Implementing the AAOS Guidelines for Screening of Developmental Dysplasia of the Hip Before the Age of 6 Months in Taiwan.

BACKGROUND: The prevalence of developmental dysplasia of the hip (DDH) has been considered to be low in East Asia, but this may be incorrect because of inconsistent diagnostic definitions and testing criteria. In 2015, the AAOS released guidelines for systematic screening for DDH in newborns. We implemented these guidelines and compared DDH incidence and outcomes before and after their implementation. METHODS: We used a historic comparison cohort of newborns with DDH between July 2015 and May 2017 before guideline implementation (the preguideline group); their data were retrieved using electronic medical records. In this group, the newborns received general hip screening without systemic follow-up. The postguideline group included newborns who were screened for hip dysplasia and followed up per the AAOS guidelines between July 2017 and May 2019. Their data were prospectively collected. The primary outcome in the postguideline group was DDH incidence. Other outcomes included rates of referral, surgery, and complications, and DDH prognosis. RESULTS: The preguideline and postguideline groups included 3534 and 2663 newborns, respectively, of whom 49 (1.1%) and 225 (8.4%), respectively, were referred to the pediatric orthopaedic clinic enrolled. In the postguideline group, 35 patients were diagnosed as having DDH (incidence: 1.3%, 95% CI: 0.8%-1.9%). Both the incidence and referral rates were significantly higher in the postguideline group than in the preguideline group. Furthermore, the mean age at referral was 6.7±10.06 months and 0.9±0.25 months in the preguideline and postguideline groups, respectively, indicating a potential for early treatment in the postguideline group. Finally, the female sex was identified as a risk factor for residual hip dysplasia at 6 months of age. CONCLUSION: DDH incidence in East Asia seems comparable to that in Western countries. Implementing the AAOS guidelines increased the diagnosis rate and opportunity for early treatment initiation, thus potentially avoiding surgical intervention. Nevertheless, residual DDH may be detected in some patients at 6 months of age, particularly in female infants. LEVEL OF EVIDENCE: Level IV.

Dynamic Pressure Stimulation Upregulates Collagen II and Aggrecan in Nucleus Pulposus Cells Through Calcium Signaling.

STUDY DESIGN: An in vitro study to investigate the effect of pressure stimulation on nucleus pulposus (NP) cells. OBJECTIVE: The aim of this study was to investigate the question whether physical stimulation can be leveraged to enhance extracellular matrix (ECM) synthesis as a preventive measure for intervertebral disc (IVD) degeneration. SUMMARY OF BACKGROUND DATA: ECM plays an important role in regulating hydration and pressure balance of the IVD. METHODS: Cellular stimulation devices with different pressurizing protocols were used to create a pressurized environment to cells cultures. The setup was used to mimic the pressurized conditions within IVD to investigate the effect of pressure stimulation on NP cells. RESULTS: Pressure stimulation at 300 kPa can enhance the synthesis of ECM proteins Collagen II and aggrecan in NP cells and the effect of dynamic pressure stimulation outperformed the static one. The difference between static and dynamic pressure stimulation was due primarily to calcium signaling activated by pressure fluctuation. The superior effect of dynamic pressure holds for a wide range of stimulation durations, relating to the range of spontaneous calcium oscillations in NP cells. CONCLUSION: The results link mechanotransduction to the downstream ECM protein synthesis and suggest slow exercises that correspond with spontaneous calcium oscillations in NP cells can be effective to stimulate ECM synthesis in IVD.

Halter Traction for the Treatment of Atlantoaxial Rotatory Fixation.

BACKGROUND: Atlantoaxial rotatory fixation (AARF) comprises a spectrum of abnormal rotational relationships between C1 (atlas) and C2 (axis). We aimed to evaluate the efficacy and long-term clinical outcomes of halter traction in treating patients diagnosed with primary AARF. METHODS: We included patients <18 years of age who presented with new-onset painful torticollis, neck pain, and sternocleidomastoid muscle spasm, had an AARF diagnosis confirmed by use of 3-dimensional dynamic computed tomography, received in-hospital cervical halter traction under our treatment protocol, and were followed for ≥12 months. Radiographic and long-term clinical outcomes were analyzed. RESULTS: A total of 43 patients (31 male and 12 female; average age of 7.9 years) satisfied the inclusion criteria. There were 5 acute, 6 subacute, and 32 chronic cases. The mean duration of initial symptoms prior to treatment was 12.1 weeks. Thirty-seven (86.0%) of the patients experienced previous minor trauma, and 6 (14.0%) had a recent history of upper-respiratory infection (Grisel syndrome). The mean duration of in-hospital traction was 17.6 days. The mean follow-up period was 8.5 years. Forty-two (97.7%) of the patients achieved normal cervical alignment after treatment. One patient (2.3%) had recurrence and received a second course of halter traction, with cervical alignment restored without any surgical intervention. No neurological deficits were noted during or after the treatment. No major complications were observed. CONCLUSIONS: Normal anatomy and restoration of cervical alignment can be achieved by cervical halter traction in most cases of AARF. LEVELS OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Pulmonary function and health-related quality of life in patients with early onset scoliosis after repeated traditional growing rod procedures.

PURPOSE: The purpose of this study was to investigate pulmonary function and health-related quality of life after traditional growing rod (TGR) procedures. METHODS: Between January 2006 and December 2017, a retrospective observational study of 17 early onset scoliosis (EOS) patients with a mean follow-up of 6.2 years (2.3 to 10.4) was conducted. The forced expiratory volume in one second (FEV1), expiratory forced vital capacity (FVC) and 24-Item Early Onset Scoliosis Questionnaire (EOSQ-24) score before the index surgery and at last follow-up were investigated. RESULTS: The mean percentage of predicted FEV1 improved from 50% (20% to 86%) to 53% (15% to 80%; p = 0.08); and the mean percentage of predicted FVC improved from 51% (24% to 81%) to 55% (25% to 89%; p = 0.06). The mean EOSQ-24 score was 78.2 (58 to 90) preoperatively and 77.2 (55 to 88) at last follow-up, there was no statistical difference (p = 0.70). The subdomain scores of pulmonary function (p < 0.01) and daily living (p < 0.01) significantly improved, whereas the subdomain scores of pain (p < 0.01), emotion (p < 0.01) and satisfaction (p = 0.02) significantly declined at last follow-up. CONCLUSION: The TGR procedure was associated with stable pulmonary function and decline in EOSQ-24 pain, emotion and satisfaction scores. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Health-related quality of life in children and adolescent with different types of scoliosis: A cross-sectional study.

BACKGROUND: The health-related quality of life (HRQoL) was affected in children and adolescents with scoliosis. However, there was lack of study to compare the HRQoL among patients with different types of scoliosis. We aimed to investigate whether the HRQoL differs among patients with idiopathic, congenital, neuromuscular, and syndromic scoliosis. METHODS: Children and adolescents with scoliosis were recruited from a single tertiary hospital. The HRQoL, as assessed by the child health questionnaire 50-item parent form, was compared with a reference health sample group using the effect size (ES). Intergroup differences related to scoliosis subtype and severity were explored. RESULTS: A total of 67 participants with scoliosis (24 idiopathic, 15 congenital, 15 neuromuscular, and 13 syndromic) were analyzed. The HRQoL in patients with neuromuscular scoliosis was affected the most, in both physical (ES range: 0.97-2.4) and psychosocial domains (ES range: 0.92-2.58). To a lesser extent, the physical (ES range: 0.99-1.13) and psychosocial (ES range: 0.8-1.18) domains were also affected in patients with syndromic scoliosis. The domains of family activities (ES = 1.1), role/social-emotional/behavioral (ES = 0.99), general health perception (ES = 0.94), and self-esteem (ES = 0.87) were affected in patients with idiopathic scoliosis. In contrast, only the general health perception domain (ES = 1.27) was affected in patients with congenital scoliosis. Scoliosis severity correlated with scores in the physical domains and some psychosocial domains, while treatment type correlated with scores in the physical domains only. Scoliosis subtype and severity both affected the physical and psychosocial domains, with a stronger impact for subtype. CONCLUSION: Differences in the HRQoL exist among scoliosis subtypes, with neuromuscular scoliosis being most affected. Although the scoliosis subtype and severity both affect the HRQoL, the subtype is more influential than severity.

Plasma Deposition and UV Light Induced Surface Grafting Polymerization of NIPAAm on Stainless Steel for Enhancing Corrosion Resistance and Its Drug Delivery Property.

When stainless steel is implanted in human bodies, the corrosion resistance and biocompatibility must be considered. In this study, first, a protective organic silicone film was coated on the surface of stainless steel by a plasma deposition technique with a precursor of hexamethyldisilazane (HMDSZ). Then, ultraviolet (UV) light-induced graft polymerization of N-isopropylacrylamide (NIPAAm) and acrylic acid (AAc) in different molar ratios were applied onto the organic silicone film in order to immobilize thermos-/pH-sensitive composite hydrogels on the surface. The thermo-/pH-sensitive composite hydrogels were tested at pH values of 4, 7.4 and 10 of a phosphate buffer saline (PBS) solution at a fixed temperature of 37 °C to observe the swelling ratio and drug delivery properties of caffeine which served as a drug delivery substance. According to the results of Fourier Transformation Infrared (FTIR) spectra and a potential polarization dynamic test, the silicone thin film formed by plasma deposition not only improved the adhesion ability between the substrate and hydrogels but also exhibited a high corrosion resistance. Furthermore, the composite hydrogels have an excellent release ratio of up to 90% of the absorbed amount after 8h at a pH of 10. In addition, the results of potential polarization dynamic tests showed that the corrosion resistance of stainless steel could be improved by the HMDSZ plasma deposition.

Localization of the trunk muscles using musculoskeletal ultrasound guidance for pedicle screw stimulation during spine surgery.

The precise placement of recording electrodes at the relevant myotome is mandatory while performing pedicle screw stimulation (PSS) during spine surgery; however, their placement at trunk muscles is challenging. This study aimed to determine whether ultrasound guidance is useful for trunk muscle localization for PSS during spine surgery. A retrospective clinical study was conducted from a prospective database. Eighty-four patients eligible for spine surgery were recruited. Ultrasound was used to localize the intercostal, rectus abdominis, and internal oblique and psoas muscles if pedicle screw placement was performed at T3 to L1. After the operation, patients were examined for any new neurological deficits related to this procedure, and computed tomography was performed to check screw position if indicated. Four to 22 pedicle screws were used for spinal fixation. The threshold of stimulus to obtain a compound muscle action potential ranged from 1.29 to >20mA during PSS. Six of our patients sustained new postoperative deficits, and only one case was related directly to pedicel screw misplacement. Loss of motor evoked potential (MEP) over both the lower limbs was noted during pedicle screw placement, and the stimulus threshold during PSS were 1.29mA at the left T9 and 3.8mA at the right T5 level. MEP remained absent at the end of surgery despite removal of those two screws. The patient woke with significant weakness in both lower limbs (muscle power 0/0) and voiding difficulty. Fortunately, he regained walking ability 4.5months later after intensive rehabilitation therapy.

Concomitant hip and distal radius fractures.

BACKGROUND: Concomitant ipsilateral hip and distal radius fractures are uncommon, and little research has been published about these injuries. Our aim was to evaluate the characteristics and results of treatment for these injuries. METHODS: Between 2006 and 2012, 35 concomitant hip and distal radius fractures were identified, comprising the study group. The characteristics and results of treatment for these injuries were evaluated and analyzed. Another matched control group with isolated hip fractures was collected for comparison of patient characteristics, fall mechanism, fracture pattern, bone density, and functional recovery. RESULTS: For the patients with concomitant fractures, the average age was 77.6 years, and the female-to-male ratio was 6:1 (30:5). The majority (91.4%) of patients sustained ipsilateral injuries. Among the controlled pairs, 20 (57.1%) patients in the study group sustained a backward fall, and 25 (71.4%) patients in the control group had a sideways fall. With respect to the pattern of hip fracture, 22 (62.9%) patients in the study group had femoral neck fractures and 20 (57.1%) patients in the control group had pertrochanteric fractures. The average hospital stay was 15.3 days in the study group versus 10.2 days in the control group. Twenty-five (71.4%) patients in the study group and 27 (77.1%) patients in the control group had osteoporosis. The average Barthel index score was 75.1 in the study group and 75.7 in the control group. CONCLUSION: Concomitant hip and distal radius fractures were generally ipsilateral and involved the femoral neck after a backward fall. These patients were younger than and not more osteoporotic than the population with isolated hip fractures; however, the hospital stay was significantly increased. The functional outcome was not influenced by concomitant wrist fracture.

Concomitant tibial shaft and posterior malleolar fractures can be readily diagnosed from plain radiographs: A retrospective study.

BACKGROUND: Concomitant tibial shaft and posterior malleolar fractures (PMFs) are often encountered in clinical settings. Plain films were reviewed for concomitant PMF, and fracture patterns were analyzed by focusing on the integrity of the fibula and the location of the fibular fracture. METHODS: A retrospective review of patients who presented with tibial shaft fractures between January 2005 and January 2010 was performed. Patients were included if they were at least 18 years of age and had a tibial diaphyseal fracture. Exclusion criteria were age less than 18 years, previous surgery on the same leg, and pathological fractures. Medical records were reviewed for information on injury mechanisms. Pre- and post-operative radiographs were analyzed for PMFs, tibial fracture pattern, fibular integrity, fibular fracture pattern, treatment type, and time to fracture union. Descriptive statistical tests were used. RESULTS: Among 240 patients, there were 20 cases (15 male and 5 female) of concomitant PMF, all detected in lateral radiograph views. The incidence of PMF was 8.3%. Most patients had a motorcycle injury (n = 15, 75%). Distal tibia spiral fracture was the most common fracture pattern (85%) and there was no proximal tibia fracture (0%). Combined fibular fractures were found in 17 patients (85%). There were nine proximal fibular fractures (45%). Intact fibulas were found in three patients (15%). Only one PMF was treated with screw fixation. All PMFs showed radiographic evidence of healing within 5 months post-operatively. CONCLUSION: We recommend careful radiographic examination to evaluate PMF, especially in patients with distal tibial spiral fractures combined with proximal fibular fractures or intact fibulas.

Role of autologous bone graft in the surgical treatment of atrophic nonunion of midshaft clavicular fractures.

A retrospective study was conducted to evaluate the role of autologous bone graft in treating atrophic nonunion of midshaft clavicle fracture with a limited-contact dynamic compression plate (LC-DCP). Between 1995 and 2008, sixty cases of atrophic nonunion of midshaft clavicle fractures were managed with open reduction and internal fixation with an LC-DCP. The cases were separated into 2 groups to evaluate the effect of autologous bone graft in the enhancement of bone union. In group 1 (n=24), autologous bone graft was not used; in group 2 (n=36), autologous bone graft was used. Pre- and postoperative management were the same in both groups. Radiographic results and functional outcomes according to the Quick Disability of Arm, Shoulder, and Hand score were evaluated. Average follow-up was 25.2 months (range, 24-48 months).No statistically significant difference was found between the 2 groups regarding demography and preoperative functional scores (P>.05). Operative time and hospital stay were statistically significant longer in group 2 (P<.001), and donor site pain was apparent in group 2. All 60 patients had uneventful union. No statistically significant differences were found between the 2 groups regarding union time (average, 9.8 weeks in group 1 and 9.2 weeks in group 2) and postoperative functional scores (P>.05). Limited-contact dynamic compression plate fixation is an effective method for treating atrophic nonunion of midshaft clavicle fractures. Autologous bone graft was not needed.

Muscarinic acetylcholine receptors present in human osteoblast and bone tissue.

Acetylcholine is the predominant neurotransmitter in the neuromuscular junction, and a role in bone has been postulated. The expression of nicotinic receptors has been reported in osteoblasts, but the expression and function of muscarinic receptor in bone remain obscure. In this study, we investigated the expression and functional activities of muscarinic receptor subtypes in human osteoblast cell lines and animal and human bone tissue. The mRNA levels of muscarinic receptor subtypes were detected by reverse-transcription polymerase chain reaction. We found that muscarinic subtypes m1, m2, m3, m4, and m5 were expressed at different levels in human osteosarcoma HOS cells, rat femur, and human rib bone tissue; m1, m4, m5 were in cultured mouse femur bone cells and cultured mouse calvarial bone cells; m2, m3, m4 were in bovine bone. The mRNA of neuronal markers, light-, medium- and heavy-neurofilament, was not found in human bone tissues to exclude the possible contamination from neuronal tissue. Methacholine induced an elevation in cytosolic calcium concentration and proliferation in HOS cells. Both effects were blocked by atropine. We conclude that muscarinic receptor is present in bone tissue to evoke calcium signaling and modulate cell proliferation. Different muscarinic receptor subtypes are distributed in various parts of the animal skeletal system including the different species and bone portions. Bone remodeling involving osteoblast proliferation leads the possibilities that muscarinic receptor may play roles in bone remodeling.

Comparing the shoulder impingement kinematics between circular and pumping strokes in manual wheelchair propulsion.

PURPOSE: The study aimed to investigate the glenohumeral kinematic difference between the circular and pumping strokes in manual wheelchair users. METHOD: This is a repeated measures design with randomised testing conditions. We recruited 10 manual wheelchair users and asked them to perform both the pumping and circular strokes on a stationary roller system. We used the Zebris motion analysis system to collect the 3-dimension glenohumeral motion data. RESULTS: The pumping and the circular strokes were similar in the starting and ending positions in the sagittal plane. However, the pumping stroke started at a significantly larger abduction and internal rotation and ended with a significantly larger abduction and even larger internal rotation, it also traveled more ranges in all three planes and stayed longer in the combined positions of rotation/flexion and rotation/abduction as compared to the circular stroke. CONCLUSIONS: The circular stroke appeared more advantageous than the pumping technique in the injury prevention prospect because the latter involved more flexion, abduction and internal rotation of the shoulder, which could add more impingement stresses to the joint. Clinicians may need to prescribe proper wheelchair propulsion techniques for their clients to avoid accumulating impingement stresses in the shoulder joints.

Nucleotide-binding domain of phosphoglycerate kinase 1 reduces tumor growth by suppressing COX-2 expression.

Phosphoglycerate kinase 1 (PGK-1) is a multifunctional protein that is involved in the glycolytic pathway and the generation of the angiogenesis inhibitor angiostatin. In a previous study, we showed that the overexpression of full-length PGK-1 in Lewis lung carcinoma (LLC-1) can reduce tumor growth in vivo by downregulation of COX-2 expression. Phosphoglycerate kinase 1 has two functional domains: a catalytic domain (CD); and a nucleotide-binding domain (NBD). To identify the functional domain of PGK-1 responsible for its antitumor effects, we evaluated the tumorigenicity of LLC-1 cells overexpressing full-length PGK-1 (LLC-1/PGK), CD (LLC-1/CD), and NBD (LLC-1/NBD). Although no difference in tumor cell growth was observed in vitro, the tumor invasiveness was reduced in the LLC-1/PGK, LLC-1/CD, and LLC-1/NBD cells compared to parental LLC-1 cells in vivo. In addition, in vivo tumor growth retardation by LLC-1/CD and LLC-1/NBD cells was observed, similar to that by LLC-1/PGK cells. However, the reduced stability of COX-2 mRNA and downregulation of the COX-2 protein and its metabolite, prostaglandin E2, was only found in LLC-1/PGK and LLC-1/NBD cells. Low levels of COX-2 were also observed in the tumor mass formed by the modified cells when injected into mice. The results indicate that COX-2 suppression by PGK-1 is independent of its catalytic activity. COX-2 targeting by PGK-1 can be attributed to its NBD and is probably a result of the destabilization of COX-2 gene transcripts brought about by the mRNA-binding property of PGK-1.

A 3D mathematical model to predict spinal joint forces for a child with spina bifida.

Children with spina bifida (SB) can exhibit excessive arm swing, trunk sway, and pelvic tilt during walking. To understand the relationship between abnormal low back forces (LBF) and gait disorders in SB, we derived a mathematical model for evaluating LBF in this population. One unimpaired child and a child with SB were tested. A 3D motion analysis system and force plate were used to collect kinematic and ground reaction force data during walking. A mathematical model created using MATLAB software was used to calculate LBF for each child. The LBF for the child with SB was three times greater in the medio-lateral direction than for the unimpaired child. In the anterior-posterior direction, the LBF for the child with SB acted mostly towards the anterior trunk. In addition, the LBF of the child with SB increased by 24.5% of body weight at the fastest walking speed.

Prospective analysis of a new minimally invasive technique for paediatric Gartland type III supracondylar fracture of the humerus.

OBJECTIVE: The purpose of this study was to introduce a minimally invasive surgery using mosquito forceps for achieving the reduction of severely displaced supracondylar fracture of the humerus in children and evaluate the clinical outcome. MATERIALS AND METHODS: Gartland type III supracondylar fractures of the humerus in children under the age of 12 were analysed from January 2000 to January 2007 at our institute. The control group cases were selected by successful reduction using the standard technique described by Rockwood and Wilkins (2001). The others composed the study group. This study included chart reviews, radiographic images of both the antero-posterior and the lateral views, physical examination, and Mayo elbow performance index scores preoperative, postoperative, and final follow-up. RESULTS: Evaluations were completed for 42 cases. The mean age was 6.9 years and the group consisted of 23 boys and 19 girls. The mean follow-up time was 34.5 months. Twenty-six cases were of injuries to the left side, and 16 were of injuries to the right. The Mayo elbow performance index score was excellent in both groups. Operation time in the control and study groups was 46 and 79min, respectively. There was one case of iatrogenic ulnar nerve injury each in the study and control group. One case of loss of reduction and another with a combination of ulnar nerve injury and loss of reduction were noted in the control group. All four cases had an excellent final outcome. No mosquito-forceps-related complication was found, and in the final follow-up, no cubitus varus was found. CONCLUSION: Minimally invasive surgery with the assistance of mosquito forceps for the reduction of severely displaced supracondylar fracture of the humerus in children was shown to be a safe and effective alternative method. The final functional outcome was the same as that of the standard technique.

Using an optimization approach to design an insole for lowering plantar fascia stress--a finite element study.

Plantar heel pain is a commonly encountered orthopedic problem and is most often caused by plantar fasciitis. In recent years, different shapes of insole have been used to treat plantar fasciitis. However, little research has been focused on the junction stress between the plantar fascia and the calcaneus when wearing different shapes of insole. Therefore, this study aimed to employ a finite element (FE) method to investigate the relationship between different shapes of insole and the junction stress, and accordingly design an optimal insole to lower fascia stress.A detailed 3D foot FE model was created using ANSYS 9.0 software. The FE model calculation was compared to the Pedar device measurements to validate the FE model. After the FE model validation, this study conducted parametric analysis of six different insoles and used optimization analysis to determine the optimal insole which minimized the junction stress between plantar fascia and calcaneus. This FE analysis found that the plantar fascia stress and peak pressure when using the optimal insole were lower by 14% and 38.9%, respectively, than those when using the flat insole. In addition, the stress variation in plantar fascia was associated with the different shapes of insole.

Isometric measurement of wrist-extensor power following surgical treatment of displaced lateral condylar fracture of the humerus in children.

Muscle disability is a common sequel after fracture management. Previous research has shown divergent results concerning muscle-power recovery after bone healing. This study has investigated the muscle function of wrist extensors after lateral condylar fracture in children, as evaluated by a hand-held dynamometer and compared with sex- and age-matched children. From 1999 to 2004, 20 patients (13 boys and seven girls; mean age: 9 years and 4 months) with displaced lateral condylar fracture of the humerus were treated by open reduction and internal fixation with Kirschner wires (K-wire). The duration of K-wire fixation was 35 days and the mean follow-up time was 50 months. A total of 180 healthy age-, sex- and weight-matched children were used as control groups. A paired Student's test was applied for the analysis of statistical significance. The range of motion of the elbow and radiographic findings were not significantly different between the injured limb and normal control groups. The maximum isometric power of wrist-extensor muscles after surgical treatment of lateral condylar fracture of the humerus in final follow-up was not statistically different from that in the normal control children. Muscle power therefore recovers to its normal status after the healing of lateral condylar fracture of the humerus in children.

Shape modification of the Boston brace using a finite-element method with topology optimization.

STUDY DESIGN: Using a finite-element (FE) method to reshape the Boston brace, and evaluating the correction effect of the modified Boston brace in terms of Cobb angle. OBJECTIVE: This study aimed to reduce the weight of the Boston brace using a FE method with topology optimization. SUMMARY OF BACKGROUND DATA: The Boston brace is widely used to correct an abnormal spinal curve in adolescent idiopathic scoliosis. However, patients wearing the brace usually complain about discomfort caused by its bulkiness. METHODS: An FE model of a traditional Boston brace was constructed using the software ANSYS 9.0. The loading condition was taken from an X-sensor measuring contact pressures between torso and brace. Topology optimization was conducted to modify the Boston brace. Three patients wearing a traditional brace and then the modified brace were examined in terms of Cobb angle. RESULTS: For the patient with King Type III scoliosis, this modified brace was able to offer the same correction effect as the traditional brace, but the modified brace was lighter by about 12.4%, with the potential to be up to 18% lighter. CONCLUSION: Based on the traditional Boston brace, this FE model, combined with topology optimization, can effectively estimate redundant material distribution and accordingly custom-design a lighter brace without any loss of its corrective effect.

Finite element analysis of the lumbar spine with a new cage using a topology optimization method.

In recent years, degenerative spinal instability has been effectively treated with a cage. However, little attention is focused on the design concept of the cage. The purpose of this study was to develop a new cage and evaluate its biomechanical function using a finite element method (FEM). This study employed topology optimization to design a new cage and analyze stress distribution of the lumbar spine from L1 to L3 with a new cage by using the commercial software ANSYS 6.0. A total of three finite element models, namely the intact lumbar spine, the spine with double RF cages, and with double new cages, were established. The loading conditions were that 10Nm flexion, extension, lateral bending, and torsion, respectively, were imposed on the superior surface of the L1 vertebral body. The bottom of the L3 vertebral body was constrained completely. The FEM estimated that the new cage not only could be reduced to 36% of the volume of the present RF cage but was also similar in biomechanical performance such as range of motion, stress of adjacent disc, and lower subsidence to the RF cage. The advantage of the new cage was that the increased space allowed more bone graft to be placed and the cage saved material. The disadvantage was that stress of the new cage was greater than that of the RF cage.

Human foamy virus bel1 sequence in patients with autoimmune rheumatic diseases.

Since the association between human foamy virus (HFV) with rheumatic autoimmune diseases remains controversial, this study was designed to determine the relationship between HFV and systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), or progressive systemic sclerosis (PSS). The bel1 and Pol sequences of HFV were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) in plasma and by PCR in peripheral blood mononuclear cells (PBMC) from patients with SLE, RA, and PSS. Antibodies against Bel1 and Pol were assessed by enzyme-linked immunosorbent assay. Active HFV infections were detected by a Bel1-responsive indicator cell line. The bel1 sequence was detected in the plasma (SLE 59, RA 32, and PSS 63%) and PBMC (SLE 54, RA 71, and PSS 57%). However, active HFV infection existed only in patients with the bel1 sequence in both plasma and PBMC. In SLE patients, antibodies against Bel1 (7.1%) and Pol (4.5%) were also detected. The results suggest a possible association between HFV infection and these autoimmune rheumatic diseases.