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.

Necrotic Bone Involvement in an Adult Afflicted with B-Cell Precursor Acute Lymphoblastic Leukemia Mimicking Osteomyelitis: A Case Report

A 41-year-old female presented with complaint of left hip and buttock pain. Magnetic resonance imaging (MRI) showed multi-focal bone marrow signal intensity changes in left iliac bone, sacrum and femur with an area of necrosis. The primary radiological differential diagnosis was multi-focal tuberculous osteomyelitis. Subsequent pelvic bone biopsy and bone marrow biopsy confirmed the diagnosis of B-cell precursor acute lymphoblastic leukemia with extensive necrosis, which is infrequent in leukemia. When musculoskeletal symptoms precede peripheral blood abnormalities and MRI scanning reveals multi-focal necrotic lesions rather than diffuse signal change, it can be difficult to identify and/or advance leukemia as differential diagnosis.

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.

Enhancement of Osseointegration of Artificial Ligament by Nano-Hydroxyapatite and Bone Morphogenic Protein-2 into the Rabbit Femur

The MTT assay showed that the cell proliferation on hydroxyapatite (HAp) and HAp/bone morphogenic protein (BMP) coated group was better than the control and BMP coated groups at 5 days. And after 7 days of culture, the mRNA expression levels of type I collagen, osteonectin, osteopontin, bonesialoprotein, BMP-2, alkaline phosphatase (ALP) and Runx-2 in the HAp/BMP coated group were significantly higher than the other groups. Also, in this group showed the most significant induction of osteogenic gene expression compared to mesenchymal stem cells (MSCs) grown on the other groups. In addition, the cells in the HAp/BMP coated group delivered higher levels of ALP than the other three groups. Also, silk scaffolds were implanted as artificial ligaments in knees of rabbits, and they were harvested 1 and 3 months after implantation. On gross examination, HE staining showed that new bone tissue formation was more observed in the HAp/BMP coated group 3 weeks postoperatively. And masson staining showed that in the HAp/BMP coated group, the silk fibers were encircled by osteoblast, chondrocyte, and collagen. Furthermore, the analysis showed that the width of the graft-bone interface in the HAp and HAp/BMP coated group was narrower than that in the other two groups 3 weeks postoperatively. So, it is concluded that BMP incorporated HAp coated silk scaffold can be enhanced osseointegration and osteogenesis in bone tunnel. As a result, these experimental designs have been demonstrated to be effective in the acceleration of graft-to-bone healing by increasing new bone or fibrocartilage formation at the interface between graft and bone.

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.

Displacement pattern of the anterior segment using antero-posterior lingual retractor combined with a palatal plate / 대한치과교정학회지

OBJECTIVE: To evaluate and compare the effects of two appliances on the en masse retraction of the anterior teeth anchored by temporary skeletal anchorage devices (TSADs). METHODS: The sample comprised 46 nongrowing hyperdivergent adult patients who planned to undergo upper first premolar extraction using lingual retractors. They were divided into three groups, based on the lingual appliance used: the C-lingual retractor (CLR) group (group 1, n = 16) and two antero-posterior lingual retractor (APLR) groups (n = 30, groups 2 and 3). The APLR group was divided by the posterior tube angulation; posterior tube parallel to the occlusal plane (group 2, n = 15) and distally tipped tube (group 3, n = 15). A retrospective clinical investigation of the skeletal, dental, and soft tissue relationships was performed using lateral cephalometric radiographs obtained pretreatment and post en masse retraction of the anterior teeth. RESULTS: All groups achieved significant incisor and canine retraction. The upper posterior teeth did not drift significantly during the retraction period. The APLR group had less angulation change in the anterior dentition, compared to the CLR group. By changing the tube angulation in the APLR, the intrusive force significantly increased in the distally tipped tube of group 3 patients and remarkably reduced the occlusal plane angle. CONCLUSIONS: Compared to the CLR, the APLR provides better anterior torque control and canine tipping while achieving bodily translation. Furthermore, changing the tube angulation will affect the amount of incisor intrusion, even in patients with similar palatal vault depth, without the need for additional TSADs.

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.

Non-operative Treatment of Femoral Neuropathy Caused by Iliacus Hematoma: A Case Report / 대한고관절학회지

Treatment of femoral neuropathy caused by iliacus hematoma can be divided according to operative treatment and non-operative treatment. Recently, percutaneous drainage has been more popular because it is relatively simple, convenient, and less invasive. After warfarin overuse, a 71-year-old male patient visited the emergency room with femoral neuropathy caused by a left iliacus muscle hematoma measuring approximately 110x64 mm, 75x60 mm in size on coronal and sagittal computed tomography angiograhy. Without trauma, weakness of the left hip flexor and left knee extensor was noted with strength of 2/5 (poor) each. Immediate medical treatment using vitamin K and fresh frozen plasma was started and percutaneous drainage was performed. Two days after visiting the emergency room, neurological symptoms were improved and non-operative treatment was continued. Twenty four days after being hospitalized, the size of the hematoma was reduced to approximately 75x45 mm, 62x40 mm in size. Approximately three months after hospitalization, most of the hematoma was absorbed. After one year, mild atrphy of quadriceps and mild diffuse pain were noted, however, no other symptoms were observed.

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.

Reader's Forum / 대한치과교정학회지

No abstract available.

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.

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.

Short Scarf Osteotomy for Moderate Hallux Valgus / 대한족부족관절학회지

PURPOSE: The aim of this study was to evaluate the radiographic and clinical results of short scarf osteotomy that has minimized longitudinal cut for moderate hallux valgus. MATERIALS AND METHODS: Total 12 patients (12 feet) were reviewed by medical records and radiographs. All patients were female and the mean age at the time of operation was 41.5 years. The mean followup time was 21.2 months. We modified original scarf osteotomy by shortening the longitudinal cut to 15~20 mm in length. Additionally, Akin osteotomy of the first proximal phalanx was done in 7 feet and Weil osteotomy of the second metatarsal was done in 4 feet. First-second intermetatarsal and hallux valgus angles were analyzed radiographically before and after the operation. And the clinical result was assessed by AOFAS (American Orthopaedic Foot and Ankle Society) hallux score. RESULTS: First-second intermetatarsal and hallux valgus angles were reduced from the mean preoperative values of 14.6degrees and 32.8degrees to 6.5degrees and 11.2degrees, respectively. The mean AOFAS hallux score was increased from 52.4 points preoperatively to 88.2 points at followup. Three complications were found: metatarsal fracture during the operation, painful scar around second metatarsal head after Weil osteotomy and postoperative neuralgia. There was no transfer metatarsalgia or recurrence of hallux valgus during followup. CONCLUSION: Short scarf osteotomy would be an effective surgical procedure for moderate hallux valgus with the benefits of minimized soft tissue dissection and stable fixation.

Reader's Forum / 대한치과교정학회지

No abstract available.

The Clinical Results of Pressurized Cement-Augmented Richard Compression Hip Screw with Trochanteric Stabilizing Plate for Intertrochanteric Fracture Compared with Pressurized Cement-Augmented Richard Compression Hip Screw Only

PURPOSE: We analyzed the radiologic and clinical outcomes of osteosynthesis using a Richard compression hip screw (RCHS) alone or RCHS with a trochanteric stabilizing plate (TSP) in patients with an intertrochanteric fracture. MATERIALS AND METHODS: From January 2006 to December 2008, 23 patients (23 cases) underwent osteosynthesis using only RCHS and 24 patients (25 cases) underwent osteosynthesis using RCHS and TSP. We evaluated the classification of fractures, the amount of collapse and shortening, and the duration of fracture union. We used a Koval classification for the evaluation of clinical outcomes. RESULTS: The amount of collapse and shortening in the RCHS-only group was statistically greater than the amount in the RCHS-with-TSP group. The union duration of fracture was 5.3 months in the RCHS-only group and 6.6 months in the RCHS-with-TSP group. The clinical outcomes in the RCHS-with TSP-group were better than the RCHS-only group. We had one case of fixation failure in the RCHS-only group and none in the RCHS-with-TSP group. There were no perioperative systemic complications or death. CONCLUSION: In patients with unstable intertrochanteric fractures, we can prevent the cut out of the lag screw or screw loosening with the use of pressurized PMMA-augmented RCHS. However, we cannot prevent excessive collapse and shortening, especially in patients with severe osteoporosis, a small diameter of the femur neck, or concealed fractures. In the case of these patients, we recommend you to use RCHS with TSP for the prevention of excessive collapse and shortening.

Weil Osteotomy for Freiberg's Disease / 대한족부족관절학회지

PURPOSE: The aim of this study was to evaluate the result of combined Weil and dorsal closing wedge osteotomy for Freiberg's disease. MATERIALS AND METHODS: We performed combined Weil and dorsal closing wedge osteotomy of the second metatarsal under the diagnosis of Freiberg's disease in 7 patients, 7 feet (2 male and 5 female). The mean age at the time of operation was 29 years and the mean follow-up period was 31 months. Patients had no trauma history and no combined deformity of the foot. The surgical results were evaluated by VAS and weight bearing radiographs in antero-posterior and oblique projection. RESULTS: According to Smillie staging system, there were 1 of stage II, 2 of stage III and 4 of stage IV patients. The osteotomy site was united at 8 weeks and the second metatarsal was shortened in length of average 2.8 mm. Remodeling of the metatarsal head was observed at 24 months. The mean VAS was decreased from 8.2 points preoperatively to 2.7 points at follow-up. And average range of motion of second metatarso-phalangeal joint was increased from 30o preoperatively to 45o at follow-up. There was no transfer metatarsalgia or arthritis of the metatarsal head during follow-up. CONCLUSION: Combined Weil and dorsal closing wedge osteotomy of the metatarsal appears to be an effective procedure for the treatment of Freiberg's disease with a view to shortening of metatarsal length and elevation of metatarsal head.

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.

Deep Infection Caused by Gas-Forming Bacteria after Total Hip Arthroplasty

A deep infection after total hip arthroplasty is a very severe complication that occurs in about 1~2% of the patients. The major cause of this infection is Staphylococcus aureus in the early stage and Staphylococcus epidermidis in the late stage A nontraumatic gas-forming infection is rare and difficult to diagnose because of its slower clinical course than that of gas gangrene. Therefore, it has a high mortality rate due to delayed treatment. There have been no reports on gas-forming infection by Escherichia coli after total hip arthroplasty. We report here on a patient who was treated by open arthrotomy and the patient expired due to a Escherichia coli, gas-forming infection after undergoing total hip arthroplasty.

Treatment of Intertrochanteric Fractures in Patients with Severe Osteoporosis with Dynamic Compression Hip Screws

PURPOSE: The purpose of this study was to compare the clinical results in the treatment of femoral intertrochanteric fractures with dynamic compression hip screws (DHS) in patients with or without osteoporosis. MATERIALS AND METHODS: Between March 2003 and February 2006, the clinical results in the treatment of intertrochanteric fractures of the femur with DHS in patients with severe osteoporosis (T score-2.5; 46 patients [group 2]) were reviewed. We retrospectively compared the mortality rate, the incidence of postoperative complications or fixation failures, and the patterns between the two groups. RESULTS: The mortality rate in group 1 was 30.4% at postoperative 1 year and 21.4% at 6 months. The mortality rate at 1 year was 21.8% in group 2 (p<0.05). There were no differences in fracture patterns according to the AO/OTA classification between the two groups. However, the incidence of fixation failures were 19.6% in group 1 vs. 13.0% in group 2 (p<0.05). CONCLUSION: There was a higher postoperative mortality rate at 1 year (30.4% vs. 21.4%), and the incidence of fixation failures (19.6% vs. 13.0%) in the treatment of osteoporotic intertrochanteric fractures by DHS in osteoporotic compared to non-osteoporotic fractures.

Risk Factors for Osteonecrosis of the Femoral Head in Patients with Heamatologic diseases

PURPOSE: We aimed to clarify the risk factors associated with the development of ONFH by comparing patients with hematologic diseases and osteonecrosis of the femur head (ONFH) to those patients without ONFH and who have hematologic diseases MATERIALS AND METHODS: The study population was limited to the patients admitted to our Hematology-Oncology department from 1 January 1994 to 31 May 2007. The patients were divided into 2 groups (those with ONFH, 54 patients and those without ONFH, 54 patients) and the risk factors for ONFH were evaluated by a comparative analysis. We analyzed the effect of a history of bone marrow transplantation (BMT), graft-versus-host disease (GVHD), total body radiation (TBI) and the amount of steroid used as the risk factors for ONFH. RESULTS: On the multiple logistic regression analysis, a total steroid use of >g/BMI was statistically identified as a significant risk factor for ONFH. The history of BMT and TBI were not statistically correlated with the development of ONFH. Among the patients with BMT, allogenic BMT and a history of GVHD were not statistically correlated with the development of ONFH on the multiple logistic regression analysis. CONCLUSION: Patients with hematologic diseases and who have used steroid >1.5g/BMI should carefully observed because they are more likely to develop ONFH.