Long-term results in nonsyndromatic unilateral coronal synostosis treated with fronto-orbital advancement

Optimal untwisting of the orbital bandeau in unicoronal craniosynostosis correction: A finite element analysis

BACKGROUND

Surgical correction of unicoronal craniosynostosis (UCS) is highly complex due to its asymmetric appearance. Although fronto-orbital advancement (FOA) is a versatile technique for craniosynostosis correction, harmonization of the orbital bandeau in UCS is difficult to predict. This study evaluates the biomechanics of the orbital bandeau using different patterns and varying characteristics of inner cortical bone layer osteotomies in a finite element (FE) analysis.

METHOD

An FE model was created using the computed tomography (CT) scan of a 6.5-month-old male infant with a right-sided UCS. The unaffected side of the orbital bandeau was virtually mirrored, and anatomical correction of the orbital bandeau was simulated. Different combinations of osteotomy patterns, numbers, depths, and widths were examined (n = 48) and compared to an uncut model.

RESULTS

Reaction forces and maximum stress values differed significantly (p < 0.01) among osteotomy patterns and between each osteotomy characteristic. Regardless of the osteotomy pattern, higher numbers of osteotomies significantly (p < 0.05) correlated with reductions in reaction force and maximum stress. An X-shaped configuration with three osteotomies deep and wide to the bone was biomechanically the most favorable model.

CONCLUSION

Inner cortical bone layer osteotomy might be an effective modification to the conventional FOA approach in terms of predictable shaping of the orbital bandeau.

Effectiveness of Automatic Planning of Fronto-orbital Advancement for the Surgical Correction of Metopic Craniosynostosis

BACKGROUND

The surgical correction of metopic craniosynostosis usually relies on the subjective judgment of surgeons to determine the configuration of the cranial bone fragments and the degree of overcorrection. This study evaluates the effectiveness of a new approach for automatic planning of fronto-orbital advancement based on statistical shape models and including overcorrection.

METHODS

This study presents a planning software to automatically estimate osteotomies in the fronto-orbital region and calculate the optimal configuration of the bone fragments required to achieve an optimal postoperative shape. The optimal cranial shape is obtained using a statistical head shape model built from 201 healthy subjects (age 23 ± 20 months; 89 girls). Automatic virtual plans were computed for nine patients (age 10.68 ± 1.73 months; four girls) with different degrees of overcorrection, and compared with manual plans designed by experienced surgeons.

RESULTS

Postoperative cranial shapes generated by automatic interventional plans present accurate matching with normative morphology and enable to reduce the malformations in the fronto-orbital region by 82.01 ± 6.07%. The system took on average 19.22 seconds to provide the automatic plan, and allows for personalized levels of overcorrection. The automatic plans with an overcorrection of 7 mm in minimal frontal breadth provided the closest match (no significant difference) to the manual plans.

CONCLUSIONS

The automatic software technology effectively achieves correct cranial morphometrics and volumetrics with respect to normative cranial shapes. The automatic approach has the potential to reduce the duration of preoperative planning, reduce inter-surgeon variability, and provide consistent surgical outcomes.

Long-Term Neurocognitive Outcomes in Sagittal Synostosis: The Impact of Reoperation

INTRODUCTION

Optimal age at surgery in nonsyndromic sagittal craniosynostosis continues to be debated. Previous reports suggest that earlier age at whole vault cranioplasty more frequently requires reoperation. It is unknown, however, whether reoperation affects neurocognitive outcome. This study examined the impact of reoperation on neurocognitive outcome in children with nonsyndromic sagittal craniosynostosis using comprehensive neurocognitive testing.

METHODS

Forty-seven school-age children (age 5-16 years) with nonsyndromic sagittal craniosynostosis who underwent whole-vault cranioplasty were included in this analysis. Participants were administered a battery of standardized neuropsychological testing to measure neurocognitive outcomes.

RESULTS

Thirteen of the 47 participants underwent reoperation (27.7%); 11 out of the 13 reoperations were minor revisions while 2 reoperations were cranioplasties. Reoperation rate was not statistically different between patients who had earlier surgery (at age ≤6 months) versus later surgery (at age >6 months) (P > 0.05). Nonreoperated patients who had only one later-in-life surgery did not perform statistically better than reoperated patients on any outcome measure of neurocognitive function, including IQ, academic achievement, visuomotor integration, executive function, and behavior. Comparing reoperated earlier surgery patients with nonreoperated later surgery patients, reoperated earlier surgery patients had higher full-scale and verbal IQ (P < 0.05), scored higher on word reading, reading comprehension, spelling, numerical operations, and visuomotor integration (P < 0.05), and had fewer indicators of suspected learning disabilities (P < 0.01) compared to nonreoperated later surgery patients.

CONCLUSION

Reoperation rate after whole vault cranioplasty was 27.7%, with few cases of repeat cranioplasty (4.2% of all patients). Reoperation was not associated with worse neurocognitive outcome. Reoperated earlier surgery patients in fact performed better in IQ, academic achievement and visuomotor integration when compared to nonreoperated later surgery patients.

A protocol of situation-dependent transfusion, erythropoietin and tranexamic acid reduces transfusion in fronto-orbital advancement for metopic and coronal craniosynostosis

PURPOSE

Assess the effect of a protocol of preoperative erythropoietin (EPO) and ferrous sulfate in addition to perioperative tranexamic acid (TXA) on blood transfusions in patients with coronal or metopic craniosynostosis undergoing cranial vault remodeling (CVR) with fronto-orbital advancement (FOA).

METHODS

Retrospective review of all coronal and metopic craniosynostosis patients undergoing CVR and FOA from March 2010 to June 2019 was performed. Before 2014 ("Control group"), all patients received blood transfusion at the start of surgery. In 2014, a protocol of preoperative EPO and ferrous sulfate with perioperative TXA and non-automatic transfusion was instituted ("Study group"). Patient demographics and anthropometrics, perioperative hemoglobin (Hb) levels, and transfusion details were collected and compared.

RESULTS

Thirty-six patients met inclusion criteria. Twenty-one patients were in the control group, and 15 in the Study group. Nineteen patients had metopic synostosis, 11 had unicoronal synostosis, and 6 had bicoronal synostosis. There were no significant differences between groups in demographics, operative time, intraoperative crystalloid volume, craniofacial syndromes, or sutures affected. The Study group had higher preoperative Hb (13.9 ± 1.0 vs. 12.6 ± 0.8 g/dL, p < 0.001), lower intraoperative Hb nadir (7.4 ± 1.8 vs. 9.2 ± 1.2 g/dL) lower intraoperative transfusion rate (66.7% vs. 100%, p = 0.008), lower postoperative transfusion rate (0% vs 28.6%, p = 0.03), and exposure to fewer unique units of packed red blood cells (0.7 ± 0.6 vs. 1.5 ± 0.9 units).

CONCLUSION

Our protocol resulted in decreased transfusion needs. These results add valuable information to the growing body of work on transfusion reduction in craniosynostosis surgery.

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.

Evaluation of Long-term Outcomes of Facial Sensation following Cranial Vault Reconstruction for Craniosynostosis

Supplemental Digital Content is available in the text.

Background:

Cranial vault reshaping to correct craniosynostosis in infants may injure terminal branches of the trigeminal nerve, namely the supraorbital, supratrochlear, zygomaticofacial, and zygomaticotemporal nerves, especially if a fronto-orbital advancement is performed. Despite numerous studies demonstrating successful esthetic outcome after FOA, there are no long-term studies assessing facial sensation after possible damage to these nerves as the result of surgery.

Methods:

A cross-sectional case-control research design was used to evaluate facial sensory threshold in the trigeminal branches after cranial vault reconstruction in children with isolated, nonsyndromic metopic, and unicoronal craniosynostosis, compared with those with sagittal craniosynostosis and age-matched nonaffected controls. Study participants were recruited from the Hospital for Sick Children between the ages of 6 and 18 years. Sensory outcome was determined using the Weinstein Enhanced Sensory Test, the Ten Test, and self-reported facial sensibility function questionnaire.

Results:

The sensory outcomes of 28 patients and 16 controls were examined at an average age of 9.6 years and 10.3 years, respectively. No subjective or objective sensory deficit was noted in supraorbital, supratrochlear, zygomaticofacial, or zygomaticotemporal nerve distributions between groups. Qualitative reports of facial sensibility function indicated no difference in subjective sensation, protective sensation, or motor behavior between groups.

Conclusions:

These results suggest that while sensory nerve injury during routine FOA may occur, it does not result in a quantifiable nor clinically significant long-term sensory deficit threshold. Patients do not develop long-term neuropathic pain following surgical intervention.

Early Surgical Treatment in Anterior Synostotic Plagiocephaly: Is This the Best Choice?

At the end of craniofacial growth, in anterior synostotic plagiocephaly, some aesthetical deficiencies may still be evident. This can depend on an inadequate initial correction or on altered postoperative growth or even on the combination of the 2 factors.Aesthetic alterations can result from various factors that could potentially affect the skeleton, the skin, subcutaneous, and muscular tissues.The pathological changes in the cutaneous and subcutaneous tissues are greater in patients who have undergone multiple surgical treatments of the frontoorbital area. The aim of this observational cohort study is to assess the residual aesthetic and functional impairment at the end of skeletal growth, in patients affected by anterior synostotic plagiocephaly who have undergone surgery at an early age. The purpose is to investigate whether early surgery can still be considered unavoidable in patients with this malformation.Between July 2012 and February 2015, patient's data were retrieved from our archives among the patients referred to our department from 2003 to 2012 for Anterior Synostotic Plagiocephaly at an early age.The authors studied this patient with CT scans and photographic documentation. On CT scans, the authors have assessed skeletal alterations, soft tissues alterations, and muscular tissue alterations. With photographic documentation, the authors have studied the perception of the malformation among external subjects.From this study it was possible to demonstrate that is many esthetical alterations are to still to be found in patients treated with an early surgical approach; for this reason in children without early complications, the authors suggest that surgical treatment should be delayed after the end of craniofacial growth.

3D morphological change of skull base and fronto-temporal soft-tissue in the patients with unicoronal craniosynostosis after fronto-orbital advancement

PURPOSE

This study aims to comprehensively evaluate the deformation of the skull base and fronto-temporal soft tissue in the patients with anterior plagiocephaly over 1 year of age by three-dimensional (3D) imaging after fronto-orbital advancement (FOA).

METHODS

We quantitatively analyzed the surgical results and outcome of FOA performed in 10 patients with anterior plagiocephaly. The measurements of the skull base and fronto-temporal soft tissue were performed based on 3D computed tomography (CT) scan. We assessed symmetry of the skull base and fronto-temporal soft tissue change.

RESULTS

The mean age of patients at FOA was 38.9 months. A significant asymmetry of the skull base was found in all the patients. The growth of the anterior and middle fossae was restricted and the deformation of the fronto-temporal region was marked by soft tissue measurements in different grades. On the follow-up CT images 23.6 months after surgery, there was prominent change (p < 0.05) between the two hemibases (CSO^ ratio) and between the lengths and angles of the anterior and middle cranial hemi-fossae (CX, CSX^, XSM^, XM ratio), especially in grade IIA. Anterior cranial vault asymmetry index obviously decreased to - 1.2 from 12% after surgery (p < 0.05). What's more, ACA^ was also proved to be less after surgical correction (19.91° versus 8.29°, p < 0.01) in grade IIA. The change of fronto-temporal soft tissue was significant such as the frontal angle, the angle of the frontal plane, the fontal-temporal angle, and the angle of the temporal plane in different grades.

CONCLUSIONS

The asymmetry of the skull base and the deformation of the fronto-temporal region can be presented by intracranial view at over 1 year of age in different grades. FOA can correct the skeletal malformation of the fronto-temporal region as well as soft tissue and the asymmetry of the skull base was improved after surgical treatment.

The Directive Growth Approach for Nonsyndromic, Unicoronal Craniosynostosis: Patient and Clinical Outcomes

Deformities of the cranium in patients with nonsyndromic single-suture synostosis occur because of growth restriction at fused sutures and growth over compensation at normal sutures. Traditional surgery includes ostectomies of the synostotic suture to release these restricted areas and osteotomies to enable immediate cranial remodeling. In the process of reshaping the cranium, traditional approaches usually involve obliteration of both the normal functioning suture and the pathologic suture. The directive growth approach (DGA) is a new, simpler, more natural way to repair deformities caused by single-suture cranial synostosis. The DGA works by reversing the original deforming forces by temporarily restricting growth in areas of over compensation and forcing growth in areas of previous synostotic restriction. Most importantly, it preserves a normal functioning suture to allow for improved future cranial growth. Eighteen consecutive nonsyndromic patients with unilateral coronal synostosis were used to illustrate the efficacy of the DGA. Ten patients who underwent DGA treatment were compared with a control group of 8 patients treated with traditional frontal orbital advancement. Postoperative three-dimensional computed tomography (CT) comparison measurements were taken, including bilateral vertical and transverse orbital dimensions, lateral orbital rim to external auditory canal, and forehead measurements from the superior aspect of the orbital rim to the pituitary fossa. The traditional treatment group showed absence of the coronal sutures bilaterally on long-term CT scans. The DGA group showed normal coronal sutures on the unaffected sides. Postoperative CT measurements showed no statistical difference between the 2 techniques (P < 0.05).

Asymmetric Multisutural Craniosynostosis: an Algorithm of Early Intervention to Prevent Evolving Deformity

BACKGROUND

Asymmetric multisutural craniosynostosis (AMC) is characterized by fusion of a midline suture combined with unilateral fusion of at least 1 nonmidline suture. Due to its rarity, complexity, and high rate of reoperation, the purpose of this study is to evaluate outcomes of our staged approach to AMC.

METHODS

Patients treated for craniosynostosis between January 2004 and December 2013 were identified retrospectively. Only patients with AMC and a minimum follow-up of 2 years were included. The 3-staged algorithm includes: extended strip craniectomy of fused sutures; postoperative helmet molding; and fronto-orbital advancement versus a touch-up procedure. Morphologic, aesthetic, and functional outcomes were evaluated.

RESULTS

Nine patients (6.8% of cases) were treated for AMC (mean follow-up: 4.1 years). Sixty-seven percent of patients (6 of 9) demonstrated signs of elevated intracranial pressure. Patients were divided into 2 groups: "Group A" included patients treated according to the staged algorithm (n = 5); "Group B" included those treated by traditional techniques (n = 4). Group A underwent their first calvarial vault procedure earlier than those from Group B (2.7 vs. 13.2 months; P < 0.02). Postoperatively, no Group A patients had developmental delay, signs of elevated intracranial pressure, or reoperation. Three of 5 patients (60%) were rated Whitaker Classification II and the others (40%) rated Whitaker Classification III.

CONCLUSIONS

Asymmetric multisutural synostosis results in a complex and evolving deformity involving the entire craniofacial complex. However, when asymmetric multisutural synostosis is approached in stages with early intervening helmet therapy, acceptable functional and appearance-related outcomes can be obtained with minimal complications.

LEVEL OF EVIDENCE

III.

Postoperative temporal hollowing: Is there a surgical approach that prevents this complication? A systematic review and anatomic illustration

BACKGROUND

Temporal hollowing is a common complication following surgical dissection in the temporal region. Our objectives were to: (1) review and clarify the temporal soft tissue relationships - supplemented by cadaveric dissection - to better understand surgical approach variations and elucidate potential etiologies of postoperative hollowing; (2) identify if there is any evidence to support a surgical approach that prevents hollowing through a systematic review.

METHODS

Cadaveric dissection was performed on six hemi-heads. A systematic review of the literature was undertaken to identify surgical approaches with a decreased risk of postoperative hollowing.

RESULTS

A total of 1212 articles were reviewed; 19 of these met final inclusion criteria. Level I and II evidence supports against the use of a dissection plane beneath the superficial layer of the deep temporal fascia or through the intermediate temporal fat pad. Level II evidence supports preservation of the temporalis muscle origin - no evidence is available to support other temporalis resuspension techniques. For intracranial exposure, refraining from temporal fat pad dissection (Level I Evidence) and use of decreased access approaches such as the minipterional craniotomy (Level I Evidence) appear to minimize temporal soft tissue atrophy.

CONCLUSIONS

This study highlights the significance of preservation of the temporal soft tissue components to prevent hollowing. Preserving the temporalis origin and avoiding dissection between the leaflets of the deep temporal fascia or through the intermediate temporal fat pad appear to minimize this complication.

Computer-assisted virtual planning and surgical template fabrication for frontoorbital advancement

OBJECT The authors describe a novel technique using computer-assisted design (CAD) and computed-assisted manufacturing (CAM) for the fabrication of individualized 3D printed surgical templates for frontoorbital advancement surgery. METHODS Two patients underwent frontoorbital advancement surgery for unilateral coronal synostosis. Virtual surgical planning (SurgiCase-CMF, version 5.0, Materialise) was done by virtual mirroring techniques and superposition of an age-matched normative 3D pediatric skull model. Based on these measurements, surgical templates were fabricated using a 3D printer. Bifrontal craniotomy and the osteotomies for the orbital bandeau were performed based on the sterilized 3D templates. The remodeling was then done placing the bone plates within the negative 3D templates and fixing them using absorbable poly-dl-lactic acid plates and screws. RESULTS Both patients exhibited a satisfying head shape postoperatively and at follow-up. No surgery-related complications occurred. The cutting and positioning of the 3D surgical templates proved to be very accurate and easy to use as well as reproducible and efficient. CONCLUSIONS Computer-assisted virtual planning and 3D template fabrication for frontoorbital advancement surgery leads to reconstructions based on standardizedmeasurements, precludes subjective remodeling, and seems to be overall safe and feasible. A larger series of patients with long-term follow-up is needed for further evaluation of this novel technique.

Perception of children's faces with unilateral coronal synostosis--an eye-tracking investigation

PURPOSE

Premature unilateral coronal craniosynostosis results in distinctive cranial and facial abnormalities of varying severity, including orbital dystopia and an abnormal head shape. As the face is affected, these children may encounter stigmatization. To avoid this scenario, many parents elect for their child to undergo surgical correction. Laypeople's perception of children with either untreated or treated unilateral coronal craniosynostosis (UCS) has not yet been objectively evaluated.

METHODS

This study introduces eye tracking as an objective instrument in order to evaluate the perception of 14 children with coronal synostosis, both pre- and postoperatively. Age-matched healthy children served as a control group. Using standardized photos, the involuntary eye movements and the fixations of 30 unaffected laypeople were evaluated.

RESULTS

In the untreated children, whose faces were characterized by striking orbital dystopia, the eyes drew more attention than those of the healthy children. The results of our study demonstrate that the operative correction of unilateral coronal synostosis results in the normalization of the asymmetry of the fronto-orbital region, whereas the C-shaped deformity of the midface, which is not addressed via surgery, subsequently attracts more attention.

CONCLUSION

Eye tracking objectively evaluates both the perception of craniofacial abnormalities and the extent of the approximation of normality after surgical correction. We introduce eye tracking as an objective measurement tool for craniofacial abnormalities for the first time.

Spectrum of positional deformities - is there a real difference between plagiocephaly and brachycephaly?

AIM

This study analyses pathomorphological and physiological head shapes and classifies the pathomorphology in positional plagiocephaly and brachycephaly.

PATIENTS AND METHODS

78 infants with a positional plagiocephaly (5.99 months) and 32 infants with a positional brachycephaly (6.53 months) with a Cephalic index > 94% were investigated in this study and compared to a matched control group of 35 infants. The head shapes were analysed by stereophotogrammetry 3D data.

RESULTS

The cephalic index, the total width, and coronal circumference were the highest values in patients with brachycephaly and the lowest values in the control group. The asymmetry of the head showed that the diagonal difference in brachycephalic patients more than doubled, and in patients with plagiocephaly almost tripled compared to the controls. A significantly higher total volume and vertex height was found for the patients with plagiocephaly and the patients with brachycephaly compared to the controls.

CONCLUSION

The cephalic index is a valuable and reliable parameter in order to differentiate positional deformities from unaffected skulls. Pathomorphology of a plagiocephaly is associated with the most severe asymmetry of the head. Plagiocephaly and brachycephaly overlap in several criteria. Therefore it seems justified to speak of a continuum rather than to differentiate between plagiocephaly and brachycephaly.