OBJECTIVE: To summarize the early clinical results and safety of Stand-alone OLIF application of lumbar lesions, and explored its surgical indications. METHODS: Total of 92 cases of lumbar spine lesions treated with Stand-alone OLIF at two medical centers from October 2014 to December 2018 were retrospectively analyzed, including 30 males and 62 females with an average age of (61.20±12.94) years old ranged from 32 to 83 years old. There were 20 cases of lumbar spinal stenosis, 15 cases of lumbar disc degeneration, 11 cases of lumbar degenerative spondylolisthesis, 6 cases of discogenic low back pain, 7 cases of giant lumbar disc herniation, 13 cases of primary lumbar discitis, 6 cases of adjacent vertebral disease after lumbar internal fixation surgery, and 14 cases of degenerative lumbar scoliosis. Pre-operative dual energy X-ray bone density examination 31 cases' T-values ranged from -1 to -2.4, 8 cases' T-values ranged from -2.5 to -3.5, and the rest had normal bone density. The number of fusion segments: 68 cases of single segment, 9 cases of two segment, 12 cases of three segment , and 3 cases of four segment. Fusion site:L_1,2 1 case, L_2,3 4 cases, L_3,4 10 cases, L_4,5 53 cases, L_2,3-L_3,4 3 cases, L_3,4-L_4,5 6 cases, L_1,2L_2,3L_3,4 1 case, L_1,2L_3,4L_4,5 1 case, L_2,3L_3,4L_4,5 10 cases, L_1,2L_2,3L_3,4L_4,5 3 cases. The clinical results and imaging results of this group of cases were observed, as well as the complications. RESULTS: The surgical time ranged from 40 to 140 minutes with an average of (60.92±27.40) minutes. The intraoperative bleeding volume was 20 to 720 ml with an average of (68.22±141.60) ml. The patients had a follow-up period of 6 to 84 months with an average of (38.50±12.75) months. The height of the intervertebral space recovered from (9.23±1.94) mm in preoperative to (12.68±2.01) mm in postoperative, and (9.11±1.72) mm at the last follow-up, there was a statistically significant difference(F=6.641, P=0.008);there was also a statistically significant difference between the postoperative and preoperative height of the intervertebral space(t=9.27, P<0.000 1);and there was also a statistically significant difference (t=10.06, P<0.000 1) between the last follow-up and postoperative height of the intervertebral space. At the last follow-up, cage subsidence grading was as follows:level 0 in 69 cases (76 segments), levelⅠin 17 cases (43 segments), level Ⅱin 5 cases (14 segments), and level Ⅲ in 1 case (1 segment);according to the number of segments, normal subsidence accounts for 56.72%, abnormal subsidence accounts for 43.28%. Bone mineral desity of normal subsidence groups was -0.50±0.07 whinch was better than that the abnormal subsidence groups -2.10±0.43, and the difference was statistically significant(χ²=2.275, P=0.014). As well as there was a statistically significant difference in the patient's VAS of backache from (6.28±2.11) in preoperative to (1.48±0.59) in last follow-up(t=8.56, P<0.05). The ODI recovered from (36.30±7.52)% before surgery to (10.20±2.50)% at the last follow-up, with a statistically significant difference (t=7.79, P<0.000 1). Complications involved 4 cases of intraoperative vascular injury, 21 cases of endplate injury, and 4 cases of combined vertebral fractures. The incision skin has no necrosis or infection. There were 4 cases of left sympathetic chain injury, 4 cases of transient left hip flexion weakness, 2 cases of left thigh anterolateral numbness with quadriceps femoris weakness, and 1 case of incomplete intestinal obstruction;8 cases were treated with posterior pedicle screw fixation due to fusion cage settlement accompanied by stubborn lower back pain, and 6 cases were treated with fusion cage settlement and lateral displacement. According to the actual number of cases, there were 38 complications, with an incidence rate of 41.3%. CONCLUSION The application of Stand alone OLIF in lumbar spine disease fusion has achieved good early results, with obvious clinical advantages, but also there are high probability of complications. It is recommended to choose carefully. It is necessary to continuously summarize and gradually clarify and complete the surgical indications and specific case selection criteria.
Humans ; Male ; Female ; Middle Aged ; Spinal Fusion/methods* ; Lumbar Vertebrae/injuries* ; Aged ; Adult ; Retrospective Studies ; Aged, 80 and over

Objective To observe the cage subsidence after oblique lateral interbody fusion(OLIF)for lumbar spondylo-sis,summarize the characteristics of the cage subsidence,analyze causes,and propose preventive measures.Methods The data of 144 patients of lumbar spine lesions admitted to our hospital from October 2015 to December 2018 were retrospectively ana-lyzed.There were 43 males and 101 females,and the age ranged from 20 to 81 years old,with an average of(60.90±10.06)years old.Disease types:17 patients of lumbar intervertebral disc degenerative disease,12 patients of giant lumbar disc hernia-tion,5 patients of discogenic low back pain,33 patients of lumbar spinal stenosis,26 patients of lumbar degenerative spondy-lolisthesis,28 patients of lumbar spondylolisthesis with spondylolisthesis,11 patients of adjacent vertebral disease after lumbar internal fixation,7 patients of primary spondylitis in the inflammatory outcome stage,and 5 patients of lumbar degenerative scoliosis.Preoperative dual-energy X-ray bone mineral density examination showed 57 patients of osteopenia or osteoporosis,and 87 patients of normal bone density.The number of fusion segments:124 patients of single-segment,11 patients of two-seg-ment,8 patients of three-segment,four-segment 1 patient.There were 40 patients treated by stand-alone OLIF,and 104 patients by OLIF combined with posterior pedicle screw.Observed the occurrence of fusion cage settlement after operation,conducted monofactor analysis on possible risk factors,and observed the influence of fusion cage settlement on clinical results.Results All operations were successfully completed,the median operation time was 99 min,and the median intraoperative blood loss was 106 ml.Intraoperative endplate injury occurred in 30 patients and vertebral fracture occurred in 5 patients.The mean follow-up was(14.57±7.14)months from 6 to 30 months.During the follow-up,except for the patients of primary lumbar interstitial in-flammation and some patients of lumbar spondylolisthesis with spondylolisthesis,the others all had different degrees of cage subsidence.Cage subsidence classification:119 patients were normal subsidence,and 25 patients were abnormal subsidence(23 patients were grade Ⅰ,and 2 patients were grade Ⅱ).There was no loosening or rupture of the pedicle screw system.The height of the intervertebral space recovered from the preoperative average(9.48±1.84)mm to the postoperative average(12.65±2.03)mm,and the average(10.51±1.81)mm at the last follow-up.There were statistical differences between postop-erative and preoperative,and between the last follow-up and postoperative.The interbody fusion rate was 94.4％.The low back pain VAS decreased from the preoperative average(6.55±2.2 9)to the last follow-up(1.40±0.82),and there was statistically significant different.The leg pain VAS decreased from the preoperative average(4.72±1.49)to the final follow-up(0.60± 0.03),and the difference was statistically significant(t=9.13,P＜0.000 1).The ODI index recovered from the preoperative av-erage(38.50±6.98)％to the latest follow-up(11.30±3.27)％,and there was statistically significant different.The complication rate was 31.3％(45/144),and the reoperation rate was 9.72％(14/144).Among them,8 patients were reoperated due to fusion cage subsidence or displacement,accounting for 57.14％(8/14)of reoperation.The fusion cage subsidence in this group had obvious characteristics.The monofactor analysis showed that the number of abnormal subsidence patients in the osteopenia or osteoporosis group,Stand-alone OLIF group,2 or more segments fusion group,and endplate injury group was higher than that in the normal bone mass group,OLIF combined with pedicle screw fixation group,single segment fusion group,and no endplate injury group,and the comparison had statistical differences.Conclusion Cage subsidence is a common phenomenon after 0-LIF surgery.Preoperative osteopenia or osteoporosis,Stand-alone OLIF,2 or more segments of fusion and intraoperative end-plate injury may be important factors for postoperative fusion cage subsidence.Although there is no significant correlation be-tween the degree of cage subsidence and clinical symptoms,there is a risk of cage migration,and prevention needs to be strengthened to reduce serious complications caused by fusion of cage subsidence,including reoperation.

The biological characteristics and pathogenicity of Klebsiella oxytoca isolated from sick carrier pigeons in Gansu province were explored by morphological observations,biochemical testing,16S rRNA PCR analysis,and RNA sequencing.The drug resistance and pathogenicity of the isolated strains were studied by histopathological observation,drug susceptibility testing,and pathogenicity analysis.The livers,lungs,hearts,and other organs of the sick pigeons were bleeding.In addition,the livers were yellow and brittle,and the lungs were purulent.A Gram-negative,short,rod-shaped bacterium was successfully isolated from the sick pigeon.Pink,smooth,moist,and round colonies grew on MacConkey's agar.The result of the indigo matrix test was positive.The homology between the amplified 16S rRNA sequence and MN330093.1 was 100.00％,indicating that the sick pigeon was infected with K.oxytoca.The strain was named GS-BY-GG.K.Oxytoca GS-BY-GG was resistant to 10 drugs,including penicillin,ampicillin,and furazolidone,and sensitive to 5 others,which included florfenicol,meropenem,and gentamicin.Histopathological observation showed bleeding in multiple organs.The liver cells were irregu-larly arranged with brown-yellow pigmentation.Extensive cell necrosis and exfoliation were observed in the trachea and mucosal epithelium,with inflammatory cell infiltration in the mucosal layer.The isolates were highly pathogenic in specific pathogen-free chickens.These findings provide support for the clinical diagnosis and control of K.oxytoca GS-BY-GG.

OBJECTIVE: To explore characteristics, management strategies and preventive measures of fusion device displacement after oblique lateral interbody fusion (OLIF) in treating lumbar lesions. METHODS: The clinical data of 12 patients with fusion device displacement after OLIF for lumbar lesions in 4 medical centers from October 2014 to December 2018 were retrospectively analyzed, including 4 males and 8 females, aged from 53 to 81 years old;2 patients with lumbar disc degeneration, 4 patients with lumbar spinal stenosis, 3 patients with lumbar degenerative spondylolisthesis and 3 patients with lumbar degenerative kyphosis;preoperative dual-energy X-ray bone mineral density (BMD) was detected in 1 patient with T-value > -1 SD, 5 patients with T-value >-1~-2.5 SD, and 6 patients with T-value <-2.5 SD;9 patients with single-segment fusion, 1 patient with 2-segment fusion, and 2 patients with 3-segment fusion;standalone OLIF was performed in 9 patients and OLIF combined with posterior pedicle screws in 3 patients. Visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate low back pain and lumbar function recovery at the time of fusion graft displacement and at the latest follow-up, respectively. In addition, according to imaging results during follow-up, the fusion device subsidence or redisplacement, loosening or fracture of internal fixation, and interbody fusion were observed, and the changes in the height of interbody space on the segment with fusion device displacement were measured and compared. RESULTS: There were no necrosis or infection in skin incision of 10 patients after reoperation, and 12 patients were followed up for 12 to 48 months. VAS for low back pain decreased from 3 to 8 points at the time of fusion device displacement to 0 to 2 points at the latest follow-up. ODI recovered from 31% to 51% at the time of fusion transfer to 5% to 13% at the latest follow-up. There was no loosening or fracture of the pedicle screw system during follow-up. All 11 patients with bone grafting with fusion apparatus had fusion apparatus subsidence and no further displacement of fusion apparatus. The vertebral space height recovered from 9.0 to 12.7 mm at the time of fusion graft displacement to 8.0 to 11.8 mm at the latest follow-up. Interbody fusion was obtained in all patients except 1 with no imaging results at the latest follow-up. CONCLUSION OLIF could be used for fusion of lumbar lesions, and there is a risk of fusion organ displacement after operation, especially in cases of bone loss or osteoporosis before surgery, end-plate injury during surgery, and Stand-alone mode, and most of them occur within 3 months after operation. Surgery is required for the transposition of the fusion apparatus in the Stand-alone OLIF mode during the primary operation. Although good clinical results could be obtained by timely detection and accurate treatment, it is still necessary to emphasize the precise selection of cases before operation, the appropriate application of OLIF, and precise operation during operation to prevent displacement of fusion device.
Humans ; Spinal Fusion/instrumentation* ; Female ; Male ; Middle Aged ; Aged ; Aged, 80 and over ; Lumbar Vertebrae/surgery* ; Retrospective Studies ; Pedicle Screws

OBJECTIVE: To explore the feasibility and clinical effect of Stand-alone oblique lateral interbody fusion (OLIF) in the treatment of lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis. METHODS: A retrospective analysis was performed on 16 cases with lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis admitted to three medical centers from January 2015 to December 2018. There were 6 males and 10 females, the age ranged from 45 to 67 years old with an average of (55.48±8.07) years old, the medical history ranged from 36 to 240 months with an average of (82.40±47.68) months. The lesion sites included L_2,3 in 2 cases, L_3,4 in 5 cases, and L_4,5 in 9 cases. All patients presented with chronic low back pain with lower limb neurological symptoms in 3 cases. All patients were treated by Stand-alone oblique lateral lumbar interbody fusion. Clinical and radiological findings and complications were observed. RESULTS: There was no vascular injury, endplate injury and vertebral fracture during the operation. The mean incision length, operation time, and intraoperative blood loss were(4.06±0.42) cm, (45.12±5.43) min, (33.40±7.29) ml, respectively. The mean visual analogue scale (VAS) of the incision pain was (1.14±0.47) at 72 hours after operation. There was no incision skin necrosis, poor incision healing or infection in patients. Sympathetic chain injury occurred in 1 case, anterolateral pain and numbness of the left thigh in 2 cases, and weakness of the left iliopsoas muscle in 1 case, all of which were transient injuries with a complication rate of 25%(4/16). All 16 patients were followed up from 12 to 36 months with an average of (20.80±5.46) months. The intervertebral space height was significantly recovered after operation, with slight lost during the follow-up. Coronal and sagittal balance of the lumbar spine showed good improvement at the final follow-up. There was no obvious subsidence or displacement of the cage, and the interbody fusion was obtained. At the final follow-up, Japanese Orthopaedic Association(JOA) score and Oswestry disability index(ODI) were significantly improved. CONCLUSION As long as the selection of case is strict enough and the preoperative examination is sufficients, the use of Stand-alone OLIF in the treatment of lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis has a good results, with obvious clinical advantages and is a better surgical choice.
Male ; Female ; Humans ; Child, Preschool ; Intervertebral Disc Degeneration/surgery* ; Retrospective Studies ; Sclerosis ; Treatment Outcome ; Lumbar Vertebrae/surgery* ; Spinal Fusion/methods*

OBJECTIVE: To analyze the causes of vertebral fracture during oblique lateral interbody fusion in the treatment of lumbar spondylopathy, summarize the clinical results, and propose preventive measures. METHODS: Retrospective analysis was made on the data of 8 cases of lumbar spondylopathy and vertebral fracture treated by oblique lateral interbody fusion in three medical centers from October 2014 to December 2018. All were female, aged from 50 to 81 years with an average of 66.4 years. Disease types included 1 case of lumbar degenerative disease, 3 cases of lumbar spinal stenosis, 2 cases of lumbar degenerative spondylolisthesis and 2 cases of lumbar degenerative scoliosis. Preoperative dual energy X-ray bone mineral density test showed that 2 cases had T-value >-1 SD, 2 cases had T-value -1 to -2.5 SD, and 4 cases had T-value <-2.5 SD. Single segment fusion was in 5 cases, two segment fusion in 1 case and three segment fusion in 2 cases. Four cases were treated with OLIF Stand-alone and 4 cases were treated with OLIF combined with posterior pedicle screw fixation. Postoperative imaging examination showed vertebral fracture, and all of them were single vertebral fracture. There were 2 cases of right lower edge fracture of upper vertebral body at fusion segment, 6 cases of lower vertebral body fracture at fusion segment, and 6 cases with endplate injury and fusion cage partially embedded in vertebral body. Three cases of OLIF Stand-alone were treated with pedicle screw fixation via posterior intermuscular approach, while one case of OLIF Stand-alone and four cases of OLIF combined with posterior pedicle screw fixation were not treated specially. RESULTS: The 5 cases of initial operation and 3 cases of reoperation did not show wound skin necrosis or wound infection. The follow-up time was from 12 to 48 months with an average of 22.8 months. Visual analogue scale (VAS) of low back pain was preoperative decreased from 4 to 8 points (averagely 6.3 points) and postoperative 1 to 3 points (averagely 1.7 points) at the final follow-up. Oswestry disability index (ODI) was preoperative 39.7% to 52.4% (averagely 40.2%), and postoperative 7.9% to 11.2% (averagely 9.5%) at the final follow-up. During the follow-up, there was no loosening or fracture of the pedicle screw system, and no lateral displacement of the fusion cage;however, the fusion cage at the vertebral fracture segment had obvious subsidence. The intervertebral space height of vertebral fracture segment was preoperaive 6.7 to 9.2 mm (averagely 8.1 mm), and postoperative 10.5 to 12.8 mm (averagely 11.2 mm). The improvement rate after operation was 37.98% compared to preoperative. The intervertebral space height at final follow-up was 8.4 to 10.9 mm (averagely 9.3 mm), and the loss rate was 16.71% compared with that after operation. At the final follow-up, interbody fusion was achieved in all cases except for one that could not be identified. CONCLUSION The incidence of vertebral fracture during oblique lateral interbody fusion in the treatment of lumbar spondylopathy is lower, and there are many reasons for fracture, including preoperative bone loss or osteoporosis, endplate injury, irregular shape of endplate, excessive selection of fusion cage, and osteophyte hyperplasia at the affected segment. As long as vertebral fracture is found in time and handled properly, the prognosis is well. However, it still needs to strengthen prevention.
Humans ; Female ; Male ; Spinal Fractures/surgery* ; Retrospective Studies ; Treatment Outcome ; Lumbar Vertebrae/surgery* ; Spondylolisthesis/surgery* ; Scoliosis ; Spinal Fusion/methods*

OBJECTIVE: To investigate the effect of RUNX2 gene overexpression vector modified exosomes derived from bone marrow mesenchymal stem cells (BMSCs) combined with calcium carbonate scaffold system in bone defect. METHODS: Rabbit BMSCs were used as the research object, and BMSCs were identified by flow cytometry. Construct RUNX2 gene overexpression vector, transfect BMSCs with lentivirus, and collect exosomes by ultracentrifugation. The morphology of exosomes was observed by transmission electron microscope, the expression of exosome marker CD63 was detected by Western blot, and the calcium carbonate scaffold was constructed by three chamber parallel automatic temperature control reaction system. According to whether the RUNX2 gene overexpression vector was transfected or not, the complex of BMSCs and calcium carbonate scaffold was divided into three groups, namely BMSCs group, RUNX2 overexpression group and exosome group. The osteogenic differentiation of BMSCs was detected by oil red O staining and RT-PCR. There were 9 clean adult healthy male New Zealand white rabbits, aged (12.97±1.21) months, with a body weight of (19.3±3.6) kg, with 3 rabbits in each group. The animal model of skull defect was constructed by surgical method, and the repair of bone defect was evaluated by imaging, he staining and Masson staining. RESULTS: The results of flow cytometry showed that the expression of CD29 protein, CD44 protein, CD11b protein and CD45 protein on the surface of BMSCs were 99.5%, 100%, 0.1% and 0.1%, respectively. Transmission electron microscopy showed that the exosomes were bilayer vesicles with a diameter of 50 to 150 nm. Western blot showed that the molecular marker CD63 of exosomes was positive. Oil red O staining showed that the osteogenic differentiation of BMSCs in exosome group was significantly higher than that in RUNX2 overexpression group and BMSCs group. The results of RT-PCR showed that the relative expressions of RUNX2, BMP-2 and ALP mRNA in BMSCs in exosome group were significantly higher than those in RUNX2 overexpression group and BMSCs group (P<0.05). The imaging results showed that the repair effect of skull defect in exosome group was better than that in RUNX2 overexpression group. HE staining and Masson staining showed that the repair effect of skull defect in exosome group was better than that in RUNX2 overexpression group (P<0.05). MSCs in exosome group was significantly higher than that in RUNX2 overexpression group and BMSCs group. The results of RT-PCR showed that the relative expressions of RUNX2, BMP-2 and ALP mRNA in BMSCs in exosome group were significantly higher than those in RUNX2 overexpression group and BMSCs group(P<0.05). The imaging results showed that the repair effect of skull defect in exosome group was better than that in RUNX2 overexpression group. HE staining and Masson staining showed that the repair effect of skull defect in exosome group was better than that in RUNX2 overexpression group(P<0.05). CONCLUSION Compared with RUNX2 gene overexpression vector transfection, extraction of exosomes directly can promote the differentiation of BMSCs into osteoblasts more efficiently, and the combination with calcium carbonate scaffold can better promote the healing of bone defects. So as to provide new ideas and methods for the clinical treatment of bone defects.
Animals ; Calcium Carbonate/metabolism* ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Exosomes/metabolism* ; Humans ; Male ; Osteogenesis/genetics* ; RNA, Messenger/metabolism* ; Rabbits

OBJECTIVE: To explore the effects of siRNA hsa-circ-0000885 modified bone marrow mesenchymal stem cells (BMSCs) on osteogenic differentiation, cell proliferation and apoptosis in order to provide new ideas and methods for the clinical treatment of osteoporosis (OP). METHODS: From September 2018 to February 2020, 13 patients with osteoporosis admitted to our hospital were selected as the research objects, including 11 females and 2 males, with an age of (65.45±10.77) years old. After obtaining the informed consent of patients, peripheral blood tissues were extracted. Then the expression level of cir-cRNA in peripheral blood mononuclear cells(PBMC) was detected by circ RNA chip. The expression of circ RNA was silenced by siRNA technology. The BMSCs were transfected with lentivirus. According to the siRNA interference plasmid hsa-circ-0000885, the cells were divided into the blank group, the empty vector group and the siRNA interference group. After 72 hours of treatment, the cell cycle was detected by flow cytometry, the apoptosis level was detected by AV-PI kit, and the osteogenic differentiation ability of BMSCs was detected by ALP staining. RESULTS: The expression of hsa-circ-0000885 in PBMC of patients with osteoporosis was significantly higher than that of healthy controls ( CONCLUSION The lentivirus mediated siRNA hsa-circ-0000885 plasmid transfected into BMSCs and osteoclast co culture system can promote cell proliferation, inhibit apoptosis and promote osteogenic differentiation of BMSCs, which can be used as a potential therapeutic target for OP patients.
Aged ; Apoptosis/genetics* ; Cell Differentiation ; Cell Proliferation/genetics* ; Cells, Cultured ; Coculture Techniques ; Female ; Humans ; Lentivirus ; Leukocytes, Mononuclear ; Mesenchymal Stem Cells ; Middle Aged ; Osteoclasts ; Osteogenesis/genetics* ; RNA, Small Interfering/genetics* ; Transfection

OBJECTIVE: To analyze the causes of vascular injury occurred in oblique lateral interbody fusion for treating lumbar degenerative diseases, and put forward preventive measures. METHODS: There were 235 patients analyzed from October 2014 to May 2017 in five hospitals, who were treated with oblique lateral interbody fusion with or without posterior pedicle screw fixation. There were 79 males and 156 females with an average age of (61.9±13.5) years old (ranged from 32 to 83 years). There were 7 cases of vascular injury, including 4 cases of segmental vessel injury, 1 case of left common iliac artery injury, 1 case of left common iliac veininjury and 1 case of ovarian vein injury. RESULTS: The follow up time ranged from 6 to 36 months, averagely (15.6±7.5) months. There was no pedicle screw loosen or fracture. The low back pain VAS decreased from preoperative 6.7±2.3 to 1.4±0.8 at the latest follow-up, which was statistically difference( CONCLUSION Oblique lateral interbody fusion technique provides a new method for minimally invasive fusion of lumbar internal fixation. However, it has a risk of vascular injury. In order to effectively prevent the occurrence of vascular injury, the operative indications and careful and meticulous operation should be strictly grasped.
Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Lumbar Vertebrae/surgery* ; Lumbosacral Region ; Male ; Middle Aged ; Pedicle Screws ; Retrospective Studies ; Spinal Fusion/adverse effects* ; Treatment Outcome ; Vascular System Injuries/surgery*

Background:Clinical outcomes of undifferentiated arthritis (UA) are diverse,and only 40 ％ of patients with UA develop rheumatoid arthritis (RA) after 3 years.Discovering predictive markers at disease onset for further intervention is critical.Therefore,our objective was to analyze the clinical outcomes of UA and ascertain the predictors for RA development.Methods:We performed a prospective,multi-center study from January 2013 to October 2016 among Chinese patients diagnosed with UA in 22 tertiary-care hospitals.Clinical and serological parameters were obtained at recruitment.Follow-up was undertaken in all patients every 12 weeks for 2 years.Predictive factors of disease progression were identified using multivariate Cox proportional hazards regression.Results:A total of 234 patients were recruited in this study,and 17 (7.3％) patients failed to follow up during the study.Among the 217 patients who completed the study,83 (38.2％) patients went into remission.UA patients who developed RA had a higher rheumatoid factor (RF)-positivity (42.9％ vs.16.8％,x2=8.228,P=0.008),anti-cyclic citrullinated peptide (CCP) antibodypositivity (66.7％ vs.10.7％,x2 =43.897,P ＜ 0.001),and double-positivity rate of RF and anti-CCP antibody (38.1％ vs.4.1％,x2 =32.131,P ＜ 0.001) than those who did not.Anti-CCP antibody but not RF was an independent predictor for RA development (hazard ratio 18.017,95％ confidence interval:5.803-55.938;P ＜ 0.001).Conclusion:As an independent predictor of RA,anti-CCP antibody should be tested at disease onset in all patients with UA.