Os Odontoideum in Children: Treatment Outcomes and Neurological Risk Factors.

BACKGROUND: Treatment outcomes and risk factors for neurological deficits in pediatric patients with an os odontoideum are unclear. METHODS: We reviewed the data for 102 children with os odontoideum who were managed at 11 centers between 2000 and 2016 and had a minimum duration of follow-up of 2 years. Thirty-one children had nonoperative treatment, and 71 underwent instrumented posterior cervical spinal arthrodesis for the treatment of C1-C2 instability. Nonoperative treatment consisted of observation (n = 29) or immobilization with a cervical collar (n = 1) or halo body jacket (n = 1). Surgical treatment consisted of atlantoaxial (n = 50) or occipitocervical (n = 21) arthrodesis. One patient also underwent transoral odontoidectomy. RESULTS: Thirty children (29%) presented with neurological deficits, 28 of whom had radiographic atlantoaxial instability (atlantoaxial distance >5 mm) or limited space (≤13 mm) available for the spinal cord (risk ratio, 7.8 [95% confidence interval, 2.0 to 31] compared with children with no radiographic risk factors). The 27 children without neurological deficits or atlantoaxial instability at presentation underwent nonoperative treatment and remained asymptomatic. Of the initial nonoperative cohort, one child developed atlantoaxial instability, and another had a persistent neurological deficit; both children underwent spinal arthrodesis during the study period. One child with cervical instability declined surgery and remained asymptomatic. Spinal fusion occurred in 68 patients in the surgical group by the end of the study period (mean, 3.7 years; range, 2.0 to 11.8 years). Surgical complications occurred in 21 children, including nonunion in 12, new neurological deficits in 4, cerebrospinal fluid leak in 2, symptomatic instrumentation requiring removal 2, and vertebral artery injury in 1. Nine children underwent revision surgery. In the surgical group, Japanese Orthopaedic Association neurological function scores improved significantly from preoperatively to the latest follow-up for the upper extremities (p = 0.026) and lower extremities (p = 0.007). CONCLUSIONS: The risk of developing a neurological deficit was strongly associated with atlantoaxial instability and limited space available for the spinal cord in children with os odontoideum. Nonoperative treatment was safe for asymptomatic patients without atlantoaxial instability. Spinal arthrodesis resolved the neurological deficits of children with symptomatic os odontoideum. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Recognition, Incidence, and Management of Spinal Cord Monitoring Alerts in Pediatric Cervical Spine Surgery.

BACKGROUND: Perioperative spinal cord injury and postoperative neurological deficits are the major complications in spinal surgery. Monitoring of spinal cord function is of crucial importance. Somatosensory evoked potentials and transcranial electric motor-evoked potentials are now widely used in cervical spine surgery. Although much has been written on spinal cord monitoring in adult spinal surgery, very little has been published on the incidence and management of monitoring of cervical spine surgery in the pediatric population. The goal of this research was to review the recognition, incidence, and management of spinal cord monitoring in pediatric patients undergoing cervical spine surgery over the course of twenty years in a single institution. We postulate spinal cord monitoring alerts in pediatric cervical spine surgery are underreported. METHODS: An IRB-approved retrospective single institution review of pediatric cervical spine cases from 1997 to 2017 was performed. Both the surgeon's dictated operative note and the neuromonitoring team's dictated note were reviewed for each case, and both were cross referenced and correlated with one another to ensure no alerts were missed. All monitoring changes were assumed to be significant and reported. The incidence of alerts, type of changes, and corrective maneuvers were noted. New postoperative neurological injuries were recorded. RESULTS: From 1997 to 2017 fifty-three patients underwent a total of 69 procedures involving the cervical spine. Fourteen procedures (20%) were not monitored, whereas 55 procedures were 80%. There were 12 procedures (21.8%) complicated by neuromonitoring alerts. CONCLUSIONS: The number of cases complicated by alerts doubles that previously reported, and it is important to note there were no new permanent neurological deficits recorded over the study period. Corrective strategies were implemented once the operating surgeon was notified of the neuromonitoring alert. Aborting the case was then considered if corrective strategies failed to restore baseline neurophysiology. LEVEL OF EVIDENCE: Level IV.

Patients Without Intraoperative Neuromonitoring (IONM) Alerts During VEPTR Implantation Did Not Sustain Neurological Injury During Subsequent Routine Expansions: A Retrospective Multicenter Cohort Study.

BACKGROUND: The purpose of this study was to determine the rate of intraoperative neurological monitoring (IONM) alerts and neurological injury during vertical expandable prosthetic titanium rib (VEPTR) treatment and evaluate the utility of IONM during VEPTR expansion procedures in patients who have not previously had neurological injury or IONM alerts. METHODS: After institutional review board approval, VEPTR procedures and IONM records were reviewed at 17 institutions for patients treated with VEPTR from 2005 to 2011. All consecutive cases in patients with minimum 2-year follow-up were included. Patients with prior history of growing rods or other invasive spine-based surgical treatment were excluded. Surgeries were categorized into implant, revision, expansion, and removal procedures. Cases with IONM alerts or neurological injury had additional detailed review. Descriptive statistics were used for data analysis. RESULTS: In total, 2355 consecutive VEPTR procedures (352 patients) consisting of 299 implant, 377 revision, 1587 expansion, and 92 removal procedures were included. In total, 620 VEPTR procedures had IONM, and 539 of those had IONM records available for review. IONM alerts occurred in 9/539 procedures (1.7%): 3/192 implants (1.6%), 3/58 revisions (5.2%), and 3/258 expansions (1.2%). New neurological injury occurred in 3/2355 procedures (0.1%), 3/352 patients (0.9%). All 3 injuries were in implant procedures, only 1 had an IONM alert. All 3 had upper extremity motor deficits (1 had sensory deficit also). All had full recovery at 17, 30, and 124 days postinjury. One patient without prior neurological injury or IONM alert had an IONM alert during expansion that resolved after an increase in blood pressure. The remaining IONM alerts during expansions were all in children with prior IONM alerts during implant, revision, or exchange procedures. CONCLUSIONS: The highest rate of neurological injury in VEPTR surgery was found for implant procedures. There were no instances of neurological injury during VEPTR expansion, revision, or removal procedures. IONM did not identify new neurological injuries in patients undergoing VEPTR expansion who did not previously have a history of IONM signal change or neurologic injury. LEVEL OF EVIDENCE: Level IV-diagnostic study.

The Recognition, Incidence, and Management of Spinal Cord Monitoring Alerts in Early-onset Scoliosis Surgery.

BACKGROUND: The objective of the research was to study the relevance of intraoperative neuromonitoring throughout all stages of surgical management in patients with progressive early-onset scoliosis (EOS).The routine monitoring of spinal cord potentials has gradually become standard of practice among spinal surgeons. However, there is not a consensus that the added expense of this technique necessitates monitoring in all stages of surgical management. METHODS: A retrospective review of 180 surgical cases of 30 patients with EOS from July 2003 to July 2012 was performed. All monitoring alerts as judged by the neuromonitoring team were identified. Both somatosensory-evoked potentials and transcranial electric motor-evoked potentials were studied and no limiting thresholds for reporting electrophysiological changes were deemed appropriate. RESULTS: Of 150 monitored cases there were 18 (12%) monitoring alerts. This represented 40% of the patient cohort over the 9-year study period. CONCLUSIONS: Index versus routine lengthening rate of alerts showed no significant difference in incidence of monitoring alerts. Conversely, several patients whose primary implantation surgeries were uneventful had monitoring alerts later in their treatment course. Intraoperative neuromonitoring is warranted throughout all stages of surgical management of EOS. LEVEL OF EVIDENCE: Level IV. This study is a retrospective review of surgical cases of 30 patients with EOS.

Outcomes of Spinal Fusion for Cervical Kyphosis in Children with Neurofibromatosis.

BACKGROUND: Cervical kyphosis may occur with neurofibromatosis type I (NF1) and is often associated with vertebral dysplasia. Outcomes of cervical spinal fusion in patients with NF1 are not well described because of the rarity of the condition. We aimed to (1) characterize the clinical presentation of cervical kyphosis and (2) report the outcomes of posterior and anteroposterior cervical fusion for the condition in these children. METHODS: The medical records and imaging studies of 22 children with NF1 who had undergone spinal fusion for cervical kyphosis (mean, 67°) at a mean age of 11 years and who had been followed for a minimum of 2 years were reviewed. RESULTS: Thirteen children presented with neck pain; 10, with head tilt; 9, with a previous cervical laminectomy or fusion; and 5, with a neurologic deficit. Two patients had spontaneous dislocation of the mid-cervical spine without a neurologic deficit. Eleven had scoliosis, with the major curve measuring a mean of 61°. Nine patients underwent posterior and 13 underwent anteroposterior surgery. Twenty-one received spinal instrumentation, and 1 was not treated with instrumentation. Preoperative halo traction was used for 9 patients, and it reduced the mean preoperative kyphosis by 34% (p = 0.0059). At the time of final follow-up, all spinal fusion sites had healed and the cervical kyphosis averaged 21° (mean correction, 69%; p < 0.001). The cervical kyphosis correction was significantly better after the anteroposterior procedures (83%) than after the posterior-only procedures (58%) (p = 0.031). Vertebral dysplasia and erosion continued in all 17 patients who had presented with dysplasia preoperatively. Thirteen patients had complications, including 5 new neurologic deficits and 8 cases of junctional kyphosis. Nine patients required revision surgery. Junctional kyphosis was more common in children in whom ≤5 levels had been fused (p = 0.054). CONCLUSIONS: Anteroposterior surgery provided better correction of cervical kyphosis than posterior spinal fusion in children with NF1. Erosion of vertebral bodies continued during the postoperative follow-up period in all patients who had presented with dysplastic changes preoperatively. The cervical spine should be screened in all children with NF1. Fusion should include at least 6 levels to prevent junctional kyphosis. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Rigid fixation improves outcomes of spinal fusion for C1-C2 instability in children with skeletal dysplasias.

BACKGROUND: Upper cervical instability is common in many skeletal dysplasias, and surgical treatment can be difficult because of small, fragile osseous elements. In this study of children with skeletal dysplasia and upper cervical instability, we compared fusion rates and complications between (1) patients treated with no instrumentation or with wiring techniques and (2) those who underwent rigid cervical spine instrumentation. We also sought to characterize the presentation and common parameters of upper cervical instability in this population. METHODS: A multicenter study identified twenty-eight children with skeletal dysplasia who underwent surgery from 2000 through 2011 for C1-C2 instability and were followed for a minimum of two years. Fourteen children were treated with no instrumentation or with instrumentation with wires or cables (nonrigid-fixation group) and fourteen were treated with screws (or hooks) and rods (rigid-fixation group). All patients received autograft, and twenty (twelve in the nonrigid group and eight in the rigid group) were treated with a halo-body jacket. RESULTS: Fourteen children had C1-C2 fusion, and fourteen had occipitocervical fusion. Eleven (39%) underwent spinal cord decompression. The nonunion rate was significantly higher in the nonrigid-fixation group (six of fourteen) than in the rigid-fixation group (zero of fourteen; p = 0.0057). Complications, including nonunion, occurred in nine patients in the nonrigid group and one patient in the rigid group. However, two of the complications in the nonrigid-fixation group were vertebral artery bleeding episodes that actually occurred during an attempt at rigid fixation (the fixation was subsequently done with wiring). No new neurologic deficits were observed. Five of the seven children with a preoperative neurologic deficit showed at least partial recovery, with significant improvement in the Japanese Orthopaedic Association upper-extremity score (p = 0.047). CONCLUSIONS: The nonunion rate is relatively high after patients undergo spinal fusion for C1-C2 instability with nonrigid instrumentation, even if a halo-body jacket is applied. Rigid fixation with screws and rods improves fusion rates.

Outcomes after salvage procedures for the painful dislocated hip in cerebral palsy.

BACKGROUND: The painful dislocated hip in the setting of cerebral palsy is a challenging problem. Many surgical procedures have been reported to treat this condition with varying success rates. The purpose of this study is to retrospectively evaluate and compare the outcomes of 3 different surgical procedures performed at our institution for pain relief in patients with spastic quadriplegic cerebral palsy and painful dislocated hips. METHODS: A retrospective chart review of the surgical procedures performed by 5 surgeons for spastic, painful dislocated hips from 1997 to 2010 was performed. The procedures identified were (1) proximal femoral resection arthroplasty (PFRA); (2) subtrochanteric valgus osteotomy (SVO) with femoral head resection; and (3) proximal femur prosthetic interposition arthroplasty (PFIA) using a humeral prosthesis. Outcomes based on pain and range of motion were determined to be excellent, good, fair, or poor by predetermined criteria. RESULTS: Forty-four index surgeries and 14 revision surgeries in 33 patients with an average follow-up of 49 months met the inclusion criteria. Of the index surgeries, 12 hips were treated with a PFRA, 21 with a SVO, and 11 with a PFIA. An excellent or good result was noted in 67% of PFRAs, 67% of SVOs, and 73% of PFIAs. No statistical significance between these procedures was achieved. The 14 revisions were performed because of a poor result from previous surgery, demonstrating a 24% reoperation rate overall. No patients classified as having a fair result underwent revision surgery. All patients receiving revision surgery were eventually classified as having an excellent or good result. CONCLUSIONS: Surgical treatment for the painful, dislocated hip in the setting of spastic quadriplegic cerebral palsy remains unsettled. There continue to be a large percentage of failures despite the variety of surgical techniques designed to treat this problem. These failures can be managed, however, and eventually resulted in a good outcome. We demonstrated a trend toward better outcomes with a PFIA, but further study should be conducted to prove statistical significance. LEVEL OF EVIDENCE: III.

Mortality and morbidity in early-onset scoliosis surgery.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: To accurately determine complication rates, particularly mortality rates, in surgically treated early-onset scoliosis. SUMMARY OF BACKGROUND DATA: The advent of modern segmental instrumentation for spinal fusion surgery in adolescent scoliosis has allowed for application of similar nonsegmental unfused techniques aimed at controlling scoliosis in the very young child. The dismal prognosis for these children without repeated spinal lengthening procedures is unquestioned, although no controlled trials exist. Many, if not most, of these children need surgery; however, the surgical complication rate is very high. METHODS: During the study period, all surgically treated children with early-onset scoliosis seen at our institution were identified. Any patient who presented to our clinic with early-onset scoliosis that was surgically managed was included. The total number of procedures, type of implants, number and type of complications, geographic origin of the cases, and final outcomes were all assessed. RESULTS: A total of 165 surgical procedures on 28 patients accrued during the study time period, including index implantation of instrumentation, lengthening, and definitive fusion, as well as operations performed for complications such as wound debridement and revision of failed implants. Clinical diagnoses included congenital scoliosis, syndromic and chromosomal abnormalities, cerebral palsy, and spinal muscular atrophy. There was a complication rate of 84% overall with a mortality rate of almost 18%. The only patients with no complications were those whose entire surgical course had been at our institution only. The mortality rate was equal in patients whose treatment was performed elsewhere versus exclusively in our center. CONCLUSION: This study underlines the grave severity of these scolioses particularly in syndromic children. The high mortality rate is alarming, suggesting that further study is needed in this area.

Bilateral unstable slipped capital femoral epiphysis: a look at risk factors.

Unstable slipped capital femoral epiphysis can have disastrous complications including osteonecrosis and chondrolysis. It has been shown that 20% to 80% of patients may develop a contralateral slip ≤18 months after diagnosis. The purpose of this article is to report and characterize patients who developed bilateral unstable slips. After Institutional Review Board approval, the patients included were only those with bilateral unstable slipped capital femoral epiphyses. A minimum 2-year follow-up was required. Seven patients, all female, were included in the study, with an average age of 11.4 years at the time of their first slips. The interval between slips averaged 127 days (range, 0-245 days). All but 1 patient presented with a severe slip. The second slip was also severe in 3 patients and less severe in 4 patients. The triradiate cartilage was open in 3 patients. Two patients required corrective osteotomies. Chondrolysis developed in 2 patients with no osteonecrosis reported. The incidence of bilateral unstable slips ranged from 4% to 20% of all unstable slipped capital femoral epiphyses based on our findings. Skeletal immaturity was not a risk factor. The surgeon must be vigilant for the possibility of bilateral slips. The family must be instructed on precautions patients must take while recuperating from unstable slipped capital femoral epiphyses. Contralateral fixation of the unaffected side may be warranted in patients with initial severe unstable slipped capital femoral epiphyses to prevent this condition.

Usefulness of electromyography compared to computed tomography scans in pedicle screw placement.

STUDY DESIGN: This is a retrospective analysis of 30 pediatric deformity surgeries. OBJECTIVE: The purpose of this study was to evaluate the accuracy of neuromonitoring in comparison to postoperative computed tomography scans for pedicle screw position. SUMMARY OF BACKGROUND DATA: Triggered electromyography potentials in aiding the placement of lumbar pedicle screws are considered useful; however, this method is less accepted in thoracic screw placement. METHODS: Thirty pediatric deformity surgeries were reviewed. All screws were placed using fluoroscopic assistance. Electromyography data were obtained on all screws. Every patient underwent postoperative computed tomography scanning. Computed tomography scans were assessed by all authors, and each screw was classified. Sensitivity, specificity, negative predictive value, and likelihood ratios were determined for the cut-off value of an electromyography > or =6 mA. RESULTS: A total of 329 screws were reviewed. No complications occurred. An overall accuracy of 93% was obtained. No retained screw had greater than 2 mm medial pedicle wall breach. Nine screws were removed intraoperatively due to medial breach. The mean electromyography potential for all classes of screws was not statistically different (P > 0.1). The negative predictive value of the test was 0.92 in the thoracic spine and 0.93 in the lumbar spine. The negative likelihood ratios were 0.96 and 0.35 for the thoracic and lumbar spines respectively, and the positive likelihood ratio was 1.4 for the thoracic spine and 12.5 for the lumbar spine. CONCLUSION: Thoracic and lumbar pedicle screws are safe surgical options in the treatment of pediatric scoliosis. Comparison of electromyography potentials and postoperative computed tomography scans showed no statistically significant difference for all classes of screws. The likelihood ratio for electromyography testing was more clinically significant in the lumbar spine. A triggered electromyography value greater than or equal to 6 mA has a high likelihood of that screw being in the "safe zone." However, there is no true electromyography cut-off value that guarantees accurate placement and avoidance of neurologic injury.

Iliac screw fixation in neuromuscular scoliosis.

STUDY DESIGN: A retrospective review of children with neuromuscular scoliosis treated at our institution with posterior spinal fusion and instrumentation including iliac screws. OBJECTIVES: To determine the safety and effectiveness of iliac screws in neuromuscular scoliosis constructs. SUMMARY OF BACKGROUND DATA: The Galveston technique has been a standard method of impacting rods in the iliac wings to provide anchorage for neuromuscular scoliosis constructs. Numerous studies have shown the increased strength of constructs using screws as part of segmental spinal instrumentation. The ideal method of caudal anchorage is still unclear, and the role of iliac screws has yet to be defined. METHODS: The medical records and radiographs of 50 patients with neuromuscular scoliosis treated with a modified Luque-Galveston posterior spinal fusion and instrumentation technique were reviewed. The instrumentation was anchored to the pelvis via iliac screws: Group A constructs included 2 screws; Group B constructs included 4 screws. The radiographs were analyzed for Cobb angle and pelvic obliquity before surgery and after surgery. Complications were recorded, including infections and implant-related problems. RESULTS: The average curve correction was 48%. The average pelvic tilt correction was 59%. Complications included 4 deep infections requiring reoperation (8%), 10 screw-related complications (7 in Group A, 3 in the Group B), and 12 non-screw-related implant complications (11 in the Group A, 1 in the Group B). CONCLUSIONS: The use of screw fixation in the ilium as a means of spinopelvic anchorage is safe and effective in the treatment of neuromuscular scoliosis. The use of 2 screws in each iliac wing provides more stable fixation with fewer implant-related complications than using a single screw.

Traumatic hip dislocation with spontaneous incomplete reduction: a diagnostic trap.

We are reporting three children and adolescents who presented with incongruous reduction of the hip following injury. In each case, the diagnosis was initially missed. None of the patients presented with a hip dislocation, but two gave a history consistent with transient hip subluxation or dislocation. Low-energy trauma was the cause in two cases. Treatment consisted of arthrotomy to remove interposed capsule and labrum to obtain concentric reduction. When reduction of a hip dislocation occurs spontaneously, the condition may be misjudged. Any child or adolescent who complains of hip pain following injury should have radiographs scrutinized for asymmetric widening of the hip joints. Any asymmetry should be evaluated by appropriate imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI). Removal of any interposed tissue is recommended, even when the diagnosis is delayed by several months.