The influence of diabetes and age-related degeneration on body balance control during static standing: a study based on plantar center-of-pressure trajectories and principal component analysis.

BACKGROUND: Aging and diabetes can impair the balance function of the elderly and diabetic patients and increase their fall risk. This study aimed to assess the shaking amplitude of the center-of-pressure (CoP) during static standing, to analyze the effects of aging and diabetes on the balance control. MATERIALS AND METHODS: This cross-sectional observational study, compared the balance performance of 20 healthy younger adults (27.65 ± 5.60 years), 16 healthy older adults (58.88 ± 3.54 years) and 15 diabetic patients (58.33 ± 5.33 years) in four static standing conditions on a force plate: horizontal, anteroposterior (AP), left and right slope planes (5° angles on AP, left and right directions, respectively). The trajectory coordinates of the CoP over time were recorded and analyzed by principal components analysis to obtain the 95% confidence ellipse and its parameters: angle, major and minor axes lengths, and area. The balance indicators were compared among the three groups using one-way analysis of variance (ANOVA), Brown-Forsythe test or Kruskal-Wallis H test, depending on the normality and homogeneity of variance assumptions. RESULTS: The diabetic group had a significantly larger confidence ellipse area than the healthy younger adults on the horizontal plane (P = 0.032) and than the healthy older adults on the horizontal (P = 0.036), AP slope (P = 0.023), and right ML slope (P = 0.037) planes. There were no significant differences in the major axis length of the confidence ellipse among the three groups. The diabetic group had a significantly longer minor axis length than the healthy younger adults on the AP slope (P = 0.039), left ML slope (P = 0.045) and right ML slope (P = 0.016) planes and than the healthy older adults on the AP slope (P = 0.007), left ML slope (P = 0.035) and right ML slope (P = 0.012) planes. CONCLUSIONS: The balance control of diabetic patients is decreased compared with healthy younger and older people, and the body swing amplitude increases mainly in the direction of minor axis of confidence ellipse during static standing, while the swing amplitude in the direction of the major axis has no significant change. Evaluating the balance function of diabetic patients can help clinicians identify people with fall risk early and intervene early, thereby reducing the occurrence of fall events in this population.

Is a Preoperative MRI Scan Necessary for Acute Achilles Tendon Rupture?

BACKGROUND: Different treatment methods have been developed for acute Achilles tendon rupture (ATR), including conservative treatment, minimally invasive or transdermal surgery, and open surgery, and there is no consensus about which method is superior. It is important to clarify the presence of Achilles tendon (AT) degeneration, the rupture site, and the rupture shape before surgery to determine whether minimally invasive or open surgery should be selected, thereby reducing the re-rupture rate following acute ATR. The aim of this study was to investigate the diagnostic value of MRI in identifying the presence of AT degeneration, the rupture site, and the rupture shape for acute closed ATR. METHODS: From January 2016 to December 2019, patients with acute closed ATR who had undergone repair surgery were retrospectively enrolled. All patients received MRI examination, and the distance between the insertion site and broken end and the rupture shape (types I, II, and III) were independently determined by two observers. Then, the stump of the AT was exposed during the operation. The rupture site and rupture shape were recorded and compared and analyzed with the MRI results. Consistency analyses (using Cohen's kappa coefficient or intraclass correlation coefficient-ICC) and calculation of diagnostic performance indexes were, respectively, conducted to evaluate the diagnostic value of the MRI. RESULTS: This study included 47 consecutive patients with acute ATR, with an average age of 38.4 years. Among them, 40 were male, and seven were female. The intraoperative exploration demonstrated a total of 34 (72.3%), 10 (21.3%), and three (6.4%) patients with type I, II, and III ruptures, respectively. The average distance between the insertion site and the proximal broken end measured intraoperatively was 4.07 ± 1.57 cm. High or excellent consistencies were found for ATR classifications (kappa: 0.739-0.770, p < 0.001) and rupture sites (ICC: 0.962-0.979, p < 0.001) between two observers and between observers 1 and 2 and intraoperative findings. Tendinopathy was identified in 22 patients by MRI and confirmed during surgery. CONCLUSIONS: MRI scanning of acute closed ATR can help determine whether there is degeneration of the AT, as well as the location and shape of the rupture, which can guide the selection of the optimal operation method for orthopedic surgeons. Therefore, it is necessary to take preoperative MRI scans for patients with acute Achilles tendon ruptures.

Comparison of material properties of heel pad between adults with and without type 2 diabetes history: An in-vivo investigation during gait.

Objective: This study was aimed to compare the material properties of heel pad between diabetes patients and healthy adults, and investigate the impact of compressive loading history and length of diabetes course on the material properties of heel pad. Methods: The dual fluoroscopic imaging system (DFIS) and dynamic foot-ground contact pressure-test plate were used for measuring the material properties, including primary thickness, peak strain, peak stress, stiffness, viscous modulus and energy dissipation ratio (EDR), both at time zero and following continuous loading. Material properties between healthy adults and DM patients were compared both at time zero and following continuous weight bearing. After then, comparison between time-zero material properties and properties following continuous loading was performed to identify the loading history-dependent biomechanical behaviour of heel pad. Subgroup-based sensitivity analysis was then conducted to investigate the diabetes course (<10 years vs. ≥10 years) on the material properties of heel pad. Results: Ten type II DM subjects (20 legs), aged from 59 to 73 (average: 67.8 ± 4.9), and 10 age-matched healthy adults (20 legs), aged from 59 to 72 (average: 64.4 ± 3.4), were enrolled. Diabetes history was demonstrated to be associated with significantly lower primary thickness (t=3.18, p=0.003**), higher peak strain (t=2.41, p=0.021*), lower stiffness (w=283, p=0.024*) and lower viscous modulus (w=331, p<0.001***) at time zero, and significantly lower primary thickness (t=3.30, p=0.002**), higher peak strain (w=120, p=0.031*) and lower viscous modulus (t=3.42, p=0.002**) following continuous loading. The continuous loading was found to be associated with significantly lower primary thickness (paired-w=204, p<0.001***) and viscous modulus (paired-t=5.45, p<0.001***) in healthy adults, and significantly lower primary thickness (paired-w=206, p<0.001***) and viscous modulus (paired-t=7.47, p<0.001***) in diabetes group. No any significant difference was found when conducting the subgroup analysis based on length of diabetes course (<10 years vs. ≥10 years), but the regression analysis showed that the length of diabetes history was positively associated with the peak strain, at time zero (r=0.506, p<0.050) and following continuous loading (r=0.584, p<0.010). Conclusions: Diabetes patients were found to be associated with decreased primary thickness and viscous modulus, and increased peak strain, which may contribute to the vulnerability of heel pad to injury and ulceration. Pre-compression history-dependent behaviour is observable in soft tissue of heel pad, with lowered primary thickness and viscous modulus.

Effect of loading history on material properties of human heel pad: an in-vivo pilot investigation during gait.

BACKGROUND: This study was aimed to develop a novel dynamic measurement technique for testing the material properties and investigating the effect of continuous compression load on the structural and mechanical properties of human heel pad during actual gait. METHODS: The dual fluoroscopic imaging system (DFIS) and dynamic foot-ground contact pressure-test plate were used for measuring the material properties, including primary thickness, peak strain, peak stress, elastic modulus, viscous modulus and energy dissipation rate (EDR), both at time zero and following continuous loading. Ten healthy pilot subjects, aged from 23 to 72 (average: 46.5 ± 17.6), were enrolled. A "three-step gait cycle" is performed for all subjects, with the second step striking at a marked position on the force plate with the heel to maintain the location of the tested foot to be in the view of fluoroscopes. The subjects were measured at both relaxed (time-zero group) and fatigue (continuous-loading group) statuses, and the left and right heels were measured using the identical procedures. RESULTS: The peak strain, peak stress, elastic modulus, and EDR are similar before and after continuous load, while the viscous modulus was significantly decreased (median: 43.9 vs. 20.37 kPa•s; p < 0.001) as well as primary thicknesses (median: 15.99 vs. 15.72 mm; p < 0.001). Age is demonstrated to be moderately correlated with the primary thicknesses both at time zero (R = -0.507) and following continuous load (R = -0.607). The peak stress was significantly correlated with the elastic modulus before (R = 0.741) and after continuous load (R = 0.802). The peak strain was correlated with the elastic modulus before (R = -0.765) and after continuous load (R = -0.801). The correlations between the viscous modulus and peak stress/ peak strain are similar to above(R = 0.643, 0.577, - 0.586 and - 0.717 respectively). The viscous modulus is positively correlated with the elastic modulus before (R = 0.821) and after continuous load (R = 0.784). CONCLUSIONS: By using dynamic fluoroscopy combined with the plantar pressure plate, the in vivo viscoelastic properties and other data of the heel pad in the actual gait can be obtained. Age was negatively correlated with the primary thickness of heel pad and peak strain, and was positively correlated with viscous modulus. Repetitive loading could decrease the primary thickness of heel pad and viscous modulus.

A novel tool for predicting the survival of endoprosthesis used for reconstruction of the knee following tumor resection: a retrospective cohort study.

BACKGROUND: Prosthesis-related complications, after knee reconstruction with endoprosthesis during operation for tumors around the knee, remain an unresolved problem which necessitate a revision or even an amputational surgery. The purpose of the current study was to identify significant risk factors associated with implant failure, and establish a novel model to predict survival of the prosthesis in patients operated with endoprostheses for tumor around knee. METHODS: We retrospectively reviewed the clinical database of our institution for patients who underwent knee reconstruction due to tumors. A total of 203 patients were included, including 123 males (60.6%) and 80 (39.4%) females, ranging in age from 14 to 77 years (mean: 34.3 ± 17.3 years). The cohort was randomly divided into training (n = 156) and validation (n = 47) samples. Univariable COX analysis was used for initially identifying potential independent predictors of prosthesis survival with the training group (p < 0.150). Multivariate COX proportional hazard model was selected to identify final significant prognostic factors. Using these significant predictors, a graphic nomogram, and an online dynamic nomogram were generated for predicting the prosthetic survival. C-index and calibration curve were used for evaluate the discrimination ability and accuracy of the novel model, both in the training and validation groups. RESULTS: The 1-, 5-, and 10-year prosthetic survival rates were 94.0, 90.8, and 83.0% in training sample, and 96.7, 85.8, and 76.9% in validation sample, respectively. Anatomic sites, length of resection and length of prosthetic stem were independently associated with the prosthetic failure according to multivariate COX regression model (p<0.05). Using these three significant predictors, a graphical nomogram and an online dynamic nomogram model were generated. The C-indexes in training and validation groups were 0.717 and 0.726 respectively, demonstrating favourable discrimination ability of the novel model. And the calibration curve at each time point showed favorable consistency between the predicted and actual survival rates in training and validation samples. CONCLUSIONS: The length of resection, anatomical location of tumor, and length of prosthetic stem were significantly associated with prosthetic survival in patients operated for tumor around knee. A user-friendly novel online model model, with favorable discrimination ability and accuracy, was generated to help surgeons predict the survival of the prosthesis.

Nomogram for Predicting the Postoperative Venous Thromboembolism in Spinal Metastasis Tumor: A Multicenter Retrospective Study.

INTRODUCTION: Venous thromboembolism can be divided into deep vein thrombosis and pulmonary embolism. These diseases are a major factor affecting the clinical prognosis of patients and can lead to the death of these patients. Unfortunately, the literature on the risk factors of venous thromboembolism after surgery for spine metastatic bone lesions are rare, and no predictive model has been established. METHODS: We retrospectively analyzed 411 cancer patients who underwent metastatic spinal tumor surgery at our institution between 2009 and 2019. The outcome variable of the current study is venous thromboembolism that occurred within 90 days of surgery. In order to identify the risk factors for venous thromboembolism, a univariate logistic regression analysis was performed first, and then variables significant at the P value less than 0.2 were included in a multivariate logistic regression analysis. Finally, a nomogram model was established using the independent risk factors. RESULTS: In the multivariate logistic regression model, four independent risk factors for venous thromboembolism were further screened out, including preoperative Frankel score (OR=2.68, 95% CI 1.78-4.04, P=0.001), blood transfusion (OR=3.11, 95% CI 1.61-6.02, P=0.041), Charlson comorbidity index (OR=2.01, 95% CI 1.27-3.17, P=0.013; OR=2.29, 95% CI 1.25-4.20, P=0.017), and operative time (OR=1.36, 95% CI 1.14-1.63, P=0.001). On the basis of the four independent influencing factors screened out by multivariate logistic regression model, a nomogram prediction model was established. Both training sample and validation sample showed that the predicted probability of the nomogram had a strong correlation with the actual situation. CONCLUSION: The prediction model for postoperative VTE developed by our team provides clinicians with a simple method that can be used to calculate the VTE risk of patients at the bedside, and can help clinicians make evidence-based judgments on when to use intervention measures. In clinical practice, the simplicity of this predictive model has great practical value.

A Novel Prediction Tool for Overall Survival of Patients Living with Spinal Metastatic Disease.

OBJECTIVE: To identify the significant prognostic factors for overall survival in patients with spinal metastases and to establish an online widget for predicting survival with an interactive visual approach. METHODS: Patients operated for spinal metastases between 2010 and 2018 were retrospectively enrolled and were randomly divided into training and validation samples with a ratio of 7:3. Patients' characteristics were analyzed with univariate and multivariate Cox analyses to identify independent prognostic factors basing on the training sample. A shiny web tool was developed by transforming the fitted multivariable Cox model into a visual interface. Time-dependent area under the curve plot and calibration curve were generated to assess the discrimination ability and consistency of the novel model, both for the training and validation samples. RESULTS: A total of 265 consecutive patients were finally included, with 185 in the training sample and 80 in the validation sample. The primary tumor types, lesion site of metastasis, visceral metastasis, Frankel grade, operation category, number of surgical segments, and the preoperative percentage of lymphocyte were demonstrated to be significantly associated with overall survival. A novel shiny model (https://yang1209xg.shinyapps.io/predictspinalmetastasis/) that could provide predicted survival curve and median survival time was established, with favorable discrimination ability and consistency between predicted and actual survival both in internal and external data, according to time-dependent area under the curve plots and calibration curves. CONCLUSIONS: A user-friendly shiny app with favorable discrimination ability and consistency was released online for predicting the survival of patients with spinal metastases. A continuous survival curve and the predicted median survival time are available to guide the treatment planning.

Does Revision Anterior Cruciate Ligament (ACL) Reconstruction Provide Similar Clinical Outcomes to Primary ACL Reconstruction? A Systematic Review and Meta-Analysis.

More revisionary reconstruction procedures are required following failing anterior cruciate ligament (ACL) reconstructions, which are often regarded as a technique challenge with very limited goals. This study will be performed to compare the outcomes between groups of primary and revision knee reconstruction. Two observers conducted the literature retrieval from the platforms of PubMed, Embase, and CENTRAL. Studies which compared knee function and stability between primary and revisionary reconstructions were included. The data was synthesized by meta-analysis with fixed- or random-effects models as appropriate. A total of 10 eligible studies were included with 954 subjects in the primary group and 378 in the revision group. The International Knee Documentation Committee International Knee Documentation Committee (IKDC) subscores, side-to-side difference, and Lysholm score were demonstrated to be significantly improved at final follow-up in both groups, while Tegner score was not. The overall IKDC, Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm scores were significantly inferior in the revision group compared to the primary group. However, knee laxity according to side-to-side difference was demonstrated to be similar between the two groups. Revision ACL reconstruction (RACLR) could provide patients with excellent restoration of knee outcomes compared to the status before revision. Also, while knee function in the revision group was inferior to the primary group, knee stability was equivalent between the two groups at the final follow-up.

Conventional Radiotherapy and Stereotactic Radiosurgery in the Management of Metastatic Spine Disease.

Spinal metastases are a common manifestation of malignant tumors that can cause severe pain, spinal cord compression, pathological fractures, and hypercalcemia, and these clinical manifestations will ultimately reduce the health-related quality of life and even shorten life expectancy in patient with cancer. Effective management of spinal bone metastases requires multidisciplinary collaboration, including radiologists, surgeons, radiation oncologists, medical oncologists, and pain specialists. In the past few decades, conventional radiotherapy has been the most common form of radiotherapy, which can achieve favorable local control and pain relief; however, it lacks precise methods of delivering radiation and thus cannot provide sufficient tumoricidal dose. The advent of stereotactic radiosurgery has changed this situation by using highly focused radiation beams guided by 3-dimensional imaging to deliver a high biologic equivalent dose to the target region, and the spinal cord can be identified and excluded from the target volume to reduce the risk of radiation-induced myelopathy. Separation surgery can provide a 2- to 3-mm safe separation of tumor and spinal cord to avoid radiation-induced damage to the spinal cord. Targets for separation surgery include decompression of metastatic epidural spinal cord compression and spinal stabilization without partial or en bloc tumor resection. Combined with conventional radiotherapy, stereotactic radiosurgery can provide better local tumor control and pain relief. Several scoring systems have been developed to estimate the life expectancy of patients with spinal metastases treated with radiotherapy. Thorough understanding of radiotherapy-related knowledge including the dose-fractionation schedule, separation surgery, efficacy and safety, scoring systems, and feasibility of combination with other treatment methods is critical to providing optimal patient care.

A multicenter, descriptive epidemiologic survey of the clinical features of spinal metastatic disease in China.

OBJECTIVE: Spinal metastases have unique epidemiological features and treatment methods. Unfortunately, the relative scarcity of spinal metastases has limited the widespread development of descriptive epidemiological studies, especially in Asian countries. The purpose of this study was to describe the epidemiological characteristics of patients with metastatic spinal tumors in China between 2007 and 2019. METHODS: From January 2007 and July 2019, data on patients with spinal metastases were collected from five cancer centers in China, and demographic characteristics, primary tumor types, segments and numbers of vertebral lesions, disease-related scores, and treatment methods were reviewed. RESULTS: A total of 2228 patients with spinal metastases were reviewed in this study, including 1279 male patients and 949 female patients, and the male to female ratio was 1.35: 1. More than half of patients developed metastatic diseases between the ages of 50 years and 69 years (64%). Overall, lung cancer (824 cases, 37%) was the most common primary tumor type and the most common level of spinal involvement was multi-level of metastases (860 cases, 39%). 705 patients (32%) had undergone surgical treatments, 1028 patients (46%) had undergone radiotherapy for metastatic vertebrae, and 855 patients (38%) had received systemic treatments. The age, primary tumor type, number of involved vertebrae, Frankel grade, and spinal instability neoplastic score would affect the surgical decision-making. DISCUSSION: This study provides insight into the epidemiological characteristics of spinal metastasis and health care service utilization in spinal metastasis patients in China. ABBREVIATIONS: ICD-10: International Classification of Disease, Tenth Revision; VAS: Visual Analogue Scale; KPS: Karnofsky Performance Status; SINS: Spinal Instability Neoplastic Score; SOSG: Spine Oncology Study Group; MRI: Magnetic Resonance Imaging; CT: Computed Tomography; ECT: Emission Computed Tomography.

Clinical Outcomes of the Central Third Patellar Tendon Versus Four-strand Hamstring Tendon Autograft Used for Anterior Cruciate Ligament Reconstruction: A Systematic Review and Subgroup Meta-analysis of Randomized Controlled Trials.

BACKGROUND: The most frequently used auto-grafts for ACL reconstruction (ACLR) are bone-patellar tendon-bone (BPTB) and four-strand hamstring tendon (4S-HT), but significant controversy exists about which graft is better. This study aimed to compare the knee outcomes following ACLR with BPTB and 4S-HT autografts. METHODS: Subgroup meta-analyses were performed basing on available randomised controlled trials (RCTs) according to different follow-up intervals. 23 RCTs were eligible for inclusion, involving 933 participants in each treatment group. RESULTS: Only short-term (≤2 years) knee anteroposterior and rotational stability were significantly poorer with 4S-HT when compared to BPTB autograft, as judged by side-to-side difference on knee laxity (WMD=-0.50, 95%CI -0.81~-0.18, p=0.002) and pivot-shift test (OR=0.58, 95%CI 0.39~0.88, p=0.010), respectively. The IKDC objective grade was evident to be in favour of 4S-HT group in mid-term (3-5 years) follow-up (OR=0.63, 95%CI 0.43~0.92, p=0.017). Several donor-site related complications, including anterior knee pain, pain with kneeling and extension deficit, were more frequent in BPTB autograft group, while lower short-term iskinetic peak flexion torques both at 60°/S (WMD=8.93, 95%CI 7.88~9.99, p<0.001) and 240°/S (WMD=11.63, 95%CI 9.92~13.34, p<0.001) were caused by HT harvesting. CONCLUSION: BPTB was associated with inferior mid- to long-term (>5 years) knee functional outcomes, and increased frequency of donor-site complications. In contrast, only short-term knee laxity was increased for 4S-HT autograft, which is expected to be improved by providing more conservative rehabilitation protocol and aperture fixation methods.

Predictive Value of the Nomogram Model in Patients With Megaprosthetic Failure Around the Knee: A Retrospective Analysis.

BACKGROUND: Megaprosthetic replacement is one of the main methods for reconstructing mega bone defects after tumor resection. However, the incidences of complication associated with tumor prostheses were 5-10 times higher than that of conventional total knee arthroplasty. The objective of this study is to establish and validate a nomogram model which can assist doctors and patients in predicting the prosthetic survival rates. METHODS: Data on cancer patients treated with tumor prosthesis replacements at our institution from November 2001 to November 2017 were collected. The potential risk factors which were well-studied and shown to be associated with megaprosthetic failure were analyzed. A nomogram model was established using independent risk factors screened out by multivariate regression analysis. The concordance index and calibration curve were selected for internal validation of the predictive accuracy of nomogram. RESULTS: The 3-, 5-, 10-, and 15-year prosthetic survival rates were 92.8%, 88.6%, 74.1%, and 48.3%, respectively. The prosthetic motion mode, body mass index, type of reconstruction, type of prosthesis, and length of bone resection were independent risk factors for tumor prosthetic failure. A nomogram model was established using these significant predictors, with a concordance index of 0.77 and a favorable consistency between predicted and actual prosthetic failure rate according to the internal validation, indicating that the nomogram model had acceptable predictive accuracy. CONCLUSION: The prediction model identifies high-risk patients for whom attached preventive measures are required. Future studies regarding reduction in incidence of prosthetic failure should attach importance to these high-risk patients.

The effects of length of femoral stem on aseptic loosening following cemented distal femoral endoprosthetic replacement in tumour surgery.

PURPOSE: Aseptic loosening is a common prosthetic failure mode. The purpose of this study was to identify dose-response relationship between length of femoral stem and aseptic loosening. METHODS: We collected data of patients who underwent distal femoral prosthetic replacements at our institution from 2001 to 2017. Cox regression and two-piecewise regression model were used to analyze the associations between stem length and aseptic loosening. RESULTS: Significant association of length of femoral stem with aseptic loosening was observed in multivariate model and a non-linear relationship could be found from the smoothed curve. In two-piecewise model, an inflection point was calculated to be 143 mm. On the left of the inflection point, every 1 mm increase in the length of stem indicated that the risk of aseptic loosening could be reduced by 6%. CONCLUSION: There was a significant non-linear relationship between the length of femoral stem and aseptic loosening, and the inflection point was 143 mm.

Assessment of the Defatting Efficacy of Mechanical and Chemical Treatment for Allograft Cancellous Bone and Its Effects on Biomechanics Properties of Bone.

OBJECTIVE: To assess the defatting efficacy of high pressure washing and gradient alcohol and biomechanical properties of defatted bone. METHODS: Fresh cancellous bone was obtained from the femoral condyle and divided into six groups according to different defatting treatments, which were: high pressure washing for 10 s (10S group), 20 s (20S group), and 30 s (30S group), gradient alcohol immersion (Alcohol group), acetone immersion (Acetone group), and non-defatted (Fresh group). The appearance of six groups was observed, and the appearance of defatted bone and fresh bone was compared. The residual lipid content and infrared spectrum were used to compare the efficacy of defatting, the DNA content was used to compare the cell content after defatting, and the maximum stress and elastic modulus were used to compare the effects of defatting treatment on biomechanical properties. RESULTS: The fresh bone was yellow and the pores contained a lot of fat. The defatted bone was white and the porous network was clear. There was no difference in residual lipid content among the three groups with high pressure washing (1.45% ± 0.16%, 1.40% ± 0.13%, and 1.46% ± 0.11%, respectively) (P = 0.828). There was no difference in residual lipid content among the 10S, alcohol, and acetone groups (1.45% ± 0.16%, 1.28% ± 0.07%, and 1.13% ± 0.22%, respectively) (P = 0.125). Infrared spectra showed that the fat content of the five defatting groups was significantly lower than that of the fresh group. There was no difference in residual lipid content among the three groups with high pressure washing (4.53 ± 0.23 ug/mL, 4.61 ± 0.18 ug/mL, and 4.66 ± 0.25 ug/mL, respectively) (P = 0.645). There was no difference in residual lipid content among the 10S, alcohol, and acetone groups (4.53 ± 0.23 ug/mL, 4.29 ± 0.24 ug/mL, and 4.27 ± 0.29 ug/mL, respectively) (P = 0.247). The maximum stress of the bone decreased significantly with the increase of the washing time (9.95 ± 0.31 Mpa, 9.07 ± 0.45 Mpa, and 8.17 ± 0.35 Mpa, respectively) (P = 0.003). The elastic modulus of the bone decreased significantly with the increase of the washing time (116.40 ± 3.54 Mpa, 106.10 ± 5.29 Mpa, and 95.63 ± 4.08 Mpa, respectively) (P = 0.003). There was no statistical difference in the maximum stress between the fresh group, the 10S group, the alcohol group, and the acetone group (10.09 ± 0.67 Mpa, 9.95 ± 0.31 Mpa, 10.11 ± 0.07 Mpa, and 10.09 ± 0.39 Mpa, respectively) (P = 0.963). There was no statistical difference in the maximum stress between the fresh group, the 10S group, the alcohol group and the acetone group (119.93 ± 4.94 Mpa, 116.40 ± 3.54 Mpa, 118.27 ± 0.85 Mpa, 118.10 ± 4.52 Mpa, respectively) (P = 0.737). CONCLUSION: The defatting efficiency was satisfactory at a time of 10 s under high pressure washing. In terms of defatting efficiency and its effect on biomechanical properties of bone, high pressure washing and gradient alcohol were similar to conventional acetone solvent extraction defatting.

Percutaneous vertebral augmentation procedures in the management of spinal metastases.

Bone metastasis is a common complication of cancer, and bone is the third most common metastatic site following the lung and liver. Among the various bones, spine is the most common site of metastatic tumors. The treatment goals of patients with spinal metastases are mostly palliative, with the aim of reducing pain and improving quality of life. The treatment of spinal metastases has made significant progress over the past few decades. Each new technology has tried to solve the shortcomings of its predecessors. Currently, there are no mature algorithms or specific techniques that have proven to be the best for spinal metastases, and the treatment method often relies on operator and institutional preferences or biases in some cases. Percutaneous vertebral augmentation has unique value in the management of spinal metastases, understanding its indications, surgical techniques, uses, advantages and complications is critical to providing optimal patient care. We believe that the application of percutaneous vertebral augmentation alone or combined with other techniques can achieve optimal pain relief and functional improvement in the patients with spinal metastases.

Establishment and validation of a nomogram model for periprosthetic infection after megaprosthetic replacement around the knee following bone tumor resection: A retrospective analysis.

BACKGROUND: Due to the particularity of patients with bone tumors, the risk of periprosthetic infection following megaprosthetic replacement is much higher than that of traditional total knee arthroplasty. Unfortunately, few studies specifically reported the risk factors for periprosthetic infection following megaprosthetic replacement. The purposes of the study were to (1) establish a nomogram model, which can provide a reference for clinicians, and patients to reduce the occurrence of periprosthetic infection (2) explore the risk factors for deep infection of megaprosthesis. HYPOTHESIS: A prediction model can be established and has favorable predictive accuracy. PATIENTS AND METHODS: One hundred and seventy-seven megaprostheses were identified. There were 61 female patients and 116 male patients with a mean age of 35 years. The following risk factors were analyzed: tumor site, sex, age, material for prosthetic stem, tumor type, smoking, diabetes, length of bone resection, operation time, chemotherapy, BMI, malignant tumor staging and hematoma formation. Finally, based on the multivariate analysis, the independent risk factors were used to develop a nomogram model. RESULTS: Univariate Cox regression analysis showed that the chemotherapy, longer operation time and hematoma formation were risk factors for periprosthetic infection. Multivariate Cox regression analysis showed that the chemotherapy, longer operation time and hematoma formation were significant risk factors for periprosthetic infection. The nomogram model was established using these significant risk factors, with a C-index of 0.766 and an acceptable consistency according to the internal validation, indicating that the prediction model had favorable predictive accuracy. DISCUSSION: This study has important implications for the future investigations of prevention of periprosthetic infection. The nomogram model identifies high-risk patients for whom attached prophylaxis measures are required. Future studies regarding reduction of incidence of periprosthetic infection should pay close attention to these high-risk patients. LEVEL OF EVIDENCE: IV, retrospective, cohort study.

Network meta-analysis of knee outcomes following anterior cruciate ligament reconstruction with various types of tendon grafts.

PURPOSE: Various grafts were selected for restoring knee stability and regaining pre-injury activity levels after anterior cruciate ligament (ACL) rupture. This review aimed to compare the short-term knee outcomes of different tendon grafts for primary ACL reconstruction (ACLR). METHODS: Databases of PubMed, Embase, and CENTRAL were retrieved for identifying the published RCT comparing the short-term (≤ 2 years) knee outcomes of different tendon grafts for ACLR. The main outcomes include the International Knee Documentation Committee (IKDC) subjective and objective scores, side-to-side difference on knee laxity, Lachman test, pivot-shift test, Lysholm score, Tegner score, all recorded complications and graft re-ruptures. RESULTS: A total of 32 trials involving 2962 patients and 17 grafts were included. Superior IKDC subjective score was found for quadriceps tendon autograft (QTB) when compared with autografts including bone-patellar tendon-bone (BPTB), four-strand hamstring tendon (4S-HT), and double-bundle HT. The 4S-HT autograft was associated with poorer anteroposterior and rotational knee stability than the BPTB autograft. Artificial ligament also was found to provide lower knee stability compared with the autografts including the BPTB, patellar tendon, 4S-HT, 4S-HT with preserved tibial insertion, 6S-HT, and four-strand semitendinosus tendon. Additionally, the BPTB allograft showed a statistically higher knee laxity than 6S-HT allograft, while no difference was found between the genuine autografts and non-irradiated allografts. CONCLUSIONS: QTB was recommended to be used even over the BPTB and 4S-HT autografts. BPTB autograft was more effective on restoring the knee stability than 4S-HT autograft. Non-irradiated allografts could be safely used as alternatives to autografts. However, artificial ligaments were not recommended for primary ACLR for significantly increased risk of knee laxity.

Efficacy and safety of bone substitutes in lumbar spinal fusion: a systematic review and network meta-analysis of randomized controlled trials.

PURPOSE: A variety of alternative grafts to autologous iliac crest bone (ICBG) have been developed for lumbar spondylodesis, due to frequent complications following ICBG harvest. The optimal alternative graft to ICBG, however, remains elusive till now. The purpose of this study was to compare the efficacy and safety of fusion materials in lumbar degeneration diseases and to provide a ranking spectrum of the grafts. METHODS: Randomized controlled trials (RCTs) comparing different bone grafts in lumbar arthrodesis were eligible for inclusion. A network meta-analysis was performed for endpoints including fusion rate and incidence of adverse events. RESULTS: Twenty-seven RCTs involving 2488 patients and 13 available interventions were included. rhBMP-2 provided the highest fusion rate, being significantly superior to that of ICBG (OR = 0.21, p < 0.001), autograft local bone (ALB) (OR = 0.18, p = 0.022), rhBMP-7 (OR = 0.15, p < 0.001), allograft (OR = 0.13, p = 0.009), and DBM + ALB (OR = 0.07, p = 0.048). The treatment efficacy of allograft could be significantly enhanced by bone marrow concentrate (BMC) supplying (OR = 0.16, p = 0.010). ICBG ranks second on the frequency of complications, which is significantly higher than that of allograft (OR = 0.14, p = 0.041) and ALB (OR = 0.14, p = 0.030). All of the other comparisons showed similar efficacy and safety profiles between groups. CONCLUSION: Ranking spectrums of the efficacy and safety for various bone grafts were provided graphically. Though rhBMP-2 was of the highest success rate, the application should be taken with proper caution because of the widely proposed life-threatening adverse events. ALB, ALB plus synthetic ceramic materials and allograft mixed with BMC were also proved to be potentially effective alternative graft to ICBG. These slides can be retrieved under Electronic Supplementary Material.

Patient Characteristics Following Surgery for Spinal Metastases: A Multicenter Retrospective Study.

OBJECTIVES: To summarize the epidemiological characteristics of patients following surgery for spinal metastases retrospectively and make a univariate analysis to identify independent variables that could affect the operation decision making. METHODS: This was a multicenter retrospective review of patients with spinal metastasis who were treated with surgery from 1 January 2007 to 31 July 2019. Basic clinical data were analyzed retrospectively by univariate analysis to identify independent variables that could affect the decision of operation modalities, including gender, age, spinal metastatic site, Frankel score, Karnofsky performance score (KPS), spinal instability neoplastic score (SINS), visual analogue scale (VAS), Tokuhashi score, urinary and fecal incontinence, spinal pathological fracture, primary tumor, extraspinal metastasis, visceral metastasis, and bone lesion (osteolytic, osteoblastic or mixed). RESULTS: A total of 580 patients including 332 males and 248 females were enrolled in the study with an average age of 58.26 years old (range, 13-86 years old). The most common spinal metastatic level was the thoracic vertebra (190 [32.76%]), followed by the lumbar vertebra (146 [25.17%]), cervical vertebra (47 [8.10%]), and sacral vertebra (35 [6.03%]). Metastases involving more than two sites of the cervical, thoracic, lumbar, and sacral vertebrae arose in 162 (27.93%) patients. For primary tumor, there were 198 (34.14%) cases of lung cancer, 41 (7.07%) cases of kidney cancer, 39 (6.72%) cases of breast cancer, 38 (6.55%) cases of gastrointestinal cancer, 35 (6.03%) cases of lymphoma and myeloma, 25 (4.31%) cases of prostate cancer, 24 (4.14%) cases of liver cancer, 23 (3.97%) cases of mesenchymal tissue sarcoma, 20 (3.45%) cases of thyroid cancer, and 84 (14.48%) cases were tumor with unknown origin. Sixty-three (10.86%) patients received minimally invasive surgery, 460 (79.31%) patients received palliative surgery, and the remaining 57 (9.83%) received tumor resection. According to the univariate analysis, the KPS score, SINS score, VAS score, Tokuhashi score, urinary and fecal incontinence, spinal pathological fracture, and bone lesion (osteolytic, osteoblastic or mixed) were independent and favorable factors affecting the surgery modalities. CONCLUSIONS: Surgical treatment for spinal metastases was mainly to relieve pain, rebuild spinal stability, improve nerve function, control local tumors, and improve the quality of life of patients. For middle-aged and elderly patients with good general conditions, severe pain, spinal pathological fracture, spine instability and without urinary and fecal incontinence, early surgical treatment should be actively carried out.

Epidemiological Characteristics of 1196 Patients with Spinal Metastases: A Retrospective Study.

OBJECTIVES: To describe the epidemiological characteristics of patients with spinal metastases between 2007 and 2019. METHODS: Patients with spinal metastases were identified from several clinical centers in China between January 2007 and July 2019. Demographics, primary tumor types, spinal involvement, and Clinical indicators of each patient were reviewed. RESULTS: A total of 1196 patients were included in this study, 717 males (59.95%) and 479 females (40.05%), with a male to female ratio of 1.50:1. Most patients (63.71%) were in the ages range of 50 to 69 years. The mean age was 58.6 ± 11.6 (range 13-89) years and the median age was 59.0 years. The average age of females was younger than that of males, and the difference was statistically significant. The proportion of male patients over 60 years old was higher than that of females, and the difference was statistically significant. The most common primary tumor was lung cancer (n = 437, 36.54%), followed by unknown origin (n = 194, 16.22%), kidney cancer (n = 78, 6.52%), breast cancer (n = 76, 6.35%), and liver/biliary cancer (n = 75, 6.27%). The most common primary tumor was lung cancer in both males and females, followed by unknown origin in males and breast cancer in females. There were 730 patients (61.04%) in the subgroup of the number<3; the highest level was lumbar vertebrae, with 250 patients (34.25%). The remaining 466 patients (38.96%) were included in the subgroup of the number ≥ 3; the highest level was tumor metastasis of multiple-level of spine, with 334 patients (71.67%). Among the 1196 patients, spinal cord injury occurred in 54.01% of patients, 76.34% of patients developed moderate and above pain, 55.69% of patients had metastatic spinal cord compression, and only 26.67% of patients had a clear history of primary tumors. CONCLUSION: This study provided a relatively detailed description of epidemiological characteristics in spinal metastases in China, which could assist orthopaedic surgeons to understand the clinical characteristics of spinal metastases, and is of great significance in guiding clinical diagnoses and scientific research.