Avoiding early complications and reoperation during occipitocervical fusion in pediatric patients

Endoscopic Ventriculocysternostomy, Magendie Foraminoplasty, and Plexusectomy With Craniovertebral Shunt Placement in a Pediatric Patient With Hydrocephalus and VACTERL Association: A Novel Treatment Option

Endoscopic third ventriculocysternostomy (ETV) is a minimally invasive neurosurgical technique with good results in the treatment of obstructive hydrocephalus. The VACTERL (vertebrae, anorectal, cardiovascular, tracheal, esophageal, renal, limb defects) association, or VATER syndrome, is defined as congenital malformations, mostly derived from the mesoderm, affecting specific areas. It is diagnosed by the presence of at least three of the seven characteristic malformations that describe it. The association of this pathology and obstructive hydrocephalus in pediatric age is not common, making management and conventional neurosurgical procedures difficult due to the number of underlying pathologies. In this study, we report the management of hydrocephalus and VACTERL association with multiple congenital malformations in a 30-day-old premature neonate (birth at 29 weeks). Operations performed prior to admission to our service included: coloesophagoplasty and placement of esophagostoma in the left anterior cervical region, perineal anorectoplasty, gastrostomy and placement of sigmoidostomy in the left anterior abdominal wall, relaparotomy, gastric suture, sanitation, and abdominal drainage. Upon admission, the patient showed a Grade 3 intraventricular hemorrhage and internal occlusive hydrocephalus due to circulatory blockage of the cerebrospinal fluid (CSF) at the level of the outlet of the fourth ventricle. This was accompanied by intracranial hypertension and refractory cervical syringomyelia. We performed endoscopic ventriculocysternostomy plus plexusectomy plus Magendie foraminoplasty with craniovertebral shunt placement, achieving excellent results after two interventions. This is the first case described in the literature placing a craniovertebral shunt using a lateral-ventricle-to-the-subarachnoid-spinal-space-stenting technique in a patient with VACTERL association, which represents an innovation in the field of minimally invasive pediatric neurosurgery.

Incidences, causes and risk factors of unplanned reoperation within 30 days of craniovertebral junction surgery: a single-center experience

PURPOSE

To investigate the incidences, causes, and risk factors for unplanned reoperation within 30 days of craniovertebral junction (CVJ) surgery.

METHODS

From January 2002 to December 2018, a retrospective analysis of patients who underwent CVJ surgery at our institution was conducted. The demographics, history of the disease, medical diagnosis, approach and type of operation, surgery duration, blood loss, and complications were recorded. Patients were divided into the no-reoperation group and the unplanned reoperations group. Comparison between two groups in noted parameters was analyzed to identify the prevalence and risk factors of unplanned revision and a binary logistic regression was performed to confirm the risk factors.

RESULTS

Of 2149 patients included, 34(1.58%) required unplanned reoperation after the initial surgery. The causes for unplanned reoperation contained wound infection, neurologic deficit, improper screw placement, internal fixation loosens, dysphagia, cerebrospinal fluid leakage, and posterior fossa epidural hematomas. No statistical difference was found in demographics between two groups (P > 0.05). The incidence of reoperation of OCF was significantly higher than that of posterior C1-2 fusion (P = 0.002). In terms of diagnosis, the reoperation rate of CVJ tumor patients was significantly higher than that of malformation patients, degenerative disease patients, trauma patients, and other patients (P = 0.043). The binary logistic regression confirmed that different disease, fusion segment (posterior) and surgery time were independent risk factors.

CONCLUSIONS

The unplanned reoperation rate of CVJ surgery was 1.58% and the major causes were implant-related failures and wound infection. Patients with posterior occipitocervical fusion or diagnosed with CVJ tumors had an increased risk of unplanned reoperation.

Cranio-cervical decompression associated with non-instrumented occipito-C2 fusion in children with mucopolysaccharidoses: Report of twenty-one cases

BACKGROUND

Mucopolysaccharidosis (MPS) is a multisystemic storage disorder of glycosaminoglycan deposits. Infiltration of the dura mater and supporting ligaments caused spinal cord compression and consecutive myelopathy, especially at the cranio-cervical junction (CCJ). Craniocervical instability and posterior decompression often raise the problem of fixation in children. The main purpose of this paper was to report the result of an original technique of occipito-cervical arthrodesis using a cranial halo-cast system in pediatric population.

METHODS

We recorded 21 patients with cervical myelopathy. All of them had spinal cord decompression by enlargement of the foramen magnum, C1 laminectomy, and occipito-C2 fusion using corticocancellous bone graft. Only one child has an extended laminectomy from C1 to C3. The occiput-C2 arthrodesis was stabilized by the cranial halo-cast system. This immobilization was performed preoperatively and kept for three months then switched to rigid cervical collar. Clinical assessment, including the Goel grade and mJOA, radiographs and magnetic resonance imaging were performed before surgery. The occipito-cervical arthrodesis was controlled by standard X-rays and CT scan.

RESULTS

According to the type of mucopolysaccharidosis, the patients were divided into MPS type I: n= 3, II: n=7, IV: n=11. The mean age of patients at surgery was 6.76 years. All mucopolysaccharidoses cases required a foramen magnum decompression by craniectomy, C1 laminectomy and occipito-C2 arthrodesis. As major complications, a child had immediate post-operative paraplegia due to spinal cord ischemia. The postoperative follow-up ranged from 1.5 to 4 years, with an average of 3.3 years. The average preoperative mJOA score was 8.9, and it improved to 14 points at the last follow-up.

CONCLUSIONS

Satisfactory fusion and good clinical results were obtained with the 2-stage approach to CCJ anomalies.

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.

C2 translaminar screw fixation in pediatric occipitocervical fusion

PURPOSE

Rigid occipitocervical (O-C) instrumentation can reduce the anterior pathology and has a high fusion rate in children with craniovertebral instability. Typically, axis (C2) screw fixation utilizes C1-C2 transarticular screws or C2 pars screws. However, anatomic variation may preclude these screw types due to the size of fixation elements or by placing the vertebral artery at risk for injury. Pediatric C2 translaminar screw fixation has low risk of vertebral artery injury and may be used when the anatomy is otherwise unsuitable for C1-C2 transarticular screws or C2 pars screws.

METHODS

We retrospectively reviewed a neurosurgical database at UCSF Benioff Children's Hospital Oakland for patients who had undergone a cervical spinal fusion that utilized translaminar screws for occipitocervical instrumentation between 2002 and 2020. We then reviewed the operative records to determine the parameters of C2 screw fixations performed. Demographic and all other relevant clinical data were then recorded.

RESULTS

Twenty-five patients ranging from 2 to 18 years of age underwent O-C fusion, with a total of 43 translaminar screws at C2 placed. Twenty-three patients were fused (92%) after initial surgery with a mean follow-up of 43 months. Two patients, both with Down syndrome, had a nonunion. Another 2 patients had a superficial wound dehiscence that required wound revision. One patient died of unknown cause 7 months after surgery. One patient developed an adjacent-level kyphosis.

CONCLUSION

When performing occipitocervical instrumentation in the pediatric population, C2 translaminar screw fixation is an effective option to other methods of C2 screw fixation dependent on anatomic feasibility.

Use of halo fixation therapy for traumatic cranio-cervical instability in children: a systematic review

PURPOSE

Traumatic cranio-cervical instability in childhood is rare and constitutes a challenge for the treating surgeon. The aim of therapy is to restore cervical stability without limiting the range of motion. The goal of this systematic review was to find out whether, over the last 10 years, halo fixation (HF) could still be considered a successful treatment option without major risks or complications.

METHODS

We analyzed studies describing the use of HF in traumatic injuries of the cranio-cervical junction in children under the age of 17. Searches were performed in PubMed, MEDLINE and Embase databases for the years from 2010 to 2020. The general success rate, the success rate related to underlying pathologies, and complication rates were evaluated.

RESULTS

The main indications for HF range from pre-surgical correction to postoperative fusion support. C2 is the most frequently injured vertebra in children. The overall success rate of HF was very high. Evaluation according to the underlying pathology showed that, except for atlanto-occipital dislocation, HF generates high fusion rates among different patient cohorts, mainly in C2 vertebra injuries and atlantoaxial rotatory subluxation. Only minor complications were reported, such as pin infections.

CONCLUSION

The current data show that, when used according to the appropriate indication, HF is an effective conservative treatment option for cranio-cervical instability, associated with only minor complications.

Protecting Against Postoperative Dyspnea and Dysphagia After Occipitocervical Fusion

BACKGROUND

Upper airway obstruction leading to dyspnea and dysphagia after occipitocervical fusion is a rare complication that has significant morbidity.

OBJECTIVE

To estimate the frequency of postoperative dyspnea and dysphagia in children after occipitocervical fusion and to identify variables associated with its occurrence.

METHODS

We retrospectively reviewed outcomes from all pediatric occipitocervical fusions at our institution between 2007 and 2014. Pre- and postoperative computed tomography (CT) scans were compared to determine differences in the clivoaxial (OC2) angles.

RESULTS

Sixty-seven pediatric patients underwent occipitocervical fusions. Median age was 9.6 yr (range 6 mo-18 yr). Fifty-six of 62 patients (90.3%) with at least 1 yr of follow-up had successful fusions. Eleven had pre-existing symptoms or otherwise compromised examination (eg, severe traumatic brain injury). None of 15 patients placed in extension (>2 degrees) relative to preoperative CT in Situ position developed new dyspnea or dysphagia. Nine of forty patients (23%) kept in Situ or flexed position developed new symptoms of dyspnea or dysphagia. Dysphagia in patients fused in the in Situ position was milder and resolved within a few weeks. No patient under age 5 (n = 20) developed symptoms of dyspnea or dysphagia regardless of head position. There were 3 cases of infection, 1 clinically silent vertebral artery injury, and 3 deaths at last follow-up.

CONCLUSION

Positioning of the child's head prior to occipitocervical fusion has considerable impact on outcomes, especially in older children. Careful measurements of the OC2 angle during surgery to ensure optimal head positioning in Situ or slightly extended position may prevent postoperative dysphagia or dyspnea.

Implant Retention or Removal for Management of Surgical Site Infection After Spinal Surgery

STUDY DESIGN

A literature review.

OBJECTIVE

To summarize the implant removal rate, common bacterial organisms found, time of onset, ratio of superficial to deep infection, and regurgitating the prevalence among all the retrospective and prospective studies on management and characterization of surgical site infections (SSIs).

METHODS

PubMed was searched for articles published between 2000 and 2018 on the management or characterization of SSIs after spinal surgery. Only prospective and retrospective studies were included.

RESULTS

A total of 49 articles were found relevant to the objective. These studies highlighted the importance of implant removal to avoid recurrence of SSI. The common organisms detected were methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermis, Staphylococcus epidermis, Staphylococcus aureus, and Propionibacterium acnes, with prevalence of 1% to 15%. A major proportion of all were deep SSI, with minority reporting on late-onset SSI.

CONCLUSION

Long-term antibiotics administration, and continuous irrigation and debridement were common suggestion among the authors; however, the key measure undertaken or implied by most authors to avoid risk of recurrence was removal or replacement of implants for late-onset SSI.

C1 hypertrophic lateral mass resection and occiput–C2 fusion

This case involved a 6-year-old boy with Down syndrome, left C1 lateral mass hypertrophy, C1–2 rotatory subluxation, and spinal cord compression. He presented after falling down some stairs at his home. Torticollis, dysphagia, and speech delay were noted on examination. Vascular imaging showed impingement on the left vertebral artery by the anomalous C1 lateral mass. Through a posterior approach, the hypertrophic C1 lateral mass was resected, and an occiput–C2 fusion was performed. Postoperatively, his torticollis and brainstem symptoms were resolved.

The video can be found here: https://youtu.be/1U0GLdw6c70

Intraoperative Use of O-arm in Pediatric Cervical Spine Surgery

INTRODUCTION

Traditionally, fluoroscopy and postoperative computed tomographic (CT) scans are used to evaluate screw position after pediatric cervical spine fusion. However, noncontained screws detected postoperatively can require revision surgery. Intraoperative O-arm is a 3-dimensional CT imaging technique, which allows intraoperative evaluation of screw position and potentially avoids reoperations because of implant malposition. This study's objective was to evaluate the use of intraoperative O-arm in determining the accuracy of cervical implants placed by a free-hand technique using anatomic landmarks or fluoroscopic guidance in pediatric cervical spine instrumentation.

METHODS

A single-center retrospective study of consecutive examinations of children treated with cervical spine instrumentation and intraoperative O-arm from 2014 to 2018 was performed. In total, 44 cases (41 children, 44% men) with a mean age of 11.9 years (range, 2.1 to 23.5 y) were identified. Instability (n=16, 36%) and deformity (n=10, 23%) were the most frequent indications. Primary outcomes were screw revision rate, neurovascular complications caused by noncontained screws, and radiation exposure.

RESULTS

A total of 272 screws were inserted (60 occipital and 212 cervical screws). All screws were evaluated on fluoroscopy as appropriately placed. Four screws (1.5%) in 4 cases (9%) were noncontained on O-arm imaging and required intraoperative revision. A mean of 7.7 levels (range, 5 to 13) were scanned. The mean CT dose index and dose-length product were 15.2±6.87 mGy and 212.3±120.48 mGy×cm. Mean effective dose was 1.57±0.818 mSv. There was no association between screw location and noncontainment (P=0.129). No vertebral artery injuries, dural injuries, or neurologic deficits were related to the 4 revised screws.

CONCLUSIONS

Intraoperative non-navigated O-arm is a safe and efficient method to evaluate screw position in pediatric patients undergoing cervical spine instrumentation. Noncontained screws were detected in 9% of cases (n=4). O-arm delivers low radiation doses, allows for intraoperative screw revision, and negates the need for postoperative CT scans after confirmation of optimal implant position.

LEVEL OF EVIDENCE

Level IV.

Rigid segmental cervical spine instrumentation is safe and efficacious in younger children

PURPOSE

The utilization of cervical spine instrumentation in the young pediatric patient is not well reported. This study presents outcomes and complications of cervical spine instrumentation in patients who underwent cervical spine fusion surgery before age 10.

METHODS

Radiographic and clinical data were collected on all patients who underwent cervical spine surgery with instrumentation at a single institution between January 1, 2006, and March 31, 2015. Patients were ≤ 10 years of age at the time of surgery with any cervical spine deformity/injury diagnosis. Patient demographics, details on cervical spine diagnosis, procedural data, imaging data, and postoperative follow-up data were collected.

RESULTS

Twenty children met the criteria and were included in the study with a mean follow-up of 10.6 months (3 months-2 years). Initial indication for cervical spine correction surgery included deformity (7 cases), trauma (6 cases), instability (3 cases), stenosis (2 cases), rotary subluxation (1 case), and infection (1 case). Fifteen cases were treated with adult 3.5-mm cervical spine instrumentation, 3 with wiring (1 sublaminar and 2 spinous process), and 2 with cannulated screws. Postoperative immobilization included 16 halo fixation, 3 collars, and 1 CTO. Overall, there were five complications related to the surgery. Two patients who had wiring (1 sublaminar and 1 spinous process) developed a non-union and required revision surgery (1 with cannulated screws and 1 with 3.5-mm segmental cervical spine instrumentation). One patient developed a postoperative infection that required incision and drainage. Five patients developed superficial pin infections for their halo. Two deformity patients experienced neurological complications that were likely unrelated to the cervical instrumentation.

CONCLUSIONS

Rigid segmental fixation can be safe and efficacious when used in pediatric cervical spine patients. Whether used with halo or orthosis, patients experience minimal to no complications from the instrumentation and achieve successful fusion. Cervical spine wiring had a high risk of non-union requiring revision surgery. The incidence of wound infection was low with one in 20 cases.

Instrumented arthrodesis for non-traumatic craniocervical instability in very young children

PURPOSE

Occipitocervical instrumentation is infrequently required for stabilization of the axial and subaxial cervical spine in very young children. However, when it is necessary, unique surgical considerations arise in children when compared with similar procedures in adults.

METHODS

The authors reviewed literature describing fusion of the occipitocervical junction (OCJ) in toddlers and share their experience with eight cases of young children (age less than or equal to 4 years) receiving occiput to axial or subaxial spine instrumentation and fixation. Diagnoses and indications included severe or secondary Chiari malformation, skeletal dysplastic syndromes, Klippel-Feil syndrome, Pierre Robin syndrome, Gordon syndrome, hemivertebra and atlantal occipitalization, basilar impression, and iatrogenic causes.

RESULTS

All patients underwent occipital bone to cervical spine instrumentation and fixation at different levels. Constructs extended from the occiput to C2 and T1 utilizing various permutations of titanium rods, autologous rib autografts, Mersilene sutures, and combinations of autografts with bone matrix materials. All patients were placed in rigid cervical bracing or halo fixation postoperatively. No postoperative neurological deficits or intraoperative vascular injuries occurred.

CONCLUSION

Instrumented arthrodesis can be a treatment option in very young children to address the non-traumatic craniocervical instability while reducing the need for prolonged external halo vest immobilization. Factors affecting fusion are addressed with respect to preoperative, intraoperative, and postoperative decision-making that may be unique to the toddler population.

Comparison of Fusion Rates Based on Graft Material Following Occipitocervical and Atlantoaxial Arthrodesis in Adults and Children

BACKGROUND

Fusion rates following rigid internal instrumentation for occipitocervical and atlantoaxial instability approach 100% in many reports. Based on this success and the morbidity that can be associated with obtaining autograft for fusion, surgeons increasingly select alternative graft materials.

OBJECTIVE

To examine fusion failure using various graft materials in a retrospective observational study.

METHODS

Insurance claims databases (Truven Health MarketScan® [Truven Health Analytics, Ann Arbor, Michigan] and IMS Health Lifelink/PHARMetrics [IMS Health, Danbury, Connecticut]) were used to identify patients with CPT codes 22590 and 22595. Patients were divided by age (≥18 yr = adult) and arthrodesis code, establishing 4 populations. Each population was further separated by graft code: group 1 = 20938 (structural autograft); group 2 = 20931 (structural allograft); group 3 = other graft code (nonstructural); group 4 = no graft code. Fusion failure was assigned when ≥1 predetermined codes presented in the record ≥90 d following the last surgical procedure.

RESULTS

Of 522 patients identified, 419 were adult and 103 were pediatric. Fusion failure occurred in 10.9% (57/522) of the population. There was no statistically significant difference in fusion failure based on graft material. Fusion failure occurred in 18.9% of pediatric occipitocervical fusions, but in 9.2% to 11.1% in the other groups.

CONCLUSION

Administrative data regarding patients who underwent instrumented occipitocervical or atlantoaxial arthrodesis do not demonstrate differences in fusion rates based on the graft material selected. When compared to many contemporary primary datasets, fusion failure was more frequent; however, several recent studies have shown higher failure rates than previously reported. This may be influenced by broad patient selection and fusion failure criteria that were selected in order to maximize the generalizability of the findings.

Identifying Factors Predictive of Atlantoaxial Fusion Failure in Pediatric Patients: Lessons Learned From a Retrospective Pediatric Craniocervical Society Study

STUDY DESIGN

Multicenter retrospective cohort study with multivariate analysis.

OBJECTIVE

To determine factors predictive of posterior atlantoaxial fusion failure in pediatric patients.

SUMMARY OF BACKGROUND DATA

Fusion rates for pediatric posterior atlantoaxial arthrodesis have been reported to be high in single-center studies; however, factors predictive of surgical non-union have not been identified by a multicenter study.

METHODS

Clinical and surgical details for all patients who underwent posterior atlantoaxial fusion at seven pediatric spine centers from 1995 to 2014 were retrospectively recorded. The primary outcome was surgical failure, defined as either instrumentation failure or fusion failure seen on either plain x-ray or computed tomography scan. Multiple logistic regression analysis was undertaken to identify clinical and technical factors predictive of surgical failure.

RESULTS

One hundred thirty-one patients met the inclusion criteria and were included in the analysis. Successful fusion was seen in 117 (89%) of the patients. Of the 14 (11%) patients with failed fusion, the cause was instrumentation failure in 3 patients (2%) and graft failure in 11 (8%). Multivariate analysis identified Down syndrome as the single factor predictive of fusion failure (odds ratio 14.6, 95% confidence interval [3.7-64.0]).

CONCLUSION

This retrospective analysis of a multicenter cohort demonstrates that although posterior pediatric atlantoaxial fusion success rates are generally high, Down syndrome is a risk factor that significantly predicts the possibility of surgical failure.

LEVEL OF EVIDENCE

3.

Complications in Craniovertebral Junction Instrumentation: Hardware Removal Can Be Associated with Long-Lasting Stability. Personal Experience

BACKGROUND

The causes of craniovertebral junction (CVJ) instabilities include trauma, rheumatological diseases, tumors, infections, congenital malformations, and degenerative disease processes; these complex pathologies often require CVJ instrumentation. Hardware complications were analyzed in a personal series of 48 treated patients. In light of the analysis of very unusual radiological and clinical findings, the authors tried to better investigate the related mechanisms and to reach possible useful conclusions.

METHODS

In a series of 48 patients who underwent CVJ instrumentation and fusion procedures in our Institution, we describe three cases of hardware failure, due to: (1) infection; (2) radio- and chemotherapy; and (3) incorrect surgical procedure.

RESULTS

1. A stable bone CVJ fusion can occur after instrumentation removal for infection, since this removal can enhance bone fusion mechanisms; 2. Radio- and chemotherapy can cause hardware failure due to interference with local bone metabolism; 3. Although old-fashioned, wiring techniques still deserve consideration, mostly in CVJ re-do surgery after screwing technique failures; nevertheless, although the procedure is simple, safe, and effective, care must be taken in the preparation of the cranial holes in order to avoid sliding complications of the U-shaped rods.

CONCLUSIONS

CVJ instrumentations provide reasonably good mechanical stabilization with a high rate of bony fusion. Complications, such as dislocation or rupture of the fixation system, screw loosening, dural fistula, neural or vascular damage, and wound infection, are relatively infrequent. Knowledge and prevention of these complications is fundamental to improve surgical results and outcomes.

Complication Rates After Bone Morphogenetic Protein (BMP) Use in Orthopaedic Surgery in Children: A Concise Multicenter Retrospective Cohort Study

BACKGROUND

The use of bone morphogenetic protein (BMP) has been associated with a number of complications in adult patients. However, this association is less established in children. The aim of this study was to evaluate the safety of BMP use in children by determining the complication rates after BMP use at multiple institutions.

METHODS

In a retrospective study (2000 to 2013), the medical records of all patients who received BMP at any of the 5 institutions were reviewed. Demographic information, preoperative data, and postoperative follow-up data were collected on those patients who were under the age of 18 at the time of surgery.

RESULTS

A total of 312 pediatric patients underwent surgery with BMP application during the study period. The surgical procedures consisted of 228 spinal fusions, 39 pars repairs, 33 nonunion repair, and 12 other various procedures. Overall 21% (65/312) of patients who had BMP utilized had a complication. Fifty-five percent (36/65) of patients with a complication required a revision surgery. The average follow-up was 27 months (range, 3 to 96 mo); 80% of patients had a follow-up period of >12 months. The average age at the time of surgery was 13 years (range, 1 to 17 y). Males and females were almost equally represented in the study: 143 males (46%) and 168 females (54%). Of the patients who received BMP, 9% had minor complications and 13% had major complications. Wound dehiscence without infection was the most common minor complication and occurred in 59% (16/27) of patients with minor complications. Infection and implant failures were the most frequent major complications, occurring in 38% (15/39) and 33% (13/39) of patients with major complications, respectively. Five of 312 (2%) patients had neurological injury, 3 of which were only temporary.

CONCLUSIONS

This multicenter study demonstrates a relatively high rate of complications after the use of BMP in children. However, further study is needed to attribute the complications directly to the use of BMP.

LEVEL OF EVIDENCE

Level IV.

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.

Reoperations within 48 hours following 7942 pediatric neurosurgery procedures

OBJECTIVE Various indicators are used to evaluate the quality of care delivered by surgical services, one of which is early reoperation rate. The indications and rate of reoperations within a 48-hour time period have not been previously reported for pediatric neurosurgery. METHODS Between May 1, 2009, and December 30, 2014, 7942 surgeries were performed by the pediatric neurosurgery service in the operating rooms at a single institution. Demographic, socioeconomic, and clinical characteristics associated with each of the operations were prospectively collected. The procedures were grouped into 31 categories based on the nature of the procedure and underlying diseases. Reoperations within 48 hours at the conclusion of the index surgery were reviewed to determine whether the reoperation was planned or unplanned. Multivariate logistic regression was employed to analyze risk factors associated with unplanned reoperations. RESULTS Cerebrospinal fluid shunt-and hydrocephalus-related surgeries accounted for 3245 (40.8%) of the 7942 procedures. Spinal procedures, craniotomy for tumor resections, craniotomy for traumatic injury, and craniofacial reconstructions accounted for an additional 8.7%, 6.8%, 4.5%, and 4.5% of surgical volume. There were 221 reoperations within 48 hours of the index surgery, yielding an overall incidence of 2.78%; 159 of the reoperation were unplanned. Of these 159 unplanned reoperations, 121 followed index operations involving shunt manipulations. Using unplanned reoperations as the dependent variable (n = 159), index operations with a starting time after 3 pm and admission through the emergency department (ED) were associated with a two- to threefold increase in the likelihood of reoperations (after-hour surgery, odds ratio [OR] 2.01 [95% CI 1.43-2.83, p < 0.001]; ED admission, OR 1.97 (95% CI 1.32-2.96, p < 0.05]). CONCLUSIONS Approximately 25% of the reoperations within 48 hours of a pediatric neurosurgical procedure were planned. When reoperations were unplanned, contributing factors could be both surgeon related and system related. Further study is required to determine the extent to which these reoperations are preventable. The utility of unplanned reoperation as a quality indicator is dependent on proper definition, analysis, and calculation.

Patient-reported outcomes of occipitocervical and atlantoaxial fusions in children

OBJECTIVE There is limited literature on patient-reported outcomes (PROs) and health-related quality of life (HRQOL) outcomes in pediatric patients undergoing surgery for craniovertebral junction pathology. The aim of the present study was to assess surgical and quality of life outcomes in children who had undergone occipitocervical or atlantoaxial fusion. METHODS The authors retrospectively reviewed the demographics, procedural data, and outcomes of 77 consecutive pediatric patients who underwent posterior occipitocervical or atlantoaxial fusion between 2008 and 2015 at Texas Children's Hospital. Outcome measures (collected at last follow-up) included mortality, neurological improvement, complications, Scoliosis Research Society Outcomes Measure-22 (SRS-22) score, SF-36 score, Neck Disability Index (NDI), and Pediatric Quality of Life Inventory (PedsQL). Multivariate linear regression analysis was performed to identify factors affecting PROs and HRQOL scores at follow-up. RESULTS The average age in this series was 10.6 ± 4.5 years. The median follow-up was 13.9 months (range 0.5-121.5 months). Sixty-three patients (81.8%) were treated with occipitocervical fusion, and 14 patients (18.1%) were treated with atlantoaxial fusion. The American Spinal Injury Association (ASIA) grade at discharge was unchanged in 73 patients (94.8%). The average PRO metrics at the time of last follow-up were as follows: SRS-22 score, 4.2 ± 0.8; NDI, 3.0 ± 2.6; the parent's PedsQL (ParentPedsQL) score, 69.6 ± 22.7, and child's PedsQL score, 75.5 ± 18.7. Multivariate linear regression analysis revealed that older age at surgery was significantly associated with lower SRS-22 scores at follow-up (B = -0.06, p = 0.03), and the presence of comorbidities was associated with poorer ParentPedsQL scores at follow-up (B = -19.68, p = 0.03). CONCLUSIONS This study indicates that occipitocervical and atlantoaxial fusions in children preserve neurological function and are associated with acceptable PROs and ParentPedsQL scores, considering the serious nature and potential for morbidity in this patient population. However, longer follow-up and disease-specific scales are necessary to fully elucidate the impact of occipitocervical and atlantoaxial fusions on children.

Bone morphogenetic protein in pediatric spine fusion surgery

BACKGROUND

There is a paucity of literature describing the use of bone graft substitutes to achieve fusion in the pediatric spine. Outcomes and complications involving the off-label use of bone morphogenetic protein 2 (BMP-2) in the pediatric spine are not clearly defined. The purpose of this study is to review the existing literature with respect to reported outcomes and complications involving the use of low-dose BMP-2 in pediatric patients.

METHODS

A Medline and PubMed literature search was conducted using the words bone morphogenetic protein, BMP, rh-BMP-2, bone graft substitutes, and pediatric spine.

RESULTS

To date, there are few published reports on this topic. Complications and appropriate BMP-2 dosage application in the pediatric spine remain unknown.

CONCLUSIONS

This report describes the potential for BMP-2 to achieve successful arthrodesis of the spine in pediatric patients. Usage should be judicious as complications and long-term outcomes of pediatric BMP-2 usage remain undefined in the existing literature.

The Use of Bone Morphogenetic Protein in Pediatric Cervical Spine Fusion Surgery: Case Reports and Review of the Literature

Study Design Case report. Objective There is a paucity of literature describing the use of bone graft substitutes to achieve fusion in the pediatric cervical spine. The outcomes and complications involving the off-label use of bone morphogenetic protein (BMP)-2 in the pediatric cervical spine are not clearly defined. The purpose of this article is to report successful fusion without complications in two pediatric patients who had instrumented occipitocervical fusion using low-dose BMP-2. Methods A retrospective review of the medical records was performed, and the patients were followed for 5 years. Two patients under 10 years of age with upper cervical instability were treated with occipitocervical instrumented fusion using rigid occipitocervical fixation techniques along with conventionally available low-dose BMP-2. A Medline and PubMed literature search was conducted using the terms "bone morphogenetic protein," "BMP," "rh-BMP2," "bone graft substitutes," and "pediatric cervical spine." Results Solid occipitocervical fusion was achieved in both pediatric patients. There were no reported perioperative or follow-up complications. At 5-year follow-up, radiographs in both patients showed successful occipital cervical fusion without evidence of instrumentation failure or changes in the occipitocervical alignment. To date, there are few published reports on this topic. Complications and the appropriate dosage application in the pediatric posterior cervical spine remain unknown. Conclusions We describe two pediatric patients with upper cervical instability who achieved successful occipital cervical fusion without complication using off-label BMP-2. This report underscores the potential for BMP-2 to achieve successful arthrodesis of the posterior occipitocervical junction in pediatric patients. Use should be judicious as complications and long-term outcomes of pediatric BMP-2 use remain undefined in the existing literature.

The importance of atlantoaxial fixation after odontoidectomy

OBJECT

Although anterior odontoidectomy has been widely accepted as a procedure for decompression of the craniovertebral junction (CVJ), postoperative biomechanical instability has not been well addressed. There is a paucity of data on the necessity for and choice of fixation.

METHODS

The authors conducted a retrospective review of consecutively treated patients with basilar invagination who underwent anterior odontoidectomy and various types of posterior fixation. Posterior fixation included 1 of 3 kinds of constructs: occipitocervical (OC) fusion with atlantoaxial (AA) fixation, OC fusion without AA fixation, or AA-only (without OC) fixation. On the basis of the use or nonuse of AA fixation, these patients were assigned to either the AA group, in which the posterior fixation surgery involved both the atlas and axis simultaneously, regardless of whether the patient underwent OC fusion, or the non-AA group, in which the OC fusion construct spared the atlas, axis, or both. Clinical outcomes and neurological function were compared. Radiological results at each time point (i.e., before and after odontoidectomy and after fixation) were assessed by calculating the triangular area causing ventral indentation of the brainstem in the CVJ.

RESULTS

Data obtained in 14 consecutively treated patients with basilar invagination were analyzed in this series; the mean follow-up time was 5.75 years. The mean age was 53.58 years; there were 7 males and 7 females. The AA and non-AA groups consisted of 7 patients each. The demographic data of both groups were similar. Overall, there was significant improvement in neurological function after the operation (p = 0.03), and there were no differences in the postoperative Nurick grades between the 2 groups (p = 1.00). According to radiological measurements, significant decompression of the ventral brainstem was achieved stepwise in both groups by anterior odontoidectomy and posterior fixation; the mean ventral triangular area improved from 3.00 ± 0.86 cm2 to 2.08 ± 0.51 cm2 to 1.68 ± 0.59 cm2 (before and after odontoidectomy and after fixation, respectively; p < 0.05). The decompression gained by odontoidectomy (i.e., reduction of the ventral triangular area) was similar in the AA and non-AA groups (0.66 ± 0.42 cm2 vs 1.17 ± 1.42 cm2, respectively; p = 0.38). However, the decompression achieved by posterior fixation was significantly greater in the AA group than in the non-AA group (0.64 ± 0.39 cm2 vs 0.17 ± 0.16 cm2, respectively; p = 0.01).

CONCLUSIONS

Anterior odontoidectomy alone provides significant decompression at the CVJ. Adjuvant posterior fixation further enhances the extent of decompression after the odontoidectomy. Moreover, posterior fixation that involves AA fixation yields significantly more decompression of the ventral brainstem than OC fusion that spares AA fixation.

Minimizing bone gaps when using custom pediatric cranial implants is associated with implant success

OBJECT

Occasionally after a craniotomy, the bone flap is discarded (as in the case of osteomyelitis) or is resorbed (especially after trauma), and an artificial implant must be inserted in a delayed fashion. Polyetheretherketone (PEEK) implants and hard-tissue replacement patient-matched implants (HTR-PMI) are both commonly used in such cases. This study sought to compare the failure rate of these 2 implants and identify risk factors of artificial implant failure in pediatric patients.

METHODS

This was a retrospective cohort study examining all pediatric patients who received PEEK or HTR-PMI cranioplasty implants from 2000 to 2013 at a single institution. The authors examined the following variables: age, sex, race, mechanism, surgeon, posttraumatic hydrocephalus, time to cranioplasty, bone gap width, and implant type. The primary outcome of interest was implant failure, defined as subsequent removal and replacement of the implant. These variables were analyzed in a bivariate statistical fashion and in a multivariate logistic regression model for the significant variables.

RESULTS

The authors found that 78.3% (54/69) of implants were successful. The mean patient age was 8.2 years, and a majority of patients were male (73%, 50/69); the mean follow-up for the cohort was 33.3 months. The success rate of the 41 HTR-PMI implants was 78.1%, and the success rate of the 28 PEEK implants was 78.6% (p = 0.96). Implants with a bone gap of > 6 mm were successful in 33.3% of cases, whereas implants with a gap of < 6 mm had a success rate of 82.5% (p = 0.02). In a multivariate model with custom-type implants, previous failed custom cranial implants, time elapsed from previous cranioplasty attempt, and bone gap size, the only independent risk factor for implant failure was a bone gap > 6 mm (odds ratio 8.3, 95% confidence interval 1.2-55.9).

CONCLUSIONS

PEEK and HTR-PMI implants appear to be equally successful when custom implantation is required. A bone gap of > 6 mm with a custom implant in children results in significantly higher artificial implant failure.

The efficacy of routine use of recombinant human bone morphogenetic protein-2 in occipitocervical and atlantoaxial fusions of the pediatric spine: a minimum of 12 months' follow-up with computed tomography

OBJECT The purpose of this study focusing on fusion rate was to determine the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) use in posterior instrumented fusions of the craniocervical junction in the pediatric population. The authors previously reported the short-term (mean follow-up 11 months) safety and efficacy of rhBMP-2 use in the pediatric age group. The present study reports on their long-term results (minimum of 12 months' follow-up) and focuses on efficacy. METHODS The authors performed a retrospective review of 83 consecutive pediatric patients who had undergone posterior occipitocervical or atlantoaxial spine fusion at Texas Children's Hospital or Riley Children's Hospital during the period from October 2007 to October 2012. Forty-nine patients were excluded from further analysis because of death, loss to follow-up, or lack of CT evaluation of fusion at 12 or more months after surgery. Fusion was determined by postoperative CT scan at a minimum of 12 months after surgery. The fusion was graded and classified by a board-certified fellowship-trained pediatric neuroradiologist. Other factors, such as patient age, diagnosis, number of vertebral levels fused, use of allograft or autograft, dosage of bone morphogenetic protein (BMP), and use of postoperative orthosis, were recorded. RESULTS Thirty-four patients had a CT scan at least 12 months after surgery. The average age of the patients at surgery was 8 years, 1 month (range 10 months-17 years). The mean follow-up was 27.7 months (range 12-81 months). There were 37 fusion procedures in 34 patients. Solid fusion (CT Grade 4 or 4-) was achieved in 89.2% of attempts (33 of 37), while incomplete fusion or failure of fusion was seen in 10.8%. Based on logistic regression analysis, there was no significant association between solid fusion and age, sex, BMP dose, type of graft material, use of postoperative orthosis, or number of levels fused. Three of 34 patients (8.8%) required revision surgery. CONCLUSIONS Despite the large number of adult studies reporting positive effects of BMP on bone fusion, our long-term outcomes using rhBMP-2 in the pediatric population suggest that rates of fusion failure are higher than observed in contemporary adult and pediatric reports of occipitocervical and atlantoaxial spine fusions.

Unilateral fixation for treatment of occipitocervical instability in children with congenital vertebral anomalies of the craniocervical junction

OBJECT Patients with occipitocervical (OC) instability from congenital vertebral anomalies (CVAs) of the craniocervical junction (CCJ) often have bony abnormalities that make instrumentation placement difficult. Within this patient population, some bilateral instrumentation constructs either fail or are not feasible, and a unilateral construct must be used. The authors describe the surgical management and outcomes of this disorder in patients in whom unilateral fixation constructs were used to treat OC instability. METHODS From a database of OC fusion procedures, the authors identified patients who underwent unilateral fixation for the management of OC instability. Patient characteristics, surgical details, and radiographic outcomes were reviewed. In each patient, CT scans were performed at least 4 months after surgery to evaluate for fusion. RESULTS Eight patients with CVAs of the CCJ underwent unilateral fixation for the treatment of OC instability. For 4 patients, the procedure occurred after a bilateral OC construct failed or infection forced hardware removal. For the remainder, it was the primary procedure. Two patients required reoperation for hardware revision and 1 developed nonunion requiring revision of the bone graft. Ultimately, 7 patients demonstrated osseous fusion on CT scans and 1 had a stable fibrous union. CONCLUSIONS These findings demonstrate that a unilateral OC fixation is effective for the treatment of OC instability in children with CVAs of the CCJ in whom bilateral screw placement fails or is not feasible.