Strategies reducing risk of surgical-site infection following pediatric spinal deformity surgery.

BACKGROUND: Identifying beneficial preventive strategies for surgical-site infection (SSI) in individual patients with different clinical and surgical characteristics is challenging. The purpose of this study was to investigate the association between preventive strategies and patient risk of SSI taking into consideration baseline risks and estimating the reduction of SSI probability in individual patients attributed to these strategies. METHODS: Pediatric patients who underwent primary, revision, or final fusion for their spinal deformity at 7 institutions between 2004 and 2018 were included. Preventive strategies included the use of topical vancomycin, bone graft, povidone-iodine (PI) irrigations, multilayered closure, impermeable dressing, enrollment in quality improvement (QI) programs, and adherence to antibiotic prophylaxis. The CDC definition of SSI as occurring within 90 days postoperatively was used. Multiple regression modeling was performed following multiple imputation and multicollinearity testing to investigate the effect of preventive strategies on SSI in individual patients adjusted for patient and surgical characteristics. RESULTS: Univariable regressions demonstrated that enrollment in QI programs and PI irrigation were significantly associated, and topical vancomycin, multilayered closure, and correct intraoperative dosing of antibiotics trended toward association with reduction of SSI. In the final prediction model using multiple regression, enrollment in QI programs remained significant and PI irrigation had an effect in decreasing risks of SSI by average of 49% and 18%, respectively, at the individual patient level. CONCLUSION: Considering baseline patient characteristics and predetermined surgical and hospital factors, enrollment in QI programs and PI irrigation reduce the risk of SSI in individual patients. Multidisciplinary efforts should be made to implement these practices to increase patient safety. LEVEL OF EVIDENCE: Prognostic level III study.

A Clinical Risk Model for Surgical Site Infection Following Pediatric Spine Deformity Surgery.

BACKGROUND: Despite tremendous efforts, the incidence of surgical site infection (SSI) following the surgical treatment of pediatric spinal deformity remains a concern. Although previous studies have reported some risk factors for SSI, these studies have been limited by not being able to investigate multiple risk factors at the same time. The aim of the present study was to evaluate a wide range of preoperative and intraoperative factors in predicting SSI and to develop and validate a prediction model that quantifies the risk of SSI for individual pediatric spinal deformity patients. METHODS: Pediatric patients with spinal deformity who underwent primary, revision, or definitive spinal fusion at 1 of 7 institutions were included. Candidate predictors were known preoperatively and were not modifiable in most cases; these included 31 patient, 12 surgical, and 4 hospital factors. The Centers for Disease Control and Prevention definition of SSI within 90 days of surgery was utilized. Following multiple imputation and multicollinearity testing, predictor selection was conducted with use of logistic regression to develop multiple models. The data set was randomly split into training and testing sets, and fivefold cross-validation was performed to compare discrimination, calibration, and overfitting of each model and to determine the final model. A risk probability calculator and a mobile device application were developed from the model in order to calculate the probability of SSI in individual patients. RESULTS: A total of 3,092 spinal deformity surgeries were included, in which there were 132 cases of SSI (4.3%). The final model achieved adequate discrimination (area under the receiver operating characteristic curve: 0.76), as well as calibration and no overfitting. Predictors included in the model were nonambulatory status, neuromuscular etiology, pelvic instrumentation, procedure time ≥7 hours, American Society of Anesthesiologists grade >2, revision procedure, hospital spine surgical cases <100/year, abnormal hemoglobin level, and overweight or obese body mass index. CONCLUSIONS: The risk probability calculator encompassing patient, surgical, and hospital factors developed in the present study predicts the probability of 90-day SSI in pediatric spinal deformity surgery. This validated calculator can be utilized to improve informed consent and shared decision-making and may allow the deployment of additional resources and strategies selectively in high-risk patients. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Perioperative major neurologic deficits as a complication of spine surgery.

STUDY DESIGN: Retrospective review of spine surgery patients with new major neurologic complication. OBJECTIVE: To define the causes and severity of new neurologic damage to the spinal cord or cauda equina caused by spinal surgery. MATERIALS AND METHODS: Consult records were reviewed for all postoperative spine surgery patients referred to a tertiary spinal cord injury rehabilitation center over a 12-year period. Any patients with a new perioperative surgery-related decrement in American Spinal Injury Association (ASIA) Impairment Scale (AIS), loss of bowel or bladder function, or loss of ability to ambulate were examined and final 1-year gaps for neurologic loss reported. RESULTS: 64 patients had a new perioperative major neurologic event with: 41% thoracic, 39% cervical, and 20% lumbar; 61% intraoperative, 31% in the immediate 2-week postoperative period, 8% unknown. Chronic myelopathy (44%) was the most common indication. The causes of neurologic injury were postoperative fluid collection (25%), malposition of instrumentation (14%), traumatic decompression (14%), cord infarct (11%), deformity correction (2%), and unknown (34%). Overall, 87% lost the ability to ambulate and 66% lost volitional bowel-bladder control. AIS decrement and loss of ambulation and bowel-bladder function did not differ statistically significantly by surgical indication. However, among the main root causes, traumatic decompressions and cord infarcts had significantly worse neurologic deterioration than fluid collections or malposition of instrumentation. CONCLUSION: The relative rate of major neurologic injury in spine surgery is higher in thoracic and cervical cases at spinal cord levels, especially when done for myelopathy, even though lumbar surgeries are most common. The most common causes of neurologic injury were potentially avoidable postoperative fluid collections, malposition of instrumentation, and traumatic decompression.

Preventing Distal Junctional Kyphosis by Applying the Stable Sagittal Vertebra Concept to Selective Thoracic Fusion in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Multicenter retrospective review. OBJECTIVE: To assess the effectiveness of using the stable sagittal vertebra (SSV) for selecting the lowest instrumented vertebrae (LIV) to prevent distal junctional kyphosis (DJK) in selective thoracic fusions. SUMMARY OF BACKGROUND DATA: Cho et al. reported that including the SSV in a fusion decreased the rate of DJK in thoracic hyperkyphosis. METHODS: A retrospective review was performed of patients from two pediatric hospitals with adolescent idiopathic scoliosis who underwent selective posterior thoracic fusion with the LIV at L2 or above from 2000 to 2012. Patients with less than 2 years' follow-up were excluded. The primary outcome measure was DJK, defined radiographically as ≥10° between the superior end plate of the LIV and the inferior end plate of the vertebra below on a standing lateral radiograph. We investigated the SSV, which was defined as the vertebral level at which 50% of the vertebral body was in front of the posterior sacral vertical line (PSVL) on a standing lateral radiograph. This particular definition was referred to as SSV. RESULTS: A total of 113 patients met the inclusion criteria. Mean age was 14.4 years. Mean Cobb angle was 58°. The overall rate of DJK was 7% (8/113). When the LIV was superior to SSV, the rate of DJK was 17% (8/46) versus 0% (0/67) when the LIV was at or inferior to SSV (p=.01). The rates of DJK for patients with the LIV one, two, and three levels above SSV were 17% (4/24), 7% (1/14), and 43% (3/7), respectively. There was no significant association between preoperative or postoperative maximum kyphosis, thoracic kyphosis, thoracolumbar kyphosis, pelvic incidence, sagittal balance or coronal balance, and development of DJK. CONCLUSION: Although LIV selection is complex, choosing the LIV at or below the SSV is a simple rule that minimizes the risk of DJK. LEVEL OF EVIDENCE: Level IV.

Management of Spinal Implants in Acute Pediatric Surgical Site Infections: A Multicenter Study.

STUDY DESIGN: A retrospective review of patients who underwent posterior spinal fusion (PSF) and returned within 90 days with an acute infection. OBJECTIVES: The study motive is to identify and understand the risk factors associated with failure of retaining spinal implants and failure to treat acute infection. BACKGROUND: The natural history of early surgical site infection (SSI) (less than 3 months) after PSF is not known and removing the implants early after PSF risks pseudarthrosis and deformity progression. METHODS: Patients ranging from 1999 to 2011 with surgical site infections (SSIs) who required irrigation and debridement within 3 months of PSF were identified from 4 institutions. Univariable and multivariable regression analysis were used to identify risk factors associated with failure of acute infection treatment. RESULTS: Eighty-two patients (59 female, 23 male) with a mean age of 13.6 years were identified. Median follow-up after initial surgery was 33 months (range: 12-112 months). Sixty-two (76%) were treated successfully with acute treatment and did not return with recurrent infection (cleared infection, group C); 20 (24%) returned later with chronic infection (recurrent infection, group R). Multivariable analysis indicated that patients with stainless steel implants (OR = 6.4, 95% CI = 1.7-32.1; p = .009) and older subjects (OR = 1.3, 95% CI = 1.0-1.6; p = .03) were more likely to present with recurrent infection. There was no difference between the groups with regard to the initial time of presentation post fusion, proportion of non-idiopathic diagnosis, rate of positive cultures, culture species, presence of fusion to pelvis, and time on antibiotic treatment. CONCLUSIONS: Seventy-six percent of patients presenting with an SSI less than 3 months after PSF did not require implant removal to clear their infection. Early postoperative SSIs can be treated with retention or implant exchange. Older patients and patients with stainless steel instrumentation are more likely to present with a late recurrent infection compared to other metals. LEVEL OF EVIDENCE: Level III.

Continuing Delay in the Diagnosis of Slipped Capital Femoral Epiphysis.

OBJECTIVE: To evaluate whether the time from symptom onset to diagnosis of slipped capital femoral epiphysis (SCFE) has improved over a recent decade compared with reports of previous decades. STUDY DESIGN: Retrospective review of 481 patients admitted with a diagnosis of SCFE at three large pediatric hospitals between January 2003 and December 2012. RESULTS: The average time from symptom onset to diagnosis of SCFE was 17 weeks (range, 0-to 169). There were no significant differences in time from symptom onset to diagnosis across 2-year intervals of the 10-year study period (P = .94). The time from evaluation by first provider to diagnosis was significantly shorter for patients evaluated at an orthopedic clinic (mean, 0 weeks; range, 0-0 weeks) compared with patients evaluated by a primary care provider (mean, 4 weeks; range, 0-52 weeks; r = 0.24; P = .003) or at an emergency department (mean, 6 weeks, range, 0-104 weeks; r = 0.36; P = .008). Fifty-two patients (10.8%) developed a second SCFE after treatment of the first affected side. The time from the onset of symptoms to diagnosis for the second episode of SCFE was significantly shorter (r = 0.19; P < .001), with mean interval of 11 weeks (range, 0-104 weeks) from symptom onset to diagnosis. There were significantly more cases of mildly severe SCFE, as defined by the Wilson classification scheme, in second episodes of SCFE compared with first episodes of SCFE (OR, 4.44; P = .001). CONCLUSION: Despite reports documenting a lag in time to the diagnosis of SCFE more than a decade ago, there has been no improvement in the speed of diagnosis. Decreases in both the time to diagnosis and the severity of findings for the second episode of SCFE suggest that the education of at-risk children and their families (or providers) may be of benefit in decreasing this delay.

The Effect of Growing Rod Treatment on Hemoglobin and Hematocrit Levels in Early-onset Scoliosis.

BACKGROUND: This study examines preoperative hemoglobin (Hgb) and hematocrit (Hct) levels in a group of early-onset scoliosis (EOS) patients and the effect of distraction-based growing rods (GRs) on these levels. Children with EOS are at risk for respiratory insufficiency and chronic hypoxemia. Increased Hgb and Hct levels have been identified as surrogate markers for chronic hypoxemia. A study of patients who underwent VEPTR surgery showed a significant decrease in Hgb levels following surgery. METHODS: Data were retrospectively collected on 66 EOS patients without confounding respiratory issues or oxygen dependence who were treated with GRs at 5 institutions. Average age at initial surgery was 5.5 years. Patients were followed for a minimum of 2 years (average 3.7 y). Preoperative and postoperative Hgb and Hct levels were converted to Z-scores based on age-adjusted mean blood indices and were compared using a paired t test. RESULTS: The prevalence of elevated Hgb and Hct levels (Z-score >2) preoperatively was 15% (10/66) and 19% (12/64), respectively. The average Hgb Z-score decreased from 0.20 to -0.31 (P=0.005) 6 to 24 months following surgery and the Hct Z-score decreased from 0.31 to -0.28 (P=0.002) 6 to 24 months following surgery. CONCLUSIONS: Following distraction-based GR treatment of children with EOS there was a significant decrease in both their Hgb and Hct. This is a physiological marker of decreased hypoxemia and improved pulmonary function. LEVEL OF EVIDENCE: Level III-therapeutic study.

Cobalt Chrome Spinal Constructs Trigger Airport Security Screening in 24% of Pediatric Patients.

STUDY DESIGN: Retrospective study. OBJECTIVES: To determine whether pediatric patients undergo additional airport security screening after posterior spinal fusion. SUMMARY OF BACKGROUND DATA: Airport security has expanded to include body scanners as well as traditional metal detectors. Families frequently ask whether spinal implants will trigger airport security, but there is limited information on modern implants and screening methods. METHODS: The researchers conducted a survey of 50 pediatric patients after posterior spinal fusion from 2004 to 2013. Inclusion criteria were posterior instrumentation, pedicle screws for at least 80% of anchors, and at least 1 trip through an American airport after surgery. Charts and radiographs were reviewed for metal type, number of levels fused, number of anchors, and rod diameter. RESULTS: A total of 16% of patients (8 of 50) were detected by body scan or metal detector and all had cobalt chrome (CoCr) rods. No patients with stainless-steel (SS) rods were detected. The CoCr rods triggered additional screening in 24% of children (8 of 33), compared with none of 17 with SS rods (p = .03). For patients with CoCr rods, the detection rate was 18% (5 of 28) by metal detector and 17% (3 of 18) by body scanner. For patients with CoCr rods, there was no significant difference between detection rates and levels fused (p = .30), number of anchors (p = .15), or rod diameter (p = .17). CONCLUSIONS: In this series, CoCr constructs were more likely to incur additional airport security compared with more traditional SS constructs.

Growing Rods Versus Shilla Growth Guidance: Better Cobb Angle Correction and T1-S1 Length Increase But More Surgeries.

STUDY DESIGN: Retrospective comparison. OBJECTIVES: To compare treatment of early-onset scoliosis (EOS) with Shilla growth guidance versus distraction-based dual growing rods (GR). SUMMARY OF BACKGROUND DATA: We are not aware of any prior studies comparing the Shilla procedure with other surgical procedures in the treatment of EOS. METHODS: The authors performed a multicenter case-matched comparison of patients with EOS treated with Shilla versus dual spine-spine GR from 1995 to 2009. A total of 36 Shilla patients from 3 centers were matched with 36 GR patients from the database by age at index surgery (±1 year), preoperative Cobb angle (±15°), and diagnosis (neuromuscular, congenital, idiopathic, or syndromic). Average follow-up was similar between groups (GR, 4.3 years; Shilla, 4.6 years; p = .353). RESULTS: Average Cobb angle improvement preoperatively to latest follow-up was 36° (range, 72° to 36°) in the GR group versus 23° (range, 69° to 45°) in the Shilla group (p = .0124). T1-S1 length increased 8.8 cm in patients treated with GR, compared with 6.4 cm in Shilla patients (p = .0170). Shilla patients had fewer surgeries (2.8) than patients in the GR group (7.4) (p < .001) but had a higher rate of unplanned surgeries for implant complications (Shilla, 1.3; GR, 0.5; p = .0151). When revisions for implant complications done at the time of scheduled lengthenings and revisions for construct maintenance were included, the groups did not differ significantly in the number of procedures for implant complications (Shilla, 1.4; GR, 1.5; p = .9451). The overall complication rate did not differ significantly between groups (Shilla, 1.9 [range, 0-7]; GR, 1.3 [range, 0-9]; p = .2085). CONCLUSIONS: The GR group had a greater improvement in Cobb angle and a greater increase in T1-S1 length than Shilla. The GR patients had more surgeries but Shilla patients had more unplanned procedures. The rate of complications overall did not differ significantly between groups.

Measurement Variability in the Evaluation of the Proximal Junction in Distraction-based Growing Rods Patients.

BACKGROUND: Proximal junctional kyphosis (PJK) is a known complication of spinal fusion and has been shown to occur in the setting of growing rod instrumentation. Previous studies have shown good reliability in measuring PJK in adolescent idiopathic scoliosis. METHODS: Four pediatric orthopaedic spine surgeons measured the proximal junction in 10 patients with growing rod instrumentation using 2 methods. In method 1, measurements were made from the inferior endplate of the upper instrumented vertebrae (UIV) to the superior endplate of 1 level above the UIV. In method 2, measurements were made from the inferior endplate 2 levels below the UIV to the superior endplate 2 levels above the UIV. These measurements were repeated 1 week later. RESULTS: Method 1 had an intraobserver variability of ±13.2 degrees and interobserver variability of ±21.6 degrees, whereas method 2 had an intraobserver variability of ±18.3 degrees and interobserver variability of ±20.7 degrees. CONCLUSIONS: Interobserver variability of PJK is >20 degrees. As PJK is commonly defined as >10 degrees of kyphosis above the UIV, measurement of PJK in patients with distraction-based growing rods on lateral radiographs has too much variability to be useful. LEVEL OF EVIDENCE: Level III-diagnostic studies.

Supracondylar humeral fractures with isolated anterior interosseous nerve injuries: is urgent treatment necessary?

BACKGROUND: It is unclear if pediatric patients with a supracondylar humeral fracture and isolated anterior interossous nerve injury require urgent treatment. METHODS: A retrospective, multicenter study of 4409 patients with operatively treated supracondylar humeral fractures was conducted. Exclusion criteria were additional nerve injuries other than the anterior interosseous nerve, any sensory changes, pulselessness, ipsilateral forearm fractures, open fractures, less than two months of follow-up, or pathological fractures. RESULTS: Thirty-five of 4409 patients met inclusion criteria. The average time to surgery was 14.6 hours (range, two to thirty-six hours). No patient developed compartment syndrome. There was no significant difference in time to return of anterior interosseous nerve function relative to the time to surgical reduction and fixation (p = 0.668). A complete return of anterior interosseous nerve function occurred in all patients with an average time of forty-nine days (range, two to 224 days). Ninety percent of patients recovered anterior interosseous nerve function by 149 days. CONCLUSIONS: To our knowledge, this is the largest series to date of supracondylar humeral fractures with anterior interosseous nerve injuries. There is no evidence that a supracondylar humeral fracture with an isolated anterior interosseous nerve injury requires urgent treatment. A delay in treatment up to twenty-four hours was not associated with an increased time of nerve recovery or other complications. This series excluded patients with sensory nerve injuries, pulselessness, and ipsilateral forearm fractures, which all may require urgent surgery. Barring other clinical indications for urgent treatment of a supracondylar humeral fracture, an isolated anterior interosseous nerve injury (no sensory changes) may not by itself be an indication for urgent surgery. The anterior interosseous nerve injuries in this series showed complete recovery at a mean time of forty-nine days.