Occipitocervical fusion using a contoured rod and wire construct in children: a reappraisal of a vintage technique

Pediatric craniocervical fusion: predictors of surgical outcomes, risk of recurrence, and re-operation

PURPOSE

Craniocervical junction abnormalities include a wide variety of disorders and can be classified into congenital or acquired. This study aimed to review the surgical outcome of pediatric patients who underwent craniocervical and/or atlantoaxial fusion.

METHODS

This is a retrospective cohort study including all pediatric patients (≤ 18 years) who underwent craniocervical and/or atlantoaxial fusion between 2009 and 2019 at quaternary medical city.

RESULTS

A total of 25 patients met our criteria and were included in the study. The mean age was 9 years (range: 1-17 years). There was a slight female preponderance (N = 13; 52%). Most patients (N = 16; 64%) had non-trauamatic/chronic causes of craniocervical instability. Most patients presented with neck pain and/or stiffness (N = 14; 56%). Successful fusion of the craniocervical junction was achieved in most patients (N = 21; 84%). Intraoperative complications were encountered in 12% (N = 3) of the patients. Early postoperative complications were observed in five patients (20%). Five patients (20%) experienced long-term complications. Revision was needed in two patients (8%). Older age was significantly associated with higher fusion success rates (p = 0.003). The need for revision surgery rates was significantly higher among younger age group (3.75 ± 2, p = 0.01).

CONCLUSIONS

The study demonstrates the surgical outcome of craniocervical and/or atlantoaxial fusion in pediatric patients. Successful fusion of the craniocervical junction was achieved in most patients. Significant association was found between older age and successful fusion, and between younger age and need for revision surgery.

The Feasibility of Anterior Occipital Condyle Screw for the Reconstruction of Craniovertebral Junction: A Digital Anatomical and Cadaveric Study of a Novel Technique

Background

Anterior occipital condyle screw (AOCS) could be a feasible alternative technique for occipitocervical fusion for reconstruction of craniovertebral junction. This study aimed to analyze the feasibility of AOCS.

Methods

The craniovertebral junction computed tomography (CT) scans of 40 adults were enrolled and imported into Mimics software. Then, the three-dimensional reconstruction digital model of craniovertebral junction was established to determine entry point, insertion angle, and screw’s trajectory. After AOCS insertion into ten human cadaver spine specimens, CT scans were performed to verify the location between screws and important structures.

Results

The optimal entry point was located caudally and medial to the ventral of occipital condyle. The optimal trajectory was in inclination angle (5.9°±3.4°) in the sagittal plane and divergence angle (26.7°±6.0°) in the axial plane with the screw length around 21.6±1.2mm. None of the screws invaded the hypoglossal canal and vertebral artery in any of the specimens.

Conclusion

AOCS fixation is a feasible, novel technique for anterior craniovertebral junction reconstruction, and it could be an effective alternative operation for anterior reconstruction with titanium mesh cage.

Traumatic atlanto-occipital dislocation in children: is external immobilization an option?

OBJECT

Traumatic atlanto-occipital dislocation (AOD) is a relatively uncommon traumatic cervical spine injury characterized by disruption and instability of the atlanto-occipital joint. At many centers, management of pediatric AOD includes occipitocervical arthrodesis, but whether external immobilization without surgery is a viable treatment option for some pediatric patients is unknown. To answer this question, we analyzed our outcomes of pediatric AOD at the Hospital for Sick Children.

METHODS

We performed a retrospective chart review of all children with clinical and radiographic evidence of traumatic AOD. A total of 10 patients met criteria for traumatic AOD: 8 were treated with external immobilization alone and 2 were treated with occipitocervical arthrodesis.

RESULTS

Eight patients were treated exclusively with 3 months of halo immobilization. Two patients were treated with occipitocervical instrumentation and arthrodesis. No patient undergoing halo immobilization required subsequent operative fusion.

CONCLUSION

Halo immobilization is a safe, viable, and definitive treatment option for the selected children with AOD.

Atlanto-Occipital Transarticular Screw Fixation for the Treatment of Traumatic Occipitocervical Instability in the Pediatric Population

BACKGROUND

Atlanto-occipital transarticular screw fixation (AOTSF) has rarely been reported for fixation of the craniovertebral junction (CVJ).

METHODS

A retrospective chart review of all pediatric patients (less than 18 years of age) with an attempt of AOTSF for fixation of traumatic CVJ instability was conducted.

RESULTS

A total of 4 patients (2 boys and 2 girls; ages 2, 3, 5, and 8 years) who suffered from acute traumatic CVJ instability managed during 2007-2018 underwent an attempted AOTSF. In 2 patients, this method was technically successful. In the other 2 instances, we were not able to engage the screw into the occipital condyle. These were converted to standard occipital plate, rod, and screw fixation. All were placed in a halo subsequently for a minimum of 3 months. Three patients were fused at last follow-up (range, 17-48 months). One patient after successful AOTSF did not fuse. There were no surgical complications or revision procedures.

CONCLUSIONS

AOTSF was feasible in half of pediatric patients suffering from traumatic CVJ instability. Therefore, intraoperative salvage options and strategies should be on hand readily. In the pediatric population, where bony anatomy may pose challenges to fixation, this technique may offer a viable first-line option in selected cases, despite the overall modest success rate.

Occipital fixation techniques and complications

Occipitocervical fusions in the adult population are most commonly indicated for neoplastic tumors invading the craniocervical junction (CCJ), rheumatological deformities compromising the foramen magnum, and traumatic dislocations resulting in occiput-C1 instability. Appropriate preoperative imaging will not only assist in identifying the pathology but also determine a treatment regimen for the diseased junction. A treatment algorithm for craniocervical disease is proposed. Lesions must first be identified as irreducible versus reducible: restore extension and/or distraction of the craniovertebral junction without injuring the neural elements. Irreducible lesions require decompression only, while reducible lesions require an added fusion. Techniques in fusion are broadly divided into external immobilization versus internal fixation. The former entails halo rings and tongs for a prolonged duration. Fixation surgeries vary from wiring to screw fixation of the occiput-C1 segment. Details of the operation as well as potential complications are discussed.

Craniovertebral junction fixation in children less than 5 years

PURPOSE

Whilst rigid fixation for craniovertebral instability is the gold standard, in very young, small children conventional management may have to be modified. We present a single-centre experience of craniocervical fixation in children under 5 years.

METHODS

A retrospective review of cases that had undergone atlantoaxial (AA) or occipitocervical (OC) fixation aged under 5 years. Fusion was assessed using computerised tomography or flexion extension X-rays.

RESULTS

Twenty-six children (median age 2.3, range 0.8-4.9 years, 19 under the age of 3) underwent OC (n = 19) or AA (n = 7) fusion between 1999 and 2016. Pathology comprised 17 congenital, five trauma, two tumour and two post-infection cases. Twenty-one patients underwent sublaminar cable fixation with calvarial, autologous bone graft and halo-body orthosis immobilisation. An occipital plate and rods to sublaminar wire construct were used in four cases. A rigid instrumented fixation with occipital plate and C2 pedicle screws was utilised in one case. Follow-up was for a median of 2.8 years (range 0.03-16.3 years). Initial fusion rate was 91%, reaching 100% following two re-operations. Ninety-two per cent of patients were neurologically stable or improved following surgery. Twenty-one patients had a good overall outcome. Two patients had post-operative neurological deteriorations, and four died due to non-procedure related causes. Pin site morbidity secondary to halo use occurred in five cases.

CONCLUSION

High fusion rates with good outcomes are achievable using semi-rigid fixation in the under 5-year-olds. Full thickness, autologous calvarial bone graft secured with wire cables and halo external orthosis offers a safe and effective alternative technique when traditional screw instrumentation is not feasible. These slides can be retrieved under Electronic Supplementary Material.

A Novel Instrumentation Approach in a Pediatric Patient with Atlanto-Occipital Dislocation and Cervical Fracture: Case Report

BACKGROUND

Although instrumented stabilization of pediatric atlanto-occipital dislocation (AOD) has been described in the literature, there is little evidence regarding instrumentation techniques in pediatric patients presenting with both AOD and a cervical fracture. We present a case of a 2-year-old male involved in a motor vehicle collision with an unstable C2 fracture and AOD, treated with an occiput-C4 posterior arthrodesis using a rod, crosslink, and cable construct.

CASE DESCRIPTION

This patient suffered a type III C2 fracture and AOD with 4 mm craniocaudal and 3 mm anterior displacement. In the operating room, 2 cobalt chrome connecting rods (3.5 mm) were connected to 1 another with crosslinks at C2 and C4. These were affixed with suboccipital and sublaminar cables at C1, C2, and C4. At 14 months postoperatively, his spine is clinically and radiographically stable. He has spontaneous movement in all 4 extremities, and remains in a persistent vegetative state because of his underlying central nervous system injury.

CONCLUSIONS

Although there is a breadth of literature investigating instrumentation approaches to pediatric AOD, there is minimal evidence on outcomes of patients presenting with both AOD and cervical fracture. The technique we describe has proven safe and effective for this patient.

Spinal instrumentation in infants, children, and adolescents: a review

OBJECTIVEThe evolution of pediatric spinal instrumentation has progressed in the last 70 years since the popularization of the Harrington rod showing the feasibility of placing spinal instrumentation into the pediatric spine. Although lacking in pediatric-specific spinal instrumentation, when possible, adult instrumentation techniques and tools have been adapted for the pediatric spine. A new generation of pediatric neurosurgeons with interest in complex spine disorder has pushed the field forward, while keeping the special nuances of the growing immature spine in mind. The authors sought to review their own experience with various types of spinal instrumentation in the pediatric spine and document the state of the art for pediatric spine surgery.METHODSThe authors retrospectively reviewed patients in their practice who underwent complex spine surgery. Patient demographics, operative data, and perioperative complications were recorded. At the same time, the authors surveyed the literature for spinal instrumentation techniques that have been utilized in the pediatric spine. The authors chronicle the past and present of pediatric spinal instrumentation, and speculate about its future.RESULTSThe medical records of the first 361 patients who underwent 384 procedures involving spinal instrumentation from July 1, 2007, to May 31, 2018, were analyzed. The mean age at surgery was 12 years and 6 months (range 3 months to 21 years and 4 months). The types of spinal instrumentation utilized included occipital screws (94 cases); C1 lateral mass screws (115 cases); C2 pars/translaminar screws (143 cases); subaxial cervical lateral mass screws (95 cases); thoracic and lumbar spine traditional-trajectory and cortical-trajectory pedicle screws (234 cases); thoracic and lumbar sublaminar, subtransverse, and subcostal polyester bands (65 cases); S1 pedicle screws (103 cases); and S2 alar-iliac/iliac screws (56 cases). Complications related to spinal instrumentation included hardware-related skin breakdown (1.8%), infection (1.8%), proximal junctional kyphosis (1.0%), pseudarthroses (1.0%), screw malpositioning (0.5%), CSF leak (0.5%), hardware failure (0.5%), graft migration (0.3%), nerve root injury (0.3%), and vertebral artery injury (0.3%).CONCLUSIONSPediatric neurosurgeons with an interest in complex spine disorders in children should develop a comprehensive armamentarium of safe techniques for placing rigid and nonrigid spinal instrumentation even in the smallest of children, with low complication rates. The authors' review provides some benchmarks and outcomes for comparison, and furnishes a historical perspective of the past and future of pediatric spine surgery.

Traumatic Occipitocervical Distraction Injuries in Children: A Systematic Review

BACKGROUND

Occipitocervical distraction injuries (OCDI) in children occur on a wide spectrum of severity, and decisions about treatment suffer from a lack of rigorous guidelines and significant inter-institutional variability. While clear cases of frank atlanto-occipital dislocation (AOD) are treated with surgical stabilization, the approach for less severe cases of OCDI is not standardized. These patients require a careful assessment of both radiographic and clinical criteria, as part of a complex risk-benefit analysis, to establish whether occipitocervical fusion (OCF) is indicated. Here, we performed a systematic review of the literature that describes traumatic OCDI in children < 18 years of age.

SUMMARY

We performed a systematic review, according to PRISMA guidelines, of children < 18 years of age presenting with traumatic etiologies of OCDI. We searched PubMed to identify papers congruent with these criteria. Exclusion criteria included (1) reports on atraumatic causes of OCDI and (2) studies with insufficient clinical and radiographic details on individual patients. We identified 16 reports describing a total of 144 patients treated for pediatric traumatic OCDI. Based on the synthesis of these findings and the collective experience of the authors, we present the demographic, clinical, and radiographic factors that underlie OC instability, which we hope will serve as components of a grading system in the future. We considered various clinical and radiographic findings including: (1) the mechanism of injury, (2) the patient's age, (3) CT/CT angiography of head and neck findings and parameters, (4) MRI findings, and (5) neurological exam, for the purpose of determining the severity of the OCDI and offering treatment guidelines based on the summative risk of underlying OC instability. Key Messages: OCDI is a potentially devastating injury, especially in children. Although missing the diagnosis can have potentially catastrophic consequences, reverting to surgical fixation in less severe cases can subject children to unnecessary operative risk and permanently reduce their range of motion. After reviewing all the available reports of pediatric traumatic OCDI in the neurosurgical literature, we propose an outline of clinical and radiographic factors influencing underlying OC instability that could be incorporated into a grading scale to guide treatment. We hope this study stimulates discussion on the standardization of treatment for pediatric OCDI.

A Modified Technique for Occipitocervical Fusion Using Compressed Iliac Crest Allograft Results in a High Rate of Fusion in the Pediatric Population

BACKGROUND

In children, high rates of occipitocervical (OC) fusion have been demonstrated with the use of rigid instrumentation in combination with harvested autograft, with or without bone morphogenetic protein (BMP). Historically, the use of allograft materials demonstrated inferior OC fusion outcomes compared with autograft. However, autograft harvest harbors an increased risk of patient morbidity, and the use of BMP is costly and controversial in children. Thus, there remains a need for safer, less costly, yet efficacious techniques for OC fusion in the pediatric population.

METHODS

We retrospectively reviewed the charts of patients younger than 21 years of age who underwent OC fusion with structural allograft placement at our institution from 2010 to 2015. Data collected included age, sex, follow-up duration, fusion outcomes, and postoperative complications.

RESULTS

A total of 19 patients (8 female and 11 male) underwent OC fusion with our surgical technique. Mean age was 8.5 ± 4.3 years. Radiographic follow up data were available for 18 of 19 patients. One patient was lost to clinical follow up but had radiographic confirmation of fusion. Thus, 18 of 18 (100%) of patients with radiographic follow-up achieved successful arthrodesis as determined by computed tomography. Median duration to documented fusion was 4.5 months. Clinical follow-up was available for 17 of 19 patients and was on average 18.8 ± 13.5 months. One patient required reoperation for graft fracture 8 months after radiographic confirmation of successful fusion. There were no vertebral artery injuries or other postoperative complications.

CONCLUSIONS

We demonstrate a modified technique for OC fusion in children with unique structural allograft shaping and affixation, leading to excellent fusion outcomes at follow up. This technique obviates the need for autograft harvest or BMP, and may decrease postoperative morbidity.

Instrumented fusion in a 12-month-old with atlanto-occipital dislocation: case report and literature review of infant occipitocervical fusion

BACKGROUND

The treatment of atlantoaxial dislocation in very young children is challenging and lacks a consensus management strategy.

DISCUSSION

We review the literature on infantile occipitocervical (OC) fusion is appraised and technical considerations are organized for ease of reference. Surgical decisions such as graft type and instrumentation details are summarized, along with the use of bone morphogenic protein and post-operative orthoses.

ILLUSTRATIVE CASE

We present the case of a 12-month-old who underwent instrumented occipitocervical (OC) fusion in the setting of traumatic atlanto-occipital dislocation (AOD).

CONCLUSION

Occipitocervical (OC) arthrodesis is obtainable in very young infants and children. Surgical approaches are variable and use a combination of autologous grafting and creative screw and/or wire constructs. The heterogeneity of pathologic etiology leading to OC fusion makes it difficult to make definitive recommendations for surgical management.

Association of Atlanto-Occipital Dislocation, Retroclival Hematoma, and Hydrocephalus: Management and Survival in a Pediatric Patient

Atlanto-occipital dislocation (AOD) is an injury with high morbidity and mortality. We present a case of survival of a pediatric patient with the diagnoses of AOD, retroclival hematoma, and resulting hydrocephalus. The patient's cervical spine was stabilized until occipital-cervical fusion provided definitive treatment, and the hydrocephalus was treated with a ventriculostomy. The patient survived with no neurological deficits. A better understanding and awareness of the radiologic criteria of AOD will lead to earlier recognition of AOD and improved outcomes, even in the presence of complications from AOD. Surgical fixation should be used for definitive treatment of injuries with AOD.

Pediatric occipitocervical fixation: radiographic criteria, surgical technique, and clinical outcomes based on experience of a single surgeon

OBJECTIVE If left untreated, occipitocervical (OC) instability may lead to serious neurological injury or death. Open internal fixation is often necessary to protect the neurovascular elements. This study reviews the etiologies for pediatric OC instability, analyzes the radiographic criteria for surgical intervention, discusses surgical fixation techniques, and evaluates long-term postoperative outcomes based on a single surgeon's experience. METHODS The charts of all patients < 18 years old who underwent internal OC fixation conducted by the senior author were retrospectively reviewed. Forty consecutive patients were identified for analysis. Patient demographic data, OC junction pathology, radiological diagnostic tools, surgical indications, and outcomes are reported. RESULTS The study population consisted of 20 boys and 20 girls, with a mean age of 7.3 years. Trauma (45% [n = 18]) was the most common cause of instability, followed by congenital etiologies (37.5% [n = 15]). The condyle-C1 interval had a diagnostic sensitivity of 100% for atlantooccipital dislocation. The median number of fixated segments was 5 (occiput-C4). Structural bone grafts were used in all patients. Postsurgical neurological improvement was seen in 88.2% (15/17) of patients with chronic myelopathy and in 25% (1/4) of patients with acute myelopathy. Preoperatively, 42.5% (17/40) of patients were neurologically intact and remained unchanged at last follow-up, 42.5% (17/40) had neurological improvement, 12.5% (5/40) remained unchanged, and 2.5% (1/40) deteriorated. All patients had successful fusion at 1-year follow-up. The complication rate was 7.5% (3/40), including 1 case of vertebral artery injury. CONCLUSIONS Occipitocervical fixation is safe in children and provides immediate immobilization, with excellent survival and arthrodesis rates. Of the radiographic tools evaluated, the condyle-C1 interval was the most predictive of atlantooccipital dislocation.

Craniovertebral fusion in an infant using struts of banked adult bone

PURPOSE

The aim of this paper is to discuss the problems of craniocervical instability and craniocervical fusion in infancy. Despite the relative frequency of carniovertebral joint malformations, actual instability is quite rare in infancy.

METHODS

An infant 8 months of age presented with tetraparesis and sleep apnea due to a complex malformation of her craniovertebral joint. An initial attempt at conservative treatment using a rigid neck collar failed, so the patient was surgically managed by the onlay placement of two autologous rib grafts. The rigid collar was maintained for 5 months.

RESULTS

Both rib grafts progressively reabsorbed within a few months, while the clinical deficits recurred. Reoperation consisted of occipitocervical interposition of two robust struts of banked cadaveric adult fibula. This time, the skull appeared mature enough to allow immobilization by the halo system. Adequate occipitocervical fusion was eventually achieved, and the patient fully recovered.

CONCLUSIONS

To the best of our knowledge, there is no other reported case of an infant undergoing craniovertebral fusion using cadaveric adult bone. When screw placement is not considered advisable to manage small infants, appropriate stability may be obtained using struts of robust cadaveric bone. A meticulous carpentry technique with graft interposition under compression and adequate postoperative immobilization remains mandatory.

Pediatric Cervical Spine Injuries: A Rare But Challenging Entity

BACKGROUND

Injuries to the cervical spine in pediatric patients are uncommon. A missed injury can have devastating consequences in this age group. Because of the lack of routine in diagnosis and management of pediatric cervical spine injuries (PCSI), each of these cases represents a logistic and personal challenge.

METHODS

By means of clinical cases, we demonstrate key points in diagnostics and treatment of pediatric spine injuries. We highlight typical pediatric injury patterns and more adult-like injuries.

RESULTS

The most common cause of injury is blunt trauma. There is an age-related pattern of injuries in pediatric patients. Children under the age of 8 frequently sustain ligamentous injuries in the upper cervical spine. After the age of 8, the biomechanics of the cervical spine are similar to adults, and therefore, bony injuries of the subaxial cervical spine are most likely to occur. Clinical presentation of PCSI is heterogeneous. Younger children can neither interpret nor communicate neurological abnormalities, which make timely and accurate diagnosis difficult. Plain radiographs are often misinterpreted. We find different types of injuries at different locations, because of different biomechanical properties of the immature spine. We outline that initial management is crucial for long-term outcome.

CONCLUSIONS

Knowledge of biomechanical properties and radiographic presentation of the immature spine can improve the awareness for PCSI. Diagnosis and management of pediatric patients after neck trauma can be demanding.

LEVEL OF EVIDENCE

Level IV.

Computed tomography parameters for atlantooccipital dislocation in adult patients: the occipital condyle-C1 interval

OBJECT

Atlantooccipital dislocation (AOD) in adults cannot be diagnosed with adequate specificity and sensitivity using only CT or plain radiography, and the spine literature offers no guidelines. In children, the most sensitive and specific radiographic measurement for the diagnosis of AOD is the CT-based occipital condyle-C1 interval (CCI). The goal of the current study was to identify the normal CCI in healthy adults and compare it with the CCI in adults with AOD to establish a highly sensitive and specific cutoff value for the neuroimaging diagnosis of AOD.

METHODS

A total of 81 patients, 59 without AOD and 22 with AOD, were included in this study. Measurements obtained from thin-slice CT scans of the craniovertebral joint to assess atlantooccipital dislocation included the CCI, condylar sum, the Wholey and Harris intervals, Powers and Sun ratios, Wackenheim line, and Lee X-lines.

RESULTS

The group of patients without AOD included 30 men (50.8%) and 29 women (49.2%) with a mean age of 42.4 ± 16 years (range 19-87 years). The group of patients with AOD included 10 men (45.5%) and 12 women (54.5%) with a mean age of 38.2 ± 9.7 years (range 20-56 years). Interrater reliabilities within a 95% CI were all greater than 0.98 for CCI measurements. A total of 1296 measurements of the CCI were made in 81 patients. The mean CCI for non-AOD patients was 0.89 ± 0.12 mm, the single largest CCI measurement was 1.4 mm, and the largest mean for either right or left CCI was 1.2 mm. The mean condylar sum was 1.8 ± 0.2 mm, and the largest condylar sum value was 2.2 mm. Linear regression with age predicted an increase in CCI of 0.001 mm/year (p < 0.05). The mean CCI in AOD patients was 3.35 ± 0.18 mm (range 1.5 mm-6.4 mm). The shortest single CCI measurements in the AOD patients were 1.1 mm and 1.2 mm. The mean condylar sum for all 22 AOD patients was 6.7 ± 2.7 mm and the shortest condylar sums were 3.0 mm. Cutoff values for AOD were set at 1.5 mm for the CCI and 3.0 mm for the condylar sum, both with a sensitivity of 1 and false-negative rate of 0. Sensitivity for the Powers, Wholey, Harris, Sun, Wackenheim, and Lee criteria were determined to be 0.55, 0.46, 0.27, 0.23, 0.41, and 0.41, respectively.

CONCLUSIONS

The CCI is shorter in adult patients as opposed to the pediatric population. The revised CCI (1.5 mm) and condylar sum (3.0 mm) cutoff values have the highest sensitivity and specificity for the diagnosis of AOD in the adult population.

[Traumatic occipitocervical and atlantoaxial dislocation with clivus fracture in a child. Case report]

BACKGROUND

Cranieovertebral junction lesions in the paediatric population are associated with a low survival rate, which has declined in recent years. Neurological disability is a major concern due to the high economical cost it represents. Paediatric patients are more susceptible to this lesion because of hyperextension capacity, flat articulation, and increased ligamentous laxity. Survival after these kinds of injuries has been more often reported in adults, but are limited in the paediatric population.

CLINICAL CASE

A case is reported of an 8-year-old male with occipitocervical and atlantoaxial dislocation associated with clivus fracture, brain oedema, and post-traumatic subarachnoid haemorrhage (SAH). A halo vest system was placed with no traction. One month after the trauma the patient was surgically treated with C1 and C2 trans-articular screws, occipitocervical fixation with plate and screws, and C1- C2 fixation with tricortical bone graft and wires without complication. He has now returned to school and is self-sufficient.

CONCLUSIONS

With better pre-hospital medical care and with improved surgical techniques the mortality rate has declined in this kind of lesion.

Occipitocervical Fusion Surgery: Review of Operative Techniques and Results

Objective Varying types of clinicoradiologic presentations at the craniovertebral junction (CVJ) influence the decision process for occipitocervical fusion (OCF) surgery. We discuss the operative techniques and decision-making process in OCF surgery based on our clinical experience and a literature review. Material and Methods A total of 49 consecutive patients who underwent OCF participated in the study. Sagittal computed tomography images were used to illustrate and measure radiologic parameters. We measured Wackenheim clivus baseline (WCB), clivus-canal angle (CCA), atlantodental distance (ADD), and Powers ratio (PR) in all the patients. Results Clinical improvement on Nurick grading was recorded in 36 patients. Patients with better preoperative status (Nurick grades 1-3) had better functional outcomes after the surgery (p = 0.077). Restoration of WCB, CCA, ADD, and PR parameters following the surgery was noted in 39.2%, 34.6%, 77.4%, and 63.3% of the patients, respectively. Complications included deep wound infections (n = 2), pseudoarthrosis (n = 2), and deaths (n = 4). Conclusion Conventional wire-based constructs are superseded by more rigid screw-based designs. Odontoidectomy is associated with a high incidence of perioperative complications. The advent of newer implants and reduction techniques around the CVJ has obviated the need for this procedure in most patients.

Traumatic atlanto-occipital dislocation in children

Although once considered an invariably fatal injury, improvements in diagnosis and management have made atlanto-occipital dislocation (AOD) a survivable injury. MRI is the preferred imaging modality; occasionally, flexion/extension/distraction fluoroscopy may be required to determine craniovertebral stability. Early surgical stabilization is recommended for all children with AOD. Early occipitocervical fusion using screws in combination with a rod or plate, or sublaminar wires with a contoured rod, coupled with autograft bone, provide immediate stabilization and a high fusion rate. Halo immobilization and traction are contraindicated in the management of AOD in children because of the risk of displacement of the injured occipitocervical joint. Postoperative hydrocephalus is frequent and should be suspected when neurologic decline occurs after fixation. Nearly half of children who survive AOD will have residual neurologic deficits.