Nanomaterials can be used in drug delivery systems to enhance drug targeting and efficacy, and reduce adverse reactions. At the same time, they can also be used in tissue engineering and regenerative medicine to promote bone tissue repair and regeneration. Nanozymes are special nanomaterials with the catalytic activity of biological enzymes, which can mediate efficient biochemical reactions and provide a new strategy for the diagnosis and treatment of orthopaedic diseases. In the treatment of tendon-related diseases, the enzymatic nanohybrid encapsulated by extracellular vesicles can effectively mimic catalase to remove reactive oxygen species, continuously release zinc ions, and induce immune regulation through extracellular vesicles. It can significantly promote functional recovery and matrix reconstruction, restore tendon morphology, and inhibit scar formation and adhesion around the tendon. In the treatment of bone and joint diseases, photothermal nanozymes with bionic characteristics can generate thermal energy under near-infrared radiation, enhance joint lubrication performance, reduce cartilage wear in early osteoarthritis, effectively remove reactive oxygen species and reactive nitrogen species, increase the production of hyaluronic acid inside and outside the cells, and help to restore the lubrication and function of articular cartilage. Hollow Prussian blue nanoenzyme prepared by template-free hydrothermal synthesis can inhibit osteoclast formation and bone resorption, inhibit intracellular reactive oxygen species production and mitogen-activated protein kinase and nuclear factor kappa-B signaling pathways, thereby improving osteoporosis. In the treatment of spinal diseases, Prussian blue nanozymes can not only remove excessive reactive oxygen species, maintain the normal Redox level of nucleus pulposus cells, but also escape lysosomal phagocytosis, achieve more effective mitochondrial targeting, and effectively alleviate intervertebral disc degeneration.

As rotator cuff injury is highly prevalent among the elderly, it significantly affects their daily life and financial status. Moreover, a high prevalence of osteoporosis in the aging population is a significant challenge to the repair and healing of the injury. Surgeons have attempted to enhance the initial fixation strength of anchors and local bone quality in recent years, but effective repair of rotator cuff injury in combination with osteoporosis remains a difficult problem. Therefore, researchers are exploring to enhance the fixation strength of anchor nails to diminish the need for surgical revisions. This article examines the relationship between osteoporosis and rotator cuff injury, the impact of osteoporosis on treatment outcomes, and current measures to improve the situation, hoping to help clinicians with reference information to achieve their treatment objectives and maximize patient satisfaction.

As rotator cuff injury is highly prevalent among the elderly, it significantly affects their daily life and financial status. Moreover, a high prevalence of osteoporosis in the aging population is a significant challenge to the repair and healing of the injury. Surgeons have attempted to enhance the initial fixation strength of anchors and local bone quality in recent years, but effective repair of rotator cuff injury in combination with osteoporosis remains a difficult problem. Therefore, researchers are exploring to enhance the fixation strength of anchor nails to diminish the need for surgical revisions. This article examines the relationship between osteoporosis and rotator cuff injury, the impact of osteoporosis on treatment outcomes, and current measures to improve the situation, hoping to help clinicians with reference information to achieve their treatment objectives and maximize patient satisfaction.

Nanomaterials can be used in drug delivery systems to enhance drug targeting and efficacy, and reduce adverse reactions. At the same time, they can also be used in tissue engineering and regenerative medicine to promote bone tissue repair and regeneration. Nanozymes are special nanomaterials with the catalytic activity of biological enzymes, which can mediate efficient biochemical reactions and provide a new strategy for the diagnosis and treatment of orthopaedic diseases. In the treatment of tendon-related diseases, the enzymatic nanohybrid encapsulated by extracellular vesicles can effectively mimic catalase to remove reactive oxygen species, continuously release zinc ions, and induce immune regulation through extracellular vesicles. It can significantly promote functional recovery and matrix reconstruction, restore tendon morphology, and inhibit scar formation and adhesion around the tendon. In the treatment of bone and joint diseases, photothermal nanozymes with bionic characteristics can generate thermal energy under near-infrared radiation, enhance joint lubrication performance, reduce cartilage wear in early osteoarthritis, effectively remove reactive oxygen species and reactive nitrogen species, increase the production of hyaluronic acid inside and outside the cells, and help to restore the lubrication and function of articular cartilage. Hollow Prussian blue nanoenzyme prepared by template-free hydrothermal synthesis can inhibit osteoclast formation and bone resorption, inhibit intracellular reactive oxygen species production and mitogen-activated protein kinase and nuclear factor kappa-B signaling pathways, thereby improving osteoporosis. In the treatment of spinal diseases, Prussian blue nanozymes can not only remove excessive reactive oxygen species, maintain the normal Redox level of nucleus pulposus cells, but also escape lysosomal phagocytosis, achieve more effective mitochondrial targeting, and effectively alleviate intervertebral disc degeneration.

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.

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.

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.

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.