Abstract:[Objective] To observe the expression of Necdin (NDN) gene in osteosarcoma, and to explore its relationship with clinico- pathological factors and prognosis of osteosarcoma. [Methods] A retrospective study was performed on 51 patients who received neoadju- vant chemotherapy, as well as tumor segment resection and prosthetic reconstruction after osteosarcoma was confirmed by biopsy in our hos- pital from October 2009 to July 2019. The clinical outcomes, NDN expression in tissue were evaluated. [Results] All the 51 patients were followed up for more than 38 months, with survival time of 78 months in the longest and 16 months in the shortest. During the follow-up, 16 patients got local recurrence and 33 patients had metastasis. At the latest follow-up, 10 patients were of survival with tumor-free (STF) , 5 patients of survival with tumor (ST) , and 36 patients died (death) . In term of grouping comparison based on the outcome at the latest followup, the proportion of stage IIB and stage III in the death group was significantly higher than that in the tumor-free survival group and the tu- mor-bearing survival group (P＜0.05) , and the death group had significantly higher ratio of lung metastasis than the STF and ST groups (P＜ 0.05) . However, there were no significant differences in terms of age, gender, tumor size and NDN expression among the three groups (P＞ 0.05) . The positive rate of NDN immunohistological staining was of 29.41% (15/51) in osteosarcoma tissues, whereas 80% (8/10) in normal bone tissues around the tumor, which was statistically significant (P＜0.05) . As results of Kaplan-Meier survival analysis and log-rank test, the mean survival time proved significantly different in terms of different Ennecking stage, lung metastasis, tumor size and NDN (P＜0.05) . With regarding to Cox analysis, the Ennecking stage (HR=1.530) , lung metastasis (HR=4.662) and tumor size (HR=3.398) were risk factors for survival, while positive NDN (HR=0.207) were protective factors for survival. [Conclusion] The osteosarcoma tissue has significantly lower positive NDN expression than the adjacent normal bone tissue. The worsened preoperative Ennecking stage, lung metastasis and tu-mor ≥5 cm are risk factors for poor prognosis of osteosarcoma, while positive NDN expression is a protective factor.

Abstract:[Objective] To explore the influence of variation of anterior condyle height (ACH) on knee flexion-extension range of mo- tion (ROM) after total knee replacement. [Methods] A retrospective study was performed on 72 patients who underwent primary unilateral total knee replacement for knee osteoarthritis in our hospital from October 2018 to January 2020, and followed up for more than 12 months. The general information, ROM, KSS clinical and functional scores, as well as radiographically measured ACH were recorded. Univariate Pearson correlation analysis and multiple stepwise regression analysis were used to explore the factors affecting ROM at the last follow-up. [Results] Patients were divided into three groups according to ACH variation (postoperative ACH minus preoperative ACH), the thinning group with ACH variation ＜-3mm, the unchanged group with -3~3 mm, the thickening group ≥3mm group. Although there was no a signifi- cant difference in the ROM before operation among the three groups (P＞0.05) , the ROM at the latest follow-up was ranked in descending order of the thinning group ＞ the unchanged group ＞ the thickening group, with a statistically significant difference among them (P＜0.05) . There was no a significant difference in preoperative KSS clinical scores among the three groups (P＞0.05) , however, the ROM at the latest follow-up in descending order was of the thinning group ＞the unchanged group ＞ the thickening group, which was statistically significant (P＜0.05). In term of Pearson correlation analysis, the ROM at the latest follow-up was negatively correlated with ACH variation (P＜0.05) , whereas the former was significantly positively correlated with KSS clinical score at the last follow-up (P＜0.05) . As results of multiple re- gression analysis, the ROM at the last follow-up was positively correlated with the ROM preoperatively (B=0.317, P=0.021) , whereas nega- tively correlated with ACH variation (B=-2.673, P＜0.001) . [Conclusion] ACH variation is closely related to ROM after operation.

Abstract:[Objective] To investigate the correlation between symptomatic benign prostatic hyperplasia (SBPH) and periprosthetic joint infection (PJI) secondary to primary total hip arthroplasty (THA) . [Methods] A total of 133 male patients who underwent primary THA in our hospital from January 2011 to December 2018 were included in this study. According to whether PJI was confirmed during the fol- low-up, the patients were divided into two groups. Univariate comparison and binary multiple logistic regression analysis were conducted to search the factors related to PJI. [Results] All the 133 patients were followed up for more than 24 months, with an average of (5.80±1.77) years. According to the PJI diagnostic criteria of MSIS in 2013, 10 patients were confirmed as PJI during follow-up, accounting for 8.13% with a mean PJI occurrence time of (6.12±2.91) months after the primary operation, and all infected patients adopted posterolateral ap- proach. As consequence of univariate comparison, the PJI group had significantly higher ratios of comorbidity of diabetes, SBPH, postoper- ative drainage placement, postoperative urinary tract infection, as well as significantly higher BMI, postoperative drainage volume and drainage time than the non-PJI group (P＜0.05) , whereas the former had significantly lower preoperative albumin level than the latter (P＜ 0.05) . There were no significant differences between the two groups in terms of age, side, preoperative ESR, preoperative WBC, preopera- tive D-dimer, operation time, transfusion volume and anesthesia mode between the two groups (P＞0.05) . As results of logistic regression, comorbidity of SBPH (OR=3.267, P＜0.05) , comorbidity of diabetes mellitus (OR=2.482, P＜0.05) , and postoperative urinary tract infection (OR=2.542, P＜0.05) were independent risk factors for PJI. [Conclusion] SBPH is an important independent risk factor for PJI after primary THA.

Abstract:[Objective] To investigate the clinical results of decompression and bone autografting under minimally invasive channel combined with local administration of zoledronic acid and platelet rich plasma (PRP) for early- stage femoral head necrosis. [Methods] From January 2017 to January 2019, 130 patients (189 hips) with early-stage femoral head necrosis were randomly divided into two groups. Of them, 95 hips were treated with minimally invasive channel decompression and bone autografting combined with zoledronic acid and PRP used locally (the combined group) , while the other 94 hips were treated with minimally invasive channel decompression bone grafting alone (simple group) . The perioperative, follow-up and imaging data were compared between the two groups. [Results] All patients in both groups had operation performed successfully without serious complications. There were no statistical differences in operative time, incision length, intraoperative blood loss and postoperative drainage between the two groups (P＞0.05) . The two groups of patients were followed up for 20~25 months, with an average of (22.35±0.92) months. At the last follow-up, the hip preservation success rate was 94/95 (98.95%) in the combined group and 90/94 (95.74%) in the simple group, and there was no significant difference between the two groups (P=0.358) . The combined group resumed walking and full weight-bearing activity significantly earlier than the simple group (P＜0.05) , additionally the former proved significantly superior to the latter in terms of VAS and Harris scores at 6 months after surgery and the latest follow-up (P＜ 0.05) . Radiographically, the combined group had significantly smaller area of femoral head lesion than the simple group at the latest follow up (P＜0.05) . Moreover, the combined group was significantly superior to the simple group in term of imaging grade of the femoral head at 6 months postoperatively and the latest follow- up (P＜0.05) . [Conclusion] The clinical outcomes of decompression and bone autografting combined with local application of zoledronic acid and PRP in the treatment of early femoral head necrosis is significantly better than that of decompression and bone autografting alone.

Abstract:[Objective] To explore the effect of selective posterior rhizotomy (SPR) on the hip development in children with spastic ce- rebral palsy. [Methods] A retrospective study was performed on 50 children (100 hips) who underwent SPR for spastic cerebral palsy in our department from February 2017 to February 2020. The patients were divided into preschool group and school age group according to the age at operation. The clinical and imaging results of the two groups were compared. [Results] All children in both groups had operation per- formed successfully without serious complications. The preschool group consumed significantly less operative time with significantly less in- traoperative blood loss than the school age group (P＜0.05) . The children were followed up from 2 to 3 years, with an average of (2.52±0.43) years. The score of Gross Motor Function Measure (GMFM) 88-E, hip flexor-extension and adduction-abduction ROMs, as well as Ash- worth muscle tone scales and MRC scale for hip muscle strength significantly improved at the latest follow-up compared with those preoper- atively in both groups (P＜0.05) . However, there were no statistically significant differences in the abovementioned clinical items between the two groups at any corresponding time points (P＞0.05) . Radiographically, compared with those preoperatively the acetabular index (AI) and neck shaft angle (NSA) had not significantly changed in both groups at the latest follow-up (P＜0.05) ; the center-edge (CE) angle in the preschool group increased significantly (P＜0.05) , whereas which remained unchanged in school-age group (P＜0.05) ; the migration per- centage (MP) of femoral head significantly decreased in both groups at the latest follow up (P＜0.05) . Comparison between the two groups before operation showed that the AI, MP and NSA of preschool group were significantly higher (P＜0.05) , and the CE angle significantly low- er than those of school-age group (P＜0.05) . Despite of the facts that the preschool group still had significantly greater AI and NSA, where- as significantly less CE angle than the school-age group (P＜0.05) , there was no significant difference in MP between the two groups at the latest follow up (P＞0.05) . [Conclusion] Lumbosacral SPR can improve the development of hip joint in children with spastic cerebral palsy.

Abstract:[Objective] To compare the clinical efficacy of polyetheretherketone (PEEK) rod versus titanium rod used in pedicle screw fixation for lumbar degenerative diseases. [Methods] From August 2019 to November 2020, a total of 60 patients received decompression and pedicle screw fixation for lumbar degenerative diseases. According to doctor- patient communication results, 30 patients had PEEK rods used, while the other 30 patients had titanium rod used. The perioperative, follow-up and imaging results were compared between the two groups. [Results] All patients in both groups were operated on successfully without serious complications. There were no significant dif- ferences in terms of operative time, incision length, intraoperative blood loss, times of fluoroscopy, incision healing grades, hospital stay and postoperative walking time between the two groups (P＞0.05) . In addition, there was no significant difference in the time to resume full weight-bearing activity between the two groups (P＞0.05) . As time went during the follow-up period lasted for more than 12 months, both VAS and ODI scores significantly decreased in the two groups (P＜0.05) . The PEEK group proved significantly superior to the titanium group in VAS score at 2 weeks after surgery (P＜0.05) , whereas which became not statistically significant between the two groups 12 months postoperatively (P＞0.05) . However, there was no significant difference in ODI score between the two groups at any matching time points (P＞0.05) . Radiographically, the PEEK group had significantly greater range of motion (ROM) of the fixed segment measured on imag- es than titanium group at 12 months after surgery (P＜0.05) , whereas there were no statistically significant differences in term of Pfirrmann classification of fixed segment, upper adjacent segment and lower adjacent segment between the two groups at any corresponding time points (P＞0.05) . [Conclusion] Both PEEK and titanium rods used for pedicle screw fixation do significantlly improve the clinical symp- toms of lumbar degenerative diseases, by comparison, PEEK group has less chance of early postoperative low back pain, with better lumbar mobility maintained.

Abstract:[Objective] To compare the clinical outcomes of meniscus repair versus meniscectomy for medial meniscus posterior root tears (MMPRT) by summarizing data from the published literatures. [Methods] The articles regarding comparison of meniscus repair with meniscectomy for MMPRT were retrieved from data bases, such as PubMed, Cochrane Library, Web of Science, CNKI, Wanfang Medical, and Weipu databases from the establishment to October 2020. After screening, data extraction, and quality evaluation were finished by two researchers, a meta-analysis was conducted by using Review Manager 5.4 software. [Results] A total of 6 papers were enrolled into this study, involving 263 patients, including 149 cases of meniscus repair and 114 cases of partial meniscectomy. As results of meta-analysis, meniscus repair proved significantly superior to the meniscectomy in terms of Lysholm score (MD=9.72, 95%CI 3.27-16.16, P=0.003) , IK- DC score (MD=11.91, 95%CI 1.21-22.61, P=0.03) , Kellgren -Lawrence grade (OR=0.09, 95%CI 0.04-0.21, P＜0.001) , and total knee ar- throplasty (OR=0.10, 95%CI 0.04-0.24, P＜0.001) . [Conclusion] For the treatment of MMPRT, meniscus repair is significantly better than the meniscectomy regarding to clinical scores and long-term prognosis in this study.

Abstract:Taurine upregulated gene 1 (TUG1) is a long non-coding RNA (lncRNA) , which involves in the occurrence and develop- ment of osteosarcoma by complex molecular mechanisms. It can promote the proliferation, invasion and metastasis, and inhibit the apopto- sis of osteosarcoma cells by inhibiting some miroRNAs (miRNAs) and regulating related signal pathways. In addition, the expression level of TUG1 is related to the prognosis of osteosarcoma, therefore, TUG1 is a potential biomarker for prognosis. In this paper, by summarizing related studies in recent years，we review the molecular mechanisms of proliferation, apoptosis, invasion and metastasis in osteosarcoma cell mediated by TUG1 and the clinical value of TUG1 in osteosarcoma.

Abstract:In recent years, the rapid development of 3D printing technology has become a new type of rapid prototyping and rapid man- ufacturing technology. It can quickly convert the CT and MRI images taken from patients into real three-dimensional objects, and realize the personalized material structure customization to meet the anatomy of the diseased parts of the patient. This technique have been widely used in the diagnosis, treatment and rehabilitation of orthopedic diseases, with broad application prospects. This article aims to review the cutting-edge research of 3D printing technology in orthopedics clinical practice and basic research, summarize the existing problems, and look to the future.

Abstract:The main characteristic of intervertebral disc degeneration (IDD) is the reduction of the number of nucleus pulposus cells and the imbalance of the metabolism of extracellular matrix mediated by various molecules under the stimulation of adverse factors. There- fore, studying the changes of molecular expression during IDD has become one of the main strategies for the treatment of IDD. In recent years, injection of growth factors has proved to be a promising biologic therapy for IDD. However, transforming growth factor-β and other factors can induce unnecessary vascular growth, thus accelerating the process of IDD. In contrast, the growth differentiation factor (GDF) family shows promise in the treatment of IDD. Studies have revealed that GDF-5 plays an important role in maintaining the structure and function of intervertebral disc. This review summarizes the pathological process of IDD and the latest research progress on the mechanism of GDF-5 used for treating IDD, aiming to provide new ideas for delaying IDD.

Abstract:Low back pain is a global health problem, which is related to intervertebral disc degeneration (IDD) , but the mechanism is unknown. At present, it is possible to explore the pathogenesis of intervertebral disc degeneration and new therapeutic targets through the establishment of animal models. Animal models of intervertebral disc degeneration can be roughly divided into 4 types. This article mainly reviews the different methods to create intervertebral disc degeneration models, and compares the advantages and disadvantages of various models to meet suitable research fields.

Abstract:[Objective] To evaluate the efficacy and safety of phrenic nerve transfer to the posterior bundle of inferior trunk of forelimb plexus (PBITFLP) to regain toe extension function in rats. [Methods] Twenty-four SD rats were randomly divided into 4 groups with 6 rats in each group. In the end-to-side anastomosis (the E-S group) , the phrenic nerve was anastomosed with the saphenous nerve graft by end-toside, and then transferred to PBITFLP. In the end-to-end anastomosis (the E-E group) , phrenic nerve was cut off and anastomosed with sa- phenous nerve graft by end-to-end suture, and transferred to PBITFLP. In situ anastomosis (the ISA group) , the PBITFLP was cut and then sutured in situ. In unrepaired anastomosis (the UR group) , the PBITFLP was cut only without anastomosis. Function observation, electro- physiological examination and reverse fluorescence tracer of the deep branch of radial nerve or posterior bundle of inferior trunk were con- ducted and compared among the 4 groups. [Results] At 7 weeks after operation, compound muscle action potential (CMAP) was recorded in the toe common extensor after stimulation of phrenic nerve in both the E-S group and the E-E group, which was not statistically significant in terms of amplitude and latency of CMAP between the two groups (P＞0.05) . In the ISA group CMAP was detected in the extensor by stimu- lation of the PBITFLP, in which the amplitude and latency of CMAP were significantly greater than those in the E-S and E-E groups (P＜ 0.05) . In addition, CMAP was detected in the diaphragm by stimulation in the E-S, ISA, and UR groups, without statistically significant dif- ferences in amplitude and latency among the groups (P＞0.05) . In terms of nerve tracer detection, positive cells were found in anterior horn of C_3/4 from deep branch of radial nerve in both the E-S group and E-E group, which in the E-E group was significantly greater than the E-S group (P＜0.05) . On the other hand, the number of positive cells traced from the deep branch of the radial nerve in the healthy side to the an- terior horn of C₈T₁ in the E-S group and the E-E group was significantly higher than those in the ISA group and UR group (P＜0.05) . [Conclusion] The end-to-side phrenic nerve transfer is safe and effective for restoring the function of toe extensor partially in this rat experiment.

Abstract:[Objective] To introduce the surgical technique and preliminary clinical results of staged induced membrane and tibial slid- ing bone grafting for septic talar defect. [Methods] A 18-year old male suffered from open comminuted fracture of talus by traffic accident. Talus osteomyelitis occurred after one-stage debridement and ankle fusion. After that, partial talar resection, debridement and antibiotic bone cement for induction membrane was conducted in other two stages. As the infection was controlled completely, the bone cement was taken out for tibial sliding bone grafting combined with an iliac bone autograft. [Results] The patient was followed up for 8 months, re- sumed partial weight-bearing walking at 3 months and full weight-bearing activity at 4 months after operation. The VAS score decreased from 6 points preoperatively to 3 points at 3 months and 1 point at 8 months postoperatively. The AOFAS score was of 71 at 8 months post- operatively, with bony fusion on radiographs. [Conclusion] The staged induced-membrane combined with tibial sliding bone graft is a safe and effective method for treating infectious talus defect.

Abstract:[Objective] To introduce the surgical technique and preliminary outcome of Tianji orthopaedic robot assisted percutaneous vertebroplasty (PVP) . [Methods] A 58-year-old female who was suffered from thoracic vertebral compression fracture (T12) secondary to falling received Tianji orthopaedic robot assisted PVP. After the two-dimensional data collected by using the C-arm X-ray machine were imputed, the robot operation platform made a operation plan, then guided and verified the needle placement and bone cement injection. The operation time, fluoroscopy times and radial dose were recorded, and clinical and imaging consequences were analyzed. [Results] The oper- ation was lasted for 55 minutes, with only once of two-dimensional scan with the C-arm X-ray machine and 6 times of X-ray fluoroscopy. The patients got about 5ml of intraoperative blood loss without any complications, and returned walking on the second day after operation. As imaging findings postoperatively, the amount and distribution of bone cement injected were satisfactory. [Conclusion] The domestic "Tianji" orthopedic robot using two-dimensional image data to assist PVP is a new accurate and minimally invasive surgical scheme.

Abstract:[Objective] To explore the clinical outcomes of two-stage total knee arthroplasty (TKA) for advanced septic arthritis of the knee. [Methods] A retrospective study was conducted on 11 patients who received surgical treatment for advanced septic arthritis of the knee in our hospital from January 2012 to December 2020. In the first stage of operation, complete debridement was conducted and antibiot- ic cement space was placed. In the second stage, TKA was performed as the infection proved totally subsidized. The perioperative data were recorded and the clinical outcome was evaluated by ROM and HSS score. [Results] The infection was effectively controlled in all the 11 pa- tients after the first stage operation, with CRP returned to normal in (3.36±1.43) weeks, whereas ESR returned to normal in (16.27±2.97) weeks. The intervals between the two stages of surgeries ranged from 12 to 14 weeks, with a mean of (12.51±0.82) weeks. Both ROM and HSS increased significantly over time (P＜0.05) . There was no recurrence of infection until the last follow-up. [Conclusion] The two-stage TKA is a reliable choice for the treatment of advanced septic arthritis of the knee and has achieved good therapeutic effet.

Abstract:[Objective] To investigate the effect of functional exercise of lumbodorsal muscle on lumbar spondylolysis accompanied with low back pain. [Methods] From August 2018 to December 2020, a total of 94 patients with lumbar spondylolysis complicated with low back pain were enrolled in this study. The patients were divided into two groups according to whether spondylolisthesis was seen on radio- graphs, 59 cases were fall into the non-slippage group, while the remaining 35 cases in the slippage group. Five-point back arch exercise was performed in all patients for 1 month. The changes of pain and function were observed. [Results] Compared with those before treat- ment, both VAS and ODI scores in two groups were significantly decreased after treatment (P＜0.05) , and VAS and ODI scores in non-slip- page group were significantly lower than those in slippage group at corresponding time points (P＜0.05) . After treatment, ROMs of lumbar flexion and extension were significantly increased in both groups compared with before treatment (P＜0.05) . The non-slippage group had significantly greater ROMs of lumbar spine flexion and extension than the slippage group before treatment (P＜0.05) , however, it became not statistically significant after treatment between the two groups (P＞0.05) . [Conclusion] This five-point back arch exercise does relieve low back pain and increase the range of motion of lumbar spine, and has reliable therapeutic effect on spondylolysis complicated with low back pain.

Abstract:[Objective] To investigate the early outcomes of doctor-nurse cooperated enhanced recovery after surgery (ERAS) for poste- rior lumbar instrumented fusion (PLIF) . [Methods] From January 2021 to June 2021, a total of 60 patients who underwent PLIF for degen- erative lumbar diseases were divided into two groups by random number table method. Of them, 30 patients received routine perioperative rehabilitation (the routine group) , while the other 30 patients received doctor-nurser cooperated ERAS. The clinical and psychological as- sessment data of the two groups were compared before and 1 week after operation. [Results] The ERAS group resumed walking significant- ly earlier than the routine group (P＜0.05) . The VAS and ODI scores significantly decreased, whereas JOA score significantly increased at 1 week after operation compared with those preoperatively in both groups (P＜0.05) . One week after surgery, the ODI and JOA scores in the ERAS group were significantly better than those in the routine group (P＜0.05) , but there was no significant difference in VAS scores be- tween the two groups (P＞0.05) . Both SDS and SAS scores significantly decreased 1 week after surgery compared with those before opera- tion in the two groups (P＜0.05) . One week after operation, the ERAS group proved significantly superior to the routine group in terms of SDS and SAS scores (P＜0.05) . [Conclusion] The doctor-nurse cooperated enhanced recovery after surgery does accelerate the recovery of lumbar function, and effectively relieve anxiety and depression in the perioperative period of posterior lumbar instrumented fusion.

Abstract:[Objective] To investigate the effect of intraoperative cervical curvature adjustment by a self-developed instrument in anteri- or cervical discectomy and fusion (ACDF) on the clinical and radiographic consequences. [Methods] From January 2020 to March 2021, 36 patients underwent ACDF with intraoperative cervical lordotic curvature adjustment by the self-developed instrument. The postoperative out- comes, involving clinical and imaging parameters, were observed and compared. [Results] All patients were successfully operated on with- out serious complications, and got significant improvement in clinical symptoms gradually postoperatively. The JOA scores increased signifi- cantly (P＜0.05) , whereas the NDI and VAS scores decreased significantly over time (P＜0.05) . Radiographically, overall lordotic curvature (C2~C7 Cobb angle) and segment lordotic curvature (local Cobb angle) were significantly increased after the intraoperative curvature adjust- ment, implant placement, and 3 days before discharge compared with those before operation and after anesthesia (P＜0.05) . After that, over- all lordotic curvature and segment lordotic curvature tended to be lost again in some extent during the following time points in the follow-up period, but which were not statistically significant (P＞0.05) . [Conclusion] This intraoperative adjustment of cervical curvature during ACDF by the self-developed instrument does maintain, even improve the postoperative overall and segmental curvature of cervical spine.

Abstract:[Objective] To compare the clinical outcomes of two arthroscopic release ranges for primary frozen shoulder (PFS) . [Methods] A retrospective study was done on 59 patients who received surgical treatment for unilateral PFS in our hospital from January 2018 to May 2010. According to doctor-patient communication results, 37 patients had arthroscopic anterior release (AR group) , while the remain- ing 22 patients underwent arthroscopic 360° release (360° group) . The perioperative period and follow-up results of the two groups were compared. [Results] All patients in both groups had operation completed successfully without serious complications. The AR group proved significantly superior to the 360° group in terms of operation time and hospital stay (P＜0.05) . The VAS scores decreased significantly (P＜ 0.05) , whereas the Constant-Murley score, as well as abduction, external rotation, forward extension, and internal rotation ROMs increased significantly over time in both groups (P＜0.05) . At the corresponding time points, there was no significant difference in the above indexes between the two groups (P＞0.05) . [Conclusion] Arthroscopic anterior release does achieve similar clinical results with 360° release for PFS, whereas has a benefit of less surgical trauma.

Abstract:[Objective] To explore the relationship between serum markers, such as C-telopeptide (CTX) of type I collagen, plasmino- gen activator inhibitor (PAI-1) and interleukin 33 (IL-33) , and bone mineral density (BMD) or osteocalcin (BGP) in femoral head necrosis. [Methods] From January 2017 to January 2020, 95 patients with femoral head necrosis admitted to our hospital were enrolled as the necro- sis group, while 80 healthy subjects were selected as the normal group. The serum CTX, PAI-1, IL-33 and BGP, as well as BMD were de- tected, furthermore, the correlation between serum markers and BMD or BGP was analyzed. [Results] The necrosis group had significantly higher levels of serum BGP, CTX, PAI-1 and IL-33, as well as BMD than the normal group (P＜0.05) . The serum CTX, PAI-1 and IL-33 were significantly positively correlated with BMD (P＜0.05) . In addition, the serum CTX, PAI-1 and IL-33 were significantly positively cor- related with BGP (P＜0.05) . [Conclusion] The serum expressions of CTX, PAI-1 and IL-33 in femoral head necrosis are closely related to BMD and BGP.

Abstract:[Objective] To observe the short-term clinical outcomes of surgery combined with chemotherapy for primary undifferentiat- ed pleomorphic sarcoma of the femur. [Methods] A retrospective study was done on 10 patients who received surgery combined with chemo- therapy for primary undifferentiated pleomorphic sarcoma of the femur diagnosed by biopsy from October 2015 to October 2019 in our de- partment. The tumor was of Enneking Stage IIA in 1 case and Stage IIB in 9 cases. Of them, 4 patients received preoperative neoadjuvant chemotherapy and 8 patients had postoperative chemotherapy conducted, and all patients received surgical treatment, including broad boundary surgical resection with hip reconstruction by prostheses for tumor in 1 case, segmental prosthetic reconstruction in 1 case, and knee reconstruction by prostheses for tumor in 8 cases. Postoperative function was assessed according to Musculoskeletal Tumor Society (MSTS) scoring system. [Results] All patients were successfully operated on without wound nonunion, infection around wound, and deep ve- nous thrombosis of lower limbs. All patients were followed up for 7~43 months, with a mean of (25.10±14.18) months. Of them, 4 patients died, 1 patient survived with tumor, and 5 patients survived without tumor. Postoperative metastasis occurred in 5 patients with the mean time of metastasis of (4.40±1.14) months, and local recurrence occurred in 2 patients. The average MSTS score of lower limbs was (26.5± 1.58) three months after surgery. [Conclusion] For this tumor, neoadjuvant chemotherapy is not necessary in some cases, whereas broad boundary surgical resection and chemotherapy might be effective to control it locally. The patients with pathological fractures and insensi- tive chemotherapy are more likely to have recurrence and metastasis after operation, however, the functional recovery of lower limbs is satis- factory after limb salvage therapy.