Since the implementation of surgery-based comprehensive treatment, there have been great advances and breakthroughs in the diagnosis and treatment of bone tumors. The survival rate of primary malignant bone tumors has significantly improved, for example, the 5-year survival rate of osteosarcoma has increased from 5%-20% to 60%-70%. Characteristics of bone tumors are as follows: (1) have a wide range of lesion sites; (2) various types; (3) high heterogeneity; (4) structural reconstruction is as important as functional reconstruction; (5) metastatic tumors are more common than primary tumors. Based on the characteristics above, the combination of clinical, imaging and pathology is the basic principle in the diagnosis of bone tumors; Following the principle of tumor resection to achieve local control, it is necessary not only to carry out effective reconstruction of bone and soft tissue structural defects, but also to obtain as perfect motor function as possible. Due to the development of genetic research, bioinformatics technology, digital medicine and computer technology, the diagnosis and treatment of bone tumors have entered the stage of precision medicine with four characteristics: accuracy, punctuality, sharing and individualization. Using the multi-omics technology of genomics, transcriptomics, proteomics and metabolomics to explore the mechanism of the occurrence and development of bone tumors and find new target genes provides a direction for the application of precision medicine in bone tumors in the future. The application of Wise Information Technology of med based on artificial intelligence is of great significance for the auxiliary diagnosis and precise treatment.

Objective:To explore the effect of decalcified bone matrix (DBM) rich in biological activity on surgical-grade medical calcium sulfate, and to observe the change of different content of DBM on the physical and chemical properties of calcium sulfate, which provide theoretical basis for the preparation of calcium sulfate bone cement with osteogenic and injectable properties.Methods:DBM with weight content of 0, 5%, 10%, 20%, 30%, 40% was fully mixed with CSH. Dissolve 0.3 g of methyl cellulose in 10 ml of deionized water to prepare a 3% methyl cellulose solution. Methylcellulose solution was added according to the liquid-solid ratio of 0.4. The mixture was evenly stirred to form slurry, then the degradation rate, compressive strength, setting time and and pH value of calcium sulfate in vitrowas measured.Results:The initial setting time and final setting time of calcium sulfate were 4.96±0.20 and 5.83±0.12 min respectively. With the increase of DBM content, the initial setting time and final setting time increased significantly ( F=49.275, P<0.05; F=124.859, P<0.05). The compressive strength of pure calcium sulfate is 23.33±6.35 MPa; when the content is 40%, the compressive strength is only 3.33 MPa. With the increase of DBM content, the compressive strength first increased and then decreased; the content of 5%, 10%, 20% DBM had little effect on the compressive strength ( P>0.05), while the compressive strength of 30% and 40% groups decreased significantly ( t=3.259, P<0.05). DBM with different contents can significantly change the degradation rate of calcium sulfate complex. When the content of DBM is 30% and 40%, the complete degradation time in vivo is only 10 d, while the degradation rate of calcium sulfate is 63% in 30 d. At any time point in vitro degradation, DBM had no significant effect on the pH value of calcium sulfate complex culture medium, and the change law was consistent with that of pure calcium sulfate. Conclusion:With the increase of DBM content, the degradation rate is gradually accelerated, the compressive strength is reduced, and the setting time is prolonged, which is not conducive to the preparation of injectable calcium sulfate cement.

Objective:To investigate the effects of different particle sizes on the collagen structure of demineralized bone matrix (DBM) and the effectiveness of dry ice as an irradiation protectant in the procedure of gamma irradiation.Methods:DBM samples with different particle sizes (0.5-1.0 mm, 1.2-2.8 mm, 3.3-4.7 mm and 5.7-7.0 mm) were prepared, and sterilized with several doses of gamma irradiation (0 kGy, 15 kGy and 25 kGy) at room temperature. Additionally, another group of DBM samples were sterilized with 25 kGy gamma irradiation with protective agent. Changes in surface and characteristics of collagen were observed by using scanning electron microscope (SEM), Sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE), differential scanning calorimetry (DSC) and carbonyl content.Results:The color of collagen extract indicated that oxidative damage is directly related to irradiation dose. SEM showed that the gamma irradiation caused collagen structure disorder and fiber breakage. As the irradiation doses increased, the damage area significantly increased. When the particle size increased, the damage area tended to decrease. The DSC showed that the thermal denaturation temperature of 5.7-7 mm, 3.3-4.7 mm, 1.2-2.8 mm and 0.5-1.0 mm were 142.8℃, 97.3℃,84.3℃ and 83.9℃, respectively. The differences of the thermal denaturation temperatures among the four particle sizes were statistically significant ( F=0.560, P=0.650). Collagen structure was destroyed by gamma irradiation, resulting in a decrease in collagen molecular weight. While, large particle DBM had a tendency to resist radiation damage. There was a significant difference on the contents of carbonyl in collagen from same particle sizes of DBM with different irradiation dose. The carbonyl content gradually decreased with the increase of particle size, but the difference was not statistically significant ( F=0.560, P=0.650). Conclusion:The gamma irradiation and collagen oxidative damage have obvious dose-response relationship. With the increase of gamma irradiation dose, the degree of collagen damage increases. The sizes of DBM could affect the sensitivity of collagen to gamma irradiation. With the decrease of particle sizes, DBM particles are more susceptible to gamma irradiation damage. Additionally, dry ice, as a radiation protection agent, has a certain degree protection effect against radiation.

Objective:To observe the epidemiological characteristics of spinal metastases by retrospectively analyzing the medical records of multicenter spinal metastases in China.Methods:Patients with spinal metastases were identified from several clinical centers between January 2007 and July 2019. A total of 1 976 patients were included in this study, including 1 129 males (57.14%) and 847 females (42.86%). The mean age was 58.6±11.6 years (range 13-92 years). The demographic characteristics, primary tumor types, spinal involvement of each patient were summarized and their clinical indicators were obtained by consulting medical records, including: Frankel grade, visual analog scale (VAS), metastatic spinal cord compression (MSCC), Tokuhashi revised score, the spinal instability neoplastic score (SINS), Karnofsky performance status (KPS), and history of malignant tumors. Finally, the intervention influencing factors of patients undergoing surgical treatment were statistically analyzed.Results:The ratio of male to female in 1 976 spinal metastases was 1.33∶1. The median age was 59.0, and most patients (63.71%) were in the ages range of 50-69. The average age of female was younger than male, and the difference was statistically significant. The proportion of male patients over 60 years old was higher than females, and the difference was statistically significant. The most common primary tumor was lung cancer (n=730, 36.94%), followed by unknown origin (n=326, 16.50%), breast cancer (n=159, 8.05%), kidney cancer (n=120, 6.07%), gastrointestinal cancer (n=109, 5.52%), etc. The most common primary tumor was lung cancer in both males and females, followed by unknown origin in males and breast cancer in females. In the past 10 years, the proportion of unknown origin has decreased, and the proportion of breast cancer has increased. According to the Tomita score, 1 284 patients (64.98%) were rapid growth tumors, 211 patients (10.68%) were moderate growth tumors, and 481 patients (24.34%) were slow growth tumors. There were 730 patients (57.14%) in the subgroup of the number<3, the most level of which was lumbar vertebrae, with 368 patients (32.60%). The remaining 847 patients (42.86%) were included in the subgroup of the number≥3, the most level of which was multiple-level of spine, with 617 patients (72.85%). Among the 1 976 patients, spinal cord injury occurred in 50.76% of patients, in which 77.18% of patients developed moderate and above pain, 14.02% of patients appeared metastatic spinal cord compression, and only 28.95% of patients had a clear history of primary tumor. In terms of treatment, 34.92% of patients underwent surgery, 5.97% underwent radiotherapy on spinal metastases, 6.02% underwent chemotherapy, and 1.77% underwent targeted therapy. Preoperative Frankel grade, SINS, and Tokuhashi revised score were important factors affecting the surgical treatment of patients.Conclusion:This study describes the epidemiological characteristics of multicenter spinal metastases in detail, which could assist orthopedic surgeons to understand the clinical characteristics of spinal metastases and was of great significance on guiding the clinical diagnoses and scientific researches.

Objective:To investigate the effect of different plasticizers on the compressive strength of injectable calcium sulfate cement (ICSC).Methods:Hydroxymethylcellulose (CMC), methylcellulose (MC), hyaluronic acid (HA), stearic acid (SA) and self-made hemihydrate calcium sulfate were used to mix them, and the compressive strength of the complex was observed after reaction with normal saline; the changes of ICSC's own properties, such as setting time and injectability, were recorded.Results:The compressive strength of calcium sulfate was 21±4.58 mPa, and the final setting time was 3.86 ± 0.09 min. Different concentrations of SA had no significant effect on the compressive strength of calcium sulfate ( F=1.593, P=0.266), but prolonged the setting time ( F=29.868, P=0.000). CMC with different concentrations significantly reduced the compressive strength of calcium sulfate ( F=23.943, P=0.000), and the setting time was prolonged to more than 120 min. Different concentrations of MC can improve the compressive strength of calcium sulfate ( F=4.808, P=0.034), and prolong the setting time ( F=191.192, P=0.000); among them, 1% and 3% MC can significantly improve the compressive strength ( P=0.007, 0.027). Different concentrations of HA can improve the compressive strength ( F=3.818, P=0.058), and prolong the setting time ( F=262.515, P=0.000), of which 3% and 5% were significantly improved ( P=0.026, 0.015), while 1% group was not significantly improved ( P=0.062). In addition, the injectable properties of HA, MC, stearic acid and CMC are better, respectively. Conclusion:SA and CMC can not be used to improve the compressive strength of calcium sulfate, while HA and MC of appropriate concentration can improve the compressive strength of ICSC, and improve the injectable performance, but MC can make the coagulation time more in line with clinical needs.

Objective To identify prognostic factors ofmotorfunctionafter surgery of metastatic spinal cord compression (MSCC).Methods The clinical data of 681 patients with spinal metastases from January 2008 to December 2017 were retrospectively analyzed.According to inclusion and exclusion criteria,a total of 206 patients with spinal metastatic were included.Postoperative neurological function was assessed using Frankel classification.The influence of age,gender,preoperative status,number of spine metastases,location of spinal metastases,visceral metastases,bone metastases,primary tumor type,interval from symptom to surgery,time of developing motor deficits,interval from primary tumor diagnosis to MSCC,preoperativethe Eastern Cooperative Oncology Group performance status (ECOG-PS),Karnofsky Performance score (KPS) and surgical procedures on postoperative function outcomes were explored.Results 140 (68.0％) patients were able to walk postoperatively compared with 88 (42.7％) patients preoperatively.Moreover,in 89.8％ of all patients,79 ambulatory patients maintained ambulation after treatment.The univariate analysis according to Ordered-logit model showed thatnumber of spine metastases,location of spinal metastases,preoperative ECOG-PS,preoperative KPS,interval from symptom to surgery and time of developing motor deficits were related with posttreatment motor functions.The multivariable analysis showed that number of spine metastases (OR=2.03;95％CI:1.12-3.33;P=0.04),preoperative ECOG-PS (OR=4.84;95％CI:2.42-8.15;P=0.038),interval from symptom to surgery (OR=3.78;95％CI:3.12-9.15;P=0.024),time of developing motor deficits(OR=2.75;95％CI:1.22-3.89;P=0.01) were independent prognostic factors for function outcomes.Conclusion 1-2 levels of metastasis,Interval from symptom to treatment ≥ 48 h,time of developing motor deficits ≥7 d,and ECOG-PS 1-2 can be considered as the most significant positive prognosticfactors for post-treatment ambulatory status.Spinal metastasis should have a higher priority,and immediate intervention should be started before the development of irreversible neurologic deficits.Increasing awareness of early symptoms and earlier screeningwith regular outpatient review might make a difference for patients with MSCC.Consequently,the identified prognostic factors can be considered as apreoperative assessment tool to predict the neurologic outcomeand guide clinical treatment for individual patients with MSCC.

Objective To assess the efficacy of internal fixation assisted with Halo-vest in the treatment of Anderson-D'Alonzo type Ⅱ and superficial type Ⅲ odontoid fractures.Methods A retrospective case series study was made on 15 patients clinically diagnosed as Anderson-D'Alonzo type Ⅱ and type Ⅲ odontoid fractures with a fracture gap over 2 mm,displacement over 5 mm and broken end angel over 11° from January 2007 to January 2015.There were nine males and six females,aged 27-61 years [(44.5 ± 10.9)years].The patients were treated in "three phases" with the assistance of Halo-vest external fixation system and a novel guide pin aiming device.The three phases were as follows:phase Ⅰ:cervical traction reduction and halo-vest external fixation;phase Ⅱ:Halo-vest assisted internal fixation using the novel aiming device;phase Ⅲ:the Halo-vest fixation removal and cervical collar fixation.Operation duration,intraoperative bleeding,and postoperative visual analogue scale (VAS) pain score one month after the operation were recorded.The cervical lateral and open mouth X-ray or atlantoaxial CT scan with sagittal and coronal two-dimensional reconstruction were regularly reviewed,and the location of screws,reduction and fracture healing were evaluated.Results Operation duration ranged from 54 to 96 minutes [(71.3-± 11.9) min].The intraoperative blood loss was 5-60 ml [(32.6 ± 16.8) ml].There was no spinal cord or nerve root injury,cerebrospinal fluid leakage,wound infection or other complications.All patients were followed up for 12-36 months (mean,28 months).Fourteen patients were seen bony union 6 months after the surgery and one patient was seen a false joint.At the last follow-up,the patient with false joint was seen bone sclerosis,and other patients with sound bone healing.The preoperative VAS and that of one month after the operation was (7.3 ± 0.6) points and (1.6 ± 0.7) points,respectively (P ＜ 0.05).Conclusion For Anderson-D'Alonzo type Ⅱ and type Ⅲ odontoid fractures,which have a fracture gap greater than 2 mm,displacement more than 5 mm,broken end angle above 11 degrees,the three-phase Halo-vest assisted internal fixation can provide good stability before operation and promote bone healing and pain relief after operation.

Objective To evaluate the prognostic factors of spinal metastases by recursive partitioning analysis (RPA)and establish a decision tree model that can guide clinicians to select individualized treatment.Methods Between January 2011 and December 2015,three institutional databases were searched to identify 169 patients with metastatic spinal tumors underwent surgery.The ratio of male and female was 1.48:1 (102 males and 67 females).The average age was 59.2±11.1 years.One-hundred eighteen cases of patients were randomly selected as training samples and the remaining 51 cases were verified samples.Preoperative factors were collected and analyzed by RPA methods,including primary tumor,KPS score,Frankel grade,gender,age,visceral metastasis,bone metastasis,spinal metastasis,blood glucose,blood pressure,surgery site,symptoms,surgery interval,serum albumin level and other risk factors.Pearson's Chi-square test was performed to judge the segmentation point of the decision tree model.The decision tree model is built using the Chi-square automatic interaction detector (CHIAD) algorithm and sensitivity and specificity was automatically calculated.Results The median postoperative survival time was 12.6±1.2 months [95％CI(10.1,15.0)].70％ were randomly selected as the experimental group (118 cases),and 30％ were the verification group (51 cases).The sensitivity was 96.9％.The specificity was 89.8％.The Kappa coefficient was 0.874 in the experimental group.The sensitivity was 95.4％.The specificity was 90.8％.The Kappa coefficient was 0.810 in the test group.The prognostic factors (weight from high to low) based on RPA were Frankel grade (F=8.132,P=0.005),the primary tumor and the KPS score (Equal,F=9.871,P=0.000 and F=1 1.945,P=0.003),serum albumin and movement time (Equal,F=7.566,P=0.018 and F=9.966,P=0.008).The decision tree model consists of 7 types.Survival time was 51 months,18 months,13 months,8 months,4 months,5 months,9 months in the class Ⅰ～Ⅶ,respectively.According to the difference of RPA survival time,the operation was classified as 3 grade.Total spinal resection was regarded as grade 1,including class Ⅰ and class Ⅱ,with an average survival time of over 18 months.Limited operation was regarded as grade 2,including class Ⅲ,Ⅴ and Ⅶ with survival time in 6-18 months.The conservative treatment was regarded as grade 3,including class Ⅳ and Ⅵ with the survival time was less than 6 months.Conclusion The decision tree model based on RPA for predicting the survival time of spinal metastases can not only identify the prognostic factors,but also classify and grade various prognostic factors;the decision tree model is simple and can guide clinicians to choose the best surgical plan by predicting the survival time.

Giant cell tumour of bone is one of the most common primary musculoskeletal tumours,accounting for 10％-21％ of bengin bone tumours,which can behave like malignant tumors and have benign histologic characteristics.Giant cell tumour (GCT) of bone is classified by the World Health Organisation (WHO) as a benign but locally aggressive tumour.Intralesional excision and wide resection may be helpful in operative treatment for GCT.However,there are limitations with these options in spite of the use of adjuvant therapy.For instance,intralesional excision had more local recurrence rate and less complications,wide resection had less local recurrence and poor functional results.Therefore,there is no widely held consensus regarding the ideal treatment selection for all GCT patients.The purpose is to review literature reports on the morphological features of GCT of bone and existing surgical method,and discuss the relationship between morphology characteristics of GCT and the selection of surgical options and postoperative recurrence rate,in order to help oncological doctors to choose surgical method in the clinical practice.

Objective To evaluate the clinical efficacy of a self-designed novel n-shaped aiming device in aiding the percutaneous cannulated screwing for treatment of odontoid fractures of Anderson-D' Alonzo type Ⅱ and shallow type Ⅲ.Methods A retrospective analysis was conducted of the 17 patients who had been treated at our department for odontoid fracture of Anderson-D' Alonzo type Ⅱ and shallow type Ⅲ between January 2009 and December 2013.They were 13 males and 4 females,with an average age of 37.5 years (from 16 to 61 years).All received surgical treatment after skull traction or jaw pillow traction preoperatively for reduction.Intraoperatively,percutaneous cannulated screwing via the anterior cervical approach was performed with the help of a self-designed novel n-shaped aiming device to fix the odontoid.Postoperatively,X-ray and CT scan were used to check the screw locations and evaluate the fracture healing.Results The 17 cases were followed up for 6 to 15 months (average,10.5 months).No intraoperative injury to the esophagus,artery,spinal cord or nerve root happened.The operating time ranged from 60 to 125 min.The bleeding was from 10 to 40 mL.Intraoperative observation revealed fine locations of the screws.Bony union was achieved in 16 cases 3 months postoperatively while separation and hardening of the fracture ends was found in one ease.Conclusion Our self-designed novel n-shaped aiming device can facilitate the percutaneous cannulated screwing for treatment of odontoid fractures of Anderson-D'Alonzo type Ⅱ and shallow type Ⅲ,given that it has advantages of simple manipulation,accurate insertion,minimal invasion,quick recovery and reliable efficacy.