True Lambdoid Craniosynostosis: Long-Term Results of Surgical and Conservative Therapy

Cognitive Development in Lambdoid Craniosynostosis: A Systematic Review and Meta-Analysis

OBJECTIVE

Lambdoid craniosynostosis affects approximately 1 in 33 000 live births per year, and surgical correction is often sought in order to achieve normocephaly and allow for adequate brain growth. However, the effects of lambdoid synostosis and its treatment on cognitive development are unknown.

DESIGN

Systematic review and meta-analysis.

PATIENTS, PARTICIPANTS

A systematic review of Ovid Medline, Embase, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov was conducted in January 2022. Included studies assessed cognitive development of patients with nonsyndromic unilateral lambdoid craniosynostosis.

MAIN OUTCOME MEASURES

Results of developmental tests were compared to normative data or controls to generate Hedges' g for meta-analysis.

RESULTS

Nine studies met the inclusion criteria. Meta-analysis of 3 studies describing general cognition showed that cases scored significantly lower than their peers, but within 1 standard deviation (g = 0.37, 95% CI [-0.64, -0.10], P = .01). Meta-analysis of verbal and psychomotor development showed no significant differences in children with lambdoid synostosis. Studies were of fair quality and had moderate-to-high heterogeneity.

CONCLUSIONS

Patients with lambdoid craniosynostosis may score slightly below average on tests of general cognition in comparison to normal controls, but results in other domains are variable. Analyses were limited by small sample sizes. Multidisciplinary care and involvement of a child psychologist may be helpful in identifying areas of concern and providing adequate scholastic support. Further research recruiting larger cohorts will be necessary to confirm these findings and extend them to other developmental domains such as attention and executive function.

Spring-Assisted Surgery of Unilambdoid Craniosynostosis

Craniosynostosis is traditionally treated with extensive cranial vault reconstructions (CVRs). Although less invasive techniques, such as endoscopic strip craniectomy with postoperative helmet therapy, have been successful, they also present difficulties. An alternative method is distraction osteogenesis using either manually controlled devices or specially designed springs. In this study, the authors provide the first comparison of spring-assisted surgery (SAS) with CVR for the treatment of unilambdoid synostosis (ULS). Fourteen consecutive patients (8 CVR and 6 SAS) treated for ULS at Sahlgrenska University Hospital between 2005 and 2018 were included. Skull shape and deviations were evaluated using previously defined measurement points on 3-dimensional computed tomography scans preoperatively, at spring removal, and at 3 years of age. Posterior and middle cranial fossa (PCF and MCF, respectively), skull-base cant, facial twist, and mastoid bulge (MB) were measured, and clinical data were obtained from chart reviews. The results indicated that at the 3-year follow-up, PCF, MCF, and MB improved in both groups, with no significant difference in outcome observed between methods. In the SAS group, duration of operation [61±27 min (mean±SD)] and perioperative bleeding (3.5±2.8 mL/kg body weight) were both significantly lower relative to the CVR group (P<0.05). These findings showed that both SAS and CVR resulted in similar improvements in treating ULS, although neither produced complete normalization of skull shape. The results suggest that early diagnosis and operation allow less extensive SAS to be performed without adversely affecting the results.

Data-driven cranial suture growth model enables predicting phenotypes of craniosynostosis

We present the first data-driven pediatric model that explains cranial sutural growth in the pediatric population. We segmented the cranial bones in the neurocranium from the cross-sectional CT images of 2068 normative subjects (age 0-10 years), and we used a 2D manifold-based cranial representation to establish local anatomical correspondences between subjects guided by the location of the cranial sutures. We designed a diffeomorphic spatiotemporal model of cranial bone development as a function of local sutural growth rates, and we inferred its parameters statistically from our cross-sectional dataset. We used the constructed model to predict growth for 51 independent normative patients who had longitudinal images. Moreover, we used our model to simulate the phenotypes of single suture craniosynostosis, which we compared to the observations from 212 patients. We also evaluated the accuracy predicting personalized cranial growth for 10 patients with craniosynostosis who had pre-surgical longitudinal images. Unlike existing statistical and simulation methods, our model was inferred from real image observations, explains cranial bone expansion and displacement as a consequence of sutural growth and it can simulate craniosynostosis. This pediatric cranial suture growth model constitutes a necessary tool to study abnormal development in the presence of cranial suture pathology.

Perioperative Comparison Between Open Cranial Vault Remodeling and Distraction Osteogenesis for Unilateral Lambdoid Craniosynostosis

There are multiple treatment options for unilateral lambdoid craniosynostosis (ULS) including open posterior cranial vault remodeling (OCVR) and distraction osteogenesis (DO). There is a paucity of data comparing these techniques in the treatment of ULS. This study compared the perioperative characteristics of these interventions for patients with ULS. An IRB-approved chart review was performed from January 1999 to November 2018 at a single institution. Inclusion criteria included the diagnosis of ULS, treatment with either OCVR or DO using a posterior rotational flap technique, and a minimum 1-year follow-up. Seventeen patients met the inclusion criteria (12 OCVR and 5 DO). Patients in each cohort were found to have a similar distribution in sex, age at the time of surgery, synostosis laterality, weight, and length of follow-up. There was no significant difference in mean estimated blood loss/kg, surgical time, or transfusion requirements between cohorts. Distraction osteogenesis patients had a longer mean hospital length of stay (3.4 +/- 0.6 d versus 2.0 +/- 0.6 d, P = 0.0004). All patients were admitted to the surgical ward postoperatively. In the OCVR cohort, complications included 1 dural tear, 1 surgical site infection, and 2 reoperations. In the DO cohort, 1 patient had a distraction site infection, treated with antibiotics. There was no significant difference in estimated blood loss, volume of blood transfusion, or surgical time between OCVR and DO. Patients who underwent OCVR had a higher incidence of postoperative complications and the need for reoperation. This data provides insight into the perioperative differences between OCVR and DO in patients with ULS.

Utilizing Computer-Assisted Design and Virtual Surgical Planning for Correction of Unilateral Lambdoid Synostosis

Unilateral lambdoid synostosis is the rarest form of single-suture craniosynostosis. Although various surgical approaches have been described, cranial vault remodeling remains the predominant approach. To aid in surgical planning, preoperative virtual surgical modeling using a patient's presenting computed tomography scan can be used to increase reconstructive precision and to reduce operative time. Presented is a 7-month-old male with unilateral lambdoid synostosis who underwent medically modeled cranial vault reconstruction.

Facial asymmetry in children with either unilateral lambdoid craniosynostosis or positional posterior plagiocephaly

BACKGROUND

In unilateral lambdoid craniosynostosis (ULC), the posteriorly situated lambdoid suture of the cranial vault fuses prematurely. Positional posterior plagiocephaly (PPP) causes flattening of the posterior side of the head, either through external forces or through underlying differences in brain development. Both conditions cause occipital flattening of the head, but the aetiology is different.

MATERIALS AND METHODS

Eight ULC children were compared with 16 sex- and age-matched PPP children. 3D computer tomography scans of all 24 children were analysed with Dolphin imaging software. The location and symmetry of the temporomandibular joint (Co), and the symmetry of the maxillary anterior nasal spine (ANS) and the mandibular symphysis (Pgn) were analysed. Furthermore, the mandibular bone (Co-Pgn) length, corpus length, ramus height, positional changes in the external acoustic meatus (PoL) and the distance from the orbital margin to the articular fossa were measured.

RESULTS

In all eight ULC children, the Co was anteriorly displaced on the affected side compared with the unaffected side. In all ULC and PPP children, the ANS, which is considered the bony maxillary midpoint, was shifted towards the affected side. In all ULC children, the mandibular bone (Co-Pgn) was shorter on the affected side. The PoL was antero-inferiorly positioned in all ULC children on the affected side compared with the unaffected side.

CONCLUSIONS

Our results show that both types of posterior plagiocephaly are associated with an asymmetric position of the Co and asymmetry of the mandible and maxilla. Facial asymmetry was more frequently seen in ULC than PPP children.

Management of Sagittal and Lambdoid Craniosynostosis: Minimally Invasive Approaches

The resurgence of strip craniectomies began in the mid-1990s with advances in surgical technique and anesthesia coupled with the critical observation that earlier interventions benefitted from an easily molded skull. Jimenez and Barone's pioneering introduction of endoscopic approaches to strip craniectomies coupled with postoperative helmeting in newborns and young infants and Claes Lauritzen's introduction of spring-mediated cranioplasty began the era of minimally invasive approaches in the surgical correction of craniosynostosis. This article provides technical descriptions of these treatment modalities, a comparative literature review, and our institutional algorithms for the correction of sagittal craniosynostosis and unilambdoid craniosynostosis.

Premature Fusion of the Posterior Intraoccipital Synchondrosis, A Minor Suture Mimic of Lambdoid Craniosynostosis

ABSTRACT

The posterior intraoccipital synchondrosis (PIOS) is a cartilaginous division separating the exoccipital and supraoccipital bones, allowing for flexibility of the cranial base at birth and which later ossifies in adolescence. The authors report a case of right PIOS synostosis that resembled right lambdoid synostosis, with left occipital bossing in a healthy, six-month-old female with an unremarkable birth history and no antecedent trauma. An initial referral was made from the pediatrician to oncology because of a concern over the presence and growth of a possible mass at the left occiput. Over 8 months, this mass grew and became more firm, accompanied by left occipital bossing and right occipital flattening. A computed tomography was obtained, which demonstrated the fusion of the PIOS, prompting a referral to plastic surgery. Cranial vault remodeling with switch cranioplasty was performed at age 14 months, complicated only by a superficial infection along the suture line. There are exceedingly few reports of PIOS synostosis, with occipital osteodiastasis related to birth trauma as the only prior explanation for this condition. With no birth trauma and delayed onset, our case likely represents idiopathic PIOS synostosis. With the many similarities in presentation, the surgical approaches commonly used for lambdoid synostosis, particularly switch cranioplasty, are suitable solutions to PIO synchondrosis with optimal functional and aesthetic outcomes.

Management of Lambdoid Craniosynostosis: A Comprehensive and Systematic Review

BACKGROUND

Craniosynostosis is a condition characterized by the premature fusion of 2 or more skull bones. Craniosynostosis of the lambdoid suture is one of the rarest forms, accounting for 1-4% of all craniosynostoses. Documented cases are separated into simple (single suture), complex (bilateral), and associated with adjacent synostoses ("Mercedes Benz" Pattern) or syndromes (i.e., Crouzon, Sathre-Chotzen, Antley-Bixler). This condition can manifest phenotypic deformities and neurological sequelae that can lead to impaired cognitive function if improperly treated or left undiagnosed. Preferred surgical techniques have varied over time but all maintain the common goals of establishing proper head shape and preventing of complications that could contribute to aforementioned sequelae.

SUMMARY

This comprehensive review highlights demographic distributions, embryological development, pathogenesis, clinical presentation, neurological sequelae, radiologic findings, surgical techniques, surgical outcomes, and postoperative considerations of patients with lambdoid craniosynostosis presentation. In addition, a systematic review was conducted to explore the operative management of lambdoid craniosynostosis using PubMed, Embase, and Scopus databases, with 38 articles included after screening. Key Messages: Due to a low volume of published cases, diagnosis and treatment can vary. Large overlap in presentation can occur in patients that display lambdoid craniosynostosis and posterior plagiocephaly, furthering the need for comprehensive analysis. Possessing the knowledge and tools to properly assess patients with lambdoid craniosynostosis will allow for more precise care and improved outcomes.

Conventional posterior cranial vault expansion: indications and results-review of the literature

In the late 1980s, craniofacial surgery units reported suboptimal cosmetic results, cranial volume restriction, and intracranial hypertension after anterior cranial vault remodeling in bilateral coronal synostosis associated with severe brachyturricephaly. A possible explanation was a severe associated growth restriction of the posterior calvaria with radiological synostosis at the lambda sutures. "Conventional" or "fixed" posterior cranial vault expansion techniques were developed to address these limitations, sometimes as the first surgical step in a two-staged protocol of total calvarial reconstruction, combined with suboccipital decompression in cases of symptomatic cerebellar tonsillar herniation or, more easily, to resolve the characteristic occipital flattening of lambdoid synostosis. Various surgical approaches have been described; however, the indications for and timing of surgical treatment and postoperative evaluation of results still remain controversial. Although more invasive, conventional posterior cranial vault expansion has proven to be safe and offers a remodeled and protective bony vault immediately after surgery, but the underlying cranial base malformation remained untreated, with implications in the postoperative growth of the facial skeleton. Overcorrection, rigid stabilization, and grafting are also concerns to be addressed.

Clinical Features and the Use of Three-Dimensional Imaging for Unilateral Lambdoid Synostosis

INTRODUCTION

True isolated lambdoid craniosynostosis is rare. It requires corrective surgery to prevent intracranial pressure and aesthetic stigma by significant dyscrania. We summarize our case series for lambdoid craniosynostosis outlining the pathophysiology, clinical findings and surgical approaches and outcomes.

METHODOLOGY

A retrospective analysis of our data from 2010 to 2020 summarized our cases of true lambdoid synostosis. We have used the medical notes and the radiological findings from computed tomography scans to summarize a case series of isolated lambdoid synostosis.

RESULTS

Our case series demonstrated 7 patients with true isolated lambdoid craniosynostosis. In most cases surgical intervention in the form of posterior cranial vault remodeling utilizing a bandeau, based on occipital advancement techniques, has demonstrated the most consistently favorable aesthetic outcome.

CONCLUSIONS

Surgical referral to a craniofacial center should be sought early in difficult to diagnose cases. Although rare, surgical intervention is indicated to correct potentially increased intracranial pressure and to ameliorate cranial dyscrania.

Synostosis of the lambdoid suture: a spectrum

PURPOSE

Lambdoid synostosis (LS) is a rare condition, which is either isolated; associated with sagittal synostosis, the "Mercedes-Benz" syndrome (MBS); or with synostosis of the coronal sutures (oxycephalic form). In addition, LS is part of the phenotype of a growing number of genetic diseases. The nosology, pathophysiology, and management are controversial. We decided to review our experience with LS.

METHODS

We reviewed retrospectively pediatric cases of LS proved on CT-scanner, isolated or associated with other conditions, followed in our craniofacial center during the last 15 years, regarding clinical presentation, anatomical lesions, syndromic associations, surgical management, and outcome.

RESULTS

We reviewed 48 cases: 6 isolated LS, 22 MBS, and 20 oxycephalic. A syndromic context was present in 72% (up to 80% of oxycephalic cases), and faciostenosis was present in 23%, mostly oxycephalic cases (40%). Transverse sinus agenesis was found in 61% of documented patients. A total of 31% of children had a dystocic birth, up to 45% of MBS. Decompressive craniectomy or cranioplasty was needed in a majority of patients, often young infants, while posterior fossa decompression was mostly performed in older children.

CONCLUSION

LS is rarely isolated and non syndromic; most cases are found in a wide spectrum of diseases, and LS is often associated with sagittal or coronal synostosis. Genetic evaluation is mandatory for LS; conversely, geneticists may require neurosurgical advice for LS in an increasing number of very rare diseases. The surgical management of LS should be tailored according to clinical presentation, age, and syndromic context.

A Posterior Rotational Flap Technique Using Distraction Osteogenesis for Unilateral Lambdoid Craniosynostosis

INTRODUCTION

The craniofacial asymmetry seen in unilateral lambdoid craniosynostosis may not be effectively treated by posterior cranial vault remodeling, endoscopic suturectomy, and helmet therapy, or suturectomy and distraction osteogenesis alone due to limitations in soft-tissue envelope expansion and relapse of the deformity. The authors report a series of unilateral lambdoid craniosynostosis patients treated with a posterior rotational cranial-flap technique using internal distraction osteogenesis.

METHODS

Posterior cranial vault reconstruction combined with internal distraction was used, aided by preoperative virtual surgical planning. An in situ posterior rotational flap osteotomy was utilized to maximize dural preservation. Primary outcome measures included age-adjusted volume change and age-adjusted percent volume change per mm distraction. Distraction characteristics and perioperative characteristics were also assessed.

RESULTS

A total of 5 patients were identified. Mean predistraction intracranial volume was 1087.5 cc (SD  = 202.3 cc) and mean postdistraction included intracranial volume was 1266.1cc (SD  = 131.8cc). Mean age-adjusted percent included intracranial volume change was 14.1% (SD  = 9.6%), and mean percent intracranial volume change per mm distraction was 0.43%/mm distraction (SD  = 0.37%/mm distraction). One patient developed a distractor site infection postoperatively that was treated successfully with oral antibiotics. All patients had a Whitaker score of 1 at one year follow up.

CONCLUSIONS

Posterior cranial vault remodeling using osteogenesis and a rotational cranial flap technique with dural preservation can be effectively used to maximize bone flap viability and limit postoperative relapse in patients with unilateral lambdoid craniosynostosis. Long term analysis as well as comparison to open techniques will need to be interrogated.

Distinguishing Craniomorphometric Characteristics of Unilateral Lambdoid Craniosynostosis

BACKGROUND

Unilateral lambdoid synostosis (ULS) represents the rarest form of single suture nonsyndromic craniosynostosis. Differentiating between posterior deformational plagiocephaly (DP) and ULS has been difficult due to overlapping clinical findings. Past analyses have been limited by sample size. This study was undertaken to clarify anatomical features of ULS.

METHODS

A multiinstitution study was undertaken, analyzing CT imaging from patients with documented ULS to determine clinical and pathological characteristics. Similar analyses were performed on DP patients to differentiate the 2 conditions.

RESULTS

Twenty-seven ULS patient scans and 10 DP scans were included. For ULS patients mean age was 6.6 months, majority male (75%), and majority left-sided ULS (71%). The synostosed side ear was anteriorly displaced in 100% of ULS patients, mean difference of 9.6° (P < 0.001), and inferiorly in 96.3% of patients, mean difference of 4.4 mm, relative to the nonsynostosed side. The posterior fossa deflection (PFD) was deviated 5.9° toward the synostosed side relative to the anterior midline. In DP, there was no significant difference between sides in EAC measurements. The PFD and EAC displacements were significantly smaller in DP relative to ULS (P < 0.001 for each). An ipsilateral mastoid bulge was found in 100% of ULS and 0% of DP on CT imaging.

CONCLUSION

Contrary to some previously published findings, the ear is more anteriorly displaced ipsilateral to the fused lambdoid suture in 100% of ULS patients. Ear position alone is not a reliable indicator to differentiate between DP and ULS. A mastoid bulge is a more reliable indicator of ULS.

A Novel Sand Dollar and Staves Technique for Unilateral Lambdoid Craniosynostosis

BACKGROUND

Unilateral lambdoid synostosis (ULS) is the rarest form of craniosynostosis. Due to the associated cranio-caudal shift seen in ULS, surgical correction is technically challenging from a morphological standpoint. Herein, the authors present a novel "Sand-Dollar and Staves" technique for the repair of ULS.

METHODS

A zigzag coronal incision is performed, and an anteriorly-based pericranial flaps are elevated. Prefabricated cutting guides are placed and the calvarium is marked. To treat the flattening on the ipsilateral side, a wedged suturectomy is performed with additional barrel staves. A large circle centered over the bulging on the contralateral side is cut out above the open lambdoid suture. This piece is barrel staved in a radial fashion, leaving the center intact and creating a Sand-Dollar appearance. This disk is then flattened and trimmed. The modified Sand-Dollar is fixed using an absorbable plating system. While gentle pressure is applied to the Sand-Dollar piece as it is being secured, the ipsilateral side demonstrates compensatory filling. Results are evaluated using the Whitaker Classification.

RESULTS

Four patients underwent surgical correction with this technique. The procedure was performed at mean age of 11.7 months. The mean operative time was 2.5 hours. Intraoperative blood loss was 50 to 100 ml. Total hospitalization time was 2 to 3 days. No post-operative complications were encountered. Whitaker scores ranged from 1 to 1.5. The mean follow-up was 10 months.

CONCLUSION

The Sand-Dollar and Staves procedure is a novel, single-stage approach for the management of ULS with decreased operative time, blood loss, and hospital stay with satisfactory aesthetic outcomes.

Diagnosis, Management, and Outcome in 9 Children with Unilateral Posterior Synostotic Plagiocephaly

BACKGROUND

Posterior synostotic plagiocephaly represents a rare challenging type of craniosynostosis, often misdiagnosed as a simple posterior positional plagiocephaly. Underdiagnosed forms may result in delayed diagnosis and neurosurgical management, with potential ophthalmologic, cognitive, and aesthetic sequelae in children.

METHODS

Here we retrospectively analyzed data of 9 posterior synostotic plagiocephaly infants treated in our center over a 10-year period (January 2000-December 2009).

RESULTS

Patients averaged 10 months of age, and there was a clear male predominance (8 males/1 female). Cerebral computed tomography scan was performed in all patients, and the abnormal suture was located at the right side in 7 cases (77.77%). Ipsilateral occipitomastoid bulge and occipital flattening were found in all cases (100%). Posterior ear displacement was found in 7 cases (77.77%), and there was minimal facial asymmetry in 4 cases (44.44%). The ophthalmoscopic examination found a papillary edema grade 1 in 2 cases and grade 2 in 4 cases. There were no deaths or reoperation in our series. All of our patients underwent a neurosurgical correction, with total ophthalmic recovery in all patients with preoperative papillae edema. Eight patients had an early satisfactory aesthetic aspect. Long-term follow-up in treated children found a normal childhood, with no major school dysfunctions and normal social integration.

CONCLUSIONS

Interesting findings in our series were male gender predominance and predilection of the right-side synostotic lambdoid suture. We think that early correct diagnosis and appropriate neurosurgical treatment may prevent potential complications such as neurocognitive and aesthetic sequelae in children with posterior synostotic plagiocephaly.

Comparative analysis of cranial vault remodeling versus endoscopic suturectomy in the treatment of unilateral lambdoid craniosynostosis

OBJECTIVE

Unilateral lambdoid synostosis is the premature fusion of a lambdoid suture or sutures and represents the least common form of craniosynostosis, occurring in 1 in 40,000 births. Cranial vault remodeling (CVR) and endoscopic suturectomy with helmet therapy (ES) are surgical approaches that are used to allow for normal brain growth and improved craniofacial symmetry. The authors conducted a comparative outcomes analysis of patients with lambdoid synostosis undergoing either CVR or ES.

METHODS

The authors conducted a retrospective consecutive cohort study of patients with nonsyndromic lambdoid synostosis who underwent surgical correction identified from a single-institution database of patients with craniosynostosis seen between 2000 and 2018. Cranial growth was measured in head circumference percentile and z score.

RESULTS

Nineteen patients (8 female and 11 male) with isolated unilateral lambdoid synostosis were identified (8 right and 11 left). Six underwent CVR and 13 underwent ES. No statistically significant differences were noted between surgical groups with respect to suture laterality, the patient's sex, and length of follow-up. Patients treated with ES presented and underwent surgery at a younger age than those treated with CVR (p = 0.0002 and p = 0.0001, respectively). Operating and anesthesia time, estimated blood loss, and ICU and total hospital days were significantly lower in ES (all p < 0.05). No significant differences were observed in pre- and postoperative head circumference percentiles or z scores between groups up to 36 months postoperatively. No patients required reoperation as of last follow-up.

CONCLUSIONS

Endoscopic management of lambdoid synostosis is safe, efficient, and efficacious in terms of intraoperative and long-term cranial growth outcomes when compared to CVR. The authors recommend this minimally invasive approach as an option for correction of lambdoid synostosis in patients presenting early in their course.

Cost comparison of surgical management of nonsagittal synostosis: traditional open versus endoscope-assisted techniques

OBJECTIVE

Management of craniosynostosis at an early age is important for mitigating the risk of abnormal cranial development, but treatment can result in significant expenses. Previous research has shown that endoscope-assisted craniectomy (EAC) is less costly than open cranial vault remodeling (CVR) for patients with sagittal synostosis. The aim of this study was to strengthen the existing body of healthcare cost research by elucidating the charges associated with open and endoscopic treatment for patients with nonsagittal synostosis.

METHODS

The authors performed a retrospective analysis of data obtained in 41 patients who underwent open CVR and 38 who underwent EAC with postoperative helmet therapy for nonsagittal, single-suture craniosynostosis (metopic, coronal, and lambdoid) between 2008 and 2018. All patients were < 1 year of age at the time of surgery and had a minimum 1 year of follow-up. Inpatient charges, physician fees, helmet charges, and outpatient clinic visits in the 1st year were analyzed.

RESULTS

The mean ages of the children treated with EAC and open CVR were 3.5 months and 8.7 months, respectively. Patients undergoing EAC with postoperative helmet therapy required more outpatient clinic visits in the 1st year than patients undergoing CVR (4 vs 2; p < 0.001). Overall, 13% of patients in the EAC group required 1 helmet, 30% required 2 helmets, 40% required 3 helmets, and 13% required 4 or more helmets; the mean total helmeting charges were $10,072. The total charges of treatment, including inpatient charges, physician fees, outpatient clinic visit costs, and helmet charges, were significantly lower for the EAC group than they were for the open CVR group ($50,840 vs $95,588; p < 0.001).

CONCLUSIONS

Despite the additional charges for postoperative helmet therapy and the more frequent outpatient visits, EAC is significantly less expensive than open CVR for patients with metopic, coronal, and lambdoid craniosynostosis. In conjunction with the existing literature on clinical outcomes and perioperative resource utilization, these data support EAC as a cost-minimizing treatment for eligible patients with nonsagittal synostosis.

Isolated Lambdoid Craniosynostosis

INTRODUCTION

Lambdoid craniosynostosis is an extremely rare anomaly in which there is premature fusion of one or both lambdoid sutures. The mainstay of treatment is surgical intervention, for which various procedures have been described, but there is a paucity of data on long-term outcomes. This study examines the long-term outcomes in the surgical management of this challenging condition, showing that accurate diagnosis and careful planning can lead to safe and consistent results.

MATERIALS AND METHODS

A retrospective chart review was performed looking at all cases of isolated lambdoid craniosynostosis treated with surgical intervention by the senior author from 1999 to 2016. Data collected included gender, age at diagnosis, age at surgery, length of follow up, method of diagnosis, side of affected suture, pre-operative and post-operative physical exam findings, surgical technique, complications, re-operation rate, and associated torticollis.

RESULTS

Twenty-five patients (N = 25) were included in the study. All patients underwent posterior calvarial remodeling with/without barrel stave osteotomies and full thickness calvarial bone grafts. Mean length of follow up after operative intervention was 43.8 months (+/- 23.2 months). All patients were judged to have significantly improved head contour which was near-normal at conversational distance during post-operative follow up by the senior author. Residual plagiocephaly was present in 24% of patients. There were no major complications in this series. Reoperation rate was 8%. Seventy-six percent of patients also presented with torticollis, of which 37% had refractory torticollis that required sternocleidomastoid (SCM) release by the senior author.

DISCUSSION

The authors present one of the largest series of operative cases of isolated lambdoid craniosynostosis to date. Our data show that with accurate diagnosis and careful planning, safe and consistent long-term results can be achieved with surgical intervention. A significant number of patients in our series also presented with concomitant torticollis. The authors recommend that all patients being evaluated for posterior plagiocephaly should also be evaluated for torticollis, because without recognition and intervention, patients may continue to have residual facial asymmetry and head shape abnormalities despite optimal surgical correction of the lambdoid synostosis.

A systematic review of endoscopic versus open treatment of craniosynostosis. Part 2: the nonsagittal single sutures

OBJECTIVE

Despite increasing adoption of endoscopic techniques for repair of nonsagittal single-suture craniosynostosis, the efficacy and safety of the procedure relative to established open approaches are unknown. In this systematic review the authors aimed to directly compare open surgical and endoscope-assisted techniques for the treatment of metopic, unilateral coronal, and lambdoid craniosynostosis, with an emphasis on quantitative reported outcomes.

METHODS

A literature search was performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant articles were identified from 3 electronic databases (MEDLINE, EMBASE, and CENTRAL [Cochrane Central Register of Controlled Trials]) from their inception to August 2017. The quality of methodology and bias risk were assessed using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies.

RESULTS

Of 316 screened records, 7 studies were included in a qualitative synthesis of the evidence, of which none were eligible for meta-analysis. These reported on 111 unique patients with metopic, 65 with unilateral coronal, and 12 with lambdoid craniosynostosis. For all suture types, 100 (53%) children underwent endoscope-assisted craniosynostosis surgery and 32 (47%) patients underwent open repair. These studies all suggest that blood loss, transfusion rate, operating time, and length of hospital stay were superior for endoscopically treated children. Although potentially comparable or better cosmetic outcomes are reported, the paucity of evidence and considerable variability in outcomes preclude meaningful conclusions.

CONCLUSIONS

Limited data comparing open and endoscopic treatments for metopic, unilateral coronal, and lambdoid synostosis suggest a benefit for endoscopic techniques with respect to blood loss, transfusion, length of stay, and operating time. This report highlights shortcomings in evidence and gaps in knowledge regarding endoscopic repair of nonsagittal single-suture craniosynostosis, emphasizing the need for further matched-control studies.

Twenty-Year Review of a Single Surgeon's Experience Using a Unique Surgical Technique to Correct Lambdoidal Synostosis

BACKGROUND

Numerous techniques for the surgical management of lambdoidal synostosis have been previously described; however, no best practice technique currently exists. Surgical procedures range from complete posterior calvarial reconstruction to distraction osteogenesis techniques. Our primary purpose is to describe a novel approach to correct unilateral or bilateral lambdoidal synostosis.

METHODS

A retrospective review was performed on a single surgeon's experience with craniosynostosis (1994-2014). Specifically, craniosynostosis cases involving the lambdoidal suture, which were repaired using a novel 'tongue and groove' technique, were identified.

RESULTS

A total of 664 craniosynostosis cases were retrieved, with 21 primarily involving the lambdoidal suture (3.2%). Of these, 18 were unilateral and 3 were bilateral lambdoidal synostosis. Male-to-female ratio was 3:1. Average age of first encounter with a craniofacial physician was 33 weeks (8 months). Average age at time of surgery was 43 weeks (10.75 months). Complications of this technique included 1 patient who experienced refusion of his lambdoidal suture and fusion of his sagittal suture, and 4 who returned for bone graft coverage of full-thickness calvarial defects owing to a lack of complete reossification.

CONCLUSION

The "tongue and groove" technique represents a novel method for the management of lambdoidal synostosis with good esthetic outcomes, allowing immediate cranial stabilization with increased skull volume. This technique, used by the senior author for >20 years, provides a reproducible and reliable method of correcting lambdoidal synostosis.

Lambdoid Craniosynostosis: The Relationship with Chiari Deformations and an Analysis of Surgical Outcomes

BACKGROUND

A relationship between lambdoid craniosynostosis and Chiari deformations has been suggested, but the true extent of this association remains uncertain. The authors reviewed a single center's experience treating lambdoid synostosis to further elucidate this relationship, examine surgical outcomes, and identify associations that might impact future treatments.

METHODS

A retrospective chart review was performed of all patients treated for lambdoid craniosynostosis, excluding the syndromic craniosynostoses. Operative data, scans, hospitalization, and subsequent surgical procedures were tracked. All patients were treated with remodeling procedures, but those with Chiari deformations underwent additional simultaneous suboccipital decompressions.

RESULTS

Over 22 years, 1006 nonsyndromic craniosynostosis patients were treated, 45 of whom (4.5 percent) presented with lambdoid involvement: 25 single-suture and 20 multiple-suture (complex craniosynostosis). Magnetic resonance imaging revealed that 60 percent of children with unilateral synostosis and 71 percent with a complex synostosis had associated Chiari deformations. The mean surgical age was 12 months, and the average follow-up was 5.7 years: two patients developed syringomyelia requiring transcervical decompressions and two underwent secondary posterior remodeling procedures (one unilateral and one complex synostosis) while undergoing later Chiari decompressions. No patients treated with initial suboccipital decompressions have subsequently developed symptoms requiring treatment.

CONCLUSIONS

The majority of children with lambdoid synostosis develop Chiari deformations; therefore, routine preoperative and postoperative magnetic resonance imaging should be considered. The treatment of lambdoid craniosynostosis with cranial remodeling procedures, including incontinuity suboccipital decompressions when Chiari deformations were present, was associated with few complications. Ninety-six percent of those with isolated fusions were managed with a single procedure.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Cranial Base and Posterior Cranial Vault Asymmetry After Open and Endoscopic Repair of Isolated Lambdoid Craniosynostosis

BACKGROUND

Previous studies have shown that open cranial vault remodeling does not fully address the endocranial deformity. This study aims to compare endoscopic-assisted suturectomy with postoperative molding helmet therapy to traditional open reconstruction by quantifying changes in cranial base morphology and posterior cranial vault asymmetry.

METHODS

Anthropometric measurements were made on pre- and 1-year postoperative three-dimensionally reconstructed computed tomography scans of 12 patients with unilateral lambdoid synostosis (8 open and 4 endoscopic-assisted). Cranial base asymmetry was analyzed using: posterior fossa deflection angle (PFA), petrous ridge angle (PRA), mastoid cant angle (MCA), and vertical and anterior-posterior (A-P) displacement of external acoustic meatus (EAM). Posterior cranial vault asymmetry was quantified by volumetric analysis.

RESULTS

Preoperatively, patients in the open and endoscopic groups were statistically equivalent in PFA, PRA, MCA, and A-P EAM displacement. At 1 year postoperatively, open and endoscopic patients were statistically equivalent in all measures. Mean postoperative PFA for the open and endoscopic groups was 6.6 and 6.4 degrees, PRA asymmetry was 6.4 and 7.6%, MCA was 4.0 and 3.2 degrees, vertical EAM displacement was -2.3 and -2.3 millimeters, and A-P EAM displacement was 6.8 and 7.8 millimeters, respectively. Mean volume asymmetry was significantly improved in both open and endoscopic groups, with no difference in postoperative asymmetry between the 2 groups (P = 0.934).

CONCLUSIONS

Patients treated with both open and endoscopic repair of lambdoid synostosis show persistent cranial base and posterior cranial vault asymmetry. The results of endoscopic-assisted suturectomy with postoperative molding helmet therapy are similar to those of open calvarial vault reconstruction.

Major clinical features of synostotic occipital plagiocephaly: mechanisms of cranial deformations

PURPOSE

The clinical diagnosis of most common single-suture craniosynostosis is easily set, based on the stereotype of deformities and knowledge of the mechanisms of cranial deformations. However, synostosis of unilateral lambdoid suture, probably due to its lower incidence and similarity with other non-synostotic deformities affecting the posterior portion of the skull, makes its clinical diagnosis more difficult and imprecise. The aim of this study is to evaluate the most easily and accurate clinical characteristics to be recognized in the synostotic occipital plagiocephaly.

METHODS

This study consisted of clinical evaluation of eight patients with synostotic occipital plagiocephaly, whose diagnosis was further corroborated by computed tomography.

RESULTS

We identified the following: unilateral occipital flattening in eight out of eight patients (100 %), bulging of ipsilateral mastoid process in eight out of eight (100 %), "edge effect" of ipsilateral lambdoid suture in eight out of eight (100 %), inferior deviation of the ear in eight out of eight (100 %), "Dumbo" ears in eight out of eight (100 %), horizontal slant of the bimastoid line in seven out of eight (87.5 %), tilt of the head viewed from behind in seven out of eight (87.5 %), trapezoidal contour of the skull in top view in six out of eight (75 %), contralateral parietal bossing in six out of eight (75 %), and bossing of the contralateral forehead three out of eight (37.5 %).

CONCLUSIONS

The most important clinical features specific to the clinical diagnosis of synostotic occipital plagiocephaly, not present in the positional posterior plagiocephaly, were bulging of the ipsilateral mastoid process, edge effect of the synostotic lambdoid suture, tilt of the head, and slant of the bimastoid line viewed from behind, inferior deviation of the ear, and contralateral parietal bossing.

Value of high-resolution ultrasound in the differential diagnosis of scaphocephaly and occipital plagiocephaly

Secondary to the increase in deformational plagiocephaly a growing number of infants with cranial deformity present to craniofacial teams. Computed tomography (CT) is diagnostic, but uses ionizing radiation. The purpose of this study was to evaluate ultrasound as a screening test for the patency of cranial sutures in scaphocephaly and occipital plagiocephaly. The cranial sutures of 54 infants with this cranial deformity were assessed by ultrasound. Sutures were read as patent or fused if a hypoechoic gap could or could not be demonstrated between the hyperechoic clavarial bones, respectively. Seven children suffered from true craniosynostosis of either the sagittal or the lambdoid suture. In five cases the ultrasound findings were diagnostic for a fused suture, in two cases the results were inconclusive. Forty-seven infants presented with deformational plagiocephaly. Ultrasound examination demonstrated patent sutures in 45 cases and was inconclusive in two cases. Sonography of the cranial sutures is a good screening tool to distinguish fused from patent cranial sutures in scaphocephaly and occipital plagiocephaly and avoids the radiation exposure associated with CT examinations.

Analysis of differences in the cranial base and facial skeleton of patients with lambdoid synostosis and deformational plagiocephaly

BACKGROUND

Earlier investigations suggest that the morphologic features of patients with lambdoid synostosis include ipsilateral occipital flattening, an ipsilateral mastoid prominence, downward cant of the posterior skull base to the affected side, and contralateral hemifacial deficiency. These features are absent in patients with deformational plagiocephaly. The authors hypothesize that significant differences in craniofacial morphology exist between patients with lambdoid synostosis and those with deformational plagiocephaly.

METHODS

Craniometric measurements were performed on patients with unilateral lambdoid synostosis (n = 9) and deformational plagiocephaly (n = 12). Measurements were performed on affected and unaffected sides and included posterior fossa deflection angle, petrous ridge angle, middle cranial fossa and anterior cranial fossa area, temporomandibular joint displacement, and maxillary and mandibular dimensions. Appropriate statistical tests were performed.

RESULTS

Statistically significant differences in posterior fossa deflection angle, petrous ridge angle, and middle cranial fossa were found between groups. Lambdoid synostosis patients demonstrated a larger petrous ridge angle (p = 0.0001) and middle cranial fossa (p = 3.37 × 10(-6)) on the unaffected side. Deformational plagiocephaly patients exhibited no discrepancies between sides. The mean posterior fossa deflection angle was 10.55 degrees for the lambdoid synostosis group and 3.59 degrees for the deformational plagiocephaly group (p < 0.0001). All lambdoid synostosis patients had deviation of the posterior cranial fossa toward the affected side. Deformational plagiocephaly patients had variable deflection. All lambdoid synostosis patients demonstrated marked posterior displacement of the contralateral temporomandibular joint. Deformational plagiocephaly patients had either symmetric temporomandibular joint position (75 percent) or slight contralateral posterior displacement (25 percent). Mandibular size was not significantly different between groups.

CONCLUSION

Patients with lambdoid synostosis and deformational plagiocephaly manifest significant differences in cranial base morphology, contributing to the phenotypic differences seen in these two groups of patients.

Posterior calvarial augmentation in premature craniosynostosis: a technique avoiding foreign implants or free bone flaps

BACKGROUND

A surgical technique of posterior calvarial augmentation without the use of plates or screws and avoiding the formation of free bone flaps is described.

DISCUSSION

Three infants with strong occipital flattening successfully underwent the procedure in their first year of life. There were no intra- or postoperative complications; the amelioration of the head shape and the cosmetic results in all three cases were convincing also in the long term.

CONCLUSION

The proposed surgical technique is both feasible and effective; it is recommended for infants with marked flat deformation of the posterior calvaria in the first year of life.

Surgical treatment of single-suture craniosynostosis: an argument for quantitative methods to evaluate cosmetic outcomes

The traditional reasons for surgical intervention in children with single-suture craniosynostosis (SSC) are cosmetic improvement and the avoidance/treatment of intracranial hypertension, which has been thought to contribute to neurocognitive deficits. Despite considerable work on the topic, the exact prevalence of intracranial hypertension in the population of patients with SSC is unknown, although it appears to be present in only a minority. Additionally, recent neuropsychological and anatomical literature suggests that the subtle neurocognitive deficits identified in children with a history of SSC may not result from external compression. They may instead reflect an underlying developmental condition that includes disordered primary CNS development and early suture fusion. This implies that current surgical techniques are unlikely to prevent neurocognitive deficits in patients with SSC. As such, the most common indication for surgical treatment in SSC is cosmetic, and most patients benefit from considerable subjective cosmetic normalization following surgery. Pediatric craniofacial surgeons have not, however, agreed upon objective means to assess postoperative cranial morphological improvement. We should therefore endeavor to agree upon objective craniometric tools for the assessment of operative outcomes, allowing us to accurately compare the various surgical techniques that are currently available.

Craniosynostosis in the Middle Pleistocene human Cranium 14 from the Sima de los Huesos, Atapuerca, Spain

We report here a previously undescribed human Middle Pleistocene immature specimen, Cranium 14, recovered at the Sima de los Huesos (SH) site (Atapuerca, Spain), that constitutes the oldest evidence in human evolution of a very rare pathology in our own species, lambdoid single suture craniosynostosis (SSC). Both the ecto- and endo-cranial deformities observed in this specimen are severe. All of the evidence points out that this severity implies that the SSC occurred before birth, and that facial asymmetries, as well as motor/cognitive disorders, were likely to be associated with this condition. The analysis of the present etiological data of this specimen lead us to consider that Cranium 14 is a case of isolated SSC, probably of traumatic origin. The existence of this pathological individual among the SH sample represents also a fact to take into account when referring to sociobiological behavior in Middle Pleistocene humans.

Familial lambdoid craniosynostosis between father and son

Lambdoid craniosynostosis is an uncommon condition, with an incidence of 1 per 33,000 live births. Its etiopathology remains controversial. Although many forms of syndromic and nonsyndromic craniosynostosis demonstrate an inherited pattern, few articles have reported lambdoid craniosynostosis in the same family. In this article, we report lambdoid synostosis in a father and son. A case review is performed. A full-term male infant was delivered by cesarean delivery because of failure to progress. He presented at 3 years of age with right unilateral lambdoid craniosynostosis with facial asymmetry and lateral deviation of his jaw, with occlusal abnormality. At presentation, the father reported skull surgery during his infancy for unilateral lambdoid craniosynostosis. Review of the computed tomographic scan of the child demonstrated a plagiocephalic appearance of the calvarium with frontal bossing and a fusion of the lambdoid suture on the right sides. The brain parenchyma showed no abnormality. The review of his father's surgical record from 33 years ago and of his computed tomographic scan ordered by our team confirmed the diagnosis of previous lambdoid craniosynostosis. Only 2 previous cases of familial isolated lambdoid craniosynostosis have been previously described in literature. Although the genetic basis has been established for many types of craniosynostosis, the etiopathogenesis of isolated lambdoid synostosis has not yet been established. We report the third case of inherited unilateral lambdoid craniosynostosis. The genetic pathogenesis of lambdoid craniosynostosis will be discussed.

The misdiagnosis of craniosynostosis as deformational plagiocephaly

Deformational plagiocephaly, unilateral coronal craniosynostosis, and lambdoid craniosynostosis all cause oblique deformities of the skull. They are separate entities with different etiologies resulting in clear differences of physical examination, radiologic findings, and clinical course. Treatment for each condition is markedly different. Surgical intervention is recommended for unilateral coronal and lambdoid craniosynostosis using different techniques. Deformational plagiocephaly, on the other hand, is often satisfactorily managed with conservative treatment. We present 4 clinical reports on patients in whom unilateral coronal craniosynostosis and lambdoid craniosynostosis were originally misdiagnosed as occipital deformational plagiocephaly and highlight individual structural distinctions.