Fabrication of gelatin-strontium substituted calcium phosphate scaffolds with unidirectional pores for bone tissue engineering.

This study fabricated homogeneous gelatin-strontium substituted calcium phosphate composites via coprecipitation in a gelatin solution. Unidirectional porous scaffolds with an oriented microtubular structure were then manufactured using freeze-drying technology. The resulting structure and pore alignment were determined using scanning electron microscopy. The pore size were in the range of 200-400 µm, which is considered ideal for the engineering of bone tissue. The scaffolds were further characterized using energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. Hydroxyapatite was the main calcium phosphate compound in the scaffolds, with strontium incorporated into the crystal structure. The porosity of the scaffolds decreased with increasing concentration of calcium-phosphate. The compressive strength in the longitudinal direction was two to threefold higher than that observed in the transverse direction. Our results demonstrate that the composite scaffolds degraded by approximately 20 % after 5 weeks. Additionally, in vitro results reveal that the addition of strontium significantly increased human osteoblastic cells proliferation. Scaffolds containing strontium with a Sr-CaP/(gelatin + Sr-CaP) ratio of 50 % provided the most suitable environment for cell proliferation, particularly under dynamic culture conditions. This study demonstrates the considerable potential of composite scaffolds composed of gelatin-strontium-substituted calcium phosphate for applications in bone tissue engineering.

The severity of the long head biceps tendinopathy in patients with chronic rotator cuff tears: macroscopic versus microscopic results.

BACKGROUND: This study investigated the histopathology of the long head of biceps (LHB) tendon and correlated the findings with the macroscopic appearances of the LHB and the size of rotator cuff tears (RCTs) in patients with chronic RCTs. METHODS: We compared biopsy specimens from LHBs in 34 patients with chronic RCTs and grossly normal LHBs in 8 patients undergoing shoulder hemiarthroplasty (controls). Duration of preoperative symptoms, the severity of RCTs, and macroscopic appearance of LHBs were recorded, classified, and compared with the histologic grading and apoptosis index of terminal deoxynucleotide transferase-mediated biotin-deoxy uridine triphosphate nick-end labeling (TUNEL) assays of LHBs. RESULTS: In the RCT group, there were 8 partial-thickness tears with 5 macroscopic LHB lesions, 12 full-thickness tears with 8 macroscopic LHB lesions, and 14 massive tears with 13 macroscopic LHB lesions. There were 6 LHB subluxations. However, the macroscopic grading and the symptom duration were not correlated with the severity of the histology. In patients with massive tears, no matter what the macroscopic appearance of the LHB, the proportion of end-stage (grade 4) histologic LHB tendinopathy significantly increased (85.7%, P < .05) compared with patients with other types of RCTs. There was a consistently high incidence of advanced LHB histology (grade 3 or higher) in each classification of RCTs (75.0%-100.0%). The 8 patients in the control group showed milder histopathology (grade 1 or 2). The apoptosis index significantly increased as the tendinopathy progressed (P < .05). CONCLUSIONS: The macroscopic pathology of LHB may not fully reflect the severity of tendinopathy, and the coexisting size of RCTs plays a role in the severity of LHB tendinopathy.

An effective method to reduce ischemia time during total knee arthroplasty.

BACKGROUND/PURPOSE: Because of controversy regarding timing of tourniquet release during total knee arthroplasty (TKA), a closed arthrotomy as a tamponade for effective hemostasis was used to save ischemia time. The study was to verify the safety and efficacy on clinical issues. METHODS: A prospective cohort study was conducted on 72 consecutive unilateral primary TKAs. They were divided into two groups according to different timing of tourniquet release. The study group was composed of 36 index procedures with an intra-operative release after a tight arthrotomy closure; while the remaining 36 TKAs with a tourniquet application throughout the procedure comprised the comparative group. In all operations, no drain was used to augment the intra-articular tamponade. RESULTS: In the study group, the tourniquet time was significantly shorter (p<0.001), and thus ischemic duration and perioperative blood loss were reduced. The postoperative course was similar on the basis of analgesics consumption and inpatient stay, but better earlier functional recovery as well as subjective performance was observed at early postoperative follow-ups. CONCLUSIONS: The results suggest that a closed tamponade with arthrotomy closure and drainage avoidance is an effective hemostasis to reduce ischemia time during TKAs.

[Reducing blood preparation for total knee arthroplasty: a practical approach].

BACKGROUND & PROBLEMS: The rate of allogenic blood preparation for an elective total knee arthroplasty (TKA) has been as high as 100% at our institute. However, most (76.2%) of these preparations were wasted. PURPOSE: This project worked to reduce unnecessary blood preparations for this elective procedure and reduce resource expenditures. RESOLUTIONS: Key issues identified as requiring resolution included: Uncertainty regarding urgent transfusion need, insufficient preoperative evaluation of high risk patients, and the use of outdated clinical pathways. Measures taken to overcome these issues included redefining transfusion triggers using relevant empirical data as conclusive evidence and building a general consensus within the medical team while acquiring practical support from decision makers. A more comprehensive assessment process for identifying risk factors was developed by reviewing and assessing the prior experiences of inpatients; New standard procedures for blood preparation and transfusion were issued; and related clinical pathways were updated with supplementary measures. RESULTS: After project implementation, the blood preparation rate declined significantly from 100% to 10.2%. The rate of effective transfusion rate rose from 23.8% to 76.2%. CONCLUSIONS: This project combined various medical professions to propose practical improvements that effectively access peer support. We recommend applying this model in all care units to ensure patient safety and lower medical costs while developing a more effective policy for blood transfusion.

Proximal fibular osteotomy relieves pain in spontaneous osteonecrosis of the knee: A retrospective study.

Spontaneous osteonecrosis of the knee (SONK) causes knee pain and joint motion limitation. Ischemia or insufficiency fracture may be the cause, but no consensus has been developed. Proximal fibular osteotomy (PFO) has been reported to relieve pain from osteoarthritis through medial compartment decompression. We reviewed the effect of this procedure on medial compartment SONK patients and explored clinical and radiological results. Since January 2018 to January 2020, the data of 12 knees (8 right and 4 left) from 11 SONK patients (9 women and 2 men) who received PFO were analyzed. The average age was 61.5 years. The diagnosis of SONK was established through weight-bearing anterior-posterior radiographs or magnetic resonance imaging (MRI). Visual analog scale (VAS) scores, Oxford knee score (OKS), Femorotibial angle (FTA), medial joint space, and lateral joint space were documented preoperatively and at follow up visits. Outcome assessment for the clinical and radiographic data was reviewed at 12- and 24-month follow-up visits. The mean follow up period was 33 months. All patients were able to walk with or without cane assistance the day after surgery. Both VAS score and OKS (preoperative: 6.6 ± 0.9 and 24.7 ± 3.8, respectively) improved significantly at the 12-month follow-up, and to 24-month follow-up (3.6 ± 1.3 and 35.6 ± 4.5, respectively, P < .05). Medial joint space ratio increased from 0.36 to 0.50 (P < .05). Changes of FTA were insignificant at any point of follow up. Four patients underwent follow-up MRI, and a decrease in the osteonecrotic area was clearly observed in 2 patients. By achieving medial knee decompression, PFO allowed quick weight-bearing recovery, pain relief, and improvement in knee function in SONK patients.

Anterior tibial artery pseudoaneurysm as a rare technical complication after corrective fibular osteotomy: a case report.

INTRODUCTION: Partial fibular osteotomy has been recognized as a surgical alternative to treat medial compartment osteoarthritis of the knee. Related peroneal neuropathies are of concern among the relatively few complications after this procedure. In our clinical practice, the osteotomy level has therefore been modified to avoid the above defects. However, a rare case of vascular injury was encountered. Herein we describe an accidental anterior tibial artery pseudoaneurysm as a rare technical complication after this corrective osteotomy. CASE PRESENTATION: A 55-year-old male visited our emergency room, presenting a painful swelling over his right anterolateral shin along with surrounding ecchymosis. Thirteen days ago, he just underwent a corrective fibular osteotomy over his right painful varus knee at our institute, and was discharged after an uneventful postoperative stay. Urgent angiography revealed an out-pouching vascular lesion, pseudoaneurysm, involving his right anterior tibial artery. Prompt endovascular repair with stent insertion and balloon compression successfully stopped the persistent extravasation from the injured artery. Follow-up angiography as well as outpatient review confirmed the regression of this lesion and associated symptoms without sequelae. CONCLUSION: Although corrective fibular osteotomy is a simple surgical procedure, it is not free of complications. The suggested osteotomized level in the pertinent literature predisposes patients to certain neuromuscular deficits, which could be avoided by the modified level of osteotomy. However, our case highlights surgeons' familiarity with certain risky neurovascular structures around the osteotomy site and corresponding technical considerations. A recent surgical history along with alarming symptoms/signs should arouse clinical suspicion, aid in timely identification and make appropriate interventions for potential vascular complications.

Tourniquet use in total knee arthroplasty: a meta-analysis.

PURPOSE: The use of an intraoperative tourniquet for total knee arthroplasty (TKA) is a common practice. However, the effectiveness and safety are still questionable. A systematic review was conducted to examine that whether using a tourniquet in TKA was effective without increasing the risk of complications. METHODS: A comprehensive literature search was done in PubMed Medicine, Embase, and other internet database. The review work and the following meta-analysis were processed to evaluate the role of tourniquet in TKA. RESULTS: Eight randomized controlled trials and three high-quality prospective studies involving 634 knees and comparing TKA with and without the use of a tourniquet were included in this analysis. The results demonstrated that using a tourniquet could decrease the measured blood loss but could not decrease the calculated blood loss, which indicated actual blood loss. Patients managed with a tourniquet might have higher risks of thromboembolic complications. Using the tourniquet with late release after wound closure could shorten the operation time; whereas early release did not show this benefit. CONCLUSIONS: The current evidence suggested that using tourniquet in TKA may save time but may not reduce the blood loss. Due to the higher risks of thromboembolic complications, we should use a tourniquet in TKA with caution.

Temporary drainage clamping after total knee arthroplasty: a meta-analysis of randomized controlled trials.

Drainage-clamping methods are thought to be effective in reducing blood loss after total knee arthroplasty (TKA). We conducted a systematic review to examine if these methods were effective without increasing the risk of complications. After a comprehensive search, 6 randomized controlled trials involving 603 knees and comparing clamping drainage and the immediate release of the drain after elective TKA were included in this analysis. The results demonstrated that drainage clamping could decrease the volume of drainage, but only clamping for no less than 4 hours could reduce the true blood loss. There was no significant difference between the 2 groups regarding blood transfusion, postoperative range of motion, incidence of thromboembolic events, and wound complications. The current evidence cannot confirm the advantage of clamping drainage after TKA.

A comparative study of the physical and mechanical properties of three natural corals based on the criteria for bone-tissue engineering scaffolds.

Coral has been used for bone grafts since 1970. Because coral has the advantages of good osteoconduction, biocompatibility, and biodegradation, it is also suitable for scaffolds used in bone-tissue engineering. However, the skeletons of different species of corals often vary significantly, and very few studies focus on the assessment of the permeability and mechanical properties of coral structure. In order to better understand the use of coral in bone tissue-engineering, we selected three typical models (Acropora sp., Goniopora sp., and Porites sp.) to analyze for pore size, porosity, permeability, and mechanical strength. We found Goniopora and Porites had homogenous structure and Acropora had oriented pores and irregular pore size. Acropora had the largest permeability, however, the transverse section was closed and the useful size was limited because of its habitat type. Porites had the smallest pore size and had the lowest permeability. Our data indicated that Goniopora sp. can be considered as the most promising source of scaffolds for bone-tissue engineering because of its high porosity (73%) and that its permeability and mechanics were similar to those in human cancellous bone. In conclusion, we analyzed the impact of the macroporous structure of coral on the permeability and mechanical properties that provide indicators for designing the optimal scaffold for bone-tissue engineering.

Surface Modification of Direct-Current and Radio-Frequency Oxygen Plasma Treatments Enhance Cell Biocompatibility.

The sand-blasting and acid etching (SLA) method can fabricate a rough topography for mechanical fixation and long-term stability of titanium implant, but can not achieve early bone healing. This study used two kinds of plasma treatments (Direct-Current and Radio-Frequency plasma) to modify the SLA-treated surface. The modification of plasma treatments creates respective power range and different content functional OH groups. The results show that the plasma treatments do not change the micron scale topography, and plasma-treated specimens presented super hydrophilicity. The X-ray photoelectron spectroscopy (XPS)-examined result showed that the functional OH content of the RF plasma-treated group was higher than the control (SLA) and DC treatment groups. The biological responses (protein adsorption, cell attachment, cell proliferation, and differentiation) promoted after plasma treatments, and the cell responses, have correlated to the total content of amphoteric OH groups. The experimental results indicated that plasma treatments can create functional OH groups on SLA-treated specimens, and the RF plasma-treated SLA implant thus has potential for achievement of bone healing in early stage of implantation.

Factors affecting the outcomes of modified tension band wiring techniques in transverse patellar fractures.

INTRODUCTION: Modified tension band wiring has been widely used to treat transverse patellar fractures. However, few studies have evaluated the clinical outcomes using different methods of Kirschner wire bending, location of the tension band, and depths of Kirschner wires. Thus, we tried to clarify these factors according to our clinical outcomes. PATIENTS AND METHODS: This retrospective cohort study recruited consecutive patients underwent surgical fixation for patellar fractures using modified tension band technique between January 2010 and December 2015. Different factors in this procedure, including the bending manner of the Kirschner wires, their depth, and location of the tension band with respect to the superior and inferior border of the patella were recorded and analysed. The primary outcome was early loss of fixation. The secondary outcomes were minor loss of reduction, implant breakage, deep infection, and the need for implant removal. RESULTS: This study included 170 patients with patellar fractures. Regarding the bending method, similar results were obtained with bilaterally or proximally bent Kirschner wires. Regarding length, the tension band was placed closely (within 25% of the patella length) in 124 patients and distantly in 46 patients. The rates of loss of reduction and implant breakage were significantly higher in the distantly placed tension bands. Regarding depth, 37 patellar fractures were fixed with the Kirschner wires at the superficial one third of the patellae while the K- wires at the middle layer of patella were used in the remaining 133 patellar fractures. A significantly higher rate of minor loss of reduction was obtained using the superficial Kirschner wires. CONCLUSION: The modified tension band technique for transverse patella fractures provides favourable clinical outcomes, with low failure (5%) and infection (2%) rates. Implant irritation is the major complication, and almost half of cases require implant removal. The location of the tension band with respect to the superior and inferior border of the patella plays an important role in clinical outcomes. Placing the wire close to the patella may prevent major loss of reduction and implant breakage. Superficially placed Kirschner wires also affect clinical outcomes by increasing the rate of minor loss of reduction.

Bone tissue engineering evaluation based on rat calvaria stromal cells cultured on modified PLGA scaffolds.

Using natural materials to coat the scaffolds used for tissue-engineered bone-repair techniques is expected to increase osteoblast adhesion to the scaffold and to express normal physiological function. To test this hypothesis, we therefore modified poly(DL-lactic-co-glycolic acid) (PLGA) substrate by coating it with natural biomaterial solutions of collagen, chitosan, or N-succinyl-chitosan, and then used these three combinations as scaffolds to evaluate their effects on osteoblast attachment, proliferation, and differentiation. The results demonstrated that the pore size of scaffolds ranging from 125-500 microm did not affect the osteoblast phenotype; however, the surface modification of the scaffolds coated with these natural biomaterials did. Collagen increased cell attachment and proliferation, but chitosan and N-succinyl-chitosan decreased them. Chitosan and N-succinyl-chitosan increased differentiation, but collagen decreased it. These results provide us a new strategy for modifying microenvironments to increase osteoblast adhesion, proliferation, and differentiation on PLGA scaffolds, a strategy that might be useful for tissue regeneration.

Kinematic navigation in total knee replacement--experience from the first 50 cases.

BACKGROUND/PURPOSE: Proper alignment of the prosthesis is critical in total knee replacement (TKR) to minimize long-term wear, risk of osteolysis, and loosening of the prosthesis. This study examined the accuracy of lower limb alignment obtained using a kinematic navigation system for TKR, and the extra time needed to adopt this system. METHODS: From August 2002 to April 2003, 71 patients with knee osteoarthritis underwent 79 primary TKR operations by the same surgical team. Fifty of these operations were performed with the aid of the CT-free kinematic navigation system, and the remaining 29 were performed with conventional manual methods. Results, including operation time, radiographic alignment of the prosthesis and complications, for the two groups were compared. RESULTS: Patients in the kinematic navigation group achieved better accuracy in the coronal plane than the conventional group in terms of postoperative mechanical axis (1.89 +/- 0.63 degrees vs. 3.38 +/- 1.07 degrees ). Less variation was noted in the navigation group (femur: SD 1.88 degrees vs. 7.12 degrees ; tibia: SD 1.54 degrees vs. 2.99 degrees ), although the difference in the mean values was not significant (p = 0.475 and 0.55, respectively). The operation time (from skin to skin) in the navigation group (100.6 +/- 4.3 minutes) was longer than that in the conventional group (92.7 +/- 5.1 minutes; p = 0.027). Two perioperative fractures occurred in the navigation group, both of which were attributed to patient factors as opposed to operation procedures. No major complications such as infection or pulmonary embolism occurred during this study. CONCLUSION: Use of a kinematic navigation system in TKR provides better accuracy than conventional manual methods. The technique is easy to use, has a short learning curve, and requires an additional operation time of less than 10 minutes. Precise alignment can be achieved with the aid of navigation in most cases.

Frequent Dental Scaling Is Associated with a Reduced Risk of Periprosthetic Infection following Total Knee Arthroplasty: A Nationwide Population-Based Nested Case-Control Study.

Oral bacteremia has been presumed to be an important risk factor for total knee arthroplasty (TKA) infection. We aimed to investigate whether dental scaling could reduce the risk of TKA infection. A nested case-control study was conducted to compare 1,291 TKA patients who underwent resection arthroplasty for infected TKA and 5,004 matched controls without infection in the TKA cohort of Taiwan's National Health Insurance Research Database (NHIRD). The frequency of dental scaling was analyzed. Multiple conditional logistic regression was used to assess the frequency of dental scaling and the risk of TKA infection. The percentage of patients who received dental scaling was higher in the control group than in the TKA infection group. The risk for TKA infection was 20% lower for patients who received dental scaling at least once within a 3-year period than for patients who never received dental scaling. Moreover, the risk of TKA infection was reduced by 31% among patients who underwent more frequent dental scaling (5-6 times within 3 years). Frequent and regular dental scaling is associated with a reduced risk of TKA infection.

The use of alendronate to prevent early collapse of the femoral head in patients with nontraumatic osteonecrosis. A randomized clinical study.

BACKGROUND: Osteonecrosis of the femoral head is the most common diagnosis leading to total hip arthroplasty in young adults. Joint-preserving treatment options have been mainly surgical, with inconsistent results. Alendronate (a bisphosphonate agent) has been shown to lower the prevalence of vertebral compression fractures and could potentially retard the collapse of an osteonecrotic femoral head. The purpose of this study was to test the effect of alendronate in preventing early collapse of the femoral head in patients with nontraumatic osteonecrosis. METHODS: Forty patients with Steinberg stage-II or III nontraumatic osteonecrosis of the femoral head and a necrotic area of >30% (class C) were randomly divided into alendronate and control groups of twenty patients each. Patients in the alendronate group took 70 mg of alendronate orally per week for twenty-five weeks, while the patients in the control group did not receive this medication or a placebo. The patients were observed for a minimum of twenty-four months. Harris hip scores, plain radiographs, and magnetic resonance imaging scans were obtained. RESULTS: During the study period, only two of twenty-nine femoral heads in the alendronate group collapsed, whereas nineteen of twenty-five femoral heads in the control group collapsed (p < 0.001). One hip in the alendronate group underwent total hip arthroplasty, whereas sixteen hips in the control group underwent total hip arthroplasty (p < 0.001). CONCLUSIONS: Alendronate appeared to prevent early collapse of the femoral head in the hips with Steinberg stage-II or IIIC nontraumatic osteonecrosis. A longer duration of follow-up is needed to confirm whether alendronate prevents or only retards collapse. LEVEL OF EVIDENCE: Therapeutic Level I.

Sonography for monitoring closed reduction of displaced extra-articular distal radial fractures.

BACKGROUND: Closed reduction and cast immobilization are employed in the primary treatment of most distal radial fractures, and conventional radiographic techniques have been essential and effective in monitoring these reductions. Radiation-free ultrasonography, however, can provide both real-time and dynamic multiple-plane images with a small and simple-to-use transducer that can be operated with only one hand. We therefore wanted to see if the real-time and dynamic multiple-plane observation capabilities of ultrasonography would allow an orthopaedic surgeon to perform a closed reduction without multiple attempts, as are frequently required when only conventional radiographic techniques are used. METHODS: Sonographically guided closed reduction was performed in twenty-seven consecutive wrists with an acute distal radial fracture. The efficacy of this method was evaluated and compared with that of conventional radiographic techniques. RESULTS: The sonographic images delineated the fractures as accurately as did the conventional radiographs. All parameters measured on the sonograms and radiographs showed substantial restoration of anatomic alignment after reduction, and all measurements were similar on the two types of images. CONCLUSIONS: Sonographically guided monitoring compared well with conventional radiographic techniques during closed reduction of extra-articular distal radial fractures. Sonography is an accurate, simple, and radiation-free tool that provides the substantial benefits of dynamic multiple-plane and real-time observation.

Biowaiver extension potential to BCS Class III high solubility-low permeability drugs: bridging evidence for metformin immediate-release tablet.

The biopharmaceutics classification system (BCS) allows biowaiver for rapid dissolving immediate-release (IR) products of Class I drugs (high solubility and high permeability). The possibility of extending biowaivers to Class III high solubility and low permeability drugs is currently under scrutiny. In vivo bioequivalence data of different formulations of Class III drugs would support such an extension. The objective of this work was to demonstrate the bioequivalence of two marketed IR tablet products of a Class III drug, metformin hydrochloride, that are rapidly dissolving and have similar in vitro dissolution profiles. The effect of race on the systemic exposure of metformin was also explored. A randomized, open-label, two-period crossover study was conducted in 12 healthy Chinese male volunteers. Each subject received a single-dose of 500 mg of each product after an overnight fasting. The plasma concentrations of metformin were followed for 24 h. No significant formulation effect was found for the bioequivalence metrics: areas under concentration-time curve (AUC0-t, AUC0-infinity) and maximal concentration (Cmax). The 90% confidence intervals for the ratio of means were found within the acceptance range of 80-125% for the log-transformed data. Based on these results, it was concluded that the two IR products are bioequivalent. The pharmacokinetic parameters of metformin in Chinese for both products were similar and were in good agreement with those reported for metformin IR tablets in other ethnic populations. This study serves as an example for supporting biowaiver for BCS Class III drugs.

Failure of hydroxyapatite-coated acetabular cups. Ten-year follow-up of 85 Landos Atoll arthroplasties.

Between March 1990 and May 1991 we performed 85 primary total hip replacements in 74 patients using the Landos Atoll hydroxyapatite (HA)-coated cup and the Corail HA-coated stem. The patients were followed up for a mean of ten years. Of the 85 cups, 26 (31%) have already been revised and a further six are radiologically unstable and awaiting revision. Two femoral stems have been revised for infection without loosening. The retrieved acetabular cups were studied by SEM and image-processing techniques to quantify the amount of residual HA on the cup. This was correlated with the clinical variables and modes of failure. The residual HA (as a percentage of the surface) on the loose cups correlated negatively with the duration of implantation (r = -0.732, p < 0.001). Six cups were stable at revision and had more residual HA coating than those which were loose (p < 0.01). The rate of failure of the Landos Atoll HA-coated, smooth hemispherical cup with screw fixation is unacceptably high. Resorption of the HA coating is markedly increased in loose cups compared with stable cups. HA coating cannot substitute for stable mechanical fixation.

Incidence and risk of venous thromboembolism among Taiwan osteoporotic fracture population under osteoporosis pharmacological treatments.

CONTEXT: There was no clear evidence for the association between oral bisphosphonates or raloxifene and venous thromboembolism (VTE). There might also be ethnic differences in VTE risk. OBJECTIVE: The purpose of this study was to compare the incidence and risk of VTEs for different classes of osteoporosis drugs in the Taiwanese osteoporotic fracture population. DESIGN: This was a retrospective cohort study from 2003 to 2007, with up to 6 years follow-up. SETTING: Enrollees were participants in Taiwan National Health Insurance. PATIENTS: PATIENTS older than 50 years who had vertebral or hip fractures and were new to osteoporosis therapy were recruited. INTERVENTION: PATIENTS were classified into the alendronate, calcitonin, or raloxifene group according to exposure after follow-up. MAIN OUTCOME MEASURE: The primary outcome of our study was all incident VTEs, including deep vein thrombosis and pulmonary embolism. Cox proportional hazard models were used to compare the relative VTE risk among alendronate, raloxifene, and calcitonin groups under an on-treatment scenario. RESULTS: There were 25 443, 9642, and 31 900 patients in the alendronate, raloxifene, and calcitonin groups, and the mean age was 74.5 years (SD, 9.6). The incidence of VTE in the alendronate, raloxifene, and calcitonin groups was 11.2, 8.5, and 18.8 per 10 000 person-years. Results from Cox analyses showed that alendronate or raloxifene recipients did not have a higher risk for VTE than calcitonin recipients (adjusted hazard ratio for alendronate, 0.84; 95% confidence interval, 0.47-1.51; adjusted hazard ratio for raloxifene, 0.64; 95% confidence interval, 0.33-1.28). CONCLUSION: This retrospective analysis found that the incidence of VTE in Taiwanese patients with osteoporosis was low, and the risk of VTE was similar across alendronate, raloxifene, and calcitonin recipients in patients with osteoporotic fractures who were new to osteoporosis therapy.

Engineering three-dimensional structures using bio-inspired dopamine and strontium on titanium for biomedical application.

The excellent mechanical properties and chemical stability of titanium and its alloys have led to their wide use as a material for dental and orthopaedic implants. However, the bio-inert nature of these materials must be overcome to enhance cell affinity and cell function following implantation. Effective implants require strong interfacial bonding, mechanical stability, osteoblast attachment, enhanced spreading and growth during early stages, and induced differentiation and mineralization in later stages. This study developed an organic-inorganic multilayer coating process for the modification of titanium implants in order to improve cell responses. A three-dimensional structure comprising strontium and micro-arc oxidized (MAO) titanium was covered with a film of poly(dopamine) to form a multilayer coating. The titanium surface formed a uniform hydrophilic oxide coating, which was firmly adhered to the surface. The poly(dopamine) film facilitated the initial attachment and proliferation of cells. Cell differentiation was enhanced by the release of strontium from the coatings. Our results demonstrate the efficacy of the proposed coating process in enhancing the multi-biological function of implant surfaces.