Design optimization of a magnesium-based metal hydride hydrogen energy storage system.

Metal hydrides (MH) are known as one of the most suitable material groups for hydrogen energy storage because of their large hydrogen storage capacity, low operating pressure, and high safety. However, their slow hydrogen absorption kinetics significantly decreases storage performance. Faster heat removal from MH storage can play an essential role to enhance its hydrogen absorption rate, resulting in better storage performance. In this regard, the present study aims to improve heat transfer performance to positively impact the hydrogen absorption rate of MH storage systems. A novel semi-cylindrical coil is first designed and optimized for hydrogen storage and embedded as an internal heat exchanger with air as the heat transfer fluid (HTF). The effect of novel heat exchanger configurations is analyzed and compared with normal helical coil geometry, based on various pitch sizes. Furthermore, the operating parameters of MH storage and HTF are numerically investigated to obtain optimal values. ANSYS Fluent 2020 R2 is utilized for the numerical simulations. Results from this study demonstrate that MH storage performance is significantly improved by using a semi-cylindrical coil heat exchanger (SCHE). The hydrogen absorption duration reduces by 59% compared to a normal helical coil heat exchanger. The lowest coil pitch from SCHE leads to a 61% reduction of the absorption time. In terms of operating parameters for the MH storage with SCHE, all selected parameters provide a major improvement in the hydrogen absorption process, especially the inlet temperature of the HTF.

Evaluation of a Vitamin D Screening and Treatment Protocol Using a Seasonal Calculator in Athletes.

ABSTRACT: Vitamin D is important in musculoskeletal health, and low serum vitamin D concentration is common in athletes. This study implemented a vitamin D screening and supplementation protocol in a cohort of National Collegiate Athletic Association Division I athletes using summer 25-hydroxyvitamin D concentration and a seasonal variation calculator to achieve sufficient vitamin D concentration year-round. After implementation of the Vitamin D Protocol, there was a nonsignificant difference in athletes with sufficient winter vitamin D concentrations (72.6%) compared with summer vitamin D concentrations (66.1%) (P = 0.40). The Seasonal Variation Calculator predicted winter vitamin D concentrations (8 ± 18 ng·mL-1) higher than actual winter vitamin D concentrations (P < 0.01). While most athletes (78%) believed vitamin D was important for athletic performance, athlete compliance to the Vitamin D Protocol was inconsistent. In the future, adjustment of vitamin D screening and supplementation protocols may help athletes achieve sufficient vitamin D status year-round.

Design Features and Rationale of the BEAR-MOON (Bridge-Enhanced ACL Restoration Multicenter Orthopaedic Outcomes Network) Randomized Clinical Trial.

BACKGROUND: BEAR (bridge-enhanced anterior cruciate ligament [ACL] restoration), a paradigm-shifting technology to heal midsubstance ACL tears, has been demonstrated to be effective in a single-center 2:1 randomized controlled trial (RCT) versus hamstring ACL reconstruction. Widespread dissemination of BEAR into clinical practice should also be informed by a multicenter RCT to demonstrate exportability and compare efficacy with bone--patellar tendon-bone (BPTB) ACL reconstruction, another clinically standard treatment. PURPOSE: To present the design and initial preparation of a multicenter RCT of BEAR versus BPTB ACL reconstruction (the BEAR: Multicenter Orthopaedic Outcomes Network [BEAR-MOON] trial). Design and analytic issues in planning the complex BEAR-MOON trial, involving the US National Institute of Arthritis and Musculoskeletal and Skin Diseases, the US Food and Drug Administration, the BEAR implant manufacturer, a data and safety monitoring board, and institutional review boards, can usefully inform both clinicians on the trial's strengths and limitations and future investigators on planning of complex orthopaedic studies. STUDY DESIGN: Clinical trial. METHODS: We describe the distinctive clinical, methodological, and operational challenges of comparing the innovative BEAR procedure with the well-established BPTB operation, and we outline the clinical motivation, experimental setting, study design, surgical challenges, rehabilitation, outcome measures, and planned analysis of the BEAR-MOON trial. RESULTS: BEAR-MOON is a 6-center, 12-surgeon, 200-patient randomized, partially blinded, noninferiority RCT comparing BEAR with BPTB ACL reconstruction for treating first-time midsubstance ACL tears. Noninferiority of BEAR relative to BPTB will be claimed if the total score on the International Knee Documentation Committee (IKDC) subjective knee evaluation form and the knee arthrometer 30-lb (13.61-kg) side-to-side laxity difference are both within respective margins of 16 points for the IKDC and 2.5 mm for knee laxity. CONCLUSION: Major issues include patient selection, need for intraoperative randomization and treatment-specific postoperative physical therapy regimens (because of fundamental differences in surgical technique, initial stability construct, and healing), and choice of noninferiority margins for short-term efficacy outcomes of a novel intervention with evident short-term advantages and theoretical, but unverified, long-term benefits on other dimensions.

Nitrogen addition, not heterogeneity, alters the relationship between invasion and native decline in California grasslands.

The presence of invasive species reduces the growth and performance of native species; however, the linear or non-linear relationships between invasive abundance and native population declines are less often studied. We examine how the amount and spatial distribution of experimental N deposition influences the relationship between non-native, invasive annual grass abundance (Bromus hordeaceus and Bromus diandrus) and a dominant, native perennial grass species (Stipa pulchra) in California. We hypothesized that native populations would decline as invasion increased, and that high nitrogen availability would cause native species to decline at lower invasion levels. We predicted that the rate of population decline would be slower in heterogeneous, compared to homogeneous, environments. We employed a field experiment that manipulated the amount and spatial heterogeneity of N addition across a range of invasive/native-dominated communities. There were strong negative and non-linear associations between level of invasion and S. pulchra proportional change (PC). Stipa pulchra PC was more negative and seedling survival was lower when N was added, and the negative effects of N addition on PC became larger in the final year of the study when S. pulchra had the largest declines. There was not strong evidence showing reduced competition in heterogeneous, compared to homogeneous, N treatments. Soil moisture was similar between S. pulchra and B. hordeaceus plots under ambient N, but B. hordeaceus under added N reduced soil moisture. Under N addition, Bromus spp. take up N earlier, reduce soil moisture, and create dry conditions in which S. pulchra declines.

Implant Distribution Versus Implant Density in Lenke Type 1 Adolescent Idiopathic Scoliosis: Does the Position of the Screw Matter?

STUDY DESIGN: Retrospective study. OBJECTIVE: Previous studies have demonstrated that increased implant density (ID) results in improved coronal deformity correction. However, low-density constructs with strategically placed fixation points may achieve similar coronal correction. The purpose of this study was to identify key zones along the spinal fusion where high ID statistically correlated to improved coronal deformity correction. Our hypothesis was that high ID within the periapical zone would not be associated with increased percent Cobb correction. METHODS: We identified patients with Lenke type 1 curves with a minimum 2-year follow up. The instrumented vertebral levels were divided into 4 zones: (1) cephalad zone, (2) caudal zone, (3) apical zone, and (4) periapical zone. High and low percent Cobb correction groups were compared, high percent Cobb group was defined as percent correction >67%. Total ID, total concave ID, total convex ID, and ID within each zone of the curve were compared between the groups. A multivariable analysis was performed to identify independent predictors for coronal correction. Subsequently increased and decreased thoracic kyphosis (TK) groups were compared, increased TK was defined as post-operative TK being larger than preoperative TK and decreased TK was defined as post-operative TK being less than preoperative TK. RESULTS: The cohort included 68 patients. The high percent Cobb group compared with the low percent Cobb group had significantly greater ID for the entire construct, the total concave side, the total convex side, the apical convex zone, the periapical zone, and the cephalad concave zone. The high percent Cobb group had greater pedicle screw density for the total construct, total convex side, and total concave side. In the multivariate model ID and pedicle screw density remained significant for percent Cobb correction. Ability to achieve coronal balance was not statistically correlated to ID (P = .78). CONCLUSIONS: Increased ID for the entire construct, the entire convex side, the entire concave side, and within each spinal zone was associated with improved percent Cobb correction. The ability to achieve coronal balance was not statistically influence by ID. The results of this study support that increasing ID along the entire length of the construct improves percent Cobb correction.

Staying ahead of the curve: the use of spinopelvic parameters to predict curve progression and bracing success in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To investigate radiographic sagittal and spinopelvic parameters of patients with adolescent idiopathic scoliosis (AIS) treated with bracing and assess differences among those treated successfully and unsuccessfully. AIS is a three-dimensional deformity of the spine, sharing an intricate relationship with pelvic morphology. However, the most relevant predictors of curve progression have historically been coronal parameters and skeletal maturity. Sagittal and spinopelvic parameters have not been thoroughly investigated as predictors of curve progression and brace treatment success. METHODS: Retrospective review of AIS patients who underwent brace treatment. Coronal Cobb angles (CC), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), thoracic kyphosis (TK), lumbar lordosis (LL), and thoracic spinopelvic angles (T1SP, T9SP) were measured prior to initiation of bracing. The sagittal and spinopelvic parameters of patients requiring surgical treatment due to curve progression were compared to those treated successfully with bracing. RESULTS: No significant differences were found for age, race, gender, Risser category (0/1 vs 2/3), initial CC, TK, LL, T1SP, or T9SP between cohorts. The cohort requiring surgery had significantly lower PI (p < 0.001, 42.0 v. 54.6), SS (p < 0.001, 37.0 v. 44.5), and PT (p = 0.003, 5.0 v. 10.2) compared to those successfully treated with bracing. Multivariable models controlling for Risser stage and Initial CC revealed the odds for successful brace treatment increases with an increase in PI (OR = 1.47, CI 1.18-1.83, p < 0.001), SS (OR = 1.26, CI 1.07-1.48, p = 0.006), and PT (OR = 1.43, CI 1.09-1.86, p = 0.006) (Table 3). The odds of successful brace treatment is given per one-unit increase for each radiographic measure after adjusting for Initial CC and Risser sign which were forced into each multivariable model. CONCLUSIONS: Spinopelvic parameters may indicate potential spine adaptability and skeletal maturity. For these reasons, we proposed that spinopelvic parameters may be a potential predictor of curve progression and brace treatment success. Our results demonstrated a higher risk of curve progression with lower PI, PT, or SS which support this hypothesis, however, given the small sample size and high variability, the magnitude of this effect should be viewed with caution and should serve as an impetus to further, larger scale studies to investigate the value spinopelvic parameters in curve progression and bracing efficacy. LEVEL OF EVIDENCE: IV.

Evaluation and Management of Traumatic Conditions in the Athlete.

The athletic training room is filled with a multitude of conditions encompassing many different specialties of medicine. When it comes to traumatic injuries in the training room, many of them are not musculoskeletal in nature. Ultrasound in the training room can help identify serious and subtle solid-organ injury and small pneumothoraces. The discussion of these conditions follows a simple outline that helps identify injury/conditions through a proper history and physical. Evidence-based treatment/management/return to play guidelines are discussed.

Periapical Wires Result in Less Curve Correction Than Pedicle Screw Constructs in Idiopathic Scoliosis.

STUDY DESIGN: Retrospective study. PURPOSE: The objective of this study was to compare percent correction between apical and periapical pedicle screw (PS) and sublaminar wire constructs for Cobb correction and coronal balance correction. OVERVIEW OF LITERATURE: The current gold standard for deformity correction in adolescent idiopathic scoliosis (AIS) are PS constructs. Sublaminar wires provide an alternative means of fixation when PS fixation cannot be safely performed. Two previous studies have compared percent curve correction between sublaminar wires and PSs, with conflicting conclusions. METHODS: The study was a retrospective review of Lenke type 1 curves with minimum follow-up of at least 1 year. Cases were divided into two groups: constructs using apical/periapical sublaminar wires (SL group) versus PS only constructs (PS group). Percent Cobb correction and coronal balance were compared between the two groups at 1 year. A multivariable regression model was used to determine the impact of apical/periapical wires on percent Cobb correction and coronal balance at 1 year when accounting for additional variables. RESULTS: The cohort included 71 patients who were predominantly female (80.2%), with average age of 14.2 years. Only 21 (29.5%) of constructs utilized apical/periapical sublaminar wires. There was a significant difference in percent Cobb correction at 1 year for the PS and SL groups (70.26% vs. 60.09%, p=0.05). No difference was observed in overall coronal balance. A multivariable model revealed that apical/periapical wires were negatively associated with percent Cobb correction at 1 year (coefficient=-8.49, p=0.023), while total implant density of the construct was positively associated with correction (coefficient=24.2, p<0.001). CONCLUSIONS: Use of PSs in the apical and periapical zones resulted in improved percent Cobb correction at 1 year in patients with AIS Lenke type 1 curves. Sublaminar wires remain a useful surgical option and result in equivalent coronal balance compared to PSs.

Gradual Deformity Correction in Blount Disease.

BACKGROUND: Blount disease is a disorder of the posteromedial proximal tibial physis which causes a progressive varus, procurvatum, and internal rotation deformity of the tibia. Untreated, it can cause significant limb malalignment. The goal of this study is to evaluate the results of correction of Blount disease using types of external fixation. METHODS: We conducted a retrospective review of 41 patients (51 limbs) who underwent correction of Blount disease with an Ilizarov external fixator or a Taylor spatial frame (TSF) by a single surgeon. The medial proximal tibial angle (MPTA), mean axis deviation (MAD), posterior proximal tibial angle, and joint line congruence angle (JLCA) were measured on radiographs preoperatively, at frame removal and at final follow-up. RESULTS: The average age at treatment was 9.6 years old, with a mean follow-up time of 34 months. Mean preoperative MPTA, MAD, and JLCA were significantly improved at the time of frame removal as well as at final follow-up with no significant changes in correction between the time of frame removal and final follow-up. There was no difference in MPTA and MAD in patients treated with an Ilizarov frame versus a TSF. MPTA, MAD, and JLCA all significantly improved regardless of the underlying diagnosis (infantile vs. adolescent Blount disease) or history of prior surgical intervention. The most common complication was superficial pin-site infection. CONCLUSIONS: Both Iliazarov and TSF are viable treatment options for infantile and adolescent Blount disease, with the ability to significantly improve both the limb mechanical axis and the mechanical axis of the affected tibia. Correction can be attained regardless of whether patients have previously failed surgical intervention. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

The Use of Distraction Osteogenesis and a Taylor Spatial Frame in the Treatment of a Tibial Shaft Nonunion and Deformity in a Pediatric Patient with Osteopetrosis: A Case Report.

CASE: Osteopetrosis is a heritable disease that causes brittle bones that are prone to fracture. Furthermore, these brittle bones have a poor healing response and a high risk of subsequent refracture. Many treatment strategies have been described for initial fracture stabilization; however, there is a paucity of literature describing treatment of refractures and subsequent deformity. We present the long-term results of a unique case in which we used a circular external fixator, the TAYLOR SPATIAL FRAME (Smith & Nephew), to correct a deformity in a patient with osteopetrosis who suffered multiple refractures of the tibia. CONCLUSION: We propose the potential use of distraction osteogenesis as an option for fracture and deformity treatment in patients with osteopetrosis.

Orthopedic and Surgical Management of the Patient With Duchenne Muscular Dystrophy.

Orthopedic care is an important aspect of the overall management of patients with Duchenne muscular dystrophy (DMD). In addition to progressive muscle weakness and loss of function, patients may develop joint contractures, scoliosis, and osteoporosis, causing fractures; all of these necessitate intervention by a multidisciplinary team including an orthopedic surgeon as well as rehabilitation specialists such as physio- and occupational therapists. The causes of these musculoskeletal complications are multifactorial and are related to primary effects on the muscles from the disease itself, secondary effects from weak muscles, and the related side effects of treatments, such as glucocorticoid use that affect bone strength. The musculoskeletal manifestations of DMD change over time as the disease progresses, and therefore, musculoskeletal management needs change throughout the life span of an individual with DMD. In this review, we target pediatricians, neurologists, orthopedic surgeons, rehabilitation physicians, anesthesiologists, and other individuals involved in the management of patients with DMD by providing specific recommendations to guide clinical practice related to orthopedic issues and surgical management in this setting.

Robotic ecology: Tracking small dynamic animals with an autonomous aerial vehicle.

Understanding animal movements that underpin ecosystem processes is fundamental to ecology. Recent advances in animal tags have increased the ability to remotely locate larger species; however, this technology is not suitable for up to 70% of the world's bird and mammal species. The most widespread technique for tracking small animals is to manually locate low-power radio transmitters from the ground with handheld equipment. Despite this labor-intensive technique being used for decades, efforts to reduce or automate this process have had limited success. Here, we present an approach for tracking small radio-tagged animals by using an autonomous and lightweight aerial robot. We present experimental results where we used the robot to locate critically endangered swift parrots (Lathamus discolor) within their winter range. The system combines a miniaturized sensor with newly developed estimation algorithms to yield unambiguous bearing- and range-based measurements with associated measures of uncertainty. We incorporated these measurements into Bayesian data fusion and information-based planning algorithms to control the position of the robot as it collected data. We report estimated positions that lie within about 50 meters of the true positions of the birds on average, which are sufficiently accurate for recapture or observation. Further, in comparison with experienced human trackers from locations where the signal was detectable, the robot produced a correct estimate as fast or faster than the human. These results provide validation of robotic systems for wildlife radio telemetry and suggest a way for widespread use as human-assistive or autonomous devices.

Minimising the Kullback-Leibler Divergence for Model Selection in Distributed Nonlinear Systems.

The Kullback-Leibler (KL) divergence is a fundamental measure of information geometry that is used in a variety of contexts in artificial intelligence. We show that, when system dynamics are given by distributed nonlinear systems, this measure can be decomposed as a function of two information-theoretic measures, transfer entropy and stochastic interaction. More specifically, these measures are applicable when selecting a candidate model for a distributed system, where individual subsystems are coupled via latent variables and observed through a filter. We represent this model as a directed acyclic graph (DAG) that characterises the unidirectional coupling between subsystems. Standard approaches to structure learning are not applicable in this framework due to the hidden variables; however, we can exploit the properties of certain dynamical systems to formulate exact methods based on differential topology. We approach the problem by using reconstruction theorems to derive an analytical expression for the KL divergence of a candidate DAG from the observed dataset. Using this result, we present a scoring function based on transfer entropy to be used as a subroutine in a structure learning algorithm. We then demonstrate its use in recovering the structure of coupled Lorenz and Rössler systems.

Identifying molecular phenotype of nucleus pulposus cells in human intervertebral disc with aging and degeneration.

Previous study claimed that disc degeneration may be preceded by structure and matrix changes in the intervertebral disc (IVD) which coincide with the loss of distinct notochordally derived nucleus pulposus (NP) cells. However, the fate of notochordal cells and their molecular phenotype change during aging and degeneration in human are still unknown. In this study, a set of novel molecular phenotype markers of notochordal NP cells during aging and degeneration in human IVD tissue were revealed with immunostaining and flow cytometry. Furthermore, the potential of phenotype juvenilization and matrix regeneration of IVD cells in a laminin-rich pseudo-3D culture system were evaluated at day 28 by immunostaining, Safranin O, and type II collagen staining. Immunostaining and flow cytometry demonstrated that transcriptional factor Brachyury T, neuronal-related proteins (brain abundant membrane attached signal protein 1, Basp1; Neurochondrin, Ncdn; Neuropilin, Nrp-1), CD24, and CD221 were expressed only in juvenile human NP tissue, which suggested that these proteins may be served as the notochordal NP cell markers. However, the increased expression of CD54 and CD166 with aging indicated that they might be referenced as the potential biomarker for disc degeneration. In addition, 3D culture maintained most of markers in juvenile NP, and rescued the expression of Basp1, Ncdn, and Nrp 1 that disappeared in adult NP native tissue. These findings provided new insight into molecular profile that may be used to characterize the existence of a unique notochordal NP cells during aging and degeneration in human IVD cells, which will facilitate cell-based therapy for IVD regeneration. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1316-1326, 2016.

Neuromuscular Scoliosis: Current Concepts.

Scoliosis is a common deformity in neuromuscular disorders. This spinal deformity usually presents at an early age, rapidly progresses during growth, and continues to progress even after skeletal maturity. Neuromuscular scoliosis classically involves the entire thoracolumbar spine, often extending to the pelvis and causing pelvic obliquity. Physical examination can be challenging, but it is important to assess the flexibility of the spinal curve and associated joint contractures. Upright anteroposterior and lateral radiographs are the preferred imaging. When formulating a treatment plan, it is important to take into account not only the degree of curvature, but also each patient's needs and quality of life, the potentially high perioperative complication rates, and the natural history of the underlying neuromuscular disorder. Different neuromuscular conditions behave differently and should therefore be treated differently. With the exception of steroids for Duchenne muscular dystrophy, bracing remains the only reliable nonoperative intervention available. Preoperative optimization of medical comorbidities is crucial given the relatively high complication rate. Posterior segmental instrumentation has revolutionized the surgical management of neuromuscular scoliosis and is the most commonly used technique today. Despite reported improvement in postoperative quality of life, there are several limitations with currently used outcome measures that prevent a well-informed discussion on the outcomes after surgery.

Ultrasound for screening and management of developmental dysplasia of the hip.

Developmental dysplasia of the hip (DDH) is a significant cause of disability in children and young adults. Early detection of this condition allows for nonoperative treatment, but the efficacy of DDH screening programs has not been clearly established. This article discusses the role of ultrasound in the diagnosis and management of DDH.

A new non-enzymatic method for isolating human intervertebral disc cells preserves the phenotype of nucleus pulposus cells.

Cells isolated from intervertebral disc (IVD) tissues of human surgical samples are one of potential sources for the IVD cellular therapy. The purpose of this study was to develop a new non-enzymatic method, "tissue incubation", for isolating human IVD cells. The IVD tissues of annulus fibrosus (AF) and nucleus pulposus (NP) were incubated separately in tissue culture flasks with culture medium. After 7-10 days incubation, cells were able to migrate out of IVD tissues and proliferate in vitro. After 3-4 weeks culture, expanded cells were harvested by trypsinization, and the remaining tissues were transferred to a new flask for another round of incubation. The molecular phenotype of IVD cells from juvenile and adult human samples was evaluated by both flow cytometry analysis and immunocytochemical staining for the expression of protein markers of NP cells (CD24, CD54, CD239, integrin α6 and laminin α5). Flow cytometry confirmed that both AF and NP cells of all ages positively expressed CD54 and integrin α6, with higher expression levels in NP cells than in AF cells for the juvenile group sample. However, CD24 expression was only found in juvenile NP cells, and not in AF or older disc cells. Similar expression patterns for NP markers were also confirmed by immunocytochemistry. In summary, this new non-enzymatic tissue incubation method for cell isolation preserves molecular phenotypic markers of NP cells and may provide a valuable cell source for the study of NP regeneration strategies.

Osteonecrosis of the femoral head in childhood malignancy.

PURPOSE: Children undergoing chemotherapeutic treatment of malignancies have up to a 9 % incidence of osteonecrosis. The purpose of this article is to determine the time from initiation of chemotherapy to the onset of symptoms and the diagnosis of osteonecrosis of the femoral head in this patient population. METHODS: A retrospective review of the records of 18 patients (29 hips) under 21 years of age with both a diagnosis of osteonecrosis of the femoral head and childhood onset malignancy was undertaken to determine the time from initiation of chemotherapy to the onset of symptoms and diagnosis of osteonecrosis of the femoral head. RESULTS: Mean time from initiation of chemotherapy to the onset of pain was 18.8 months (8.0-49.1). The mean time from development of pain to diagnosis of osteonecrosis was 3.9 months (-13.1 to 25). The mean overall time from initiation of chemotherapy to diagnosis of osteonecrosis was 22.7 months (9.0-54.1). 11/18 patients had bilateral disease. 16/18 patients (21/29 hips) had already progressed to stage 4 osteonecrosis at the time of diagnosis. CONCLUSIONS: There was a high incidence of stage 4 or greater osteonecrosis at the time of diagnosis. Providers caring for these patients should be aware of the potential for osteonecrosis, and the need for prompt diagnosis and referral to an orthopedic surgeon. Screening with advanced imaging studies may be warranted for children undergoing chemotherapeutic regimens for childhood malignancy to prevent delay in the diagnosis and management of this process so that joint preservation therapies remain an option.

Radiographic outcomes of ring external fixation for malunion and nonunion.

Ring external fixators such as the Ilizarov external fixator (IEF) and Taylor Spatial Frame (TSF) have revolutionized management of limb deformity. This study examines radiographic outcomes for treatment of malunions and nonunions with secondary emphasis on comparing radiographic union rates of TSF and IEF. A retrospective chart and radiograph review was performed. Fifty-four patients were included. Most injuries were in the tibia (96%). Fifty patients (93%) achieved radiographic union, two patients required further fixation, and two patients elected to undergo amputation. The preoperative coronal deformity improved from a mean of 12° (range, 0°-41°) to within 3° anatomic. Sagittal deformity improved from a mean of 11° (range, 0°-49°) to within 5° anatomic with some patients intentionally left in recurvatum to accommodate plantarflexion contractures. Limb length discrepancies were corrected to within 1 cm. Twenty-five patients experienced complications (mostly superficial pin tract infections). No statistically significant differences in the radiographic outcomes of TSF compared to IEF were identified.

Differential expression of galectin-1 and its interactions with cells and laminins in the intervertebral disc.

Galectin-1 (Gal-1), an endogenous ß-galactoside-binding protein, binds to laminins, which are highly expressed in the nucleus pulposus (NP) of the intervertebral disc (IVD). The objective of this study is to evaluate the expression of Gal-1 protein in IVD tissues during aging and the effect of Gal-1 on IVD cell adhesion to laminins. Tissues from rat, porcine, and human (scoliosis or disc degeneration) IVDs were used to evaluate Gal-1 expression via immunostaining, RT-PCR, and Western blot analysis. Attachment of isolated IVD cells (porcine and human) on select laminin isoforms (LM-111 and LM-511) was compared with/without pre-incubation with exogenous Gal-1. A biotinylated Gal-1(B-Gal-1) was used to evaluate for binding to IVD cells and to select for IVD cells by magnetic activated cell sorting (MACS). NP cells expressed high levels of Gal-1 protein as compared to anulus fibrosus (AF) cells in immature tissues, while exogenous Gal-1 increased both NP and AF cell attachment to laminins and exhibited a similar binding to both cell types in vitro. With aging, Gal-1 levels in NP tissue appeared to decrease. In addition, incubation with B-Gal-1 was able to promote the retention of more than 50% of IVD cells via MACS. Our results provide new findings for the presence and functional role of Gal-1 within IVDs. Similar staining patterns for Gal-1 and LM-511 in IVD tissue suggest that Gal-1 may serve as an adhesion molecule to interact with both cells and laminins. This MACS protocol may be useful for selecting pure IVD cells from mixed cells of pathological tissue.