Sports injury is quite common with negative impact on patients' sport performance and functional capacity. Rehabilitation for patients with sports injury mainly aims at recovering their functional capacity to preinjury level, assisting them to return to sports safely, and preventing re‐injury. However, the rehabilitation outcomes of sports injury remain suboptimal. The author outlines the constraints to the improvement of rehabilitation outcomes and emphasizes on the acute phase and post-acute phase rehabilitation management as well as other important issues in the practice of rehabilitation management so as to better standardize the rehabilitation practice, optimize the rehabilitation process, and eventually improve the clinical and functional outcome of sports injury.

Objective:To investigate MRI texture features reflecting short-term medial femoral cartilage variations after anterior cruciate ligament (ACL) reconstruction.Methods:A retrospective case series analysis was conducted referring to the data of 20 patients who received ACL reconstruction at First Affiliated Hospital of Fujian Medical University from January 2017 to January 2020 including 17 males and 3 females, aged 23-43 years [(32.1±5.4)years]. The patients were evaluated before operation and at 1, 4, 12, 24, 48 weeks after operation: (1) the region of interest (ROI) in medial femoral cartilage was divided into ROI1 (meniscus anterior horn cartilage), ROI2 (meniscus body cartilage) and ROI3 (meniscus posterior horn cartilage) according to MRI image acquisition of the affected knee. The texture feature parameters were extracted for screening and analyzing to obtain the parameters reflecting sensitivity to cartilage variations; (2) the level of urinary C-telopeptide of type II collagen (uCTX-II) was measured by ELISA. At different time points, differences in texture feature parameters were compared to screen the parameters most sensitive to cartilage variations, and uCTX-II level were compared as well. Then, Pearson correlation analysis was used to determine the correlation between texture feature parameters most sensitive to cartilage variations and uCTX-II level.Results:After screening and analyzing, the horizontal direction of gray level non-uniformity (Horzl_GlevNonU) and Skewness of histogram (Skewness) of ROI3 were selected as sensitive texture feature parameters reflecting sensitivity to cartilage variations. There were significant difference in the Horzl_GlevNonU and Skewness of ROI3 before operation and at 1, 4, 12, 24, 48 weeks after operation (all P<0.05). Meanwhile, the Horzl_GlevNonU and Skewness of ROI3 were gradually increased over time, with a more significant tendency in the Horzl_GlevNonU. The Horzl_GlevNonU of ROI3 was similar at 4 weeks and 12 weeks after operation ( P>0.05), with significant differences at other time points (all P<0.05). The Skewness of ROI3 was significantly different at 1 week and 48 weeks after operation ( P<0.05), with insignificant differences at other time points (all P>0.05). The Horzl_GlevNonU of ROI3 was selected as the most sensitive texture feature parameter reflecting cartilage variations. Significant difference was reported in uCTX-II level before operation and at 1, 4, 12, 24, 48 weeks after operation (all P<0.05). After Pearson correlation analysis, the Horzl_GlevNonU of ROI3 was positively correlated with uCTX-II level before operation and at 1, 4, 12, 24, 48 weeks after operation ( r=0.554, 0.596, 0.550, 0.632, 0.756, 0.514, P<0.05 or 0.01). Conclusion:The Horzl_GlevNonU of ROI3 is the most sensitive texture feature parameter that reflects the early variations of medial femoral cartilage after ACL reconstruction and is positively correlated with uCTX-II level.

Objective:To explore the molecular mechanism of pathological changes in osteoarthritis (OA) through applying bioinformatics to analyze the miRNA-mRNA regulatory network.Methods:MiRNA expression data from human serum samples were downloaded from the Gene Expression Omnibus database. Differentially-expressed miRNA was identified using the linear modelling package of the Bioconductor software suite. The target differentially-expressed mRNA was predicted using version 2.0 of the miRWalk database. Version 3.7.1 of the Cytoscape software was used to construct the miRNA-mRNA regulatory network for OA. The target genes were analyzed by using gene ontology and the Kyoto Encyclopedia of Genes and Genomes. The protein-protein interaction network was constructed and the core genes in osteoarthritis pathology were screened out.Results:A total of 7 differentially-expressed miRNAs (all down-regulated) and 900 mRNAs were identified, mostly involved in the negative regulation of protein binding, DNA binding, or transcription in the cell cycle. Ten core genes were screened out: MAPK1, TP53, MAPK14, CCND1, EP300, POLR2E, POLR2F, ABL1, RAC1 and SKIV2L2.Conclusions:Multiple miRNAs, target genes and signaling pathways are involved in the development of OA. The miRNA-mRNA regulatory network identified provides new ideas for exploring the molecular mechanism of OA′s pathology and its clinical diagnosis and treatment.

Objective: To investigate the spatio-temporal distribution characteristics of pulmonary tuberculosis in Ningbo City from 2015 to 2020, so as to provide insights into tuberculosis control. Methods: The data of pulmonary tuberculosis cases in Ningbo City from 2015 to 2020 were collected from Tuberculosis Management Information System of China Disease Control and Prevention Information System, and were linked with the geographic information database of Ningbo Planning Design and Research Institute. The software SaTScan version 10.3 was employed for monthly spatio-temporal scanning and cluster analysis of reported pulmonary tuberculosis cases, populations, longitude and latitude in 153 townships of Ningbo City from 2015 to 2020. Results: There were one class Ⅰ cluster and two class Ⅱ clusters of pulmonary tuberculosis cases in Ningbo City from 2015 to 2020, and the class Ⅰ cluster was centered in Song'ao Township and covered 37 townships, with aggregation time from January 1, 2015 to December 31, 2017, while class Ⅱ clusters were covered 38 tounships which were centered in Sanqishi Township of Yuyao County, and one township in Hangzhou Bay New Town. The aggregation time was from January to June in 2015 and 2016, from March to August between 2017 and 2019 and between May and October, 2020. The overall reported incidence of pulmonary tuberculosis appeared a tendency towards a decline in each township of Ningbo City from 2015 to 2020; however, the incidence of pulmonary tuberculosis was more than 80 per 100 thousand in Fuming Township of Yinzhou District and Juexi Township of Xiangshan County in 2020. Conclusions There were significant spatio-temporal clustering characteristics of pulmonary tuberculosis incidence at a township level in Ningbo City from 2015 to 2020, and the clusters were mainly concentrated in the central and eastern Ningbo City. The reported incidence of pulmonary tuberculosis is high in Fuming Township of Yinzhou District and Juexi Township of Xiangshan County, where targeted regional tuberculosis control strategies should be implemented.

Objective To investigate the value of endoscopic retrograde appendicitis therapy ( ERAT) in the diagnosis and treatment of atypical acute appendicitis. Methods All the 48 patients suspected of atypical acute appendicitis in Jiangsu Province Hospital from January 2015 to December 2016 were randomly divided into ERAT group and conservative treatment group according to the treatment method. The final appendectomy rate of the two groups was analyzed. Results Only 17 of the 24 patients in the ERAT group received endoscopic treatment because of complex conditions or personal wishes, and 16 cases were diagnosed as acute appendicitis. Surgical resection was performed in 5 cases because of recurrence of the disease after ERAT, and the appendectomy rate was 31. 2％ ( 5/16 ) . In the conservative treatment group, all 24 patients were treated with antibiotics. Twenty of them underwent surgical resection with appendectomy rate of 83. 3％ ( 20/24) , and 1 of them had appendiceal perforation. The appendectomy rate of the ERAT group was significantly lower than that of the conservative treatment group (χ2=11. 111, P<0. 05) . Conclusion ERAT has a high diagnostic and therapeutic value for atypical acute appendicitis.

Objective To explore the effect of treadmill running at different intensities on three-dimensional structure of rat subchondral bones.Methods A total of 24 female Wistar rats were randomly assigned into a sedentary (SED) group,a low-intensity running (LIR) group,a medium-intensity running (MIR) group,or a high-intensity running (HIR) group,each of 6.Rats in LIR,MIR and HIR groups underwent treadmill running exercises with respective protocol,while rats in SED group serve as controls.Eight weeks later,all animals were sacrificed and their proximal end of tibia was examined using Micro-CT.Results Compared with SED group,in HIR group the subchondral plate became thicker with higher BMD and lower porosity,while trabecular bone became more and denser with higher BMD and a more plate-like architecture.LIR and MIR failed to result in considerable changes in the microstructure.Conclusion Treadmill running has an intensity-dependent effect on the three-dimensional structures of subchondral bones.High-intensity running can evoke significant structural changes in subchondral bones.

Objective To investigate the effect of treadmill running with different intensities on type Ⅱ collagen (Col2) of knee joint articular cartilages in rats.Methods A total of 48 adult Sprague-Dawley rats were randomly divided into a control (C) group,a low-intensity exercise (L) group,a moderate-intensity exercise (M)group and a high-intensity exercise (H) group,each of 12.Rats in three exercises groups were regularly trained on treadmill at low,moderate,and high intensities respectively.Eight weeks later,all the animals were sacrificed.The right tibial plateau samples were collected to observe collagen fibers under polarizing light microscopy,and the collagen Ⅱ content were examined using immunohistochemistry.The mRNA expression of biglycan (BGN),fibromodulin (FMOD) and Col2 was tested using the quantitative real-time reverse transcription-polymerase chain reaction.Results Compared with group C,collagen fibers in group L and M exhibited almost the same organization,whereas,alteration in organization and shape of collagen fibers was found in group H.Significantly lower content of type Ⅱ collagen was found in group H than that in group C.In comparison with group C,group L had significantly higher gene expression of Col2,whereas group H had significantly higher BGN mRNA expression.Conclusion Low-or moderate-intensity treadmill running appears to have beneficial effect on articular cartilages to maintain its integrity.Highintensity exercises induce lower content and disorder of type Ⅱ collagen in articular cartilages,but the self-healing of cartilage may still exist.

Objective To investigate the effect of cyclic tensile stress (CTS) on the metabolism inand apoptosis of rat chondrocytes.Methods Primary rat chondrocytes were cultured on a Bioflex plate for one day and then stretched cyclically for 24 hours at a frequency of 0.5 Hz using a Flexcell-5000T apparatus.The cells were divided into 5 groups according to their stretching ratio:0％ (the control group),2％,6％,10％ and 14％.After the stretching,Col Ⅱ,Aggrecan,MMP-13 and ADAMTS-5 mRNA were measured using qPCRs,and the NO and PGE2 levels were measured using ELISA kits.Moreover,TUNEL staining and Annexin V-FITC/PI were used to analyze the apoptosis of chondrocytes.Results Compared with the control group,the average levels of Col Ⅱ and Aggrecan mRNAdecreasedin 10％ and 14％ groups [(0.738±0.11) and (0.58±0.13),(0.75±0.11) and (0.55±0.09)].In those groups,the MMP-13 [(2.47±0.47) and (2.88±0.36)] and ADAMTS-5 mRNA level [(2.39±0.33) and (2.75±0.49)],the NO [(6.96±0.96) and (8.28±0.82)] and PGE2 level [(6.83±0.66) and (7.15±0.71)] had increased significantly.In the 6％ group the average levels of Col Ⅱ(1.76±0.30) and Aggrecan mRNA (1.93±0.14)of 6％ group were significantly higher than the control group,but the NO level of the former (3.07±0.20) was significantly lower than the control group (3.89 ± 0.33).The apoptosis rate of chondrocytesin 2％ and 6％ groups were (0.065±0.013) and (0.063 ± 0.147),without significant differences to that of the control group (0.045 ± 0.008).However,compared with the control group,apoptosis in the 10％ and 14％ groups [(0.135 ±0.026) and (0.184±0.020)] increased significantly.Conclusion The effect of cyclic tensile stress on chondrocyte metabolism and apoptosis was magnitude-dependent.Ten percent and 14％ CTS can increase the catabolism and apoptosis of chondrocytes.Ten percent and 14％ strain can increase the catabolism and apoptosis of chondrocytes.Cyclic 6％ strain can increase the anabolism of chondrocytes,but 2％ strain has no impact on metabolism or apoptosis.

Objective To evaluate the effects of different intensities of treadmill running on changes in tibial bone composition in a rat model.Methods A total of 24 female Wistar rats were randomly assigned into 4 even groups (n =6) of free movement (FM),low-intensity running (LR),medium-intensity running (MR),and high-intensity running (HR).Rats in LR,MR,and HR groups underwent treadmill running with respective intensities (15 m/min and a 0° gradient,20 m/min and a 5° gradient,25 m/min and a 10° gradient) for 8 weeks (1 h/d and 5 d/week).FM group were taken as controls.The cortical and trabecular bone at the left tibial metaphysis was harvested after 8 weeks in each group for Raman spectroscopy to analyze mineral-matrix ratio,carbonate-phosphate ratio and crystallinity.Results In MR group,the mean mineral-matrix ratio was 4.883 ± 0.128 for cortical bone and 4.216 ±0.213 for trabecular bone,both significantly higher than those in FM group (4.113 ±0.132 and 3.773 ±0.122) (P ＜ 0.05).The mean mineral-matrix ratio was 3.222 ± 0.329 for trabecular bone in HR group,significantly lower than that in FM group (P ＜ 0.05).In MR group,the mean carbonate-phosphate ratio was 0.166 ± 0.013 for trabecular bone,significantly lower than that in FM group (0.177 ± 0.011) (P ＜ 0.05).In HR group,the mean carbonate-phosphate ratio was 0.195 ± 0.012 for cortical bone and 0.187 ± 0.010 for trabecular bone,both significantly higher than those in FM group (0.183 ± 0.014 and 0.177 ± 0.011) (P ＜ 0.05).In HR group,the mean crystallinity was 0.0521 ± 0.0012 for cortical bone and 0.0522 ± 0.0017 for trabecular bone,both significantly higher than those in the other 3 groups (P ＜ 0.05).Conclusions Running with medium intensity may increase bone mineralization and turnover,thus enhancing bone quality.However,running with high intensity may decrease bone mineralization and thus bone quality.

OBJECTIVETo evaluate the effects of treadmill running exercise of different intensity on early repair of full-thickness defects on the patellofemoral articular surface and the changes in the expressions of matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in SD rats.

METHODSTwenty-four male SD rats with full-thickness defects on the patellofemoral articular surface were randomly assigned into sedentary control (SED) group and low-, moderate- and high-intensity running groups (LIR, MIR, and HIR groups, respectively). The running groups were trained on treadmill for 6 consecutive weeks. Blood samples were collected to detect serum MMP-3 and TIMP-1 levels using ELISA before and after the experiment, and the femoral trochlea were collected to assess tissue repair by gross appearance scoring and O Driscoll histological scoring with Safranine O-Fast Green staining and Toluidine blue staining.

RESULTSIn rats in SED group, the defect was filled with hyaline articular cartilage-like tissues, as compared to fibrous tissues in LIR and MIR groups and subchondral bone damage in HIR group. The SED group scored the highest and HIR group the lowest among the 4 groups in gross appearance scoring and O Driscoll histological scoring. No significant differences were found in MMP-3 or TIMP-1 levels among the groups before training (P>0.05), but after 6 weeks of training, serum MMP-3 and TIMP-1 levels differed significantly among the 4 groups (P<0.05), and all the 3 running groups had a significantly higher MMP-3 level than the control group (P<0.05). After the 6-week training, TIMP-1/MMP-3 ratio was significantly higher in SED group than in the 3 running groups, and was the lowest in HIR group.

CONCLUSIONBoth low- and moderate-intensity exercise failed to promote resurfacing of full-thickness cartilage defects on the patellofemoral articular surface in rats, and high-intensity exercise even induces subchondral bone damage. The expression of MMP-3 and TIMP-1 is related to exercise, and the TIMP-1/MMP-3 ratio reflects the extent of tissue repair.

Animals ; Cartilage, Articular ; metabolism ; pathology ; Male ; Matrix Metalloproteinase 1 ; metabolism ; Matrix Metalloproteinase 3 ; metabolism ; Physical Conditioning, Animal ; Rats ; Rats, Sprague-Dawley ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Wound Healing