Spinal rod gripping capacity: how do 5.5/6.0-mm dual-diameter screws compare?

STUDY DESIGN: Biomechanical comparative study. OBJECTIVE: To evaluate pedicle screw gripping capacity from five suppliers, comparing single-diameter (S-D) systems using 5.5-mm-diameter rods to dual-diameter (D-D) systems accepting 5.5- and 6.0-mm-diameter rods with both cobalt chromium (CoCr) and titanium alloy (Ti) rods. D-D systems have become increasingly prevalent; however, these systems theoretically may compromise spinal rod gripping, particularly when a smaller-diameter rod is used within a D-D pedicle screw. METHODS: D-D pedicle screw systems from three suppliers (accepting 5.5- and 6.0-mm-diameter, Ti and CoCr rods), and S-D systems from two suppliers (accepting 5.5-mm-diameter, Ti and CoCr rods) were tested on an MTS MiniBionix machine. Axial load was applied in line with the rod to measure axial gripping capacity (AGC), and torsional load was applied to measure torsional gripping capacity (TGC) for each rod material and diameter. AGC and TGC were compared between D-D and S-D constructs, suppliers, rod diameters, and materials with subsequent classification and regression tree (CART) analysis. RESULTS: 5.5-mm rods within D-D screws were no weaker than 5.5-mm rods in S-D systems for AGC (dual > single, p = 0.043) and TGC (p = 0.066). As a whole, D-D systems had greater AGC than S-D systems (p = 0.01). AGC differed between suppliers (p < 0.001). No rod diameter (p = 0.227) or material (p = 0.131) effect emerged. With CART analysis, Supplier was the most significant predictor for greater AGC. As a whole, D-D systems had greater TGC than S-D systems (p = 0.008). TGC differed between suppliers (p < 0.001). Rod diameter was a significant predictor of higher TGC (6.0 > 5.5 mm, p = 0.002). CoCr rods had greater TGC than Ti (p < 0.001). CART analysis revealed that Supplier and CoCr material were significant predictors for increased TGC. CONCLUSIONS: Despite 30%-70% variability in gripping capacity due to rod supplier and material, overall D-D pedicle screw systems had similar AGC and TGC as S-D systems. LEVEL OF EVIDENCE: N/A.

Patient Engagement and Cost Savings Achieved by Automated Telemonitoring Systems Designed to Prevent and Identify Surgical Site Infections After Joint Replacement.

BACKGROUND: We designed two telemonitoring text and voice messaging interventions, EpxDecolonization (EpxDecol) and EpxWound, to improve management of orthopedic joint replacement patients at Washington University. We reviewed the use of these tools for a period of 88 weeks. METHODS: Cohorts of 1,392 and 1,753 participants completed EpxDecol and EpxWound, respectively. All patients who completed EpxDecol also completed EpxWound. We assessed patient use of and satisfaction with these interventions. A return on investment (ROI) analysis was conducted to determine the cost savings generated by EpxWound and EpxDecol. RESULTS: The proportions of patients who responded daily to EpxDecol and EpxWound were 91.9% and 77.7%, respectively, over the lengths of each intervention. The percent of daily responders declined <5% during each intervention. Ultimately, 88.4% of EpxDecol patients and 67.8% of EpxWound patients responded to ≥80% of all messages. Median patient survey responses (n = 1,246) were 9/9 (best possible) for care, 8/9 for improved communication, and 5/9 (perfect number) for number of messages received. ROI analysis for this 88-week period showed that using EpxDecol and EpxWound to engage patients (instead of nurses calling patients) saved the equivalent of 2.275 full-time nursing equivalents per week. We calculated net savings of $260,348 with an ROI of 14.85x for 1,753 patients over 88 weeks. One-year cost savings from these interventions were $153,800 with an ROI of 14.79x. CONCLUSIONS: EpxDecol and EpxWound may serve important roles in the perioperative process for orthopedic joint reconstruction surgery given high patient usage of and satisfaction with these interventions. Implementing EpxDecol and EpxWound for a large patient population could yield substantial cost savings and ROI.

Relationship Between Lumbar Lordosis and Pelvic Incidence in the Adolescent Patient: Normal Cohort Analysis and Literature Comparison.

STUDY DESIGN: Retrospective review; literature comparison. OBJECTIVES: To review the literature on the relationship between lumbar lordosis (LL) and pelvic incidence (PI) and evaluate this relationship in asymptomatic adolescents while testing the validity of previously reported adult correlation models between LL and PI in an adolescent population. SUMMARY OF BACKGROUND DATA: Accurate understanding of the normal spinopelvic relationship is critical when considering surgical fusion of the lumbar spine. Many studies have reported relationships between pelvic measurements and LL in adult populations, but data in pediatric populations is lacking. METHODS: A literature search was performed to identify previously reported relationships between pelvic parameters and LL in adults and pediatric patients. A cohort of 125 asymptomatic adolescent patients evaluated at our institution was evenly split into two cohorts for model development and validation. Linear regression between LL and PI was performed. The resultant regression model was tested in the validation cohort along with previously reported formulae with LL as a function of PI. Mean absolute error (MAE) was calculated and compared between prior models and the newly developed adolescent model using analysis of variance and post-hoc testing. RESULTS: In our adolescent cohort (mean age: 13 ± 2), there was a strong correlation between PI and LL (r = 0.53). Regression analysis in the development cohort produced the following predictive model: LL = 0.66(PI) + 24.2. Testing in the validation cohort revealed a good correlation between predicted and actual LL (r = 0.51) and an MAE of 8.3. All but three previously reported models functioned with similar accuracy in the adolescent population, with only two methods having an MAE over 10. CONCLUSIONS: The majority of previously published formulae for predicting LL as a function of PI developed in adults can be extrapolated to adolescent populations. These relationships are important in understanding how to surgically restore the sagittal alignment in adolescents with spinal deformity. LEVEL OF EVIDENCE: Level IV.

Accessible Communication Tools for Surgical Site Infection Monitoring and Prevention in Joint Reconstruction: Feasibility Study.

BACKGROUND: The National Surgical Quality Improvement Program logs surgical site infections (SSIs) as the most common cause of unplanned postoperative readmission for a variety of surgical interventions. Hospitals are making significant efforts preoperatively and postoperatively to reduce SSIs and improve care. Telemedicine, defined as using remote technology to implement health care, has the potential to improve outcomes across a wide range of parameters, including reducing SSIs. OBJECTIVE: The purpose of this study was to assess the feasibility and user satisfaction of two automated messaging systems, EpxDecolonization and EpxWound, to improve perioperative care in a quality improvement project for patients undergoing total joint replacement. METHODS: We designed two automated text messaging and calling systems named EpxDecolonization, which reminded patients of their preoperative decolonization protocol, and EpxWound, which monitored pain, wound, and fever status postoperatively. Daily patient responses were recorded and a post-usage survey was sent out to participants to assess satisfaction with the systems. RESULTS: Over the 40-week study period, 638 and 642 patients were enrolled in EpxDecolonization (a preoperative decolonization reminder) and EpxWound (a postoperative surgical site infection telemonitoring system), respectively. Patients could be enrolled in either or both EpxDecolonization and EpxWound, with the default option being dual enrollment. The proportion of sessions responded to was 85.2% for EpxDecolonization and 78.4% for EpxWound. Of the 1280 patients prescribed EpxWound and EpxDecolonization, 821 (64.14%) fully completed the postoperative system satisfaction survey. The median survey score (scale 1-9) was 9 for patient-rated overall care and 8 for whether the telemonitoring systems improved patient communication with providers. The majority of patients (69.0%, 566/821) indicated that the systems sent out an ideal number of messages (not too many, not too few). CONCLUSIONS: EpxDecolonization and EpxWound demonstrated high response rates and improved patient-rated communication with providers. These preliminary data suggest that these systems are well tolerated and potentially beneficial to both patients and providers. The systems have the potential to improve both patient satisfaction scores and compliance with preoperative protocols and postoperative wound monitoring. Future efforts will focus on testing the sensitivity and specificity of alerts generated by each system and on demonstrating the ability of these systems to improve clinical quality metrics with more authoritative data.

Presenting features of extremity necrotizing fasciitis in the pediatric patient: a case-control analysis.

This analysis sought to develop a tool for early differentiation between pediatric necrotizing fasciitis (NF) of the extremity and more benign infection. All diagnoses of extremity NF, cellulitis, and abscess from a single institution from 2009 to 2015 were included. Vitals and laboratory values were compared between cohorts using analysis of variance and decision tree analysis. NF was associated with thrombocytopenia, hyperthermia, tachycardia, and tachypnea. Decision tree analysis identified C-reactive protein more than 7.0 to be 100% sensitive and 95.7% specific for differentiating NF from cellulitis or abscess. The results offer quantitative support for clinical suspicion of NF in the evaluation of pediatric extremity infection.

Use of Short Message Service and Smartphone Applications in the Management of Surgical Patients: A Systematic Review.

BACKGROUND: Mobile health and telemedicine are rapidly evolving fields used to provide healthcare remotely to patients. For surgical patients, telemedicine can improve patient education and remote monitoring of postoperative symptoms. We performed a systematic review of studies involving the use of short message service (SMS) and mobile application-based interventions in surgical patients to evaluate the advantages and disadvantages of each system, as well as of mobile interventions as a whole. MATERIALS AND METHODS: Major electronic databases were searched using relevant keywords from inception until November 2016. Studies involving SMS or mobile application-based communication protocols involving at least 25 preoperative or postoperative patients were included. Studies of systems involving communication exclusively between healthcare professionals were excluded. RESULTS: A total of 2,492 unique studies were identified through keyword search. After applying inclusion and exclusion criteria, 15 studies were included in this review. Intervention modalities were SMS (8 studies), mobile application (4), combined SMS and application (1), automated phone call (1), and electronic transmission of pictures to the physician (1). Intervention methods were symptom monitoring (7), patient education (2), protocol adherence reminders (4), and combined symptom monitoring and protocol adherence reminders (2). Both mobile applications and SMS-based interventions increased adherence to medications and protocols and improved clinic attendance. Lower readmission rates and emergency room visits were reported. Satisfaction with automated communication systems was high for both patients and physicians. CONCLUSIONS: Mobile interventions provide a sophisticated yet simple tool to improve perioperative healthcare. Future considerations to address include usage fatigue and Health Insurance Portability and Accountability Act compliance concerns.

Torsional Growth Modulation of Long Bones by Oblique Plating in a Rabbit Model.

BACKGROUND: There is evidence that oblique tension band plating can affect torsional growth in long bones. This study sought to determine if the torsional growth could be modulated based on the angles of the tension band plating and whether or not oblique plating affected overall longitudinal growth. METHODS: New Zealand White rabbits (10.5 wk old) had one screw placed on the metaphyseal side and one on the epiphyseal side of both medial and lateral sides of the right knee distal femoral physis. The sham group (n=5) included screw placement only. For the plate group (n=13), unlocked plates, angled from 0 to 76 degrees, connected the screws and spanned the physis. Radiographs were taken at biweekly intervals. After 6 weeks of growth, hindlimbs were harvested and microCT scans performed. Femoral length, distances between screw heads and angle between the plates were measured on radiographs. Femoral length differences were compared between groups. Femoral version was measured from 3D microCT. Plate angle changes were correlated to the difference in femoral version between limbs using Pearson correlation (significance was set to P<0.05 for all comparisons). RESULTS: Femur length difference between the contralateral and the operative side was significantly greater in the plate group compared with the sham group over time (P=0.049). Medial and lateral screw distances changed significantly more in the sham group than the plate group on both sides (P<0.001). A greater initial angle between plates resulted in a greater change in the angle between plates (P<0.001). Significant correlations were found between right-left side femoral version differences and initial plate angle (P=0.003) and plate angle change (P=0.014). CONCLUSIONS: The torsional effect of oblique plating seems to correlate with the amount of initial plate angle, with an additional, not negligible, longitudinal growth effect. CLINICAL SIGNIFICANCE: Placing plates at given angles across open physes may result in predictable changes in bone torsion allowing for a safer and less invasive option when treating childhood torsional deformities, but the resulting shortening of the ipsilateral femur must be considered.

Low Infection-Related Re-Admission Rates in a Retrospective of 4725 Children with Appendicitis Using a Clinical Pathway in a Tertiary Care Pediatric Center.

BACKGROUND: Standardization of antibiotic management of appendicitis in tertiary care pediatric centers has been associated with improved outcomes. Rady Children's Hospital-San Diego implemented an appendicitis clinical pathway in 2005. We evaluated infection-related re-admission risk factors since 2010, when an electronic medical record was established, with the aim to optimize the clinical pathway. METHODS: Between January 2010 and August 2015, 4725 children with a diagnosis of appendicitis were evaluated for demographic data, pathology diagnoses, culture results, and inpatient and oral step-down antibiotic therapy regimens. From children originally admitted for appendicitis, those who were re-admitted with infection were compared with those who were not re-admitted for infection. The populations were controlled by severity of infection using a pathology-defined appendicitis severity scale: Grade 0, no appendicitis; grade 1, simple acute appendicitis with gross and microscopic evidence of inflammation, but no perforation; grade 2, gangrenous/necrotizing/micro-perforated appendicitis with subserosal or serosal exudate, but no frank or visually appreciated perforation; and grade 3, frank perforation. RESULTS: Of 4725 children (total population, TP) admitted with a diagnosis of appendicitis, only 199 (4.2%) were re-admitted, with 125 of these admissions for infection (2.65% of the TP). Age, race/ethnicity, language preference, and body mass index were not found to correlate with re-admission for infection. Length of stay significantly differed between the no infection-related re-admission population and infection-related re-admission population (3.02 vs. 4.03 d, p < 0.001). There was a trend toward higher infection-re-admission rates as the pathology grade increased (odds ratio grade 1 vs. grade 3 = 2.28, 95% confidence interval 1.03, 5.03). CONCLUSIONS: Infection-related re-admission rates for children on the clinical pathway in our institution were infrequent. The greater association of all-cause and infection-related re-admission rates with pathology grade suggest that defining appendicitis by pathology and clinical severity may provide an evidence-based scoring system to support clinical observation in the use and duration of antibiotic therapy.