Objective:To investigate the risk factors for periprosthetic joint infection (PJI) after primary total knee arthroplasty (TKA) and construct a nomogram model for prediction of such risks.Methods:In this retrospective study, we enrolled 69 patients with PJI after primary TKA (the infection group, n=69) who had been admitted to Department of Orthopedics, Nanjing Jinling Hospital, The First School of Clinical Medicine, Southern Medical University from January 2010 to December 2019. The non-infection group included the patients of the same kind but without postoperative infection during the same period who were matched according to time of admission, age, and gender in a ratio of 1∶3 ( n=207). The data on body mass index, anesthesia method, operation time, preoperative C-reactive protein, preoperative albumin, and comorbid medical conditions were collected from both groups to screen the risk factors for postoperative development of PJI using univariate and multivariate conditional logistic regression analyses. After a nomogram of the risk factors was plotted using R software, the consistency index (C-index) was calculated. The receiver operating characteristic curve, calibration curve, and clinical decision curve were drawn. Results:Multivariate conditional logistic regression analysis showed that preoperative albumin <35 g/L ( OR=7.166, 95% CI: 3.427 to 14.983, P<0.001), operation time >90 min ( OR=3.163, 95% CI: 1.476 to 6.779, P=0.003), diabetes mellitus ( OR=3.966, 95% CI: 1.833 to 8.578, P<0.001), rheumatic diseases ( OR=3.531, 95% CI: 1.362 to 9.156, P=0.009), and chronic lung diseases ( OR=4.734, 95% CI: 1.790 to 12.521, P=0.002) were risk factors for development of PJI after primary TKA. The nomogram constructed with R software visualized the model. The C-index of the nomogram was 0.809 (95% CI: 0.751 to 0.867), indicating a good predictive capability of the model. The calibration curves of the model showed that the nomogram was in good agreement with the actual observations. The decision curves showed that the threshold probabilities of the model ranged from 0.08 to 0.75, providing a good net clinical benefit. Conclusions:Preoperative low albumin, prolonged operation time, diabetes, rheumatic diseases, and chronic lung diseases may be the risk factors for PJI after primary TKA. The nomogram prediction model based on these factors can provide a reference for clinicians to prevent PJI.

Bone defects are bone loss caused by factors such as severe trauma, infection, tumor resection and congenital malformations. Bone transplantation, induced membrane technique or stem cell bone tissue engineering is needed for the defects that are difficult to heal naturally. However, the techniques related to bone transplantation are complex and have limited application scope; the induced membrane technique shows uncontrollable cement degradation rate and requires a second surgery; the stem cell bone tissue engineering still has some unstable factors such as undirected differentiation of stem cells. Exosomes are the key liposomes in the communication between cells. Compared with natural stem cell-derived exosomes, engineered exosomes with the advantages of high production and low immunogenicity are expected to replace stem cells in clinical applications. The authors review the mechanism of action of mesenchymal stem cell (MSC)-derived exosomes in repairing bone defects and application of engineered exosomes based on MSC in bone regeneration, so as to provide new ideas for the basic research and clinical treatment of bone defects.

Femoral neck fracture (FNF) in the elderly patients is currently a major health challenge worldwide, with excessive consumption of medical resources, high incidence of complications as well as suboptimal outcome and prognosis. Hip joint arthroplasty (HJA) has been the mainstream treatment for FNF in the elderly, but the conventional surgical approaches and techniques are still confronted with a series of bottlenecks such as dislocation, limp and limb length discrepancy. In recent years, direct anterior approach (DAA) for HJA (DAA-HJA) has been a major new choice in the field of joint replacement, which achieves improved clinical effectiveness of HJA in the treatment of elderly FNF, due to the fact that DAA approach involves the neuromuscular interface and accords with the idea of soft tissue retention and enhanced recovery after surgery. However, there is still a lack of unified understanding of standard technique and procedure of DAA-HJA in the treatment of elderly FNF. Therefore, relevant experts from the Hip Joint Group of Chinese Orthopedics Association of Chinese Medical Association, Youth Arthrology Group of Orthopedic Committee of PLA, Orthopedic Committee of Chongqing Medical Association, Branch of Orthopedic Surgeons of Chongqing Medical Doctor Association and Sport Medicine Committee of Chongqing Medical Association were organized to formulate the " Chinese expert consensus on the technical standard of direct anterior hip arthroplasty for elderly femoral neck fracture ( version 2023)" based on evidence-based medicine. This consensus mainly proposed 13 recommendations covering indications, surgical plans, prosthesis selections, surgical techniques and processes, and postoperative management of DAA-HJA in elderly patients with FNF, aiming to promote standardized, systematic and patient-specific diagnosis and treatment to improve the functional prognosis of the patients.

Objective:To compare the clinical effects of platelet-rich plasma (PRP) and sodium hyaluronate on rotator cuff injury.Methods:From February 2022 to December 2022, 226 patients with rotator cuff injury caused by military training were treated at Department of Orthopaedics, Jinling Hospital, School of Medicine, Nanjing University. They were all male, aged (24.5±3.7) years, and their time from injury to treatment was (4.6±2.2) months. They were divided into 2 even groups according to different treatments: an observation group of 113 cases into whose subacromial space PRP was injected, and a control group of 113 cases into whose subacromial space sodium hyaluronate was injected. In both groups, the injection was performed once a week for consecutive 3 weeks. The 2 groups were compared in terms of visual analogue scale (VAS) and Constant-Murley shoulder function scale (CMS) before treatment and 4 and 8 weeks after treatment, and the levels of TNF- α and IL-6 in the shoulder synovial fluid before treatment and 8 weeks after treatment. Results:There was no statistical difference between the 2 groups in general clinical data before treatment, indicating comparability ( P>0.05). At 4 and 8 weeks after treatment, compared with the pre-treatment values, the VAS scores were significantly decreased and the Constant-Murley scores significantly increased in both groups ( P<0.001). At 4 and 8 weeks after treatment, the VAS scores in the observation group (3.1±0.9 and 1.5±0.5) were significantly lower than those in the control group (3.7±0.8 and 2.3±0.6) while the Constant-Murley scores in the observation group (58.6±4.5 and 72.2±4.1) significantly higher than those in the control group (55.2±5.3 and 67.8±5.0) ( P<0.001). At 8 weeks after treatment, the levels of TNF- α and IL-6 in the 2 groups were significantly lower than the levels before treatment ( P<0.001). At 8 weeks after treatment, the levels of TNF- α and IL-6 in the observation group [(2.9±0.9) μg/L and (0.8±0.2) μg/L] were significantly lower than those in the control group [(4.0±0.4) μg/L and (1.1±0.4) μg/L] ( P<0.001). Conclusion:Injection of PRP or sodium hyaluronate can relieve pain and improve shoulder function obviously in patients with rotator cuff injury, but PRP is superior to sodium hyaluronate in the treatment of rotator cuff injury.

Objective:To compare the short-term curative effects between 3 fixations of the tibial end with an interface screw, an interface screw + a portal nail and an interface screw + a knotless rivet in reconstruction of the anterior cruciate ligament (ACL).Methods:A retrospective study was conducted to analyze the data of 150 patients who had undergone reconstruction surgery for ACL injury at Department of Orthopaedics, Jinling Clinical Medical College, Nanjing Medical University from January 2019 to December 2021. The patients were divided into 3 groups according to their different fixations of the tibial end. In group A of 51 cases subjected to fixation of the tibial end with an interface screw, there were 40 males and 11 females with a mean age of (29.8±10.6) years. In group B of 55 cases whose tibial end was fixated with an interface screw + a portal nail, there were 47 males and 8 females with a mean age of (28.6±6.9) years. In group C of 44 cases whose tibial end was fixated with an interface screw + a knotless rivet, there were 39 males and 5 females with a mean age of (28.6±8.1) years. The 3 groups were compared in terms of International Knee Documentation Committee (IKDC) scoring and Lysholm knee function scoring at 12 and 48 weeks after operation, incidence of local pain at 4 weeks after operation, and stability of the knee at 48 weeks after operation.Results:There was no significant difference in the preoperative general data or follow-up time between the 3 groups, indicating comparability ( P>0.05). At 12 weeks after surgery, in Group B and Group C, the IKDC scores [(74.27±3.32) and (76.48±3.83) points] and Lysholm knee joint scores [(77.65±3.14) and (79.75±5.39) points] were significantly better than those in Group A [(69.73±6.04) and (71.63±3.36) points] ( P<0.05). However, there was no statistically significant difference in the above scores among the 3 groups at 48 weeks after surgery ( P>0.05). The incidence of local pain at the tibial end in group B (9.1%, 5/55) was significantly higher than that in group A (0, 0/51) and group C (2.3%, 1/44) at 4 weeks after surgery, and the results of the anterior drawer test in group A (36 negative cases, 14 cases of grade Ⅰ, and 1 case of grade Ⅱ) were significantly worse than those in group B (50 negative cases, and 5 cases of grade Ⅰ) and group C (40 negative cases, and 4 cases of grade Ⅰ) at 48 weeks after surgery ( P<0.05). Conclusions:In ACL reconstruction, all the 3 fixations of the tibial end can achieve fine short-term curative effects. Fixation with an interface screw + a knotless rivet may lead to a lower rate of ligament relaxation and a higher score of early knee function than fixation with an interface screw, and a lower incidence of local pain at the tibial end than fixation with an interface screw + a portal nail.

Objective:To construct rehabilitation exercise program after rotator cuff repair under arthroscopic, so as to provide a reference for guiding the clinical orthopedic rehabilitation nursing practice and promoting the postoperative functional rehabilitation of patients.Methods:From January to December 2020, through literature review and group discussion, the first draft of the rehabilitation exercise program after rotator cuff repair under arthroscope was formulated. The Delphi method was used to conduct 2 rounds of consultation with 25 experts, and the final version of the rehabilitation exercise program after rotator cuff repair under arthroscope was determined according to the expert consultation.Results:The effective recovery rates of the 2 rounds of expert consultation questionnaires were 80% (20/25) , 85% (17/20) , the coefficients of expert authority were 0.853 and 0.850. The rehabilitation exercise program after rotator cuff repair under arthroscope included 5 basic rules (the significance of program construction, exercise principles, exercise methods, exercise time division, exercise objectives) and 39 specific implementation strategies.Conclusions:The rehabilitation exercise program after rotator cuff repair under arthroscope is scientific, reliable and feasible, which provides a basis for clinical nurses to guide postoperative rehabilitation.

Objective:To investigate the risk factors for postoperative delirium in the elderly patients with hip fracture and to construct an online nomogram of the risk factors.Methods:Retrospectively analyzed were the data of 483 elderly patients with hip fracture who had been treated with artificial joint replacement from May 2020 to August 2021 at Department of Orthopaedics (Department of Joint Surgery), Jinling Hospital Affiliated to Medical College of Nanjing University. There were 166 males and 317 females, aged from 61 to 99 years (average, 82.1 years). Fracture types: 333 femoral neck fractures and 150 intertrochanteric fractures. The patients were divided into a delirium group ( n=149) and a delirium-free group ( n=334) according to whether postoperative delirium occurred after surgery. The 2 groups were compared in terms of general data like age, gender, body mass index, and concomitant diseases, as well as in terms of indexes like pre-operative albumin, preoperative hemoglobin, and postoperative C-reactive protein (CRP). Factors with P < 0.05 were included in the multi-factor logistic regression analysis to screen out the risk factors for postoperative delirium. The "rms" package of R software was used to draw the nomogram; the Bootstrap method was used to repeat the sampling 1,000 times for evaluation, calculation of the consistency index ( CI), and drawing of the ROC curve and correction curve; the decision curve was plotted using the "rmda" package. Results:There were significant differences between the delirium group and the delirium-free group in age, preoperative anxiety, Alzheimer＇s disease, history of cerebrovascular disease, preoperative albumin, intraoperative hypotension and postoperative CRP ( P < 0.05). The multifactorial logistic regression analysis showed that high age, preoperative anxiety, Alzheimer＇s disease, preoperative albumin < 35 g/L, and postoperative CRP ≥90 mg/L were the risk factors for postoperative delirium in the elderly patients with hip fracture after artificial joint replacement ( P < 0.05). The area under the ROC curve of the nomogram constructed by incorporating the risk factors for postoperative delirium was 0.894 (95% CI: 0.865 to 0.923) with a CI of 0.889; the calibration curve showed that the calibration curve of this nomogram model tended to be close to the ideal curve. The decision curve analysis showed that the threshold value was 0.01 to 1.00, showing the net benefit rate of this nomogram model > 0 when used to predict the postoperative delirium in the elderly patients with hip fracture. Conclusions:High age, preoperative anxiety, Alzheimer's disease, preoperative albumin < 35 g/L, and postoperative CRP ≥90 mg/L may be the risk factors for postoperative delirium in the elderly patients with hip fracture after artificial joint replacement. The online nomogram based on these factors demonstrates a good value in prediction of postoperative delirium.

Objective:To analyze the clinical efficacy of debridement, antibiotics irrigation and implant retention (DAIR) in the treatment of acute periprosthetic infection (PJI) and to explore the risk factors leading to the failure of DAIR.Methods:From January 2010 to January 2021, 122 patients underwent DAIR for acute PJI at Department of Orthopedics, General Hospital of Eastern Theater of PLA. They were 55 males and 67 females, aged from 50 to 86 years (mean, 68.0 years). Their C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), body temperature, white blood cell count and visual analogue scale (VAS) were compared at admission and discharge to analyze the clinical efficacy of DAIR. The 122 patients were assigned into a cured group (81 cases) and an uncured group (41 cases). Risk factors were screened by univariate analysis out of their gender, age, body mass index, site of infection, type of infection (early postoperative infection or acute hematogenous infection), type of surgery (primary or revision), comorbidities, CRP, ESR, albumin and hemoglobin at admission, duration of symptoms, Staphylococcus aureus infection, multiple bacterial mixed infection, and preoperative sinus tract. For the factors of P<0.05, multivariate binary logistic regression analysis was used to determine the risk factors for failure of DAIR. Survival curves were plotted for the patients using DAIR failure as the endpoint event. Results:The CRP, ESR, VAS score, body temperature and white blood cell count at discharge in the 122 patients were significantly lower than the corresponding values at admission ( P<0.05). The success rate of DAIR was 66.39%(81/122). The multivariate binary logistic regression analysis suggested that duration of symptoms over 3 weeks( OR=1.230, 95% CI: 1.092~1.576, P=0.020), Staphylococcus aureus infection( OR=4.607, 95% CI: 2.057~10.318, P<0.001), preoperative sinus tract( OR=6.115, 95% CI: 2.630~14.220, P<0.001) and multiple bacterial mixed infection( OR=2.600, 95% CI: 1.131~5.977, P=0.020) were risk factors for DAIR failure; Kaplan-Meier survival curve also confirmed that the patients with Staphylococcus infection, multiple bacterial mixed infection, duration of symptoms over 3 weeks, or preoperative sinus tract had a significantly lower rate of survival than their controls ( P<0.05). Conclusions:For acute PJI, DAIR can be used to retain the prosthesis and control infection. However, DAIR is not recommended for the patients with Staphylococcus aureus infection, multiple bacterial mixed infection, symptoms lasting more than 3 weeks, or preoperative sinus formation.

Objective:To evaluate the methodological quality and reliability of the conclusions of systematic reviews on the effectiveness of early exercise on rehabilitation after arthroscopic rotator cuff repair.Methods:Systematic reviews related to early exercise after rotator cuff repair were retrieved by computer from China National Knowledge Infrastructure (CNKI) , WanFang, Cochrane Library, Embase and PubMed. The retrieval time limit was from the establishment of the database to October 31, 2020. Two reviewers independently screened the articles, extracted data, and used A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2 and the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) to evaluate the methodology and quality of evidence of the included studies, respectively.Results:A total of 8 systematic reviews were included. The evaluation results of the AMSTAR 2 showed that 3 articles were of low methodological quality, and 5 articles were of very low methodological quality. The GRADE was used to evaluate the quality of evidence for 51 outcome indicators, and the results showed that 52.94% (27/51) were moderate evidence, 21.57% (11/51) were low-level evidence, 25.49% (13/51) were very low-level evidence, and no evidence quality was shown as high.Conclusions:Current evidence shows that early exercise can promote early recovery of joint range of motion in patients with arthroscopic rotator cuff repair, while also increasing the risk of rotator cuff tendon re-tear to a certain extent. In terms of long-term effects, no significant difference is seen between early exercise and delayed exercise. However, the methodological quality and the reliability of the evidence level of the systematic reviews are low, and high-quality original studies are needed to be further confirmed.

Osteoporosis is one of the common metabolic diseases, which can easily lead to osteoporotic fractures. Accurate prediction of bone biomechanical properties is of great significance for the early prevention and diagnosis of osteoporosis. Bone mineral density measurement is currently used clinically as the gold standard for assessing bone strength and diagnosing osteoporosis, but studies have shown that bone mineral density can only explain 60% to 70% of bone strength changes, and trabecular bone microstructure is an important factor affecting bone strength. In order to establish the connection between trabecular bone microstructure and bone strength, this paper proposes a prediction method of trabecular bone modulus based on SE-DenseVoxNet. This method takes three-dimensional binary images of trabecular bone as input and predicts its elastic modulus in the z-axis direction. Experiments show that the error and bias between the predicted value of the method and the true value of the sample are small and have good consistency.
Biomechanical Phenomena ; Bone Density ; Cancellous Bone/diagnostic imaging* ; Elastic Modulus ; Humans ; Osteoporosis/diagnostic imaging*