3D-CT imaging data sets obtained from volumetric CT. The mean age of the patients at preoperative CT imaging was 0.48 (range 0.13-1.3) years. Mann-Whitney U test was used in the statistical analyses.ResultsSagittal synostosis was combined with SQS in four children (11.7%) but the additional SQS did not affect the ICV. SQS was unilateral in all children, two were located on the right and two on the left side. The length of the SQS varied between 4 and 27mm. The children with SQS had a shorter sagittal suture synostosis length ratio (length of synostosis/total sagittal suture lengthx100) than those without SQS.ConclusionsThe incidence of SQS in non-syndromic sagittal synostosis was 11.7% but SQS did not affect the ICV.
  • Ritvanen, A.; Savolainen, M.; Nowinski, D.; Saiepour, D.; Paulasto-Krockel, M.; Hukki, J.; Tukiainen, E.; Leikola, J. (2017)
    Posterior calvarial vault osteodistraction (PCVO) has become increasingly popular in the correction of craniosynostosis. When compared to cranioplasty, PCVO offers a shorter, less invasive operation, greater intracranial volume advancement and a lower rate of relapse. In general, distraction protocols are based primarily on clinical observations rather than systematic research. Faster distraction protocols may reduce complications. However, distraction protocols producing higher forces can increase complications. Thus, we need to understand these forces in order to improve distraction protocols and devices. We developed a force measurement method that can be used on PCVO devices. Here, we present preliminary data about the forces developed during PCVO. We measured the forces in four bicoronal craniosynostosis patients during PCVO. We observed a linear-like trend between the force increase and the distraction distance within distraction sessions. We also observed a step-wise force increase between distraction sessions and found that the distraction force relaxed rapidly shortly after the distraction session. The mean maximum pre distraction force for one distracter was 20.4 N, while the mean maximum end-distraction force for one distracter was 57.6 N. Our data suggests that current treatment protocols might be re-evaluated favouring shorter distraction distances and more frequent distraction sessions. (C) 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
  • Heliövaara, Arja; Leikola, Junnu; Koljonen, Virve; Vuola, Pia; Koivikko, Mika (2018)
    The aim of this study is to compare the length of synostosis and segmented intracranial volume (SIV) with age in children with non-syndromic sagittal synostosis. Thirty-three consecutive patients (22 boys) who had been operated by cranial vault remodeling because of sagittal synostosis were compared retrospectively from 3D-CT imaging data sets obtained from volumetric CT. The mean age of the patients at preoperative CT imaging was 0.49 (range 0.13-1.3) years and at 1-year postoperative imaging 1.8 (range 1.3-3) years. The mean interval between preoperative CT imaging and surgery was 0.25 (range 0-0.8) years. Pearson's correlation and Student's t test were used in the statistical analyses. Length of sagittal synostosis correlated positively with age at preoperative CT (r = 0.688, p <0.01). Children with total synostosis (n = 9) were significantly older (mean age 0.74 vs. 0.4 years, p <0.01) than those with partial synostosis. Of partial synostoses, 9 were located anteriorly, 3 in the middle, and 12 posteriorly. The mean synostosis ratio (synostosis length/total sagittal suture length x 100) was 83%. Preoperative SIV correlated positively with age at preoperative CT (r = 0.788, p <0.01), whereas the 1-year postoperative SIV did not correlate with age at operation. The older the child at the time of the operation, the less the percentage SIV increased. Length of sagittal synostosis and SIV increased with age.
  • Savolainen, M.; Ritvanen, A.; Tukiainen, E.; Leikola, J. (2018)
    Distraction osteogenesis (DO) has become increasingly popular to correct craniosynostosis. Disadvantages of DO include the secondary operation needed for device removal and titanium screw related dura injury. To reduce invasiveness of the secondary device removal operation and to overcome titanium-related problems, fixation of the cranial distractor with resorbable materials is a potential alternative. New resorbable fixation methods, such as ultrasound-activated pins (UAPs) or heat-activated pins (HAPs), allow faster attachment on thinner bone than conventional resorbable screws (CRSs) since tapping is not required. However, resorbable materials are designed to be attached with a resorbable plate, not with a titanium distractor. We evaluated the suitability of CRSs, HAPs and UAPs for the cranial distractor fixation in a laboratory setting with a mechanical testing machine. Fracture tests were conducted in two directions with respect to the longitudinal axis; vertical i.e. axial pull-out strength, and horizontal i.e. shear strength. Mean maximum pull-out strength for CRS, HAP and UAP was 48.9 N, 32.5 N and 14.7 N, respectively. Mean maximum shear strength for CRS, HAP and UAP was 40.8 N, 77.9 N and 38.9 N, respectively. According to our in vitro tests, the cranial distractor attachment with four CRSs or six HAPs per footplate would provide sufficient fixation stability. (C) 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
  • Savolainen, M.; Ritvanen, A.; Hukki, J.; Vuola, P.; Telkka, J.; Leikola, J. (2017)
    Correction of calvarial defects after calvarial vault reconstruction (CVR) is challenging in craniosynostosis patients of advanced age and typically employs autologous bone. Demineralized bone matrix (DBM) is a potential alternative material for autologous bone, but its use has not been extended to correct calvarial defects. CVR patients operated at the Department of Plastic Surgery, Helsinki University Hospital, during 2008-2010 were retrospectively reviewed. Inclusion criteria of the study were CVR patients who received DBM plate, with or without bone dust, on calvarial defects and who had suitable uncovered defect on the contralateral side as control. This study included 17 craniosynostosis and one positional plagiocephaly patient, whose mean age was 6.9 years (range 0.9-19 years). The mean follow-up time was 5.6 years. The fusion degree of all defects was measured from 1 week to 1 year postoperatively using three-dimensional computed tomography (3D CT) images by the OsiriX (R) method. Medical records were reviewed for DBM-related complications. A total of 26 defects were covered with a DBM plate (mean area 11.1 cm(2)) and 26 control defects were identified (mean area 7.8 cm2). The mean fusion degree of the DBM defects was 74% and 54% for the controls (p <0.001). The mean fusion degree of nine DBM defects that lacked bone dust deposition was 66% and 55% for the nine controls (p <0.059). The difference between the DBM and control defects was statistically significant for patients older than 30 months (p <0.03). No DBM-related complication was observed. DBM plate is a safe and useful material to promote ossification in calvarial defects in CVR. Furthermore, DBM appears to be more effective in older patients (> 30 months) than in younger patients or when used with bone dust. (C) 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
  • Kuusela, Linda; Hukki, Ada; Brandstack, Nina; Autti, Taina; Leikola, Junnu; Saarikko, Anne (2018)
    Ionising radiation exposure is especially harmful to brain development. The purpose of this study was to evaluate whether black-bone (BB) magnetic resonance imaging (MRI), a non-ionising imaging method, offers an alternative to ionising imaging methods such as computed tomography (CT) in the examination of cranial deformities. From 2012 to 2014, a total of 408 children were referred to the Craniofacial Centre at the Helsinki University Hospital for further examination due to flatness of the posterior skull. Fifteen of these patients required further diagnostic imaging. To avoid ionising radiation, we used an MRI protocol that included sequences for evaluation of both brain anatomy and skull bone and sutures by BB-MRI. A semi-automatic skull segmentation algorithm was developed to facilitate the visualisation. Two patients with scaphocephaly were included in the study to confirm the ability to differentiate synostosis with BB-MRI. We obtained informative 3D images using BB-MRI. Seven patients (7/15, 46.7%) had plagiocephaly on the right side and seven on the left side (7/15, 46.7%). One patient (1/15, 6.7%) had symmetric posterior flatness affecting both sides. Neither structural nor signal-intensity alterations of the brain were detected in visual analysis. BB-MRI provides an alternative to CT when imaging craniofacial deformities. BB-MRI provides not only high-quality 3D-reconstructed imaging of the bony structures and sutures but also information on brain structure in one imaging session. With further development, this method could replace ionising radiation-based methods in analysing deformities of the skull.