Three-dimensional changes in head shape after extended sagittal strip craniectomy with wedge ostectomies and helmet therapy

Creation of the Scaphocephalic Index: Measurement of Global and Regional Severity in Scaphocephaly

BACKGROUND

The recently described frontal bossing index (FBI) and occipital bullet index (OBI) allow for quantification of scaphocephaly. A similar index examining biparietal narrowing has not been described. Addition of such an index measuring width would allow for direct evaluation of the primary growth restriction in sagittal craniosynostosis and the formation of an optimized global width/length measure.

METHODS

Computed tomography scans and three-dimensional photographs were used to recreate scalp surface anatomy. Equidistant axial, sagittal, and coronal planes were overlaid, creating a Cartesian grid. Points of intersection were analyzed for population trends in biparietal width. Using the most descriptive point coupled with the sellion protrusion to control for head size, the vertex narrowing index is formed. By combining this index with the FBI and OBI, the scaphocephalic index (SCI) is created as a tailored width/length measure.

RESULTS

Using 221 controls and 360 individuals with sagittal craniosynostosis, the greatest difference occurred superiorly and posteriorly at a point 70% of the head's height and 60% of the head's length. This point had an area under the curve of 0.97 and sensitivity and specificity of 91.2% and 92.2%, respectively. The SCI has an area under the curve of 0.9997, sensitivity and specificity greater than 99%, and interrater reliability of 0.995. The correlation coefficient between computed tomography imaging and three-dimensional photography was 0.96.

CONCLUSIONS

The vertex narrowing index, FBI, and OBI evaluate regional severity, while the SCI is able to describe global morphology in patients with sagittal craniosynostosis. These measures allow for superior diagnosis, surgical planning, and outcome assessment, independent of radiation.

3D Analysis of the Cranial and Facial Shape in Craniosynostosis Patients: A Systematic Review

With increasing interest in 3D photogrammetry, diverse methods have been developed for craniofacial shape analysis in craniosynostosis patients. This review provides an overview of these methods and offers recommendations for future studies. A systematic literature search was used to identify publications on 3D photogrammetry analyses in craniosynostosis patients until August 2023. Inclusion criteria were original research reporting on 3D photogrammetry analyses in patients with craniosynostosis and written in English. Sixty-three publications that had reproducible methods for measuring cranial, forehead, or facial shape were included in the systematic review. Cranial shape changes were commonly assessed using heat maps and curvature analyses. Publications assessing the forehead utilized volumetric measurements, angles, ratios, and mirroring techniques. Mirroring techniques were frequently used to determine facial asymmetry. Although 3D photogrammetry shows promise, methods vary widely between standardized and less conventional measurements. A standardized protocol for the selection and documentation of landmarks, planes, and measurements across the cranium, forehead, and face is essential for consistent clinical and research applications.

Endoscopic Strip Craniectomy and Helmet Therapy for Sagittal Craniosynostosis: An Analysis of Cranial Growth Changes in the Early Postoperative Period

OBJECTIVE

The purpose of this study is to analyze cranial width and length growth curves in the early postoperative period of patients by undergoing endoscopic sagittal strip craniectomy (ESC) to determine the timing of the maximal growth curve change. By analyzing the complex interplay of cephalic length and width measurements, we hope to better understand the cephalic index (CI) growth curve during this early period. This is the first of a multistep process to elucidate the ideal cranial remolding orthosis (CRO) treatment duration.

DESIGN

Retrospective review.

SETTING

Tertiary academic institution.

PATIENTS

Children with isolated sagittal craniosynostosis.

INTERVENTIONS

ESC and postoperative CRO treatment (2015-2019).

MAIN OUTCOME MEASURES

One cranial orthotist obtained preoperative and postoperative measurements. The maximal rate of change of width, length, and CI were compared against the postoperative week these occurred.

RESULTS

Thirteen children (mean age: 3.3 months, average preoperative CI: 73.4) underwent this intervention. CI reached its highest growth rate by 4.9 average weeks postoperatively, which correlated with the maximal width growth rate (5.2 weeks). Length curves reached their maximal growth rate by 15.5 weeks. CI peaked (81.3) by 22.7 weeks postoperatively, a significant increase from baseline.

CONCLUSIONS

Following ESC, in the early postoperative period, the CI growth curve has 4 phases: initial rapid expansion, early and late slowed expansion, and plateau, followed by possible regression phases. This highlights the importance of early postoperative CRO initiation, CRO compliance, and properly fitting CROs, especially in the first 2 phases. This data sets the stage for investigating the ideal treatment length.

Craniometric and Aesthetic Outcomes in Craniosynostosis Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically review the published comparative aesthetic outcomes, and its determinants, for craniosynostoses surgically treated by minimally-invasive cranial procedures and open cranial vault remodeling (CVR).

DESIGN

PRISMA-compliant systematic review.

SETTING

Not-applicable.

PATIENTS/PARTICIPANTS

Articles were included if they compared spring cranioplasty, strip minimally-invasive craniectomy or CVR for outcomes related to aesthetics or head shape. Forty-two studies were included, comprising 2402 patients.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE(S)

The craniometric and PROM used to determine surgical outcomes.

RESULTS

Twenty-five studies (59%) evaluated sagittal craniosynostosis, with metopic (7;17%) and unicoronal (4;10%) the next most prevalent. Thirty-eight studies (90%) included CVR, 24 (57%) included strip craniectomy with helmeting, 9 (22%) included strip craniectomy without helmeting, 11 (26%) included spring cranioplasty, and 3 (7%) included vault distraction. A majority of studies only used 1 (43%) or 2 (14%) craniometric measures to compare techniques. In sagittal synostosis, 13 (59%) studies showed no difference in craniometric outcomes, 5 (23%) showed better results with CVR, 3 (14%) with strip craniectomy, and 1 (5%) with springs. In studies describing other synostoses, 10/14 (71%) were equivocal. Subjective outcome measures followed similar trends. Meta-analysis shows no significant difference in cranial index (CI) outcomes between CVR and less invasive procedures in patients with sagittal synostosis.

CONCLUSIONS

There is no difference in CI outcomes between CVR and less invasive procedures. The majority of literature comparing craniometric and aesthetic outcomes between CVR and less invasive procedures shows equivocal results for sagittal synostosis. However, the heterogeneity of data for other craniosynostoses did not allow meta-analysis.

Comparative Analysis of 2D and 3D Metrics for Evaluation of Postoperative Outcomes Following Endoscopic Suturectomy for Sagittal Craniosynostosis

To assess whether 3-dimensional (3D) volumetrics can be used to track and evaluate postoperative course of patients treated with endoscopic suturectomy for nonsyndromic sagittal synostosis, we compared changes in 2-dimensional (2D) measurements along with 3D volumetric correlates throughout the period of helmet therapy. Forty-six patients treated at our institution with endoscopic suturectomy for sagittal synostosis were retrospectively reviewed. Head circumference (HC), cephalic index (CI), and total cranial volumes (TCVs) were measured at 3 timepoints following surgery using optical surface scans obtained for helmet orthotics. All measurements showed significant differences between timepoints on the analysis of variance ( P <0.001). There was a significant correlation between CI and TCV (r=0.35, P =0.004) and between HC and TCV (r=0.81, P <0.001). The normalized rate of change over the course of treatment was significantly higher for TCV (36.7%) than for CI (8.8%) and HC (8.4%, P <0.001), with no difference between HC and CI. The authors conclude that 3D metrics were able to reliably follow the course of postoperative 2D metrics. There was a direct and linear correlation between HC and CI with TCV. Total cranial volumes showed the highest rate of sustained change at every timepoint. Although CI and HC plateau after the first measurement, TCV continues to adapt over the course of treatment. These results demonstrate the feasibility and value of volumetrics from 3D imaging to provide a more comprehensive evaluation of postoperative surgical outcomes than traditional 2D metrics without the ionizing radiation traditionally utilized for CT to obtain 3D metrics.

Combined Dynamic Osteotomies for Craniosynostosis

Background

In primary craniosynostosis, the premature fusion of one or more sutures prevents the perpendicular expansion of brain tissue (primary defect). Providing space for the brain to expand, the compensatory growth of unaffected sutures causes progressive skull deformation (secondary defect). Understanding the need to treat the osteogenic matrix responsible for the cranial vault's shape was essential to develop a novel surgical concept known as dynamic osteotomy. It uses springs to activate stenotic sutures and trigger dura-mater distension while flexibilizing compensatory osseous defects via helicoid osteotomy (nautilus technique), allowing for efficient bone expansion and remodeling in craniosynostosis.

Method

This case series describes patients with craniosynostosis treated with dynamic osteotomy utilizing structural transformation inductors such as springs and helicoid osteotomy (nautilus technique), operated on between July 2004 and January 2020 at a single center in Brazil.

Result

Dynamic osteotomy longitudinally achieved stable osseous remodeling during growth period while maintaining good vitality and continuity of the osteotomized cranial vault.

Conclusion

Dynamic osteotomy utilizing springs and nautilus technique, alone or in combination, is a successful treatment of craniosynostosis regardless of patient's age.

Modified Cephalic Index Measured at Superior Levels of the Cranium Revealed Improved Correction With Helmet Therapy for Patients With Sagittal Suture Craniosynostosis

OBJECTIVE

Historically, studies have shown that cranial remolding therapy improves surgical correction and protects against regression for patients with sagittal suture craniosynostosis. This study aimed to define the most responsive cranial height for measuring cephalic index (CI) following cranial remolding therapy for infants with sagittal suture craniosynostosis.

METHODS

The authors performed a retrospective analysis of data between January 2018 and August 2019. The outcomes measured were CI-3 (level of glabella) through CI-7 (superior to eurions), where each value was defined as the width at levels 3 through 7 divided by the length at level 3. Differences between baseline- and post-treatment measurements were assessed using a 5 × 2 repeated measures analysis of variance.

RESULTS

Data from thirty-four patients (19 males, 15 females, and mean age 2.79 months) were analyzed. Mean treatment duration was 4.59 ± 1.86 months. There was a significant increase between baseline and posttreatment measurements (baseline: 72.60% ± 0.70%, post: 76.30% ± 0.80%; F1,33 = 27.74, P < 0.001). The interaction effect for CI level * baseline-post was also significant (F1.43,47.16 = 6.75, P = 0.006). Post hoc analyses revealed the posttreatment measures were significantly greater than baseline measures at every CI level. The magnitude of the measured differences systematically decreased from CI-7 to CI-3, with a greater effect size at the most superior level (ie CI-7) of 0.961 compared to 0.778 at the traditional level (ie CI-3).

CONCLUSIONS

The CI measurement at level 7 demonstrated the greatest responsiveness to treatment, whereas the traditional CI measurement taken at level 3, the current standard, proved the least responsive.

Three-Dimensional Treatment Outcomes of a Virtual Helmet Design Protocol for Sagittal Strip Craniectomy

BACKGROUND

The helmet worn after sagittal strip craniectomy must be customized to the surgical procedure and the patient's anatomy to achieve optimal outcomes. This study compares three-dimensional head shape outcomes obtained from a novel virtual helmet design and from a traditional helmet design.

METHODS

Twenty-four patients underwent extended sagittal strip craniectomy performed by a single surgeon and helmet management performed by a single orthotist. Eleven patients constitute the traditional helmet group, with helmet design based on laser scans. Thirteen patients constitute the virtual helmet group, with helmet design based on an overlay of a three-dimensional volume rendering of a low-radiation protocol computed tomographic scan and three-dimensional photograph. Cephalic index and vertical height were recorded from three-dimensional photographs. Three-dimensional whole-head composite images were generated to compare global head shape outcomes to those of age-matched controls.

RESULTS

There was no significant difference in mean cephalic index between the virtual helmet group (83.70 ± 2.33) and controls (83.53 ± 2.40). The differences in mean cephalic index between the traditional helmet group (81.07 ± 3.37) and controls and in mean vertical height were each significant (p < 0.05). Three-dimensional analysis demonstrated normal biparietal and vertical dimensions in the virtual helmet group compared to controls. The traditional helmet group exhibited narrower biparietal dimension and greater vertical dimension compared to controls.

CONCLUSIONS

Traditional and virtual helmet protocols improved mean cephalic index, but the virtual helmet group yielded more consistent and greater change in cephalic index. The virtual helmet design protocol yielded three-dimensional outcomes similar to those of age-matched controls. Traditional helmet design yielded a narrower biparietal dimension and greater vertical dimension to the cranial vault compared to the virtual helmet group and controls.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Quantitative outcomes of endoscopic strip craniectomy for metopic craniosynostosis in children with severe trigonocephaly

PURPOSE

To assess intermediate-term (> 3 years) outcomes of endoscopic strip craniectomy with postoperative helmet therapy (ESC + HT) for the treatment of infants with severe trigonocephaly.

METHODS

This retrospective study examined cranial morphology of consecutive patients with severe trigonocephaly treated with minimally invasive ESC + HT. Preoperative and follow-up clinical parameters were collected from patient charts. Interfrontal divergence angle (IFDA), a validated and accurate measure of forehead narrowing, was measured on preoperative CT scans and on preoperative and postoperative 2D photographs.

RESULTS

Seven patients (4 male, 3 female) were included with a mean age at surgery of 2.76 months (range 1.8 to 4.1 months) and mean clinical follow-up of 3.71 years (photographic follow-up 2.73 years). The mean operative time was 91.4 min, with a mean estimated blood loss (EBL) of 57.1 ml and mean hospital length of stay of 1.14 days. IFDA improved from 118.8° to 135.9° (p < 0.01), with the mean final measurement falling within normal limits. The head circumference percentile was not significantly changed in follow-up. There was a statistically significant improvement in the inner-to-outer canthal distance ratio (p = 0.01) in follow-up, showing an improvement in hypotelorism. There were no dural tears, CSF leaks, infections, or other significant surgical morbidities, and there were no serious complications related to the use of helmet therapy. All patients achieved excellent aesthetic results judged by photographic comparison.

CONCLUSION

This study demonstrated that patients treated with ESC + HT for metopic craniosynostosis showed measurable and significant improvement in forehead shape. This technique is a safe and effective alternative to more invasive surgical interventions.

Comparison of Head Shape Outcomes in Metopic Synostosis Using Limited Strip Craniectomy and Open Vault Reconstruction Techniques

AIM

Metopic craniosynostosis (MCS), with its trigonocephalic head shape, is often treated with either limited incision strip craniectomy (LISC) followed by helmet orthotic treatment, or open cranial vault reconstruction techniques (OCVR). There is controversy regarding resultant shape outcomes among craniofacial surgeons. Those adverse to LISC claim normal head shape is never attained, while proponents believe there is gradual correction to an equivalent outcome. This study aims to quantitate, over time, the three-dimensional (3D) head shapes in patients who have undergone LISC or OCVR intervention for MCS.

METHODS

Sixty-three 3D images of 26 patients with MCS were analyzed retrospectively. Head shape analyses were performed at: (1) preoperative, (2) 1-month postoperative, (3) 10 to 14 months postoperative (1 year), and (4) 2 years postoperative. Composite 3D head shapes of patients were compared at each time point. Two-dimensional (2D) standardized cross sections of the forehead were also compared.

RESULTS

Composite head shapes for both groups were nested, to allow visual comparison as the child's forehead grows and expands. The difference between LISC and OCVR 2D cross sections was calculated; 108.26 mm preoperatively, 127.18 mm after 1-month postoperative, 51.05 mm after 10 to 14 months postoperative, and 27.03 mm after 2 years postoperative.

CONCLUSIONS

This study found excellent head shape outcomes for both the LISC and OCVR techniques at 2 years of age. It also corroborates the slow and progressive improvement in head shape with the LISC technique. This study highlights the advantages of 3D photography for measurement of contour outcomes, utilizing both 2D vector and 3D whole head analytical techniques.

Public Perception of a Normal Head Shape in Children With Sagittal Craniosynostosis

: A question that remains unanswered is at what level of surgical correction does the public perceive a head shape to be "normal" or "acceptable?" For most cases of non-syndromic asymptomatic craniosynostosis, the parents desire for surgical correction is to improve the cosmetic appearance of head shape. At the time of this writing, the intraoperative surgeons' perspective of what constitutes an acceptable head shape is the target for surgical correction. In introducing an improved objectively cosmetic goal, an appropriate outcome measure would be to assess what the general public considers a normal or acceptable head shape in children with craniosynostosis.

METHOD

Twenty-two unique images were presented via an online crowdsourcing survey of a severe case of non-syndromic sagittal craniosynosis gradually corrected to an age and gender matched normalized head shape. Participants were recruited via the Sick Kids Twitter account. Participants were invited to rate the head shapes as "normal" or "abnormal."

RESULTS

The 538 participants completed the online survey. Participants were able to reliably and consistently identify normal and abnormal head shapes with a Kappa Score >0.775. Furthermore, participants indicated that a correction of 70% is required in order for the cranial deformity to be regarded as "normal." This threshold closely reflects a normal Cranial Index, which is a widely used morphometric outcome in craniosynostosis.

CONCLUSION

Crowdsourcing provides an ideal method for capturing the general population's perspective on what constitutes a normal and acceptable head shape in children with sagittal craniosynostosis. Laypersons are able to reliably and consistently distinguish cranial deformities from a "normal" head shape. The public indicates a threshold correction of 70% in sagittal craniosynosis to regard it as a "normal" head shape.

Diagnosis and treatment of positional plagiocephaly

Positional plagiocephaly is increasing in infants. Positional plagiocephaly is an asymmetric deformation of skull due to various reasons; first birth, assisted labor, multiple pregnancy, prematurity, congenital muscular torticollis and position of head. Positional plagiocephaly can mostly be diagnosed clinically and by physical examinations. The simplest way to assess the severity of plagiocephaly is to use a diagonal caliper during physical examination, which measures the difference between the diagonal lengths on each side of the head. Plagiocephaly can be treated surgically or conservatively. Positional plagiocephaly, which is not accompanied by craniosynostosis, is treated conservatively. Conservative treatments involve a variety of treatments, such as change of positions, physiotherapy, massage therapy, and helmet therapy. Systematic approaches to clinical examination, diagnosis and treatment of positional plagiocephaly can be necessary and the age-appropriate treatment is recommended for patients with positional plagiocephaly.

Long-term 3D CT follow-up after endoscopic sagittal craniosynostosis repair

OBJECTIVE

Surgical treatment of sagittal synostosis involves various surgical modalities. Long-term follow-up issues include increased intracranial pressure, secondary sutural fusion, incomplete reossification, and suboptimal cosmetic appearance. The authors' objective in this study was to review their long-term endoscopic surgical results in children with sagittal synostosis using 3D CT.

METHODS

The authors reviewed the long-term results of their first 38 patients who underwent endoscopic sagittal synostosis repair at age 16 weeks or younger. A standard vertex craniectomy with biparietal wedges was done in each case. After surgery, the children were fitted with a helmet, which they wore until 8 months of age. Patients were followed up for 5 years or longer, at which point a 3D CT scan was obtained. The authors examined data on the cranial index, area of bony defect, presence or absence of secondary sutural fusion, neosuture formation, and scalloping of the inner table of the skull.

RESULTS

Thirty-two of 38 children met inclusion criteria. There was a small but significant recession of the cranial index after the completion of helmeting (from 0.772 after completion of helmeting to 0.755 at 5 years). Of 32 children, 14 had a bony defect area > 4 cm2. Three children had secondary sutural fusion (two unilateral coronal, one bicoronal). Ten of 32 patients had partial neosuture formation.

CONCLUSIONS

The authors report their experience with 32 of their first 38 children who underwent endoscopic sagittal synostosis repair at 16 weeks of age or younger. With a minimum duration of 5 years, this is the longest clinicoradiological follow-up utilizing 3D CT to date in children with sagittal synostosis treated with endoscopic surgery. The authors report detailed measurements of bony loss, adjacent sutural fusion, and neosuture formation.

Molding Helmet Therapy for Deformational Brachycephaly

BACKGROUND

Molding helmet therapy is used for the treatment of infants with deformational brachycephaly (DB). There is a lack of rigorous outcome measures of helmet therapy in patients with DB using 3-dimensional (3D) imaging, with most reports rely on either subjective or 2-dimensional analyses. Furthermore, the longitudinal assessment of head shape improvement over the course of helmet therapy has not been documented. Our goal was to assess the outcome of molding helmet therapy using 3D surface imaging, and to document the pace of improvement during treatment.

METHODS

The head shape of 18 infants with DB who underwent orthotic molding helmet therapy was assessed. The 3D scans were obtained before treatment, during treatment, and at the end of treatment. First, we applied shape analysis techniques based on template deformation to obtain average (composite) heads of the 18 patients at the 3 time points of treatment (pretreatment, during, and posttreatment). In addition, we used 3D curvature analysis to quantify the degree of flatness at the same time points.

RESULTS

Molding helmet therapy started at 6.7 ± 0.9 months of age and lasted for 4.3 ± 0.8 months. The overall difference in the occipital contour between pretreatment and end of treatment was 6.3 ± 1.7 mm. Curvature analysis revealed that 15% of the back of the head had prehelmet marked flatness (mean curvature <5/m), which decreased to 9% at 2.5 months into treatment and 7% at the end of treatment.

CONCLUSION

Over 65% of the head shape improvement occurred during the 2.5 months of molding helmet therapy.