Prevalence of osteoporosis in patients awaiting unicompartmental knee arthroplasty: a cross-sectional study.

Objectives: Osteoporosis may contribute to failure of unicompartmental knee arthroplasty (UKA), yet the prevalence of osteoporosis in the population awaiting UKA has not been adequately studied. The objectives of this study were to report the prevalence of osteoporosis in people awaiting UKA and the rate of anti-osteoporosis treatment, and to explore factors associated with osteoporosis prevalence in people awaiting UKA. Methods: Participants awaiting UKA from January 2019 to May 2023 were consecutively enrolled. Participants ' age, gender, BMI, knee K-L score, VAS score, history of previous DXA testing, history of anti-osteoporosis treatment, and possible underlying risk factors were recorded. All participants were given a dual-energy x-ray absorptiometry (DXA) test after the visit. The diagnosis of osteoporosis was made according to the World Health Organization criteria. Compare the prevalence of osteoporosis between people waiting for UKA and the general population. Risk factors associated with osteoporosis were analyzed using multiple linear regression and binary logistic regression models. Results: A total of 340 participants were included in the study, 259 in female and 81 in male, with a mean age of 63.53 years (range: 41-84 years), and all participants completed UKA and had DXA prior to UKA. The prevalence of osteoporosis was 40.88% (44.79% in female and 28.40% in male). The prevalence of osteoporosis was higher in female than in male (p<0.001). The prevalence of osteoporosis in the population waiting for UKA was significantly higher than that in the general population (p < 0.001). DXA testing was performed in 12.06% within 1 year prior to the visit. The percentage of those who had received anti-osteoporosis treatment was 20.59% (20.86% in osteoporosis, 22.39% in Osteopenia and 16.42% in normal bone mass). The correlation between age, gender, body mass index, visual analogue scale score and osteoporosis was statistically significant. Conclusion: Osteoporosis is common in people waiting for UKA, but screening and treatment rates are low. Female patients of advanced age and low weight combined with significant pain should be considered for osteoporosis screening and appropriate treatment before UKA.

[Comparison of outcomes of mixed unicompartmental knee arthroplasty and total knee arthroplasty in the treatment of medial osteoarthritis of the knee].

OBJECTIVE: To evaluate outcomes of mixed unicompartmental knee arthroplasty(UKA) and total knee arthroplasty(TKA) in the treatment of medial osteoarthritis(OA) of the knee. METHODS: Retrospective analysis of 156 patients, 44 males and 112 females, aged from 50 to 75 years old with an average of(58.76±4.97) years old, who underwent knee arthroplasty from October 2017 to October 2019. The patients were divided into two groups:81 cases(81 knees) underwent TKA, including 23 males and 58 females, aged from 51 to 75 years old with an average of (58.60±5.01) years old, and 75 case (75 knees) underwent UKA with mixed phase 3 Oxford, including 21 males and 54 females, aged from 50 to 72 years old with an average of (58.92±4.95) years old. The two groups were compared regarding to the clinical outcomes, assessed using surgical information and complications, American Knee Society score(AKSS) clinical score and functional score. Radiographs were assessed using hip-knee-ankle angle(HKA), tibial component valgus/varus angle(TCVA), tibial component posterior slope angle(TCPSA), femoral component valgus/varus angle(FCVA), femoral component posterior slope angle(FCPSA), looking for bearing dislocation, prosthesis loosening, progression of OA in lateral compartment. RESULTS: Intraoperative bleeding, operative time and hospital days were significantly better in the UKA group than in the TKA group (P<0.05), and there were no postoperative complications in either group. Patients in both groups were enrolled with an average follow-up time of (38.01±8.90) months, ranged from 24 to 54 months. AKSS functional, AKSS clinical, HKA in both groups significantly improved at the final follow-up compared with those before operation. At the final follow-up, the UKA group was significantly better than the TKA group in AKSS functional and AKSS clinical, whereas HKA in the TKA group was better. At the final follow-up. TCVA and FCVA between the two groups were not significantly different, while TCPSA and FCPSA in the UKA group were significantly greater than the TKA group. No signs of progression of OA to the lateral compartment were observed. CONCLUSION: Mixed phase 3 Oxford UKA in medial unicompartmental knee osteoarthritis was considerably better than TKA for less blood loss, shorter operation time, shorter hospital stay, rapid postoperative recovery, helping achieve satisfactory function, provided satisfactory outcome.

miR-126 mitigates the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells by targeting the ERK1/2 and Bcl-2 pathways.

Human bone marrow mesenchymal stem cells (hBMMSCs) are a promising cell source for bone engineering owing to their high potential to differentiate into osteoblasts. The objective of the present study is to assess microRNA-126 (miR-126) and examine its effects on the osteogenic differentiation of hBMMSCs. In this study, we investigate the role of miR-126 in the progression of osteogenic differentiation (OD) as well as the apoptosis and inflammation of hBMMSCs during OD induction. OD is induced in hBMMSCs, and matrix mineralization along with other OD-associated markers are evaluated by Alizarin Red S (AR) staining and quantitative PCR (qPCR). Gain- and loss-of-function studies are performed to demonstrate the role of miR-126 in the OD of hBMMSCs. Flow cytometry and qPCR-based cytokine expression studies are performed to investigate the effect of miR-126 on the apoptosis and inflammation of hBMMSCs. The results indicate that miR-126 expression is downregulated during the OD of hBMMSCs. Gain- and loss-of function assays reveal that miR-126 upregulation inhibits the differentiation of hBMMSCs into osteoblasts, whereas the downregulation of miR-126 promotes hBMMSC differentiation, as assessed by the determination of osteogenic genes and alkaline phosphatase activity. Furthermore, the miR-126 level is positively correlated with the production of inflammatory cytokines and apoptotic cell death. Additionally, our results suggest that miR-126 negatively regulates not only B-cell lymphoma 2 (Bcl-2) expression but also the phosphorylation of extracellular signal­regulated protein kinase (ERK) 1/2. Moreover, restoring ERK1/2 activity and upregulating Bcl-2 expression counteract the miR-126-mediated suppression of OD in hBMMSCs by promoting inflammation and apoptosis, respectively. Overall, our findings suggest a novel molecular mechanism relevant to the differentiation of hBMMSCs into osteoblasts, which can potentially facilitate bone formation by counteracting miR-126-mediated suppression of ERK1/2 activity and Bcl-2 expression.

Predicting Collapse in Osteonecrosis of the Femoral Head Using a New Method: Preserved Angles of Anterior and Lateral Femoral Head.

BACKGROUND: Femoral head collapse (FHC) is associated with a poor prognosis in osteonecrosis of the femoral head (ONFH). Preserved angles (PAs), including the lateral preserved angle (LPA), the anterior preserved angle (APA) and the combined preserved angle (CPA), can be used to quantify the extent of femoral head necrosis and predict the risk of femoral head collapse. The purpose of this retrospective cohort study was to assess the efficacy of these preserved angles in the prediction of femoral head collapse using plain radiographs. METHODS: Patients with ONFH treated conservatively between January 2010 and January 2019 were analyzed retrospectively to assess the risk of FHC. A logistic regression model was used to evaluate the independent prognostic factors associated with FHC, including age, sex, etiology, onset of symptom, The Japanese Investigation Committee classification, and PAs (LPA, APA, and CPA). RESULTS: A total of 137 patients, with 180 hips, had follow-up of at least two years and were included. During the follow-up period, FHC occurred in 89 hips (49.44%) after the initial diagnosis. Multivariable analysis indicated that CPA (odds ratio [OR] = 0.95; 95%CI = 0.93-0.97; P < 0.01) was a stronger predictor of femoral head collapse compared with the Japanese Investigation Committee classification (OR = 2.40, 95%CI = 0.92-6.25; P > 0.01). The receiver operating characteristic and survival curve analyses revealed that the predictive cutoff point for the CPA was 118.7° (sensitivity = 96.70%, specificity = 79.78%, log-rank test: P < 0.01). CONCLUSIONS: Assessment of preserved angles on plain radiographs is a simple method to quantify the extent of lateral and anterior necrosis of the femoral head. Specifically, CPA has a potential value in predicting femoral head collapse.

SOCS1, the feedback regulator of STAT1/3, inhibits the osteogenic differentiation of rat bone marrow mesenchymal stem cells.

Our study showed that Signal transducer and activator of transcription (STAT)1 and STAT3 phosphorylation was firstly upregulated in the early stage of osteogenic differentiation (OD), and quickly eliminated in hours. Following with phosphorylation of STAT1/3, its downstream feedback regulator Suppressor of cytokine signaling 1 (SOCS1) protein also underwent a quick elevation. Further activation and deactivation of STAT1/3, by administrated with Colivelin and Nifuroxazide in Bone mesenchymal stem cells (BMSCs), increased and decreased SOCS1 expression, inhibited and promoted OD of BMSCs, respectively, as evidenced by Alizarin staining, alkaline phosphatase (ALP) activity, and determination of Run-related transcription factor 2 (RUNX2), Osteocalcin (OCN), ALP, and Bone sialoprotein (BSP). In addition, administration of Colivelin and Nifuroxazide caused and blocked inflammation and apoptosis of BMSCs. To further elucidate the role of STAT1/3-SOCS1 regulatory loop on OD of BMSCs, we overexpressed or silenced SOCS1 in BMSCs during OD. WB data showed that overexpression of SOCS1 repressed STAT1/3 phosphorylation, and knockdown of SOCS1 increased the phosphorylated STAT1/3. Further mechanism study showed that OD of BMSCs was elevated or reduced by SOCS1 overexpression or knockdown, respectively. The findings presenting indicated that the STAT1/3-SOCS1 axis may be exploited as an innovative strategy to enhance osteogenesis in regenerative medicine.

Long noncoding RNA XIST modulates microRNA-135/CREB1 axis to influence osteogenic differentiation of osteoblast-like cells in mice with tibial fracture healing.

Fracture healing is a complex event with the involvement of many cell systems, cytokines, as well as mRNAs. Herein, we report the interactions among long noncoding RNA X-inactive specific transcript (XIST)/microRNA-135 (miR-135)/cAMP response element-binding protein 1 (CREB1) axis during fracture healing. We observed increased expression of XIST in patients with long-term unhealed fracture by microarray analysis. Subsequently, a mouse model with tibial fracture and a cell model using osteoblast-like MC3T3-E1 cells were generated. The XIST overexpression during fracture healing decreased proliferation and differentiation of MC3T3-E1 cells, while silencing of XIST facilitated MC3T3-E1 cell growth. Furthermore, miR-135 targeted CREB1 and negatively regulated its expression. XIST acted as a sponge for miR-135, thereby upregulating CREB1 and promoting the activity of the TNF-α/RANKL pathway. Transfection of miR-135 inhibitor or CREB1 overexpression blocked the stimulating effects of XIST knockdown on MC3T3-E1 cell growth. Besides, specific inhibitors of the TNF-α/RANKL pathway reversed the repressive role of XIST in cell osteogenic differentiation. All in all, these findings suggest that XIST knockdown induces the differentiation of osteoblast-like cells via regulation of the miR-135/CREB1/TNF-α/RANKL axis. XIST, as a consequence, represents an attractive therapeutic strategy to accelerate fracture healing.

Overexpression of fucosyltransferase 8 reverses the inhibitory effect of high-dose dexamethasone on osteogenic response of MC3T3-E1 preosteoblasts.

BACKGROUND: Core fucosylation catalyzed by FUT8 is essential for TGF-ß binding to TGF-ß receptors. METHODS: Indirect TGF-ß1 binding assay was used to evaluate the ability of TGF-ß1 to bind to TGFBRs, Alizarin red and alkaline phosphatase staining were used to detect osteogenic differentiation and mineralization ability , western blot and quantitative RT-PCR were used to measure the differential expression of osteogenesis-related proteins and genes. Plasmid-mediated gain-of-function study. The scale of core fucosylation modification was detected by Lectin-blot and LCA laser confocal. RESULTS: Our results showed that compared with vehicle treatment, high-dose (10-6 and 10-5 M) dexamethasone significantly inhibited cell proliferation, osteogenic differentiation, and FUT8 mRNA expression while promoting mRNA expression of adipogenesis-related genes in MC3T3-E1 cells, suggesting that downregulation of FUT8 is involved in the inhibitory effect of high-dose dexamethasone on osteogenesis. Overexpression of FUT8 significantly promoted osteogenic differentiation and activated TGF-ß/Smad signaling in MC3T3-E1 cells in the presence of high-dose dexamethasone, suggesting that FUT8 reverses the inhibitory effect of high-dose dexamethasone on osteogenesis. In addition, lectin fluorescent staining and blotting showed that overexpression of FUT8 significantly reversed the inhibitory effects of high-dose dexamethasone on core fucosylation of TGFBR1 and TGFBR2. Furthermore, indirect TGF-ß1 binding assay showed that overexpression of FUT8 remarkably promoted TGF-ß1 binding to TGFBRs in MC3T3-E1 cells in the presence of high-dose dexamethasone. CONCLUSIONS: Taken together, these results suggest that overexpression of FUT8 facilitates counteracting the inhibitory effect of dexamethasone on TGF-ß signaling and osteogenesis.

Avascular necrosis after femoral neck fracture in children and adolescents: poor prognosis and risk factors.

INTRODUCTION: Avascular necrosis (AVN) after femoral neck fracture (FNF) is a rare and severe paediatric condition, but only few studies described its prognosis and risk factors. The present study aimed to evaluate the outcomes and independent factors for poor prognosis of AVN after FNF in children and adolescents. METHOD: This retrospective study included children and adolescents with AVN after FNF who received conservative treatment (CT group) or non-vascularized bone grafting (NVBG group) between 2000 and 2018. The primary outcomes were the risk of hip arthritis (Tönnis grade) and hip deformity risk (Stulberg classification). All patients were followed for at least two years to assess AVN progression. RESULTS: Study included 81 patients. In the CT group, 23/43 patients (53.4%) developed hip arthritis, and 24/43 patients (55.8%) showed hip deformity. In the NVBG group, 23/38 patients (60.5%) developed hip arthritis, and 34/38 patients (89.5%) had a hip deformity. The multivariable analysis indicated that NVBG surgery had no significant effect on the outcomes. Post-treatment femoral head collapse (P = 0.05, OR = 3.80, 95% CI = 1.01-14.29) and post-treatment hip subluxation (P = 0.01, OR = 2.85, 95% CI = 2.31-129.56) were independent risk factors for severe hip arthritis. Post-treatment femoral head collapse (P < 0.01, OR = 7.64, 95% CI = 3.23-18.04) and pre-treatment hip subluxation (P = 0.02, OR = 7.33, 95% CI = 1.44-37.41) were independent risk factors for severe hip deformity. CONCLUSION: Neither CT nor NVBG have demonstrated superiority regarding long-term outcomes in patients with AVN after FNF. Upon the disease progression to severe collapse with subluxation and severe arthritis, further hip preservation attempts could be futile.

Osteoporosis is associated with varus deformity in postmenopausal women with knee osteoarthritis: a cross-sectional study.

BACKGROUND: Varus deformity of the knee is a common pathological characteristic in knee osteoarthritis (KOA), and not enough attention has been given to the relationship between knee varus deformity and the state of systemic bone mass. The purpose of this study was to evaluate the potential relationship between bone mineral density (BMD) and varus deformity in postmenopausal women with KOA. METHODS: A total of 202 postmenopausal women with KOA(KL grade ≥ 2)in our department from January 2018 to June 2020 were reviewed in this cross-sectional study. The hip-knee-ankle angle of the lower extremity (HKA), medial distal femoral angle (MDFA), medial proximal tibial angle (MPTA), and the angle of the joint line (JLCA) were measured in all patients. According to the HKA Angle, these participants were divided into the varus deformity group (HKA < 175.3°) and the normal limb alignment group (175.3°≤ HKA ≤ 180.3°). The BMD of the lumbar (L1-L4), left femoral neck, and left hip were measured by dual-energy X-ray absorptiometry in all patients. The difference in BMD between the knee varus deformity group and the normal limb alignment group was compared, and the relationship between the different angles of limb alignment and the BMD values at different sites was evaluated. RESULTS: There were 144 cases (71.3 %) in the varus deformity group and 58 cases (28.7 %) in the normal limb alignment group. BMD at different joint sites within the knee varus deformity group was lower than of the normal limb alignment group, and the prevalence of osteoporosis was higher. After adjusting for confounding factors such as age, BMI, pain duration, and affected side, binary logistic regression showed that osteoporosis was an independent risk factor for varus deformity of KOA, and multiple linear regression showed that the BMD of spine, femoral neck, and hip was significantly associated with varus deformity of KOA. Pearson correlation analysis showed that BMD of the lumbar spine (L1-L4), left femoral neck and left hip joint were positively correlated with the HKA, but negatively correlated with JLCA. MPTA was positively correlated with the left femoral neck and left hip joint BMD, but not correlated with lumbar bone density. Furthermore, in the normal limb alignment group, the HKA was only negatively correlated with JLCA, but not significantly correlated with MDFA and MPTA. In the varus deformity group, the HKA was not only negatively correlated with JLCA but also positively correlated with MDFA and MPTA. CONCLUSIONS: Osteoporosis should be a major risk factor for varus deformity in postmenopausal women with KOA. The progression of varus deformity of the knee should be concerned in postmenopausal women who simultaneously has KOA and osteoporosis.

Inhibition of miR-93-5p promotes osteogenic differentiation in a rabbit model of trauma-induced osteonecrosis of the femoral head.

Trauma-induced osteonecrosis of the femoral head (TIONFH) is characterized by femoral head collapse accompanied by degenerative changes of the hip. We previously reported that miR-93-5p expression is abnormally high in patients with TIONFH, but the role of miR-93-5p in the TIONFH process remains unclear. Herein, we investigated the role of miR-93-5p in TIONFH in a rabbit model. Bone marrow mesenchymal stem cells (BMSCs) were used for both in vivo and in vitro experiments. A rabbit model of TIONFH was injected with BMSCs transfected with miR-93-5p inhibitor. In addition, both an miR-93-5p mimic and negative control were transfected into BMSCs. Expression of miR-93-5p was significantly increased in the model group compared with control samples. An miR-93-5p inhibitor induced the expression of bone morphogenetic protein 2 (BMP-2) and alkaline phosphatase. Furthermore, expression of osteogenesis-related markers (BMP-2, secreted phosphoprotein 1, RUNX family transcription factor 2 and Osterix) was higher in the miR-93-5p inhibitor group, as revealed by quantitative PCR and western blotting. In addition, in vitro experimentation revealed that an miR-93-5p mimic decreased BMP-2 and TNF receptor superfamily member 11b expression, but increased receptor activator of nuclear factor-kappaB ligand expression. In summary, the miR-93-5p inhibitor could promote osteogenic differentiation by increasing BMP-2 expression during the development of TIONFH. Thus, miR-93-5p may have potential as a therapeutic target for TIONF treatment.

CircRNA_25487 inhibits bone repair in trauma-induced osteonecrosis of femoral head by sponging miR-134-3p through p21.

We aimed to identify specific circular RNAs (circRNAs) involved in bone repair of trauma-induced osteonecrosis of femoral head (TIONFH) and to explore the potential mechanism. CircRNA sequencing on the blood sample collected from patients with and without TIONFH was performed to select cirRNAs that were significantly differentially expressed, followed by qRT-PCR confirmation. Furthermore, the functions of one selected circRNA and the potential mechanisms in bone repair of TIONFH were validated based on the bone marrow mesenchymal stem cells (BMSCs) and osteoclast-like cells (OLCs) through CCK-8, flow cytometry, transwell assay, luciferase reporter assay, and western blot. A total of 234 upregulated and 148 downregulated differentially expressed circRNAs were identified, and qRT-PCR showed that circRNA_25487 was significantly upregulated in the peripheral blood of TIONFH patients. Luciferase reporter assay confirmed the binding effect between miR-134-3p and circRNA_25487. CircRNA_25487 suppression and miR-134-3p overexpression could promote cell proliferation and invasion while inhibited apoptosis of BMSCs and OLCs. miR-134-3p could target p21. CircRNA_25487 inhibited bone repair in TIONFH by sponging miR-134-3p to upregulate the expression of p21.

Relationship between hip joint medial space ratio and collapse of femoral head in non-traumatic osteonecrosis: a retrospective study.

To retrospectively analyze the medial space ratio (MSR) of the hip joint to evaluate its efficacy in predicting osteonecrosis of femoral head (ONFH)-induced collapse and its impacts on the mechanical environment of necrotic femoral head. In this retrospective analysis of traditional Chinese medicine, non-traumatic ONFH (NONFH) patients from January 2008 to December 2013 were selected. The patients were divided into collapse group and non-collapse group based on whether the femoral head collapsed. The anatomical parameters including center-edge (CE) angle, sharp angle, acetabular depth ratio and MSR were evaluated. Receiver operating characteristic curves were estimated to evaluate the sensitivity and specificity of MSR and CE angle in collapse prediction. The results showed that 135 patients (151 hips) were included in this study. The differences in CE angle and MSR between collapse group and non-collapse group were statistically significant. The mean survival time of the hips of patients with MSR <20.35 was greater (P < 0.001) than that of patients with MSR >20.35. The ONFH patients with MSR >20.35 were prone to stress concentration. We could conclude that the hip joint MSR and CE angle strongly correlated with the collapse of NONFH. The specificity of MSR is higher than that of CE angle. When MSR is >20.35, the collapse rate of ONFH will increase significantly.

Diagnosis, preoperative evaluation, classification and total hip arthroplasty in patients with long-term unreduced hip joint dislocation, secondary osteoarthritis and pseudoarthrosis.

BACKGROUND: Neglected long-term unreduced hip joint dislocation with secondary osteoarthritis and pseudoarthrosis poses a great challenge to hip surgeons. However, as this is an uncommon injury, few studies have systematically investigated these patients. METHODS: We retrospectively reviewed 16 patients from 2010 to 2017. The diagnostic values of three different types of common radiological examinations were evaluated. We evaluated the bone conditions of the original acetabulum and classified the patients into three types (four subtypes). The surgical procedures and prognosis of the patients were also investigated. RESULTS: With the combined application of X-ray, CT scans and 3D reconstruction, 93.8% of these patients (sensitivity = 93.8%, Youden's index = 0.93, intraclass correlation coefficient = 0.95) could be diagnosed correctly. There were 6/16 (37.5%) type A patients, 4/16 (25.0%) type B1 patients, 5/16 (31.3%) type B2 patients and 1/16 (6.3%) type C patient. For patients with type A injury, the surgical procedures for total hip arthroplasty were similar to "standard" total hip arthroplasty. For patients with type B injury, due to atrophy or partial bone deficiency of the original acetabulum, the surgical procedure for total hip arthroplasty was probably similar to those for patients with developmental dysplasia of the hip. For patients with type C injury, the situation was similar to that of revision surgery. The average Harris hip score postoperatively was 89.94 ± 5.78 points (range: 79-98 points). CONCLUSIONS: The new classification system could help surgeons estimate potential difficulties during total hip arthroplasty. The prognosis of most patients after total hip arthroplasty is expected to be excellent or good.

Pathological progress of traumatic femur head necrosis after femoral neck fracture in children and adolescents: a case series study.

The pathological progression and prognosis of traumatic femur head necrosis (TFHN) after femoral neck fracture (FNF) in children and adolescent is relatively unknown and has never been specifically characterized. As we speculated, the prognosis in such population would be poor and characterized as the high risk of femoral head collapse, hip deformity and degeneration in a short term. This retrospective case series enrolled 64 children and adolescent with TFHN who treated with observational treatment from 2000.1 to 2018.1. The primary outcomes, the progression of femoral head collapse, hip deformity (Stulberg classification) and hip degeneration (Tönnis grade), and their prognostic factors were analysed. Sixty-four patients with a mean age of 13 years (6-16 years) were included. A total of 28 hips (44%) showed unsatisfactory outcome and 25 (39%) hips collapsed progressively during a mean follow-up of 48 months (24-203 months). Finally, 38 hips (59%) experienced hip deformity, 20 of them were Class IV/V. Thirty-four hips (53%) generally progressed to osteoarthritis, 14 of them were classified as Grades II/III. The location of the lesion and the presence of subluxation were found to be related to progression of collapse; however, the presence of subluxation was the only independent risk factor of severe hip deformity and degeneration. TFHN in children and adolescent is a rapidly progressing disease with a poor prognosis characterized by a high risk of femoral head collapse progression. If the subluxation emerged, collapsed cases showed increasingly tendency towards hip deformity and degeneration.

[Effectiveness of total knee arthroplasty using three-dimensional printing technology for knee osteoarthritis accompanied with extra-articular deformity].

Objective: To evaluate the effectiveness of total knee arthroplasty (TKA) using three-dimensional (3D) printing technology for knee osteoarthritis (KOA) accompanied with extra-articular deformity. Methods: Between March 2013 and December 2015, 15 patients (18 knees) with extra-articular deformity and KOA underwent TKA. There were 6 males (6 knees) and 9 females (12 knees), aged 55-70 years (mean, 60.2 years). The mean disease duration was 10.8 years (range, 7-15 years). The unilateral knee was involved in 12 cases and bilateral knees in 3 cases. The clinical score was 57.44±1.06 and the functional score was 60.88±1.26 of Knee Society Score (KSS). The range of motion of the knee joint was (72.22±0.18)°. The deviation of mechanical axis of lower limb was (18.89±0.92)° preoperatively. There were 8 cases (10 knees) with extra-articular femoral deformity, 5 cases (5 knees) with extra-articular tibial deformity, and 2 cases (3 knees) with extra-articular femoral and tibial deformities. Bone models and the navigation templates were printed and the operation plans were designed using 3D printing technology. The right knee joint prostheses were chosen. Results: The operation time was 65-100 minutes (mean, 75.6 minutes). The bleeding volume was 50-150 mL (mean, 90.2 mL). There was no poor incision healing, infection, or deep venous thrombosis after operation. All patients were followed up 12- 30 months (mean, 22 months). Prostheses were located in the right place, and no sign of loosening or subsidence was observed by X-ray examination. At last follow-up, the deviation of mechanical axis of lower limb was (2.00±0.29)°, showing significant difference when compared with preoperative one ( t=13.120, P=0.007). The KSS clinical score was 87.50±0.88 and function score was 81.94±1.41, showing significant differences when compared with preoperative ones ( t=27.553, P=0.000; t=35.551, P=0.000). The range of motion of knee was (101.94±1.42)°, showing significant difference when compared with preoperative one ( t=31.633, P=0.000). Conclusion: For KOA accompanied with extra-articular deformity, TKA using 3D printing technology has advantages such as individualized treatment, reducing the difficulty of operation, and achieving the satisfactory function.

Optimized Parallelization for Nonlocal Means Based Low Dose CT Image Processing.

Low dose CT (LDCT) images are often significantly degraded by severely increased mottled noise/artifacts, which can lead to lowered diagnostic accuracy in clinic. The nonlocal means (NLM) filtering can effectively remove mottled noise/artifacts by utilizing large-scale patch similarity information in LDCT images. But the NLM filtering application in LDCT imaging also requires high computation cost because intensive patch similarity calculation within a large searching window is often required to be used to include enough structure-similarity information for noise/artifact suppression. To improve its clinical feasibility, in this study we further optimize the parallelization of NLM filtering by avoiding the repeated computation with the row-wise intensity calculation and the symmetry weight calculation. The shared memory with fast I/O speed is also used in row-wise intensity calculation for the proposed method. Quantitative experiment demonstrates that significant acceleration can be achieved with respect to the traditional straight pixel-wise parallelization.