Double-level noncontiguous thoracic Chance fractures treated with percutaneous stabilization: illustrative case

BACKGROUND Chance fractures are unstable due to horizontal extension of the injury, disrupting all three columns of the vertebra. Since being first described in 1948, Chance fractures have been commonly found at a single level near the thoracolumbar junction. Noncontiguous double-level Chance fractures that result from a single traumatic event are rarely reported in the literature. OBSERVATIONS The authors report a case of an 18-year-old male who presented to the emergency department after a rollover motor vehicle accident. The patient complained of severe back pain when at rest and had no neurological deficits. Computed tomography revealed two unstable Chance fractures of bony subtype located at T6 and T11. The patient underwent percutaneous stabilization from T4 to T12. The postoperative assessment revealed continued 5/5 power bilaterally in all extremities, back pain, and the ability to ambulate with a walker. At 3 months after the operation, clinical assessment revealed no significant back pain and the ability to walk independently. Imaging confirmed stable fixation of the spine with no acute osseous or hardware complications. LESSONS This report complements previous studies demonstrating support for more extensive stabilization for such unique fractures. Additionally, rapid radiological imaging is needed to identify the full injury and lead patients to appropriate treatment.

1346 Hardware Complications in Cephalomedullary Nailing for Intertrochanteric Hip Fractures: A Retrospective Cohort Study

Introduction Intertrochanteric hip fractures are common injuries in elderly patients and can result in significant morbidity. The use of cephalomedullary femoral nailing (CMN) has gained popularity, particularly for unstable fracture patterns. We investigated hardware complications and mortality of patients undergoing long and short CMN for intertrochanteric hip fractures. Method We conducted a retrospective cohort study of consecutive cases in a single UK-based trauma unit between 01 July 2016 – 31 Dec 2019. Primary outcome measures were implant failure and revision surgery. The secondary outcome measure was mortality. Results 335 patients were included, mean age 82.9 years. 176 long (LN) and 167 short (SN) CMNs were performed. 25/335 (7.5%) hardware complications occurred resulting in 19 (5.7%) revision surgeries. Overall implant survivorship was 94.3%. There was no statistically significant difference in implant survivorship between LN and SN (p = 0.93), or between proximal screw configuration (p = 0.20). Cox regression analysis did not identify any independent predisposing factors leading to hardware complications. 30-day, 90-day and 1-year mortality rates were 7.9%, 15.2% and 26.5% respectively. There was no significant difference in mortality between LN and SN (p = 0.53). Regression analysis identified age and male gender as statistically significant independent factors of increased mortality. Conclusions For intertrochanteric fractures, there is no difference in hardware complications or mortality between long and short cephalomedullary nails. We highlight the risk of implant fracture at the lag screw-nail interface; accounting for one-quarter of failures. The revision rate of 5.7% due to hardware failure should be a consideration for surgeons undertaking CMN for intertrochanteric fractures.

Implantable Pulse Generators for Deep Brain Stimulation: Challenges, Complications, and Strategies for Practicality and Longevity

Deep brain stimulation (DBS) represents an important treatment modality for movement disorders and other circuitopathies. Despite their miniaturization and increasing sophistication, DBS systems share a common set of components of which the implantable pulse generator (IPG) is the core power supply and programmable element. Here we provide an overview of key hardware and software specifications of commercially available IPG systems such as rechargeability, MRI compatibility, electrode configuration, pulse delivery, IPG case architecture, and local field potential sensing. We present evidence-based approaches to mitigate hardware complications, of which infection represents the most important factor. Strategies correlating positively with decreased complications include antibiotic impregnation and co-administration and other surgical considerations during IPG implantation such as the use of tack-up sutures and smaller profile devices.Strategies aimed at maximizing battery longevity include patient-related elements such as reliability of IPG recharging or consistency of nightly device shutoff, and device-specific such as parameter delivery, choice of lead configuration, implantation location, and careful selection of electrode materials to minimize impedance mismatch. Finally, experimental DBS systems such as ultrasound, magnetoelectric nanoparticles, and near-infrared that use extracorporeal powered neuromodulation strategies are described as potential future directions for minimally invasive treatment.

Early Results of a Novel Intramedullary Fixation Device for Proximal Fifth Metatarsal Fractures

Background Proximal fifth metatarsal fractures are commonly treated surgically due to their poor healing capacity. While intramedullary screws may be the most popular operative treatment choice, newer fixation methods continue to develop. We present a case series utilizing a novel intramedullary fixation device for proximal fifth metatarsal fractures. To our knowledge, no other study in the literature has assessed the safety and efficacy of this fixation method. Methods A retrospective analysis was performed for 16 patients with proximal fifth metatarsal fractures who underwent fixation with the same novel intramedullary device. Patient charts were reviewed for fracture union, plantar fracture gapping, time to weight-bearing, refracture, perioperative complications, and secondary surgeries. Results Sixteen patients with an average age of 43.3 years underwent fixation with this novel device from 2015 to 2020. Mean follow-up was 32.4 weeks. Fifteen of the 16 patients achieved radiographic union at a mean of 8.9 weeks. One patient suffered a nonunion. Mean time to full weight-bearing in, and out of, a walking boot was 6.4 and 9.8 weeks, respectively, for healed fractures. Mean plantar fracture gap improved from 1.22 mm to 0.88 mm following surgery. There were zero infections, refractures, or hardware complications. Three patients suffered iatrogenic fracture during implant insertion. Conclusion To our knowledge, this is the first report of early results for this novel intramedullary device. Excellent union rates, acceptable time to weight-bearing, and a low complication profile can be achieved. Based on our findings, we propose a safe and effective treatment option for proximal fifth metatarsal fractures. Levels of Evidence Level IV: Clinical case series

Radiographic analysis of specific morphometrics and patient-reported outcomes (PROMIS) for surgical repair of zones 2 and 3 fifth metatarsal fractures

Background Zones 2 and 3 fifth metatarsal fractures are often treated with intramedullary fixation due to an increased risk of nonunion. A previous 3-dimensional (3D) computerized tomography (CT) imaging study by our group determined that the screw should stop short of the bow of the metatarsal and be larger than the commonly used 4.5 millimeter (mm) screw. This study determines how these guidelines translate to operative outcomes, measured using Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) surveys. Radiographic variables measuring the height of the medial longitudinal arch and degree of metatarsus adductus were also obtained to determine if these measurements had any effect on outcomes. And lastly, this study aimed to determine if morphologic differences between males and females affected surgical outcomes. Methods We retrospectively identified 23 patients (14 male, 9 female) who met inclusion criteria. Eighteen patients completed PROMIS surveys. Preoperative PROMIS surveys were completed prior to surgery, rather than retroactively. Weightbearing radiographs were also obtained preoperatively to assist with surgical planning and postoperatively to assess interval healing. Correlation coefficients were calculated between PROMIS scores and repair characteristics (hardware characteristics [screw length and diameter] and radiographic measurements of specific morphometric features). T tests determined the relationship between repair characteristics, PROMIS scores, and incidence of operative complications. PROMIS scores and correlation coefficients were also stratified by gender. Results The average screw length and diameter adhered to guidelines from our previous study. Preoperatively, mean PROMIS PI = 57.26±11.03 and PROMIS PF = 42.27±15.45 after injury. Postoperatively, PROMIS PI = 44.15±7.36 and PROMIS PF = 57.22±10.93. Patients with complications had significantly worse postoperative PROMIS PF scores (p=0.0151) and PROMIS PI scores (p=0.003) compared to patients without complications. Females had non-significantly worse preoperative and postoperative PROMIS scores compared to males and had a higher complication rate (33 percent versus 21 percent, respectively). Metatarsus adductus angle was shown to exhibit a significant moderate inverse relationship with postoperative PROMIS PF scores in the overall cohort (r=−0.478; p=0.045). Metatarsus adductus angle (r=−0.606; p=0.008), lateral talo-1st metatarsal angle (r=−0.592; p=0.01), and medial cuneiform height (r=−0.529; p=0.024) demonstrated significant inverse relationships with change in PROMIS PF scores for the overall cohort. Within the male subcohort, significant relationships were found between the change in PROMIS PF and metatarsus adductus angle (r=−0.7526; p=0.005), lateral talo-1st metatarsal angle (r=−0.7539; p=0.005), and medial cuneiform height (r=−0.627; p=0.029). Conclusion Patients treated according to guidelines from our prior study achieved satisfactory patient reported and radiographic outcomes. Screws larger than 4.5mm did not lead to hardware complications, including screw failure, iatrogenic fractures, or cortical blowouts. Females had non-significantly lower preoperative and postoperative PROMIS scores and were more likely to suffer complications compared to males. Patients with complications, higher arched feet, or greater metatarsus adductus angles had worse functional outcomes. Future studies should better characterize whether patients with excessive lateral column loading benefit from an off-loading cavus orthotic or plantar-lateral plating.

WEIGHTLESS PROCESSING OF QUANTIZED SIGNAL LOAD

Optimal methods for processing input information signals often involve operations, implementation of which is extremely difficult and significantly increases the requirements for automated information processing systems. However, the use of various approaches to solving this problem has led to the appearance of synthesized methods for processing a sequence of signals that allow solving the detection problem with the required quality without significant hardware complications. The article considers a method for weightless processing packets of input quantized signals, which allows us to evaluate the potential (limit) quality of information processing and quantify the amount of loss of this quality when excluding certain operations. The considered method is given with a reasonable structure of implemented devices in practice. A special feature of weightless signal processing is analysis of increasing unit density in a fixed interval of close positions, which gives information about the possible presence of an information signal. To identify this factor, two logical criteria are used, such as “m out of m” and “n out of m”, which will be described in this article.

Treatment of displaced fractures of the patella: Tension band wiring technique with the one-end or both-ends K-wire bending fixation method

Purpose: Tension band wiring technique has been widely used for treating patellar fracture. Conventional techniques are associated with some complications and several modifications have been introduced to increase stabilization. The purpose of this study was to compare two different fixation techniques, the one-end and both-ends Kirschner wire bending fixation methods. Methods: We retrospectively reviewed patient data from 2013 to 2017, including the age, sex, body height, body weight, BMI, lesion of injury, trauma mechanism, fracture displacement and classification, type of fixation, fracture healing duration, length of follow-up, clinical results and complications. The surgical outcome was assessed using the pain score (VAS), Lysholm knee score, and knee joint ROM. Plain radiographs were used to evaluate radiographic outcomes and assess the fracture union duration and hardware complications. We performed statistical analysis to compare these two different fixation techniques. Results: There were no significant differences between the two groups in terms of demographic data, fracture healing duration, level of the K-wires, distance between the K-wires, or length of the K-wires over the patella length (all p > 0.05). There were significant differences in the VAS score, K-wire migration, flexion degree, ROM, and Lysholm score (all p < 0.001) between the two different fixation methods. Conclusion: The both-ends K-wire bending fixation method has a lower complication rate and results in a better clinical outcome than the one-end K-wire bending fixation method. This revised technique can effectively control both ends of the K-wires, thus eliminating the possibility of K-wire migration and improving the fixation stability.