Surgical Treatment of Nonsyndromic Unicoronal Craniosynostosis:

Towards a radiation free numerical modelling framework to predict spring assisted correction of scaphocephaly

Sagittal Craniosynostosis (SC) is a congenital craniofacial malformation, involving premature sagittal suture ossification; spring-assisted cranioplasty (SAC) - insertion of metallic distractors for skull reshaping - is an established method for treating SC. Surgical outcomes are predictable using numerical modelling, however published methods rely on computed tomography (CT) scans availability, which are not routinely performed. We investigated a simplified method, based on radiation-free 3D stereophotogrammetry scans.Eight SAC patients (age 5.1 ± 0.4 months) with preoperative CT and 3D stereophotogrammetry scans were included. Information on osteotomies, spring model and post-operative spring opening were recorded. For each patient, two preoperative models (PREOP) were created: i) CT model and ii) S model, created by processing patient specific 3D surface scans using population averaged skin and skull thickness and suture locations. Each model was imported into ANSYS Mechanical (Analysis System Inc., Canonsburg, PA) to simulate spring expansion. Spring expansion and cranial index (CI - skull width over length) at times equivalent to immediate postop (POSTOP) and follow up (FU) were extracted and compared with in-vivo measurements.Overall expansion patterns were very similar for the 2 models at both POSTOP and FU. Both models had comparable outcomes when predicting spring expansion. Spring induced CI increase was similar, with a difference of 1.2%±0.8% for POSTOP and 1.6%±0.6% for FU.This work shows that a simplified model created from the head surface shape yields acceptable results in terms of spring expansion prediction. Further modelling refinements will allow the use of this predictive tool during preoperative planning.

Pre-Operative Ocular Findings and Long-Term Follow-Up in a Large Cohort of Non-Syndromic Unicoronal Craniosynostosis

(1) Background: Non-syndromic unicoronal craniosynostosis (UCS) is associated with a high prevalence of ocular anomalies. Currently, the etiology of this association remains obscure, however, it is presumed to be primarily attributed to their orbital malformations and/or secondary to craniofacial surgery. We assessed pre-operative ophthalmological examinations of non-syndromic UCS patients and compared them with their postoperative outcomes and long-term follow-up. (2) Methods: A retrospective case series was conducted on medical records of patients with non-syndromic UCS at Sophia Children's Hospital, Rotterdam. Ophthalmologic examinations were collected at different time periods: T1 (first visit), T2 (<1 year after cranioplasty), and T3 (long-term follow-up at last visit). The McNemar's test was used for statistical analysis. (3) Results: A total of 101 patients were included, for whom examinations were available at T1 and T3. Patients had a mean age of 2.8 years (±2.7) and 9.5 (±4.9) at T1 and T3, respectively. At T1, 52 patients (51.5%) were diagnosed with strabismus, and 61 patients (60.4%) at T3. Vertical strabismus increased significantly from 23 patients (22.8%) at T1 to 36 patients (35.6%) at T3 (p = 0.011). Followed by astigmatism, which increased significantly from 38 (37.6%) at T1 to 59 (58.4%) patients at T3 (p = 0.001). T1 was available in 20 patients prior to fronto-orbital advancement (FOA), therefore, a sub-analysis was conducted on these patients, which was followed shortly after FOA at T2. Prior to FOA, strabismus was present in 11 patients (55.0%) and in 12 patients (60.0%) at T2. After FOA, strabismus worsened in two patients. (4) Conclusions: This study showed the high prevalence of ocular anomalies in patients with non-syndromic UCS before and after cranioplasty and at long-term follow-up. The findings of this study show that ophthalmic and orthoptic examinations are an important part of the optimal treatment of patients with non-syndromic UCS.

Orbital and Eyelid Characteristics, Strabismus, and Intracranial Pressure Control in Apert Children Treated by Endoscopic Strip Craniectomy versus Fronto-Orbital Advancement

Apert syndrome is characterized by eyelid dysmorphology, V-pattern strabismus, extraocular muscle excyclorotation, and elevated intracranial pressure (ICP). We compare eyelid characteristics, severity of V-pattern strabismus, rectus muscle excyclorotation, and ICP control in Apert syndrome patients initially treated by endoscopic strip craniectomy (ESC) at about 4 months of age versus fronto-orbital advancement (FOA) performed about 1 year of age.

Methods

Twenty-five patients treated at Boston Children's Hospital met inclusion criteria for this retrospective cohort study. Primary outcomes were magnitude of palpebral fissure downslanting at 1, 3, and 5 years of age, severity of V-pattern strabismus, rectus muscle excyclorotation, and interventions to control ICP.

Results

Before craniofacial repair and through 1 year of age, none of the studied parameters differed for FOA versus ESC treated patients. Palpebral fissure downslanting became statistically greater for those treated by FOA by 3 (P < 0.001) and 5 years of age (P = 0.001). Likewise, severity of palpebral fissure downslanting correlated with severity of V-pattern strabismus at 3 (P = 0.004) and 5 (P = 0.002) years of age. Palpebral fissure downslanting and rectus muscle excyclorotation were typically coexistent (P = 0.053). Secondary interventions to control ICP were required in four of 14 patients treated by ESC (primarily FOA) and in two of 11 patients initially treated by FOA (primarily third ventriculostomy) (P = 0.661).

Conclusions

Apert patients initially treated by ESC had less severe palpebral fissure downslanting and V-pattern strabismus, normalizing their appearance. Thirty percent initially treated by ESC required secondary FOA to control ICP.

Neurodevelopment in unilateral coronal craniosynostosis: a systematic review and meta-analysis

OBJECTIVE

The current literature on unilateral coronal craniosynostosis is replete with repair techniques and surgical outcomes; however, information regarding neurodevelopment remains unclear. Therefore, the aim of this systematic review and meta-analysis was to comprehensively assess the neurodevelopmental outcomes of patients with unicoronal craniosynostosis compared with their healthy peers or normative data.

METHODS

A systematic review of the Ovid MEDLINE, Embase, Web of Science, Scopus, Cochrane Library, and ClinicalTrials.gov databases from database inception to January 19, 2022, was performed. Included studies assessed neurodevelopment of patients with unicoronal craniosynostosis. Two independent reviewers selected studies and extracted data based on a priori inclusion and exclusion criteria. Results of developmental tests were compared with normative data or controls to generate Hedges' g statistics for meta-analysis. The quality of included studies was evaluated using the National Institutes of Health Assessment Tool.

RESULTS

A total of 19 studies were included and analyzed, with an overall fair reporting quality. A meta-analysis of 325 postoperative patients demonstrated that scores of general neurodevelopment were below average but within one standard deviation of the norm (Hedges' g = -0.68 [95% CI -0.90 to -0.45], p < 0.001). Similarly, postoperative patients exhibited lower scores in verbal, psychomotor, and mathematic outcome assessments.

CONCLUSIONS

This systematic review and meta-analysis found that patients with unicoronal craniosynostosis had poorer neurodevelopment, although scores generally remained within the normal range. These data may guide implementation of regular neurocognitive assessments and early learning support of patients with unicoronal craniosynostosis.

One-piece fronto-orbital distraction osteogenesis without bandeau in patients with coronal craniosynostosis: A five-year follow-up retrospective study of 45 consecutive patients

This study aimed to review the surgical outcomes, complications, and long-term relapses in patients with unilateral or bilateral coronal craniosynostosis, who underwent one-piece fronto-orbital distraction osteogenesis (FODO) without bandeau. The cephalic index, frontal angle, and supraorbital symmetry ratio were measured on the initial and follow-up computed tomography images. Esthetic outcomes were evaluated using the Whitaker classification. 45 patients were included in this study. The average follow-up interval was 5.4 ± 1.1 years (range 2.5-8.5 years). In patients with bilateral coronal craniosynostosis, the frontal angle decreased with a relapse ratio of -2.8 ± 4.3% during long-term follow-up compared with that during short-term follow-up (p = 0.028). In patients with unilateral coronal craniosynostosis, the supraorbital symmetry ratio decreased slightly, with a relapse ratio of -3.8 ± 2.6% during long-term follow-up (p = 0.017). Complications included dural tears during osteotomy (n = 2), early distractor removal (n = 2), and wound problems (n = 3). Within the limitations of the study it seems that one-piece fronto-orbital distraction osteogenesis (FODO) generates successful and sustainable results even in the long term. Therefore, this treatment option should be considered for patients with unilateral and bilateral coronal craniosynostoses whenever appropriate.

Comparing the Increased Intracranial Volume From Different Surgical Methods for Syndromic Craniosynostosis

PURPOSE

Fronto-orbital advancement (FOA) is the traditional surgical method used to increase intracranial volume, but posterior cranial vault distraction osteogenesis (PVDO) has been gaining popularity as an initial treatment option. This study aimed to compare the effects of FOA and PVDO on intracranial volume.

PATIENTS AND METHODS

Sixteen patients with multiple-suture synostosis and severe intracranial volume restriction were treated with FOA or PVDO at Children's Hospital of Fudan University between January 2016 and December 2019. Data on age at surgery, sex, preoperative intracranial volume, and postoperative intracranial volume were collected.

RESULTS

Seven patients underwent FOA and 9 underwent PVDO. All patients underwent surgery for the first time, and the surgeries were performed by the same physician. There was no statistically significant difference in age at surgery or in the intracranial volumes before and after surgery between the 2 groups (P>0.05). There was a statistically significant difference in the intracranial volume changes between the 2 groups before and after surgery (P=0.028).

CONCLUSIONS

Posterior cranial vault distraction osteogenesis provided statistically greater intracranial volume expansion than FOA.

Treatment of Unicoronal Craniosynostosis by Rotational Flap Technique Preserves Blood Supply to the Frontal Bone Flap

BACKGROUND

Surgical correction of unicoronal craniosynostosis (UCS) remains a challenging problem. Long-term results are often unsatisfactory secondary to recurrence of the original deformity, requiring secondary operations such as fat grafting or complete revision of the calvarial remodeling. Distraction osteogenesis (DO) has recently emerged as a new modality for treatment of UCS, with promising results and decreased rates of reoperation compared with open cranial vault remodeling. A theoretical benefit of DO is preservation of blood supply to the frontal bone following osteotomy, as the frontal bone can be retained in situ compared with the complete removal and reshaping of the frontal bone during traditional fronto-orbital advancement. Preservation of blood supply to the frontal bone may allow for more robust bony healing and preservation of long-term growth potential; however, the vascularity of the frontal bone flap in DO has not previously been demonstrated. Here, we demonstrate unequivocally that blood supply to the frontal bone is preserved after creation of a rotational bone flap in DO management of UCS.

METHODS

Frontal bone flap creation via osteotomy for DO treatment of UCS was performed via previously reported technique. Indocyanine green was injected intravenously, and bone perfusion was assessed with a fluorescence imaging system.

RESULTS

Four patients underwent three cranial remodeling and three distractor removal procedures. After frontal bone flap creation via osteotomy for DO, perfusion to the osteotomized portion of the frontal bone flap is preserved. Blood flow is seen crossing the midline of the frontal bone. After removal of the distractor, perfusion in the osteoid consolidate is also observed.

CONCLUSIONS

Preservation of blood supply has not been previously demonstrated empirically in the setting of DO treatment of UCS. We show for the first time that during frontal bone flap creation, blood flow to the osteotomized portion of the frontal bone flap is maintained. Robust blood flow to the osteoid consolidate is also demonstrated. These data support the use of DO in treatment of UCS, as preserved blood supply to the bone is more likely to support improved healing and long-term results.

Endoscopic strip craniectomy with orthotic helmeting for safe improvement of head growth in children with Apert syndrome

OBJECTIVE

Bilateral coronal craniosynostosis in Apert syndrome is traditionally managed with open cranial vault remodeling procedures like fronto-orbital advancement (FOA). However, as minimally invasive procedures gain popularity, limited data exist to determine their efficacy in this syndromic population. This study examines whether endoscopic strip craniectomy (ESC) is inferior to FOA in correcting head growth in patients with Apert syndrome.

METHODS

The authors conducted a retrospective review of children with Apert syndrome over a 23-year period. Postoperative head circumferences until 24 months of age were compared for patients treated with ESC versus FOA by using normative growth curves. Intraoperative and postoperative morbidity was compared between groups.

RESULTS

The median postoperative follow-up for the FOA (n = 14) and ESC (n = 16) groups was 40 and 28.5 months, the median age at operation was 12.8 and 2.7 months, and the median operative time was 285 and 65 minutes, respectively (p < 0.001). The FOA group had significantly higher rates of blood transfusion, ICU admission, and longer hospital length of stay (p < 0.01). There were no statistically significant differences in premature reossification rates, complications, need for further procedures, or complaints of asymmetry. Compared to normative growth curves, all patients in both groups had head circumferences comparable to or above the 85th percentile at last follow-up.

CONCLUSIONS

Children with Apert syndrome and bilateral coronal craniosynostosis treated with ESC experience early normalization of head growth and cephalic index that is not inferior to those treated with FOA. Longer-term assessments are needed to determine long-term aesthetic results and the correlation between head growth and neurocognitive development in this population.

School-age outcomes in patients with unilateral coronal synostosis: comparison of fronto-orbital advancement and endoscopic strip craniectomy

OBJECTIVE

Outcomes research on unilateral coronal synostosis is mostly limited to the early postoperative period. This study examines facial asymmetry, desire for revision, and patient-reported outcomes at school age in children who received either endoscopic strip craniectomy with helmet therapy or fronto-orbital advancement (open repair).

METHODS

Patients with repaired unilateral coronal synostosis born between 2000 and 2017, with 3D photographs taken when they were between 3.5 and 8 years of age, were eligible for study inclusion. Three pairs of bilateral linear measurements and two angular measurements were taken. Parent- and physician-reported desire for revision and patient-reported outcomes (Patient-Reported Outcomes Measurement Information System cognitive function and Quality of Life in Neurological Disorders stigma scores) were collected from patient charts.

RESULTS

Thirty-five patients qualified, including 25 with open repair and 10 with endoscopic repair. The median patient ages at repair were 3 months and 8 months in the endoscopic and open groups, respectively. The average ages at final 3D photography were 5.8 years and 5.5 years in the endoscopic and open groups, respectively. Digital anthropometry revealed no significant differences in measures of facial asymmetry between the repair groups (p ≥ 0.211). Midface depth (tragion to subnasale) was significantly less symmetric at school age than other linear measures (F(2,102) = 9.14, p < 0.001). Forehead asymmetry was significantly associated with parent- and physician-reported desire for revision (p ≤ 0.006). No significant associations were found between physical asymmetry and patient-reported stigma or cognitive function (p > 0.046, Holm-Bonferroni correction).

CONCLUSIONS

Children who underwent open or endoscopic repair for unilateral coronal synostosis have comparable facial symmetry at school age, but midface depth remains highly asymmetrical in both groups. Forehead asymmetry at school age correlates with parent- and physician-reported desire for revision.

Ophthalmological findings in children with unicoronal craniosynostosis

INTRODUCTION

Among non-syndromic, single-suture craniosynostoses, unicoronal craniosynostosis (UCS) presents the highest rate of ophthalmic manifestations requiring a visual follow-up, due to the high risk of amblyopia. After birth or during childhood, children with UCS have a high risk to present an aniso-astigmatism and a strabismus. The aim of this study was to characterize clinical ophthalmologic findings associated with UCS in a paediatric cohort.

METHODS

This retrospective study included children admitted in our unit between 2015 and 2021, with isolated UCS treated in our institution and complete ophthalmological assessment comprising visual assessment, refractive status and oculomotor examination. Children with associated craniofacial disorders were excluded.

RESULTS

A total of 28 children met the inclusion criteria. Median age was 62 [13-192] months with a large proportion of girls (86%) and 71% of right-sided UCS. The mean best corrected visual acuity was 0.07 (±0.13) LogMAR, including 10 (36%) children with an amblyopia or history of amblyopia. Astigmatism was significantly higher on the contralateral side of the UCS than on the ipsilateral side, with a refractive cylinder error of 0.97 (±1.06) vs 0.56 (±0.68) diopters, respectively (p = 0.03). Strabismus was observed in 20 patients (71%) with a main pattern of esotropia with a vertical component. A pseudo-superior oblique palsy was found in 13 children (65%) with a median cyclodeviation of 8.7° [-5,4°-20.6°].

CONCLUSION

Children with UCS experience a high rate of various visual manifestations. This study highlights their need for a strict ophthalmological follow-up, in order to early diagnose and prevent visual complications.

Distraction osteogenesis in craniosynostosis

PURPOSE OF REVIEW

Craniosynostosis, a condition of premature cranial suture fusion, can have significantly detrimental effects on development and growth due to sequelae of increased intracranial hypertension (ICP), exophthalmos, and upper airway obstruction. Evolving surgical treatments now include distraction osteogenesis (DO) due to its many benefits relative to standard cranial vault remodeling procedures. This article provides an overview and update of different surgical applications of DO for patients with craniosynostosis.

RECENT FINDINGS

DO has been utilized successfully for single and multisuture craniosynostosis with or without midface hypoplasia to increase intracranial volume, decrease ICP and improve aesthetics. It has been applied in single suture synostosis, posterior vault DO, fronto-orbital advancement, monobloc DO and Le Fort III DO. DO has been applied through modification of traditional surgical procedures with success in maintaining goals of surgery while reducing risk.

SUMMARY

DO is still a relatively new and evolving surgical technique for patients with syndromic and nonsyndromic craniosynostosis. With promising benefits, consideration for each procedure should be weighed until longer-term data is available.

A Single-Center Retrospective Review of Perioperative Complications and Reoperation Rates Between Open Cranial Vault Remodeling and Distraction Osteogenesis for Unilateral Coronal Craniosynostosis

BACKGROUND

Unilateral coronal craniosynostosis (UCS) is the third most prevalent form of craniosynostosis. Traditional treatment of UCS has been achieved with fronto-orbital advancement and cranial vault remodeling (FOAR), but utilization of cranial distraction osteogenesis (DO) techniques has increased. This study aims to compare perioperative complications and reoperation trends in FOAR versus DO techniques at a single institution.

METHODS

An Institutional Review Board-approved retrospective review was performed from January 1999 to November 2018 at a single institution. Patients were those that have undergone FOAR or DO with an anterior rotational flap technique as previously described. Indications for secondary procedures included: contour deformities, relapse, surgical site infection, and persistent cranial defects.

RESULTS

Eighty-one patients with UCS were identified, 64 patients underwent FOAR and 17 patients underwent DO. When perioperative characteristics were compared, patients who underwent DO were younger in age, however, there was no significant difference in transfusion requirement or length of stay between patient cohorts. Surgery time was increased in DO patients. When perioperative complications were compared, more intraoperative dural tears were observed in the FOAR cohort. When unplanned reoperation rates were compared, patients who had undergone FOAR had a statistically significant higher reoperation rates at 5 years of follow up. When including routine distractor removal as a reoperation, reoperative rate was increased in the DO cohort. No difference in reoperation rates was noted at 5 years following index operation.

CONCLUSIONS

The safety profile of DO is similar to that of traditional FOAR techniques for treatment of UCS. Longer-term follow-up studies are needed to elucidate whether outcomes are durable, but the unplanned reoperation rate in DO is less than that of FOAR at 5 years and presents several advantages that warrants its use in patients with UCS.

Orbital Volumetric Analysis in Patients With Unicoronal Craniosynostosis: A Comparison Between Distraction Osteogenesis and Fronto-Orbital Advancement

BACKGROUND

Unicoronal craniosynostosis is associated with orbital restriction and asymmetry. Surgical treatment aims to both correct the aesthetic deformity and prevent the development of ocular dysfunction. We used orbital quadrant and hemispheric volumetric analysis to assess orbital restriction and compare the effectiveness of distraction osteogenesis with anterior rotational cranial flap (DO) and bilateral fronto-orbital advancement and cranial vault remodeling (FOAR) with respect to the correction of orbital restriction in patients with unicoronal craniosynostosis.

METHODS

A retrospective review of all patients with a diagnosis of unicoronal craniosynostosis and treated with either DO or FOAR from 2000 to 2019 was performed. Preoperative and postoperative total orbital volumes, as well as quadrant and hemispheric volume ratios, were calculated from 3-dimensional head computed tomography scans. Selected preoperative and postoperative orbital measurements, including the maxillary length of the orbit (MLO; zygomaticofrontal suture to the top of zygomatic arch) and the sphenoid length of the orbit (SLO; the top of sphenoid suture to the top of zygomatic arch), were also obtained.

RESULTS

Data were available for 28 patients with unicoronal craniosynostosis. Mean preoperative total orbital volume was significantly smaller on the synostotic side compared with the nonsynostotic side (10.94 vs 12.20 cm3, P = 0.04). Preoperative MLO and SLO were significantly longer on the synostotic side compared with the nonsynostotic side (MLO: 20.26 vs 17.75 mm, P < 0.001; SLO: 26.91 vs 24.93 mm, P = 0.01). Distraction osteogenesis and FOAR produced significantly different changes in orbital quadrant and/or hemispheric volume ratios on the nonsynostotic side but not on the synostotic side.

CONCLUSIONS

Before correction, patients with unicoronal craniosynostosis have significantly smaller total orbital volumes on the synostotic side compared with the nonsynostotic side and significantly greater MLO and SLO on the synostotic side compared with the nonsynostotic side. There is no significant difference between DO and FOAR with regard to correcting the observed orbital restriction in these patients.

A Comparative Analysis of the Sonopet Ultrasonic Bone Aspirator to Traditional Instrumentation for Endoscopic Suturectomy for Craniosynostosis

OBJECTIVE

The goal of endoscopic treatment for craniosynostosis is to remove the fused suture and achieve calvarial remodeling with external orthosis. To reduce the need for secondary surgery and to minimize blood loss, instruments that maximize bone removal while minimizing blood loss and risk of dural injury are evolving. The authors therefore assess the safety and efficacy of the Sonopet Ultrasonic Bone Aspirator (UBA) (Stryker, Kalamazoo, MI) for endoscopic suturectomy compared to traditional instrumentation at our institution.

METHODS

Retrospective chart review of consecutive endoscopic suturectomies performed from 2011 to 2019 at Weill Cornell Medical Center was conducted, including demographics, cephalic index, surgical indications, operative time, cosmetic and functional results, complications, estimated blood loss (EBL), re-operation rate, length of stay, and length of helmet therapy. These variables were then compared between the Sonopet and non-Sonopet cohorts.

RESULTS

Of the 60 patients who underwent endoscopic suturectomy, 16 cases (26.7%) utilized the Sonopet. Mean operative time was 2.8 ± 0.4 hours in the Sonopet group, compared to 3.2 ± 1.2 hours (P = 0.05) without the Sonopet. EBL was 17.8 ± 23.9 cc versus 34.7 ± 75.5 cc (P = 0.20) with versus without the Sonopet respectively. Length of stay and duration of helmet therapy were similar in both groups, ranging from 1 to 3 days (P = 0.68) and 7.25 to 12 months (P = 0.30) respectively. There were no reoperations in the Sonopet group with a mean follow up of 9.18 months. There were 3 reoperations in the non-Sonopet group with a mean follow up of 11.3 months. Among the cases utilizing the Sonopet, 13 (81%) were metopic and three (19%) were coronal synostoses. Of the non-Sonopet cases, 27 (61%) were sagittal, 8 (18%) were metopic, 7 (16%) were coronal, and 2 (5%) were lambdoid synostoses.

CONCLUSIONS

The use of the Sonopet resulted in a mean decrease in operative time at our institution (P = 0.18). Lower EBL and reoperation rates with comparable LOS and helmet therapy duration were also seen. This modality should be considered a safe and effective adjunct in appropriate endoscopic craniosynostosis cases.

Neurological Functional Connectivity in Unilateral Coronal Synostosis: A Side-Based Comparison

PURPOSE

Unicoronal synostosis (UCS) has been associated with reading, language, and social dysfunction. Limited brain function connectivity studies exist for UCS with none devoted to comparing outcomes by side of synostosis (left versus right-sided UCS).

METHODS

Twelve patients with surgically treated UCS, 7 right-sided and 5 left-sided, were age matched to healthy controls. Resting state functional MRI was acquired in a 3T Siemens TIM Trio scanner (Erlangen, Germany). Data was collected with intrinsic connectivity distribution and seed-connectivity analysis using BioImage Suite (Yale School of Medicine). Region of interest analysis was performed based on Brodmann areas related to emotional, executive, language, motor, and visuo-spatial function. Significance was set at P < 0.05.

RESULTS

Compared to controls, all UCS patients demonstrated decreased connectivity in areas of the parietal and temporal cortices responsible for visuo-motor coordination and language function. Right UCS patients demonstrated decreased intrinsic connectivity in regions related to complex motor movement and proprioception relative to control subjects. Left UCS patients demonstrated decreased seed connectivity between regions of the parietal lobe and occipital lobe related to motor coordination, visual function, and language compared to right UCS patients.

CONCLUSION

Unicoronal synostosis had decreased functional connectivity in regions associated with memory, visual information processing, and motor function. Moreover, left-sided UCS had decreased connectivity in circuits for motor coordination and language when compared to right-sided UCS. This study provides data suggestive of long-term sequelae of UCS that varies by sidedness, which may be responsible for neurocognitive impairments found in previous cognitive analyses.

Test-retest validation of a cranial deformity index in unilateral coronal craniosynostosis

Unilateral coronal craniosynostosis (UCS) affects many infants resulting in abnormalities affecting the forehead and orbits. As a result, the deformity caused by UCS is very noticeable and there are several surgical treatment options available to normalize the head shape. However, there is a lack of consistently used outcome measures, resulting in difficulty assessing surgical outcomes and on-going debate over optimal treatments. Current techniques to quantify deformity in UCS are cumbersome, provide limited information, or are based on subjective assessments. In this study, a cranial deformity index was developed to quantify abnormality at the frontal bones for UCS that is accessible, user-friendly, and generates objective surface distance measurements. The cranial deformity index is defined as the Euclidean distance at the point of the largest deviation between the deformed skull compared to a reference skull. In addition, the index was successfully used to quantify post-operative changes in a single case of UCS that underwent corrective surgery. The reproducibility of the index was assessed using test-retest reliability and was demonstrated to be highly reproducible (ICC = 0.93). A user-friendly measurement index that is based on open-source software may be a valuable tool for surgical teams. In addition, this information can augment the consultation experience for patients and their families.

Skeletal Deformity in Patients With Unilateral Coronal Craniosynostosis: Perceptions of the General Public

Study Design

A two-alternative forced choice design was used to gather perceptual data regarding unicoronal synostosis (UCS).

Objective

Cranial vault remodeling aims at improving the aesthetic appearance of infants with UCS by reshaping the forehead and reducing the potential for psychosocial discrimination. People's perception of craniofacial deformity plays a role in the stigma of deformity. The purpose of this study is to examine the relationship between objective skull deformity in UCS patients and laypersons' perception of skull normality.

Methods

Forty layperson skull raters were recruited from the general public. Skull raters were asked to categorize 45 infant skull images as normal or abnormal. Twenty-one of the images were UCS skulls, and 24 were normal skulls. Skulls were displayed briefly on a computer to simulate a first impression scenario and generate a perceptual response. A χ ² analysis and mixed-effects regression model were used to analyze the response data.

Results

Members of the general public were good at distinguishing between skull groups, χ ² (1) = 281.97, P < .001. In addition, skull raters' responses were predicted by the severity of deformity in the UCS skulls (b = -0.10, z = -2.6, P = .010, CI: -0.18, -0.02). A skull with a deformity value of 2.8 mm (CI: 1.8, 4.1) was equally likely to be rated normal or abnormal.

Conclusions

This is the first study to investigate the relationship between objective skull deformity in UCS and public perception. Laypersons were good at distinguishing the difference between normal and UCS skulls, and their perceptions of normality were predicted by the degree of skull deformity.

Strabismus in Unicoronal Craniosynostosis: Effect of Orbital Dysmorphology and Fronto-Orbital Advancement and Remodeling

BACKGROUND

The purpose of this study was to determine what craniometric changes occur to both orbits of unicoronal craniosynostosis patients undergoing fronto-orbital advancement and remodeling, and which of these changes are associated with new onset of postoperative strabismus.

METHODS

A retrospective analysis was performed of the preoperative and postoperative orbits of 24 unicoronal craniosynostosis patients and the orbits of 24 control subjects, totaling 144 orbits. Eight parameters were evaluated using multivariate logistic regression analysis. One of the parameters was modified orbital index, an indicator of severity of harlequin deformity.

RESULTS

Significant differences in orbital dimensions and angles were present bilaterally in unicoronal craniosynostosis orbits when compared to controls. Fronto-orbital advancement and remodeling increased the ipsilateral unicoronal craniosynostosis orbital volume from 13,184 ± 2003 mm to 16,220 ± 2323 mm (p < 0.001). Ipsilateral horizontal cone angles were increased from 48 ± 5 degrees to 54 ± 7 degrees (p = 0.004). Ipsilateral vertical cone angles were decreased from 73 ± 8 degrees to 66 ± 10 degrees (p = 0.003). Ipsilateral modified orbital index improved from 0.83 ± 0.06 to 0.88 ± 0.06 (p = 0.003). Three of the 19 unicoronal craniosynostosis patients developed transient postoperative strabismus. Logistic regression analysis displayed a strong significant association between new-onset strabismus and a change in modified orbital index with a coefficient of 30.84 ± 14.51 (p < 0.05).

CONCLUSIONS

The orbital dysmorphology in unicoronal craniosynostosis is bilateral in nature, and it is not wholly treated with conventional fronto-orbital advancement and remodeling. The severity of ipsilateral orbital dysmorphology is correlated with the incidence of postoperative strabismus following conventional fronto-orbital advancement and remodeling. Future research is needed to develop strategies to mitigate the risk of development of strabismus in this group of patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Computational Evaluation of Potential Correction Methods for Unicoronal Craniosynostosis

Unicoronal craniosynostosis is the second most common type of nonsyndromic craniosynostosis: it is characterized by ipsilateral forehead and fronto-parietal region flattening with contralateral compensatory bossing. It is a complex condition; therefore, which is difficult to treat because of the asymmetry in the orbits, cranium, and face. The aim of this study is to understand optimal osteotomy locations, dimensions, and force requirements for surgical operations of unicoronal craniosynostosis using a patient-specific finite element model and - at the same time - to evaluate the potential application of a new device made from Nitinol which was developed to expand the affected side of a unicoronal craniosynostosis skull without performing osteotomies. The model geometry was reconstructed using Simpleware ScanIP. The bone and sutures were modeled using elastic properties to perform the finite element analyses in MSc Marc software. The simulation results showed that expanding the cranium without osteotomy requires a significant amount of force. Therefore, expansion of the cranium achieved by Nitinol devices may not be sufficient to correct the deformity. Moreover, the size and locations of the osteotomies are crucial for an optimal outcome from surgical operations in unicoronal craniosynostosis.

Extraocular muscle positions in anterior plagiocephaly: V-pattern strabismus explained using geometric mophometrics

INTRODUCTION

Ophthalmological involvement in anterior plagiocephaly (AP) due to unicoronal synostosis (UCS) raises management challenges. Two abnormalities of the extraocular muscles (EOM) are commonly reported in UCS without objective quantification: (1) excyclorotation of the eye and (2) malposition of the trochlea of the superior oblique muscle. Here we aimed to assess the positions of the EOM in AP, using geometric morphometrics based on MRI data.

MATERIALS AND METHODS

Patient files were listed using Dr WareHouse, a dedicated big data search engine. We included all patients with AP managed between 2013 and 2018, with an available digital preoperative MRI. MRIs from age-matched controls without craniofacial conditions were also included. We defined 13 orbital and skull base landmarks in order to model the 3D position of the EOM. Cephalometric analyses and geometric morphometrics with Procrustes superimposition and principal component analysis were used with the aim of defining specific EOM anomalies in UCS.

RESULTS

We included 15 preoperative and 7 postoperative MRIs from patients with UCS and 24 MRIs from age-matched controls. Cephalometric analyses, Procrustes superimposition and distance computations showed a significant shape difference for the position of the trochlea of the superior oblique muscle and an excyclorotation of the EOM.

CONCLUSIONS

Our results confirm that UCS-associated anomalies of the superior oblique muscle function are associated with malposition of its trochlea in the roof of the orbit. This clinical anomaly supports the importance of MRI imaging in the surgical management of strabismus in patients with UCS.

Papilledema in unicoronal synostosis: a rare finding

OBJECTIVE

Unicoronal synostosis results in frontal plagiocephaly and is preferably treated before the patient is 1 year of age to prevent intracranial hypertension (ICH). However, data on the prevalence of ICH in these patients is currently lacking. This study aimed to establish the prevalence of preoperative and postoperative signs of ICH in a large cohort of patients with unicoronal synostosis and to test whether there is a correlation between papilledema and occipitofrontal head circumference (OFC) curve stagnation in unicoronal synostosis.

METHODS

The authors included all patients with unicoronal synostosis treated before 2 years of age at a single center between 2003 and 2013. The presence of ICH was evaluated by routine fundoscopy. The OFC growth curve was analyzed for deflection and in relationship to signs of ICH.

RESULTS

In total, 104 patients were included in this study, 84 (81%) of whom were considered to have nonsyndromic unicoronal synostosis. Preoperatively, none of the patients had papilledema as determined by fundoscopy (mean age at surgery 11 months). Postoperatively, 5% of patients with syndromic synostosis and 3% of those with nonsyndromic synostosis had papilledema, and this was confirmed by optical coherence tomography. Raised intracranial pressure was confirmed in 1 patient with syndromic unicoronal synostosis. Six of 78 patients had OFC stagnation, which was not significantly correlated to papilledema (p = 0.22). One child with syndromic unicoronal synostosis required repeated surgery for ICH (0.96%).

CONCLUSIONS

Papilledema was not found in patients with unicoronal synostosis when they underwent surgery before the age of 1 year and was also very rare during follow-up. There was no relationship between papilledema and OFC stagnation.