The adjunct use of descending neurogenic-evoked potentials when transcranial motor-evoked potentials degrade into warning criteria in pediatric spinal deformity surgery: minimizing false-positive events.

PURPOSE: This studies objective was to evaluate the utility of descending neurogenic-evoked potentials (DNEPs) in the setting of transcranial motor-evoked potentials (TCeMEPs) degradation into warning criteria during pediatric spinal deformity surgery. METHODS: An institutional spinal cord monitoring database was queried to identify all primary and revision pediatric spinal deformity cases, < / = 21 years of age performed from 1/2006 to 12/2021, in which TCeMEPs were the primary motor tract assessment modality which degraded into warning criteria, with subsequent initiation of adjunct DNEPs. RESULTS: Fourteen surgical cases (0.42%; 3351 total cases) in fourteen patients met inclusion criteria. Mean age was 13.2 years (7.5-21.3). DIAGNOSES: syndromic (n = 7), kyphosis (n = 3), congenital (n = 2), and idiopathic (n = 2). Three-column osteotomies (3CO)were done in eight patients. TCeMEPs degraded into warning criteria during screw placement (n = 7), 3CO performance/closure (n = 4), or deformity correction (n = 3). DNEPs were present in all cases of warning-criteria TCeMEPs and one case had degradation of DNEPs. Intraoperative Stagnara wake-up tests were performed in only 2/14 cases, with one transient new neurologic deficit (NND). In this specific scenario, DNEPs sensitivity was 50%, specificity 100%, positive predictive value 100%, and negative predictive value 92% to detect aNND. CONCLUSION: DNEPs were useful in assessing spinal cord function in the setting of TCeMEP data degradation in complex pediatric deformity surgeries. DNEPs demonstrated a higher specificity and positive predictive value in this clinical setting than TCeMEPs when assessing long-term neurologic function after surgery. Based on this small cohort, DNEPs appear to be a useful adjunct modality to TCeMEPs, in this challenging clinical scenario.

Positive security screening episodes of patients with spinal implants are influenced by detector type and not implant material.

BACKGROUND CONTEXT: Previous research on rates of spinal detection showed a low frequency of patients (5%) experienced delays and additional screening going through airport security. With continuous technology advances in screenings and the rise in cobalt chrome implantation, updated data on patient experiences was needed. PURPOSE: 1) Assess the rates of detection and additional screening by traditional metal detectors and full body scanners in patients with metal spinal implants, 2) Compare the rates of detection of various metal types (Titanium and cobalt-chrome, titanium only, and stainless steel) STUDY DESIGN: Retrospective PATIENT SAMPLE: All spine surgical follow-ups over survey period. OUTCOME MEASURES: Self-reported open questionnaire; frequency of airport screening, patients' feelings and attitudes towards screening. METHODS: Patients were surveyed in the outpatient setting on exposure to metal detectors (Traditional and full-body scanners) after spinal surgery with metallic implants at a single institution. A total of 182 patients were identified and consented. The medical records were reviewed for details on implant material and location. RESULTS: Mean age at surgery was 53 years (range=12-88) with a mean 5.9 levels fused (range 2-20). Mean time from surgery to survey was 34 months (range=2-351) and number of airport screenings was 5.8 (range=0-54). The most common implants were titanium/cobalt-chrome (Ti/CoCr) (n=96, 53%) and titanium only (n=72, 40%). Overall, 40% of patients reported a detector alert at an airport requiring processing delay and additional screening: 86% from full body scanners, 54% from traditional metal detectors, and 41% of patients reporting both. Full body scanners were more likely to detect implants compared to traditional metal detectors (OR 5.1, p<.0001). No significant difference in number of screenings between patients who set off detectors and patients who did not (p=.185). Twenty percent of patients reported trouble at non-airport locations with detectors due to their spinal implants, with 70% of these patients reporting additional manual screenings. There was no correlation between levels spanned by the construct and number of times detected by traditional metal detectors or full body scanners, and no significant difference between levels spanned by constructs, or construct locations, in patients who set off detectors and those who did not. There was no significant difference between Ti/CoCr vs. titanium or other constructs in positive screenings. Subanalysis of fusions <5 levels demonstrated Ti/CoCr implants did not have an impact on positive screenings vs. other metal types (OR 0.88, p=.756). Interestingly, there was a significant difference in age and the positive screenings (p=.0025). Patients 60+ years of age had statistically significant greater positive screening than patients 0 to 40 years and 41 to 60 years. This data raises the possibility the presence of total joint arthroplasties (Mean age of patients with arthroplasty 65.5 years, range 50-88) likely play a significant role in the frequency of positive screenings. CONCLUSIONS: 40% of patients had their spinal implants detected at airports and 20% reported detections at other non-airport locations. Full body scanners detect spinal implants more frequently compared to traditional metal detectors (86% vs. 54% of detections, respectively). There was no difference in rate of airport and non-airport detection in patients with cobalt chrome implants compared to other materials. The presence of total joint arthroplasties likely has a significant contribution to the detector alerts.

Impact of Spinal Deformity Characteristics on Patient-reported Outcome Measurement Information System Scores in Patients With Idiopathic Scoliosis Undergoing Posterior Spinal Fusion.

INTRODUCTION: The impact of posterior spinal fusion (PSF) on physical function and pain and mental health in pediatric patients as quantified by the Patient-Reported Outcomes Measurement Information System (PROMIS), developed by the National Institute of Health, is largely unknown. The purpose of this study is to report the changes of PROMIS scores for upper extremity (UE), pain interference (PI), mobility (MOB), and peer relationships (PR) after PSF in patients with idiopathic scoliosis (IS), compare postoperative changes in PROMIS PI and Scoliosis Research Society-30 pain scores, and evaluate associations between curve characteristics and PROMIS scores. METHODS: A retrospective cohort of 122 patients (<18 years old) who underwent PSF for IS was identified through electronic medical record search. PROMIS scores were obtained preoperatively and 6 weeks, 6 months, 1 years, 2 years, and 3 years postoperatively. RESULTS: The mean age of the cohort was 14.2 ± 1.6 years, and the mean Cobb angle was 62.9 ± 13.8° at surgery. Eighty patients had preoperative PROMIS data. UE and MOB scores were statistically lower at 6 weeks and 6 months postoperatively and returned to baseline with a longer follow-up. PI scores were significantly lower at 1 and 2 years postoperatively. PR was unchanged up to 2 years postoperatively and then showed significant improvement. There was a statistically significant negative relationships between lowest instrumented vertebra and PROMIS UE and MOB scores at 6 weeks and 1 year postoperatively, but not at a longer follow-up. There were no significant differences noted in PI and PR PROMIS scores and lowest instrumented vertebra. PROMIS scores were not statistically associated with the Lenke Classification, number of vertebral levels fused, or percentage coronal correction. DISCUSSION: Changes in PROMIS functional domains (UE and MOB) postoperatively normalize at longer follow-ups. Changes in PI and PR demonstrated improvements over preoperative values at 1 to 2 years postoperatively. Preoperative coronal and sagittal measures, and the percentage correction did not correlate with any PROMIS scores.

Ogden Type I to III tibial tubercle fractures in skeletally immature patients: is routine anterior compartment fasciotomy of the leg indicated?

PURPOSE: Determine the frequency of compartment syndrome of the leg after displaced, operatively treated modified Ogden I to III tibial tubercle fractures (TTFxs), evaluate the preoperative assessment and use of advanced imaging, and need for prophylactic fasciotomies. METHODS: Retrospective analysis of operatively treated, displaced modified Ogden I to III TTFxs, at our level 1 paediatric trauma centre between 2007 and 2019. Modified Ogden Type IV and V fracture patterns were excluded. Fracture patterns were determined by plain radiographs. RESULTS: There were 49 modified Ogden I to III TTFxs in 48 patients. None had signs nor symptoms of vascular compromise, compartment syndromes or impending compartment syndromes preoperatively. In all, 13 of the 49 fractures underwent anterior compartment fasciotomy at surgery; eight of the 13 had traumatic fascial disruptions, which were extended surgically. All incisions were primarily closed. There were no instances of postoperative compartment syndromes, growth arrest, leg-length discrepancy or recurvatum deformity postoperatively. All patients achieved radiographic union and achieved full range of movement. CONCLUSION: The potentially devastating complications of compartment syndrome or vascular compromise following TTFx did not occur in this consecutive series of patients over 12 years. The presence of an intact posterior proximal tibial physis and posterior metaphyseal cortex (Modified Ogden TTFx Type I to III) may mitigate the occurrence of vascular injury and compartment syndrome. Plain radiographs appear appropriate as the primary method of imaging TTFxs, with use of advanced imaging as the clinical scenario dictates. Routine, prophylactic fasciotomies do not appear necessary in Ogden I to III TTFxs, but should be performed for signs and symptoms of compartment syndrome. LEVEL OF EVIDENCE: Level IV.

Monteggia Fracture in an Extremely Preterm Infant with Biochemical Rickets: A Case Report.

CASE: A preterm neonate with biochemical rickets is found to have a Monteggia fracture. The infant underwent percutaneous pinning. There was loss of fixation; however, the infant has been followed since discharge from the hospital and has completely healed with full range of motion. CONCLUSIONS: The medical management of this entity involves enteral feedings and optimization of nutrients. The optimal surgical treatment of this injury in the neonatal period is not yet known, although percutaneous pinning resulted in normal healing and function. These aspects require clinician awareness of this unique fracture type in a premature patient with fragile bone.

Fracture Table Application for Pediatric Femur Fractures: Incidence and Risk Factors Associated With Adverse Outcomes.

BACKGROUND: Flexible elastic nails, submuscular plating, and rigid locked intramedullary nails are common methods of fixation for pediatric femur fractures (PFF) in which the fracture table is used to aid reduction. Little is known about complications associated with fracture table application in PFF. The purpose of this study was to determine the incidence and risk factors associated with adverse outcomes related to fracture table application for the treatment of PFF. METHODS: A retrospective chart review of all children (younger than 18 y) treated for a femur fracture with the use of the fracture table between 2004 and 2015 at a single tertiary pediatric hospital was performed. Data on demographics, mechanism of injury, treatment modality, radiographic characteristics, and fracture table-related complications were gathered. Complications of interest included nerve palsy, skin breakdown/ulceration, vascular injury, and compartment syndrome. Penalized likelihood logistic regression was used to determine risk factors associated with adverse outcomes. RESULTS: In total, 260 patients were included. There were 8 patients with nerve palsies related to positioning and traction on the fracture table (1 bilateral and 6 ipsilateral peroneal nerve palsies, 1 contralateral tibial nerve palsy; incidence of 3.1%). No other fracture table-related complications were recorded. Patients who developed a nerve palsy were significantly heavier (78.7 vs. 44.3 kg, P<0.001) and had a significantly longer mean surgical time (188.6 vs. 117.0 min, P<0.001). Multivariate analysis demonstrated weight to be the only significant risk factor for complications, with a 5% increase in odds of complication with each additional kilogram (odds ratio, 1.05; confidence interval, 1.03-1.08; P<0.001). CONCLUSIONS: Nerve palsy related to the use of the fracture table during the fixation of PFF occurred in 3.1% of patients in our series. Patients who developed nerve palsies were significantly heavier and had significantly longer surgical times. Although the use of the fracture table for fixation of PFF is safe, every effort should be made to minimize time in traction to avoid iatrogenic nerve palsy, particularly in heavier children (>80 kg). LEVEL OF EVIDENCE: Level III.

Risk of Injury to Neurovascular Structures During Open Cerclage Wiring of the Femur: A Cadaveric Study.

The objective of this study was to examine the risk to the sciatic nerve and femoral artery during open passage of cerclage wires and to evaluate the safest techniques. After a standard lateral approach, cerclage passes along the femur were made in cadaveric specimens. Distance to the sciatic nerve and femoral artery was recorded. Careful technique resulted in an increase in distance to the sciatic nerve and femoral artery. There was an increase in the distance to the femoral artery with passes in an anterior to posterior direction. There was decreased distance to structures proximally and distally. There was a trend toward increased safety with smaller passers. Open cerclage wiring of the femur is safest if proper technique is used, care is taken at the proximal and distal ends of the femur, passes are made in an anterior to posterior direction, and the smallest cerclage passer that can be passed is utilized.

Pediatric forearm fractures with in situ intramedullary implants.

PURPOSE: The purpose of this investigation is to present our institutional experience with fractures of the pediatric forearm with in situ intramedullary nails. METHODS: Six patients treated at our institution for forearm fracture with in situ intramedullary implants between 2004 and 2013 were reviewed. Patient demographics, injury and radiographic characteristics, method of treatment, time to union, and complications were collected from the medical record. RESULTS: 485 patients with forearm fractures were treated with intramedullary implants and six patients presented with a fracture with in situ implants (1.2 %). Fractures in all six patients resulted from a second traumatic event after radiographic healing but before implant removal at a mean of 13.0 months from the initial procedure. One patient had an adequately aligned fracture and was treated with casting without reduction. The remaining five patients (83 %) returned to the operating room for treatment. Two patients underwent rod removal and placement of new intramedullary implants, and two patients were treated with rod removal and plating without attempt at closed reduction. One patient underwent closed reduction in the operating room with successful re-bending of the radial implant and replacement of the ulna implant. All patients went on to uncomplicated radiographic union at a mean 3.6 months. CONCLUSIONS: The incidence of fracture of pediatric forearm with in situ intramedullary implants is low. This rare complication can be treated by several different methods, including revision TENS placement, revision to plate fixation, or in situ bending of rods, with the expectation for successful uncomplicated union.

Platelets and plasma stimulate sheep rotator cuff tendon tenocytes when cultured in an extracellular matrix scaffold.

The addition of platelet-rich plasma (PRP) to rotator cuff repair has not translated into improved outcomes after surgery. However, recent work stimulating ligament healing has demonstrated improved outcomes when PRP or whole blood is combined with an extracellular matrix carrier. The objective of this study was to evaluate the effect of three components of blood (plasma, platelets, and macrophages) on the in vitro activity of ovine rotator cuff cells cultured in an extracellular matrix environment. Tenocytes were obtained from six ovine infraspinatus tendons and cultured over 14 days in an extracellular matrix scaffold with the following additives: (1) plasma (PPP), (2) plasma and platelets (PAP), (3) plasma and macrophages (PPPM), (4) plasma, platelets and macrophages (PAPM), (5) phosphate buffered saline (PBS), and (6) PBS with macrophages (PBSM). Assays measuring cellular metabolism (AlamarBlue), proliferation (Quantitative DNA assay), synthesis of collagen and cytokines (SIRCOL, TNF-α and IL-10 ELISA, and MMP assay), and collagen gene expression (qPCR) were performed over the duration of the experiment, as well as histology at the conclusion. Plasma was found to stimulate cell attachment and spreading on the scaffold, as well as cellular proliferation. Platelets also stimulated cell proliferation, cellular metabolism, transition of cells to a myofibroblast phenotype, and contraction of the scaffolds. The addition of macrophages did not have any significant effect on the sheep rotator cuff cells in vitro. In vivo studies are needed to determine whether these changes in cellular function will translate into improved tendon healing.

Exposed versus buried intramedullary implants for pediatric forearm fractures: a comparison of complications.

BACKGROUND: The purpose of this study was to compare the rate of complications between buried and exposed intramedullary implants after fixation of pediatric forearm fractures. METHODS: A retrospective comparative cohort study of 339 children treated with intramedullary fixation for displaced forearm fractures between 2004 and 2009 was performed. Implants were left exposed in 128 patients (37.8%) and buried beneath the skin in 208 patients (61.4%); 3 patients had buried and exposed hardware (0.9%). Data on demographics, injury, surgical technique, and complications were analyzed. RESULTS: The buried implant group was older (mean 10.3 vs. 8.5 y; P < 0.001), heavier (mean 38.6 vs. 31.9 kg; P < 0.001), and had fewer open injuries (23% vs. 41%; P < 0.001) than the exposed implant group. The buried group had their implants removed later than the exposed group (median 3.5 vs. 1.2 mo; P < 0.001). There was no difference between time to removal for patients with refracture and those without (median 1.3 vs. 2.0 mo; P = 0.78). A total of 36.2% of exposed implants were successfully removed in the office. Complications were seen in 56 patients (16.5%). There were 16 patients (4.7%) with refracture and 12 patients (3.5%) with infection. The buried and exposed implant groups did not differ significantly with respect to refracture (3.1% vs. 7.0%; P = 0.20), infection (3.5% vs. 2.3%; P = 0.66), or overall complications (14.5% vs. 17.2%; P = 0.87). There was also no difference between groups with respect to loss of reduction, nondelayed or delayed union, loss of motion, hypertrophic granuloma, or tendon rupture. Buried implants were also associated with penetration through the skin (3.9%). Injury to the dominant arm and need for open reduction were significant predictors of complication (OR = 1.01; 95% CI, 1.001-1.012; P = 0.02 and OR = 0.51; 95% CI, 0.264-0.974; P = 0.04, respectively). CONCLUSIONS: There were no significant differences seen in number of infections, refractures, or overall complications based on whether implants were left exposed or buried beneath the skin after surgery. LEVEL OF EVIDENCE: Level III, therapeutic.

Agrobacterium-mediated T-DNA transfer and integration into the chromosome of Streptomyces lividans.

Summary Agrobacterium tumefaciens is the prototype of a prokaryotic organism transmitting DNA across natural kingdom barriers into higher cells. In nature, a specific segment (T-DNA) of the resident Ti plasmid is transferred from this bacterium into plant cells and integrated into the plant cell genome. Expression of the integrated oncogenes contained in the T-DNA results in the tumour disease known as crown gall. Besides plants, the range of transformable recipients is broad and includes fungi and mammalian cells. We now show further extension of this host range, whereby the actinomycete Streptomyces lividans is also a recipient of the T-DNA. A. tumefaciens cells containing a binary vector system with a vir helper plasmid, pUCD2614, and a T-DNA donor plasmid, pUCD5801, were co-cultured with S. lividans hyphae. A. tumefaciens-S. lividans aggregate when the vir genes are induced with acetosyringone, resulting in the transfer of the T-DNA, as evidenced by the formation of transconjugants containing T-DNA genetic markers and the appearance of the T-DNA in these transconjugants. Close examination of the interacted cells revealed a presumably coiled thread-like interconnection with an average width of approximately 30 nm between A. tumefaciens and S. lividans. This interconnecting structure is dependent on virB genes and appears only under the same conditions as that required for T-pilus formation. Insertion of the T-DNA via A. tumefaciens into the S. lividans genome provides a useful genetic tool for generating novel mutants.