David P. Roye

Coronal and sagittal plane correction in adolescent idiopathic scoliosis : A comparison between all pedicle screw versus hybrid thoracic hook lumbar screw constructs

Study Design. This was a retrospective cohort study using a previously matched convenience sample of 34 patients. Objective. This study sought to determine the relative corrective benefits of these 2 types of constructs in the correction of coronal and sagittal curves in patients with adolescent idiopathic scoliosis (AIS). In addition, the 2 constructs were compared for coronal and sagittal balance. Summary of Background Information. Recent clinical research suggests that thoracic pedicle screw constructs (all-screw constructs) are more effective than hybrid lumbar screw thoracic hook constructs (hybrid constructs) in correcting spine deformity. Methods. The sample consisted of patients with AIS who underwent isolated posterior spinal fusion and instrumentation. Seventeen patients underwent fusion using all-screw constructs, and 17 underwent fusion with hybrid constructs; preoperative and postoperative radiographs and measurements were compared. Results. There was no significant difference observed when comparing the 2 groups, although there was a trend toward better correction of the main thoracic curve in the all-screw construct group (P = 0.089). In the all-screw group, mean thoracic kyphosis decreased from 29.6° to 19.4° (P = 0.012). Sagittal balance changed in the hybrid group from −21.2 mm to 8.2 mm, and in the all-screw group changed from −28.8 mm to 1.5 mm. The major curve in the hybrid group improved from 54.06° to 20.25° and improved from 54.88° to 15.06° in the all-screw group. Conclusions. There was no statistically significant difference comparing the 2 groups, although a trend was observed toward better correction of the main thoracic curve in the all-screw construct group. The all-screw group demonstrated a significant decrease in kyphosis, which was not seen in the hybrid group. Hybrid constructs were comparable to all-screw constructs in the correction of coronal plane deformity and sagittal balance.

Building consensus: development of a Best Practice Guideline (BPG) for surgical site infection (SSI) prevention in high-risk pediatric spine surgery.

Background: Perioperative surgical site infection (SSI) after pediatric spine fusion is a recognized complication with rates between 0.5% and 1.6% in adolescent idiopathic scoliosis and up to 22% in “high risk” patients. Significant variation in the approach to infection prophylaxis has been well documented. The purpose of this initiative is to develop a consensus-based “Best Practice” Guideline (BPG), informed by both the available evidence in the literature and expert opinion, for high-risk pediatric patients undergoing spine fusion. For the purpose of this effort, high risk was defined as anything other than a primary fusion in a patient with idiopathic scoliosis without significant comorbidities. The ultimate goal of this initiative is to decrease the wide variability in SSI prevention strategies in this area, ultimately leading to improved patient outcomes and reduced health care costs. Methods: An expert panel composed of 20 pediatric spine surgeons and 3 infectious disease specialists from North America, selected for their extensive experience in the field of pediatric spine surgery, was developed. Using the Delphi process and iterative rounds using a nominal group technique, participants in this panel were as follows: (1) surveyed for current practices; (2) presented with a detailed systematic review of the relevant literature; (3) given the opportunity to voice opinion collectively; and (4) asked to vote regarding preferences privately. Round 1 was conducted using an electronic survey. Initial results were compiled and discussed face-to-face. Round 2 was conducted using the Audience Response System, allowing participants to vote for (strongly support or support) or against inclusion of each intervention. Agreement >80% was considered consensus. Interventions without consensus were discussed and revised, if feasible. Repeat voting for consensus was performed. Results: Consensus was reached to support 14 SSI prevention strategies and all participants agreed to implement the BPG in their practices. All agreed to participate in further studies assessing implementation and effectiveness of the BPG. The final consensus driven BPG for high-risk pediatric spine surgery patients includes: (1) patients should have a chlorhexidine skin wash the night before surgery; (2) patients should have preoperative urine cultures obtained; (3) patients should receive a preoperative Patient Education Sheet; (4) patients should have a preoperative nutritional assessment; (5) if removing hair, clipping is preferred to shaving; (6) patients should receive perioperative intravenous cefazolin; (7) patients should receive perioperative intravenous prophylaxis for gram-negative bacilli; (8) adherence to perioperative antimicrobial regimens should be monitored; (9) operating room access should be limited during scoliosis surgery (whenever practical); (10) UV lights need NOT be used in the operating room; (11) patients should have intraoperative wound irrigation; (12) vancomycin powder should be used in the bone graft and/or the surgical site; (13) impervious dressings are preferred postoperatively; (14) postoperative dressing changes should be minimized before discharge to the extent possible. Conclusions: In conclusion, we present a consensus-based BPG consisting of 14 recommendations for the prevention of SSIs after spine surgery in high-risk pediatric patients. This can serve as a tool to reduce the variability in practice in this area and help guide research priorities in the future. Pending such data, it is the unsubstantiated opinion of the authors of the current paper that adherence to recommendations in the BPG will not only decrease variability in practice but also result in fewer SSI in high-risk children undergoing spinal fusion. Level of Evidence: Not applicable.

A retrospective cohort study of pulmonary function, radiographic measures, and quality of life in children with congenital scoliosis: an evaluation of patient outcomes after early spinal fusion.

Study Design. Retrospective cohort study. Objective. The purpose of this study is to evaluate pulmonary function and quality of life (QOL) in children treated with early spinal fusion for progressive congenital scoliosis. Summary of Background Data. The relationships between radiographic measures, pulmonary function tests (PFT), and QOL were examined. Methods. Twenty-one patients with congenital scoliosis treated with early spinal fusion were evaluated using radiographs, PFT, and the Child Health Questionnaire (CHQ) at 12.6 ± 3.5 years. They were 6.9 ± 2.3 years postdefinitive fusion, which occurred at 4.9 ± 3.1 year of age. The cohort was also divided in two groups, “thoracic fusion” (apex above the thoracolumbar T–L junction) and “nonthoracic fusion” (below T–L junction). Results. Forced vital capacity, forced expiratory volume (FEV1), vital capacity (P < 0.0001), and total lung capacity (P = 0.017) were significantly lower compared with healthy children. CHQ scores were significantly lower than in healthy children in physical function (P = 0.036), general health (P = 0.007), physical summary (P = 0.026), and parental impact/emotional (P = 0.01). Correlation analysis showed that the degrees of thoracic curves were negatively correlated with FEV1 (P < 0.05), family activities, role/social physical (P < 0.05), and physical summary (P < 0.01). The degree of kyphosis was negatively correlated with Self-Esteem (P < 0.01). Patients who had thoracic fusions had shorter spinal height (P = 0.049), lower forced vital capacity (P = 0.004), FEV (P = 0.012), vital capacity (P = 0.031), and reported more pain (P = 0.033) than nonthoracic fused. Conclusion. Compared with healthy peers, congenital scoliosis patients treated with early spinal fusion have worse PFT and QOL scores at 6.9 years follow up. Patients with thoracic fusions had shorter spines, worse pulmonary function, and more pain than nonthoracic fused. The results may support alternatives to early spinal fusion such as growing rods, epiphysiodesis, and distraction thoracoplasty. Current efforts are underway to compare outcomes of this study to those of other treatments.

Correction of adolescent idiopathic scoliosis using thoracic pedicle screw fixation versus hook constructs.

This retrospective study was undertaken to determine the effectiveness and cost of thoracic pedicle screws versus laminar and pedicle hooks in patients undergoing surgical correction of adolescent idiopathic scoliosis (AIS). Immediate preoperative and 6-week postoperative radiographs were examined in 25 consecutive cases of children with AIS who were divided into two groups, those with thoracic pedicle screw constructs and those with thoracic hook constructs. Endpoints collected included radiographic measures, complications, surgical time, implant cost, and quality-of-life measures. Ten children underwent spinal fusion using thoracic pedicle screw fixation and 15 underwent thoracic constructs composed of hooks. Similar sex and age distribution were noted in both groups, and among the 20 girls and 5 boys the average age was 14.5. The mean preoperative Cobb angle was 53.5 degrees for the screw group and 52.5 degrees for the hook group. Correction averaged 70.2% for the screw group and 68.1% for the hook group. There were no significant differences between the two patient groups in terms of percentage of or absolute curve change after surgery. The apical vertebral translation, end vertebral tilt angle, and coronal balance did not differ significantly between the two patient groups. Comparison of operative time and quality of life revealed no significant differences. Screw constructs were significantly more expensive than hook constructs. The correction obtained from thoracic pedicle screw fixation is comparable to traditional hook constructs in AIS. Surgery using either construct effectively corrects AIS.

Treatment of congenital pseudarthrosis of the tibia with recombinant human bone morphogenetic protein-7 (rhBMP-7). A report of five cases.

Congenital pseudarthrosis of the tibia is one of the most frustrating conditions encountered in pediatric orthopaedics because of the difficulty in achieving healing. Numerous treatment options have been explored with varying degrees of success1-19. Although some reports have demonstrated successful healing7,9,19, it is very difficult to restore the normal structural and functional integrity of the bone such as that which occurs after treatment of other types of fractures in children4,10,16. Advances in molecular biology have provided a better understanding of the mechanisms of fracture-healing as well as possible new solutions for the problem, including the use of bone morphogenetic protein (BMP)20-24. In a controlled, prospective, randomized study of 124 tibial nonunions (in 122 adult patients) treated with insertion of an intramedullary rod and recombinant human (rh) BMP-7, no significant difference (p = 0.939) was noted between the BMP group and the group that received an intramedullary rod and autogenous iliac crest bone grafts20. In a prospective, randomized, controlled, single-blind study of 450 patients with an open tibial fracture, patients who were treated with rhBMP-2 (1.50 mg/mL) had significantly (p = 0.005) superior results compared with patients who were treated with intramedullary nail fixation and routine soft-tissue management as dictated by the injury21. These two large clinical series suggest that BMPs may be a good alternative to autogenous iliac-crest bone-grafting. Bone morphogenetic proteins have shown promising results in experimental animal models, and their clinical efficacy has been shown in the treatment of adult tibial nonunions and in spinal fusion20-24. They have not been tested in children because of uncertainty as to the effect on adjacent physes and because of concern about unexpected reactions. …

Intraoperative monitoring of motor evoked potentials : A review of 116 cases

We reviewed the results of motor evoked potential (MEP) and somatosensory evoked potential (SEP) monitoring during 116 operations on the spine or spinal cord.We monitored MEPs by electrically stimulating the spinal cord and recording compound muscle action potentials from lower extremity muscles and monitored SEPs by stimulating posterior tibial or peroneal nerves and recording both cortical and subcortical evoked potentials. We maintained anesthesia with an N2 O/O2/opioid technique supplemented with a halogenated inhalational agent and maintained partial neuromuscular blockade using a vecuronium infusion. Both MEPs and SEPs could be recorded in 99 cases (85%). Neither MEPs nor SEPs were recorded in eight patients, all of whom had preexisting severe myelopathies. Only SEPs could be recorded in two patients, and only MEPs were obtained in seven cases. Deterioration of evoked potentials occurred during nine operations (8%). In eight cases, both SEPs and MEPs deteriorated; in one case, only MEPs deteriorated. In four cases, the changes in the monitored signals led to major alterations in the surgery. We believe that optimal monitoring during spinal surgery requires recording both SEPs and MEPs. This provides independent verification of spinal cord integrity using two parallel but independent systems, and also allows detection of the occasional insults that selectively affect either motor or sensory systems. NEUROLOGY 1996;47: 999-1004

Surgical Site Infection Following Spinal Instrumentation for Scoliosis: A Multicenter Analysis of Rates, Risk Factors, and Pathogens

BACKGROUND Surgical site infection following correction of pediatric scoliosis is well described. However, we are aware of no recent multicenter study describing the rates of surgical site infection, and associated pathogens, among patients with different etiologies for scoliosis. METHODS A multicenter, retrospective review of surgical site infections among pediatric patients undergoing spinal instrumentation to correct scoliosis was performed at three childrens hospitals in the United States. Study subjects included all patients undergoing posterior spinal instrumentation from January 2006 to December 2008. Surgical site infections were defined according to the Centers for Disease Control and Preventions National Healthcare Safety Network case definition, with infections occurring within one year after surgery. RESULTS Following the analysis of 1347 procedures performed in 946 patients, surgical site infection rates varied among procedures performed in patients with different scoliosis etiologies. Procedures performed in patients with neuromuscular scoliosis had the highest surgical site infection rates (9.2%), followed by those performed in patients with syndromic scoliosis (8.8%), those performed in patients with other scoliosis (8.4%), those performed in patients with congenital scoliosis (3.9%), and those performed in patients with idiopathic scoliosis (2.6%). Surgical site infection rates varied among procedures in patients undergoing primary spinal arthrodesis based on etiology, ranging from 1.2% (95% confidence interval, 0.1% to 1.3%) in patients with idiopathic scoliosis to 13.1% (95% confidence interval, 8.4% to 17.8%) in patients with neuromuscular scoliosis. Surgical site infection rates following primary and revision procedures were similar among patients with different etiologies. In distraction-based growing constructs, rates were significantly lower for lengthening procedures than for revision procedures (p = 0.012). Multivariate analysis demonstrated that non-idiopathic scoliosis and extension of instrumentation to the pelvis were risk factors for surgical site infections. The three most common pathogens were Staphylococcus aureus (25.0% [95% confidence interval, 17.8% to 32.2%]), coagulase-negative staphylococci (17.1% [95% confidence interval, 10.9% to 23.3%]), and Pseudomonas aeruginosa (10.7% [95% confidence interval, 5.6% to 15.8%]). Overall, 46.5% (95% confidence interval, 35.5% to 57.5%) of surgical site infections contained at least one gram-negative organism; 97.0% (95% confidence interval, 90.8% to 100.0%) of these infections were in patients with non-idiopathic scoliosis. CONCLUSIONS Surgical site infection rates were significantly higher following procedures in patients with non-idiopathic scoliosis (p < 0.001). Lengthening procedures had the lowest rate of surgical site infection among patients with early onset scoliosis who had undergone instrumentation with growing constructs. Gram-negative pathogens were common and were most common following procedures in patients with non-idiopathic scoliosis. These findings suggest a role for targeted perioperative antibiotic prophylaxis to prevent surgical site infection following pediatric scoliosis instrumentation procedures.

Capturing quality of life in pediatric orthopaedics: two recent measures compared.

There is a clear need for standardized measures to assess health status that are valid and appropriate to the needs of children with orthopaedic problems. The Child Health Questionnaire and the American Academy of Orthopaedic Surgeons Pediatric Outcomes Data Collection Instrument, two new pediatric health status measures, were assessed for their ability to detect differences in health states in a pediatric orthopaedic population. The instruments have a range of scales designed to measure various aspects of physical and psychosocial health. Two hundred forty-two patients with wide-ranging diagnoses were enrolled in this cross-sectional study. The instruments exhibited ceiling effects in some domains but generally performed as they were intended in this large cohort. Using secondary factor analysis, it was shown that the domains of the instruments appropriately distinguish physical and psychosocial health. Several domains from each instrument discriminated between diagnosis groups and patients with varying numbers of comorbidities. Both of these measures show significant promise and have an important role in helping define the outcomes of children with orthopaedic problems.

Assessment of quality of life in adolescent patients with orthopaedic problems : Are adult measures appropriate?

New pressures of accountability brought on by a rapidly evolving system of health care financing have underscored the need for standardized, valid measures of patient outcome that reflect the effect of clinical intervention on all aspects of quality of life. In response, there has been a burgeoning interest in the area of outcomes assessment and measurement of quality of life after orthopaedic intervention in adults, but less attention has been focused on the assessment of broadly defined outcomes in children. In an effort to borrow from the broader adult experience in this area, the authors sought to examine whether the Medical Outcomes Study Short Form 36 (SF-36) or the EuroQol questionnaire, widely accepted adult health status measures, would be valid in this setting. These two measures were administered to 196 adolescent patients (10–18 years old) seeking orthopaedic evaluation. Tests of scale properties and construct validity show that these properties are maintained in this population, but neither instrument reflected known differences in health status among this cohort. Most importantly, both the SF-36 and the EuroQol exhibited serious ceiling effects (most respondents scored at the top of their scales), despite evidence indicating those patients often had suboptimal health status. Thus, neither the SF-36 nor the EuroQol is valid for use in this population. The assessment of pediatric health status demands outcomes measures specifically designed to reflect the unique needs of this population.

What's the evidence? Systematic literature review of risk factors and preventive strategies for surgical site infection following pediatric spine surgery.

Background: Despite relatively high rates of surgical site infections (SSIs) after pediatric spine surgery, practice guidelines are absent. We performed a systematic review of the literature, determining the level of evidence for risk factors for SSIs and prevention practices to reduce SSIs following pediatric spine surgery. Methods: The search utilized the root search words “spine,” “scoliosis,” and “infection” resulting in 9594 abstracts. Following removal of duplicate abstracts, those that assessed only SSI rates, SSI treatment, nonoperative spine infections, or adult populations, 57 relevant studies were rated for level of evidence and graded using previously validated scales. Results: Very few studies lead to grade A (good evidence) or grade B (fair evidence) recommendations. Ceramic bone substitute did not increase the risk of SSIs when compared with autograft (grade A). Comorbid medical conditions, particularly cerebral palsy or myelodysplasia; urinary or bowel incontinence; nonadherence to antibiotic prophylaxis protocols; and increased implant prominence increase the risk of SSIs (grade B). SSIs caused by gram-negative bacilli were more frequent in neuromuscular populations and first-generation stainless steel implants increased the risk of delayed infection compared to newer generation titanium implants (grade B). Evaluations of other risk factors for SSIs yielded conflicting or poor-quality evidence (grade C); these included malnutrition or obesity; number of levels fused or fusion extended to the sacrum/pelvis; blood loss; and use of allograft. Insufficient evidence (0 to 1 published studies) was available to recommend numerous practices shown to reduce SSI risk in other populations such as chlorhexidine skin wash the night before surgery, preoperative nasal swabs for Staphylococcus aureus, chlorhexidine skin disinfection, perioperative prophylaxis with intravenous vancomycin, vancomycin, or gentamicin powder in the surgical site or graft. Conclusions: Few studies have evaluated risk factors and preventive strategies for SSIs following pediatric spine surgery. This systematic review documents the relative lack of evidence supporting SSI prevention practices and highlights priorities for research. Level of Evidence: Level III therapeutic study.