Titanium Powder Coating Using Metal 3D Printing: A Novel Coating Technology for Cobalt-Chromium Alloy Implants

BACKGROUND: Three-dimensional (3D) printing with a direct metal fabrication (DMF) technology has been innovatively introduced in the field of surface treatment of prostheses. The purpose of this study was to determine whether such modifications on the surface of cobalt-chromium (CoCr) alloy by titanium powder coating using DMF improves the osseointegration ability of CoCr alloy. METHODS: We compared the in vitro and in vivo ability of cells to adhere to DMF-coated CoCr alloy with machining. Biological and morphological responses to human osteoblast cell lines were examined by measuring cell proliferation rate and observing expression of actin filament. For in vivo study, we inserted different specimens in each medulla of the distal femurs of rabbit. After 3 months, the distal femurs were harvested, and a push-out test and histomorphometric analyses were performed. RESULTS: The cell proliferation rate and cell adhesion in the DMF group were higher compared with those in the machined group. Human osteoblast cells on the DMF-coated surface were more strongly adhered and well-proliferated compared with those on the other surface. In the in vivo test, there was a significant difference in the ultimate shear strength between the DMF and machined groups (2.49 MPa vs. 0.87 MPa, respectively, p = 0.001). In the histomorphometric analysis, there was a significant difference in the mean bone-to-implant contact percentages between the DMF and machined groups (72.3 ± 6.2% vs. 47.6 ± 6.9%, respectively, p < 0.001). CONCLUSION: Titanium coating of CoCr alloy with 3D metal printing provides optimal surface characteristics and a good biological surface both in vitro and in vivo.

Comparative Study of Peripheral Rim Fixation Using Jumbo Cup in Revisional Hip Arthroplasty / 대한고관절학회지

PURPOSE: It is challenging procedure to revise acetabular component in acetabulum with severe bone defect or deformity. The jumbo cup is good option for revisional arthroplasty in large bone defect. The purpose of this study is to compare the prognosis of revisional total hip arthroplasty using jumbo cup with peripheral rim fixation and no rim fixation. MATERIALS AND METHODS: We included the patients who had performed acetabular revisional total hip arthroplasty from January 2002 to March 2015 in our institute. Total of 51 hips (51 patients) were included. The mean follow up period was 51 months (range, 12 to 154 months) and mean age was 60.7 years (range, 30 to 81 years). We divided into two groups (peripheral rim fixation group and no rim fixation group) by anteroposterior and lateral plain radiograph. We compared survival rate, hip center change and clinical outcomes between two groups. RESULTS: There were 37 patients in peripheral rim fixation group and 14 patients in no rim fixation group. There was one patient who had aseptic loosening necessary to re-revision in rim fixation group and 3 patients in no rim fixation group. And one patient had superficial infection in rim fixation group and one patient had periprosthetic fracture in no rim fixation group. Survival rate was higher in the peripheral rim fixation group (97.3%) than no rim fixation group (78.6%, P=0.028) CONCLUSION: Based on our findings, peripheral rim fixation might be recommended to improve short-term outcome after revision total hip arthroplasty using jumbo cup.

Near-Road Exposure and Impact of Air Pollution on Allergic Diseases in Elementary School Children: A Cross-Sectional Study

PURPOSE: The study aims to classify schools based on traffic pollutants and their complex sources, to assess the environment, to determine the state of allergic diseases among students using the International Study of Asthma and Allergies in children (ISAAC) questionnaire, and to assess their connection to air pollutants. MATERIALS AND METHODS: A total of seven schools were divided into three categories according to the characteristics of their surrounding environments: three schools in traffic-related zones, two schools in complex source zones I (urban), and two schools in complex source zones II (industrial complex). ISAAC questionnaires were administered and the 4404 completed questionnaires were analyzed. RESULTS: The frequency of asthma treatment during the past 12 months showed a significant increase (p<0.05) with exposure to NO2 [1.67, 95% confidence intervals (CIs) 1.03-2.71] in the complex source zones. The frequency of allergic rhinitis treatment during the past 12 months increased significantly with exposure to Black Carbon (1.60, 95% CIs 1.36-1.90) (p<0.001), SO2 (1.09, 95% CIs 1.01-1.17) (p<0.05), NO2 (1.18, 95% CIs 1.07-1.30) (p<0.01) for all subjects. CONCLUSION: In terms of supporting children's health, care, and prevention related to major spaces for children, such as school zones, spaces used in coming to and leaving school, playgrounds, and classrooms are essential to ensuring not only the safety of children from traffic accidents but also their protection from local traffic pollutants and various hazardous environmental factors.

Total Hip Arthroplasty in Patient with Aplastic Anemia / 대한고관절학회지

PURPOSE: Patients with aplastic anemia (AA) are now living longer and therefore are at increased risk for the development of osteonecrosis of the hip. However, studies on the results of total hip arthroplasty (THA) are lacking. The purpose of this study is to present the result of THA in patients with AA. MATERIALS AND METHODS: We retrospectively reviewed the data for a group of 29 patients (45 hips) with AA who presented to our institution for THA between May 2008 and May 2012. All hips were replaced because of osteonecrosis of the femoral head. A specific prospective protocol was followed for the perioperative transfusion of platelets and blood. The clinical and radiographic evaluations were done, and the minimum follow-up period was 3 years (mean, 49.2 months; range, 36 to 84 months). RESULTS: Three hips had excessive perioperative bleeding and hematoma formation, and then hematoma evacuations were done; one hip was finally revised because of infection of acetabular component. One patient with poorly controlled AA died due to delayed infection on the hip joint. All hips showed stable fixation, and the mean Harris hip score was improved from 54.2 points (range, 42 to 69 points) preoperatively to 90.8 points (range, 73 to 97 points) at the time of the latest follow-up. CONCLUSION: In the present study, the durability of implant fixation was maintained and the clinical results demonstrated a sustained increase in function of the hip. Postoperatively, paying attention to bleeding and infection should be needed.

Surface Characteristics and Biocompatibility of Micro Arc Oxidized Titanium Alloy / 대한정형외과연구학회지

PURPOSE: The aim of this research was to characterize micro arc oxidized titanium (MAO-Ti), accompanied by biocompatibility test in vivo as well as in vitro in comparison to the different types of surface modification; machined, blasted and plasma spray. MATERIALS AND METHODS: XRD and SEM investigations were performed in order to assess the structure and morphology. Biologic and morphologic responses to the osteoblast cell lines (Saos-2) were then examined, using Promeg(R) proliferation assay, alkalinephosphatase activity, alphavbeta3 integrin expression and cytoskeleton staining (Rhodamine-Phallodine). The analysis of gene expression for osteocalcin and collagen I was done through RT-PCR. RESULTS: MAO-Ti showed more activity on osteointegration and cell differentiation compared to other types of surface modification. CONCLUSION: In summary, MAO-Ti appears to exhibit more favorable biocompatibility than the compared groups in vitro and in vivo as well.

House-plant placement for indoor air purification and health benefits on asthmatics

OBJECTIVES: Some plants were placed in indoor locations frequented by asthmatics in order to evaluate the quality of indoor air and examine the health benefits to asthmatics. METHODS: The present study classified the participants into two groups: households of continuation and households of withdrawal by a quasi-experimental design. The households of continuation spent the two observation terms with indoor plants, whereas the households of withdrawal passed the former observation terms with indoor plants and went through the latter observation term without any indoor plants. RESULTS: The household of continuation showed a continual decrease in the indoor concentrations of volatile organic compounds (VOCs) during the entire observation period, but the household of withdrawal performed an increase in the indoor concentrations of VOCs, except formaldehyde and toluene during the latter observation term after the decrease during the former observation term. Peak expiratory flow rate (PEFR) increased in the households of continuation with the value of 13.9 L/min in the morning and 20.6 L/ min in the evening, but decreased in the households of withdrawal with the value of -24.7 L/min in the morning and -30.2 L/min in the evening in the first experimental season. All of the households exhibited a decrease in the value of PEFR in the second experimental season. CONCLUSIONS: Limitations to the generalizability of findings regarding the presence of plants indoors can be seen as a more general expression of such a benefit of human-environment relations.

Total Hip Arthroplasty in Patient with the Sequelae of Legg-Calve-Perthes Disease / 대한고관절학회지

PURPOSE: Patients who have secondary hip osteoarthritis as sequelae of Legg-Calve-Perthes disease (LCPD) are severe deformities of femoral head and acetabulum. A few studies have presented that the clinical results and risks associated with total hip arthroplasty (THA) for patients with a history of LCPD were not satisfactory. In this study, we reported the radiographic and clinical outcomes of THA in patients with sequelae of LCPD. MATERIALS AND METHODS: Between March 2007 and May 2012, 23 hips (23 patients) underwent cementless THA and were followed up at least 2 years after surgery. There were 11 male patients and 12 female patients with an average age of 49.2 years old (range, 25 to 69 years old), and the average follow up period was 40.8 months (range, 24 to 84 months). The clinical and radiological evaluations were performed. RESULTS: The Harris hip score improved from 48.3 points preoperatively to 92.4 points at the time of the last follow-up. The shortening of affected limb was improved from -1.6 cm to 0.2 cm. The complications included one case of sciatic nerve palsy that developed after extensive lengthening of lower extremity, three cases of intraoperative femur fractures. There was no component loosening. CONCLUSION: Fractures and motor nerve palsies may be more frequent in this population. Careful preoperative planning should be performed to overcome the technical pitfalls. If overcoming this early complication, the clinical and radiological evaluations showed excellent outcomes at average 40-month follow-ups.

Minimum Seven-year Follow-up of Cementless Total Hip Arthroplasty with the COREN Hip System / 대한고관절학회지

PURPOSE: We previously reported results of a mean 3.2-year follow-up of the COREN hip system, which is the first total hip prosthesis developed in Korea. The aim of this prospective study was to update the previous report with regard to the hip function and radiographic implant performance. MATERIALS AND METHODS: Between 2003 and 2004, a consecutive series of 68 primary, cementless, total hip prostheses (COREN) were implanted in 57 patients(68 hips) and followed up for a minimum of 7 years. Sixty-three of the 68 hips were available for clinical scoring and radiographic analysis. RESULTS: The mean Harris hip and WOMAC scores were improved from 48.1 and 54.7, preoperatively, to 96.4 and 22.1 at the final follow-up. The mean patient activity increased from 3.1, preoperatively, to 8.2 at the final follow-up. All hips showed stable bony ingrowth on the radiographs. No hips showed evidence of osteolysis or prosthesis loosening, and no revision was required during the follow-up. A Periprosthetic fracture (Vancouver type B1) was encountered in one hip 4.7 years after surgery, which was treated by reoperation. CONCLUSION: This study shows that the COREN hip system produces excellent mid-term results in cementless hip arthroplasty.

Sensitization rates to inhalant allergens in children and adolescents of Incheon and Asan area and the relationship between polysensitization and prevalence of allergic diseases

PURPOSE: Sensitization to allergens is considered as major mechanism of allergy and related to the development of allergic diseases. The objective of this study was to evaluate overall sensitization rates of inhalant allergens and the relationship between polysensitization and prevalence of allergic diseases in children and adolescents. METHODS: A cross-sectional pilot study of 122 elementary school students, 114 middle school students, and 115 high school students from Incheon and Asan was conducted by using the International Study of Asthma and Allergies in Childhood (ISSAC) questionnaire. The skin prick tests were performed with 14 common inhalant allergens on 339 students. RESULTS: The inhalant allergen that has a significantly different sensitization rate according to age was Dermatophagoides farinae. And the inhalant allergen that has significantly different sensitization rate according to region was Japanese hop. In addition, girls have higher sensitization rate to any mold allergens than boys. In case of having sensitization more than two allergens, the risks of diagnosis of asthma and allergic rhinitis on questionnaire were increased. Asthma is related to sensitization of dog or cat and allergic rhinitis is related to sensitization of house dust mites. However, atopic dermatitis is not related to sensitization of any inhalant allergens. CONCLUSION: The sensitization rates of inhalant allergens may differ among age, gender, and region in children and adolescents of Incheon and Asan area. The polysensitized children and adolescents with inhalant allergens showed higher prevalences of allergic diseases such as asthma and allergic rhinitis on questionnaire than monosensitized group.

Stem cell implantation for osteonecrosis of the femoral head

What is the most effective treatment for the early stages of osteonecrosis of the femoral head? We assessed multiple drilling and stem cell implantation to treat the early stages of osteonecrosis of the femoral head. We report the clinical and radiological results of stem cell implantation and core decompression. In total, 128 patients (190 hips) who had undergone surgery were divided into two groups based on which treatment they had received: (1) multiple drilling and stem cell implantation or (2) core decompression, curettage and a bone graft. The clinical and radiographic results of the two groups were compared. At 5-year follow-up, in the stem cell implantation group, 64.3% (27/42) of the patients with Stage IIa disease, 56.7% (21/37) of the patients with Stage IIb disease and 42.9% (21/49) of the patients with Stage III disease had undergone no additional surgery. In the conventional core decompression group, 64.3% (9/14) of the patients with Stage IIa disease, 55.6% (5/9) of the patients with Stage IIb disease and 37.5% (3/8) of the patients with Stage III disease had undergone no additional surgery. Success rates were higher in patients with Ficat Stage I or II lesions than in those with Stage III lesions. There were no statistically significant differences between the groups in terms of success rate or in the clinical and radiographic results of the two methods. Essentially the same results were found with stem cell implantation as with the conventional method of core decompression.

Exposure and Toxicity Assessment of Ultrafine Particles from Nearby Traffic in Urban Air in Seoul, Korea

OBJECTIVES: We investigated the particle mass size distribution and chemical properties of air pollution particulate matter (PM) in the urban area and its capacity to induce cytotoxicity in human bronchial epithelial (BEAS-2B) cells. METHODS: To characterize the mass size distributions and chemical concentrations associated with urban PM, PM samples were collected by a 10-stage Micro-Orifice Uniform Deposit Impactor close to nearby traffic in an urban area from December 2007 to December 2009. PM samples for in vitro cytotoxicity testing were collected by a mini-volume air sampler with PM10 and PM2.5 inlets. RESULTS: The PM size distributions were bi-modal, peaking at 0.18 to 0.32 and 1.8 to 3.2 microm. The mass concentrations of the metals in fine particles (0.1 to 1.8 microm) accounted for 45.6 to 80.4% of the mass concentrations of metals in PM10. The mass proportions of fine particles of the pollutants related to traffic emission, lead (80.4%), cadmium (69.0%), and chromium (63.8%) were higher than those of other metals. Iron was the dominant transition metal in the particles, accounting for 64.3% of the PM10 mass in all the samples. We observed PM concentration-dependent cytotoxic effects on BEAS-2B cells. CONCLUSIONS: We found that exposure to PM2.5 and PM10 from a nearby traffic area induced significant increases in protein expression of inflammatory cytokines (IL-6 and IL-8). The cell death rate and release of cytokines in response to the PM2.5 treatment were higher than those with PM10. The combined results support the hypothesis that ultrafine particles from vehicular sources can induce inflammatory responses related to environmental respiratory injury.

Corrigendum: Health Risks Assessments in Children for Phthalates Exposure Associated with Childcare Facilities and Indoor Playgrounds

In Table 6, the unit concentration of phthalates was not correctly indicated.

Comparative Analysis of Two Cementless Stems in Total Hip Arthroplasties in Patients with Osteonecrosis of Femoral Head: Summit(R) Stem and Bencox(R) Stem

PURPOSE: We compared the clinical and radiological outcomes of total hip arthroplasty (THR) using Summit and Bencox stems. MATERIALS AND METHODS: The patients who underwent cementless total hip arthroplasty were recruited with a satisfactory condition of a minimum three years of follow-ups after THR. Those patients were divided into two groups, those with Summit stems and those with Bencox stems. Summit stems were in 36 patients(40 hips), and Bencox stems in 36 patients(48 hips). Summit and Bencox stems had 78 months and 42.2 months as a mean follow-up, respectively. The clinical and radiological evaluations of femoral components were performed. RESULTS: There was no difference in clinical results between the two groups. Under the radiological findings, there were no osteolytic changes or loosening. Osseointegration was detected at an average of 6.4 months(3-12 months) in the Bencox stem on the distal portion of the femoral stem, and cortical hypertrophy was detected on 6 hips with a Summit stem. CONCLUSION: The clinical and radiological evaluations in both systems showed excellent outcomes at the three year follow-ups, and there was no statistical difference on the clinical and radiological results between the two groups. Thigh pain and cortical hypertrophy were not detected in the Bencox stem, and that wound would be caused by surface treatment methods of the femoral stem, and morphological differences.

Joint Preserving Non-surgical Treatment of Osteonecrosis of Femoral Head / 대한고관절학회지

A patient and physician initially consider how to preserve a joint, and make a goal to achieve this aim when osteonecrosis is initially diagnosed. On the other hand, it is almost impossible to make a decision with only a therapeutic approach based on the pathology, because osteonecrosis of the femoral head is caused by a range of factors. An objective prognosis has now become possible due to the development of radiologic diagnostic assessment tools, such as CT, bone scans and MRI. Most osteonecrosis patients are in their 20-50's. Therefore, physicians make a primary goal to control pain. The surgical approach, such as total joint replacement, is not the first option for early stage osteonecrosis. In the first stage, osteonecrosis should be treated to prevent secondary degenerative diseases and preserve the hip joint. This paper introduces a non-surgical joint preserving treatment in scientific and clinical aspects for early stage osteonecrosis.

Health Risk Assessment of Lead Ingestion Exposure by Particle Sizes in Crumb Rubber on Artificial Turf Considering Bioavailability

OBJECTIVES: The purpose of this study was to assess the risk of ingestion exposure of lead by particle sizes of crumb rubber in artificial turf filling material with consideration of bioavailability. METHODS: This study estimated the ingestion exposure by particle sizes (more than 250 um or less than 250 um) focusing on recyclable ethylene propylene diene monomer crumb rubber being used as artificial turf filling. Analysis on crumb rubber was conducted using body ingestion exposure estimate method in which total content test method, acid extraction method and digestion extraction method are reflected. Bioavailability which is a calibrating factor was reflected in ingestion exposure estimate method and applied in exposure assessment and risk assessment. Two methods using acid extraction and digestion extraction concentration were compared and evaluated. RESULTS: As a result of the ingestion exposure of crumb rubber material, the average lead exposure amount to the digestion extraction result among crumb rubber was calculated to be 1.56x10(-4) mg/kg-day for low grade elementary school students and 4.87x10(-5) mg/kg-day for middle and high school students in 250 um or less particle size, and that to the acid extraction result was higher than the digestion extraction result. Results of digestion extraction and acid extraction showed that the hazard quotient was estimated by about over 2 times more in particle size of lower than 250 um than in higher than 250 um. There was a case of an elementary school student in which the hazard quotient exceeded 0.1. CONCLUSIONS: Results of this study confirm that the exposure of lead ingestion and risk level increases as the particle size of crumb rubber gets smaller.

Fixing Leg Length Discrepancies after Total Hip Arthroplasty

Leg length discrepancies are a common cause of patient dissatisfaction after total hip arthroplasty (THA). The equalization of limb lengths and restoration of the anatomic geometry of the hip to restore normal gait and function are the primary goals during THA. Patients recognize a leg length discrepancy when one leg is shorter than the other by 6 mm or longer than the other by 10 mm after THA. Outside of this range, several problems would occur. Therefore, we should try to maintain leg length during THA via preoperative and intra-operative planning.

Comparison of Cytocompatibility Between Grit Blasted Titanium Alloy (Ti-6Al-4V) with or without Pure Titanium Coating / 대한정형외과연구학회지

PURPOSE: A composite of aluminum and vanadium (Ti-6Al-4V) is one of the most common compositions of titanium-based alloys. Unfortunately, vanadium has been found to cause adverse reactions. We evaluated the effects of vanadium containing titanium alloy (Ti-6Al-4V) on an osteoblast-like cell line (SaOS-2). MATERIALS AND METHODS: We studied the biologic and morphologic responses of SaOS-2 cell to Ti alloy with grit blasting and Ti coated Ti alloy with grit blasting. We performed energy-dispersive x-ray spectroscopy (EDS) and scanning electron microscopy (SEM) investigations and performed a cell proliferation assay, ALP activity, and cell migration assay of SaOS-2 cells. RESULTS: The morphologic assessment of cells through SEM showed that the two surfaces were covered with similar amounts of small slender osteoblast like cells. The amount of proliferation, ALP activity and the migration extent of SaOS-2 cells on the surfaces of each group were not statistically different. CONCLUSION: We used a grit-blasted Ti-coated Ti alloy, coated using electron beam deposition, and a grit-blasted Ti alloy to evaluate the toxicity of Ti-6Al-4V on SaOS-2 cell. Compared with pure titanium, the vanadium-containing Ti-alloy did not show an adverse effect on SaOS-2 cells.

Health Risks Assessment in Children for Phthalate Exposure Associated with Childcare Facilities and Indoor Playgrounds

OBJECTIVES: This study assessed the health risks for children exposed to phthalate through several pathways including house dust, surface wipes and hand wipes in child facilities and indoor playgrounds. METHODS: The indoor samples were collected from various children's facilities (40 playrooms, 42 daycare centers, 44 kindergartens, and 42 indoor-playgrounds) in both summer (Jul-Sep, 2007) and winter (Jan-Feb, 2008). Hazard index (HI) was estimated for the non-carcinogens and the examined phthalates were diethylhexyl phthalate (DEHP), diethyl phthalate (DEP), dibutyl-n-butyl phthalate (DnBP), and butylbenzyl phthalate (BBzP). The present study examined these four kinds of samples, i.e., indoor dust, surface wipes of product and hand wipes. RESULTS: Among the phthalates, the detection rates of DEHP were 98% in dust samples, 100% in surface wipe samples, and 95% in hand wipe samples. In this study, phthalate levels obtained from floor dust, product surface and children's hand wipe samples were similar to or slightly less compared to previous studies. The 50th and 95th percentile value of child-sensitive materials did not exceed 1 (HI) for all subjects in all facilities. CONCLUSIONS: For DEHP, DnBP and BBzP their detection rates through multi-routes were high and their risk based on health risk assessment was also observed to be acceptable. This study suggested that ingestion and dermal exposure could be the most important pathway of phthalates besides digestion through food.

Osteosynthesis for Nonunion of the Lateral Condyle of the Humerus / 대한정형외과학회잡지

PURPOSE: Although nonunion of the lateral humeral condyle is a rare complication in children, it can result in a number of complications, and treatment is controversial. Our study shows the results of using osteosynthesis in patients whose lateral humeral condyle was not united. MATERIALS AND METHODS: We studies 16 patients (M : F=13 : 3; Age: 11.8+/-5.2 years) who were diagnosed with nonunion of the lateral humeral condyle and who underwent osteosynthesis. The mean period of nonunion was 56.2 months (5-132 months). Outcome measures were range of movement, bone union, functional score, and carrying angle and were assessed both before and after surgery. RESULTS: Bones of all patients were united within 3 months of the operation; there were no complications. After surgery, a decreased range of movement was observed for 3 of 16 patients. However, the functional index for all patients was improved. In other words, the range of movement could be reduced while the functional index was improved so that the deformity would be lessened. CONCLUSION: Osteosynthesis was successful in repairing the nonunion of the humeral lateral condyle. Therefore, osteosynthesis is suggested for patients who have had no treatment for nonunion of lateral humeral condyle for a long time.

The Medical Treatment of Osteoporosis

The purpose of this article is to provide orthopaedic surgeons with a guide for the management and treatment of osteoporosis. Preventing fracture prevention is the key efficacy end point in the medical management of osteoporosis for any patient. Enhancement of the bone mass and improving the bone quality are achieved by a combination of lifestyle modification, dietary supplementation with calcium and Vitamin D and pharmacologic treatment. This has proved effective for the prevention and treatment of osteoporosis. The orthopedic surgeon is frequently contacted to identify patients with an osteoporotic fracture. As the orthopaedic surgeon is often the only physician to see a patient who has sustained such a fracture, orthopaedic surgeons must make every effort to determine if the injury is a fragility fracture so that the patient can be treated to prevent future fractures.