Objective:To compare the safety and efficacy of 3D-printed porous bioceramic artificial bone and artificial bone substitutes in the treatment of limb bone defects.Methods:A total of 220 patients with post-traumatic limb bone defects admitted to Xijing Hospital Affiliated to Air Force Medical University of the Chinese People's Liberation Army (34 cases), the Third Hospital of Hebei Medical University (60 cases), Xi'an Honghui Hospital (28 cases), the Third Hospital of Southern Medical University (18 cases), Changsha Third Hospital (28 cases), Foshan Traditional Chinese Medicine Hospital (16 cases), Foshan Fuxing Chancheng Hospital (12 cases), and Henan Provincial Orthopaedic Hospital (24 cases) from May 2022 to October 2023 were included as research subjects. According to the manufacturing method of the bone graft material, the subjects were randomly divided into the 3D printed porous bioceramic artificial bone group (3D printing group) and the artificial bone substitute group (non-3D printing group) at a ratio of 1:1 by the envelope method. Adverse events that might be related to the surgery were selected through correlation evaluation and classified as abnormal laboratory indicators, systemic or other site symptoms and abnormalities, and local symptoms and abnormalities of the affected limb. The safety of the two groups was compared. The bone graft fusion rate, bone defect repair and healing rate, and short form 12 (SF-12) score of the two groups were calculated to evaluate the postoperative recovery.Results:Thirty-two cases were excluded (4 cases refused to use their data after reconsideration, 7 cases were not used after preoperative assessment, and 21 cases exceeded the standard for body mass index and laboratory indicators upon re-examination). A total of 188 cases were randomly divided into the 3D printing group and the non-3D printing group according to the random method, with 94 cases in each group. Among them, 11 cases in the 3D printing group and 9 cases in the non-3D printing group dropped out due to loss to follow-up. Finally, 168 cases completed the follow-up, including 83 cases in the 3D printing group and 85 cases in the non-3D printing group. In the 3D printing group, there were 53 males and 30 females, with an average age of 47.9±12.7 years; in the non-3D printing group, there were 53 males and 32 females, with an average age of 48.6±12.9 years. A total of 51 cases in the two groups experienced adverse events related to the surgery, including 13 cases of abnormal laboratory indicators (5 cases in the 3D printing group and 8 cases in the non-3D printing group), 15 cases of systemic or other site symptoms and abnormalities (9 cases in the 3D printing group and 6 cases in the non-3D printing group), and 23 cases of local symptoms and abnormalities of the affected limb (13 cases in the 3D printing group and 10 cases in the non-3D printing group). There was no statistically significant difference in the incidence of adverse events between the two groups ( P>0.05). The bone graft fusion rates of the 3D printing group and the non-3D printing group at 6 months after surgery were 99%(82/83) and 99%(84/85), respectively, and the bone defect repair and healing rates were 89%(74/83) and 89%(76/85), respectively. At the time of 12 months after surgery, the bone graft fusion rates were 99%(82/83) and 99%(84/85), respectively, and the bone defect repair and healing rates were 94%(78/83) and 92%(78/85), respectively. There was no statistically significant difference in the bone graft fusion rate and bone defect repair and healing rate between the two groups ( P>0.05). The SF-12 scores during the screening period were 27.82±2.96 points and 27.22±4.23 points in the 3D printing group and the non-3D printing group, respectively, and at 3 months after surgery were 28.08±3.13 points and 27.64±3.16 points, at 6 months after surgery were 29.42±3.10 points and 28.55±3.45 points, and at 12 months after surgery were 29.78±2.80 points and 29.58±2.94 points, respectively. There was no statistically significant difference between the groups ( P>0.05). Both groups of surgeries were successfully completed without any serious surgical or bone graft-related complications. Conclusion:The safety and efficacy of 3D-printed porous bioceramic artificial bone in the treatment of limb bone defects are not significantly different from those of currently clinically applied artificial bone substitutes.

Objective:To evaluate the therapeutic role of balanced matching concept in the surgical release of moderate and severe elbow stiffness after trauma.Methods:A retrospective study was conducted to analyze the clinical data of 20 patients who had been treated by surgical release from June 2022 to January 2024 for elbow stiffness after moderate and severe trauma at Department of Orthopedic Trauma, The First Hospital Affiliated to Air Force Medical University of PLA using the balanced matching concept (combination of elbow soft tissue balance and bone matching). There were 15 males and 5 females, with an age of (33.0±8.9) years. Six left sides and 14 right sides were affected. The elbow stiffness was severe in 13 cases and moderate in 7 cases. Six patients had mainly bony stiffness, 4 patients mainly soft stiffness, and 10 patients mixed stiffness. The elbow flexion and extension, Mayo elbow performance score (MEPS) and disabilities of the arm, shoulder, and hand (DASH) score were recorded and compared before release and at the last follow-up. The recurrence of ectopic ossification, infection, iatrogenic fracture and other complications of the elbow joint of the affected limb were recorded.Results:All the 20 patients were followed up for (16.6±3.5) months. At the last follow-up, the elbow flexion and extension (121.8°±8.9° and 14.8°±8.2°) were significantly greater than those before operation (73.5°±25.7° and 47.3°±19.2°), and the MEPS and DASH scores [ (90.0±5.6) points, (5.6±3.0) points] were significantly better than those before operation [(53.0±12.8) points, (62.1±14.0) points] ( P<0.05). Iatrogenic fracture of the ulna occurred in 1 patient, and pinky numbness occurred in 1 patient after surgery. None of the patients had recurrence of ectopic ossification or wound infection. Conclusion:In the surgical release of moderate and severe elbow stiffness after trauma, the concept of balanced matching plays a positive role by facilitating the functional restoration of the elbow and reducing the incidence of complications.

Objective:To compare the safety and efficacy of 3D-printed porous bioceramic artificial bone and artificial bone substitutes in the treatment of limb bone defects.Methods:A total of 220 patients with post-traumatic limb bone defects admitted to Xijing Hospital Affiliated to Air Force Medical University of the Chinese People's Liberation Army (34 cases), the Third Hospital of Hebei Medical University (60 cases), Xi'an Honghui Hospital (28 cases), the Third Hospital of Southern Medical University (18 cases), Changsha Third Hospital (28 cases), Foshan Traditional Chinese Medicine Hospital (16 cases), Foshan Fuxing Chancheng Hospital (12 cases), and Henan Provincial Orthopaedic Hospital (24 cases) from May 2022 to October 2023 were included as research subjects. According to the manufacturing method of the bone graft material, the subjects were randomly divided into the 3D printed porous bioceramic artificial bone group (3D printing group) and the artificial bone substitute group (non-3D printing group) at a ratio of 1:1 by the envelope method. Adverse events that might be related to the surgery were selected through correlation evaluation and classified as abnormal laboratory indicators, systemic or other site symptoms and abnormalities, and local symptoms and abnormalities of the affected limb. The safety of the two groups was compared. The bone graft fusion rate, bone defect repair and healing rate, and short form 12 (SF-12) score of the two groups were calculated to evaluate the postoperative recovery.Results:Thirty-two cases were excluded (4 cases refused to use their data after reconsideration, 7 cases were not used after preoperative assessment, and 21 cases exceeded the standard for body mass index and laboratory indicators upon re-examination). A total of 188 cases were randomly divided into the 3D printing group and the non-3D printing group according to the random method, with 94 cases in each group. Among them, 11 cases in the 3D printing group and 9 cases in the non-3D printing group dropped out due to loss to follow-up. Finally, 168 cases completed the follow-up, including 83 cases in the 3D printing group and 85 cases in the non-3D printing group. In the 3D printing group, there were 53 males and 30 females, with an average age of 47.9±12.7 years; in the non-3D printing group, there were 53 males and 32 females, with an average age of 48.6±12.9 years. A total of 51 cases in the two groups experienced adverse events related to the surgery, including 13 cases of abnormal laboratory indicators (5 cases in the 3D printing group and 8 cases in the non-3D printing group), 15 cases of systemic or other site symptoms and abnormalities (9 cases in the 3D printing group and 6 cases in the non-3D printing group), and 23 cases of local symptoms and abnormalities of the affected limb (13 cases in the 3D printing group and 10 cases in the non-3D printing group). There was no statistically significant difference in the incidence of adverse events between the two groups ( P>0.05). The bone graft fusion rates of the 3D printing group and the non-3D printing group at 6 months after surgery were 99%(82/83) and 99%(84/85), respectively, and the bone defect repair and healing rates were 89%(74/83) and 89%(76/85), respectively. At the time of 12 months after surgery, the bone graft fusion rates were 99%(82/83) and 99%(84/85), respectively, and the bone defect repair and healing rates were 94%(78/83) and 92%(78/85), respectively. There was no statistically significant difference in the bone graft fusion rate and bone defect repair and healing rate between the two groups ( P>0.05). The SF-12 scores during the screening period were 27.82±2.96 points and 27.22±4.23 points in the 3D printing group and the non-3D printing group, respectively, and at 3 months after surgery were 28.08±3.13 points and 27.64±3.16 points, at 6 months after surgery were 29.42±3.10 points and 28.55±3.45 points, and at 12 months after surgery were 29.78±2.80 points and 29.58±2.94 points, respectively. There was no statistically significant difference between the groups ( P>0.05). Both groups of surgeries were successfully completed without any serious surgical or bone graft-related complications. Conclusion:The safety and efficacy of 3D-printed porous bioceramic artificial bone in the treatment of limb bone defects are not significantly different from those of currently clinically applied artificial bone substitutes.

Objective:To evaluate the therapeutic role of balanced matching concept in the surgical release of moderate and severe elbow stiffness after trauma.Methods:A retrospective study was conducted to analyze the clinical data of 20 patients who had been treated by surgical release from June 2022 to January 2024 for elbow stiffness after moderate and severe trauma at Department of Orthopedic Trauma, The First Hospital Affiliated to Air Force Medical University of PLA using the balanced matching concept (combination of elbow soft tissue balance and bone matching). There were 15 males and 5 females, with an age of (33.0±8.9) years. Six left sides and 14 right sides were affected. The elbow stiffness was severe in 13 cases and moderate in 7 cases. Six patients had mainly bony stiffness, 4 patients mainly soft stiffness, and 10 patients mixed stiffness. The elbow flexion and extension, Mayo elbow performance score (MEPS) and disabilities of the arm, shoulder, and hand (DASH) score were recorded and compared before release and at the last follow-up. The recurrence of ectopic ossification, infection, iatrogenic fracture and other complications of the elbow joint of the affected limb were recorded.Results:All the 20 patients were followed up for (16.6±3.5) months. At the last follow-up, the elbow flexion and extension (121.8°±8.9° and 14.8°±8.2°) were significantly greater than those before operation (73.5°±25.7° and 47.3°±19.2°), and the MEPS and DASH scores [ (90.0±5.6) points, (5.6±3.0) points] were significantly better than those before operation [(53.0±12.8) points, (62.1±14.0) points] ( P<0.05). Iatrogenic fracture of the ulna occurred in 1 patient, and pinky numbness occurred in 1 patient after surgery. None of the patients had recurrence of ectopic ossification or wound infection. Conclusion:In the surgical release of moderate and severe elbow stiffness after trauma, the concept of balanced matching plays a positive role by facilitating the functional restoration of the elbow and reducing the incidence of complications.

The high incidence and untreated rate of root caries,a common and frequently occurring oral disease with challenging treatment in elderly individuals,is the main cause of tooth loss among elderly people,as rapid develop-ment results in pulpitis and periapical periodontitis or residual crown and root,which has been regarded as one of the common chronic oral diseases seriously affecting the quality of life of elderly people.Thus,early intervention and pre-vention are important.Traditional dental materials for preventing root caries have been widely used in clinical practice;however,they have the disadvantages of tooth coloring,remineralization and low sterilization efficiency.A series of new dental materials for preventing root caries have gradually become a research hotspot recently,which have the advantag-es of promoting the mineralization of deep dental tissue,prolonging the action time and enhancing adhesion.Future car-ies prevention materials should be designed according to the characteristics of root surface caries and the application population and should be developed toward simplicity,high efficiency and low toxicity.This review describes current re-search regarding anti-caries prevention material application,serving as a theoretical underpinning for the research of root caries prevention materials,which is important for both promotion in the effective prevention of root caries and im-provement in the status of oral health and the quality of life among old people.

Objective:To identify the risk factors affecting the healing of defective bony nonunion.Methods:The studies reporting the risk factors for healing of defective bony nonunion between January 2000 and March 2022 were retrieved by computer from the VIP, Wanfangdata, CNKI, Web of Science, PubMed, and Medline databases. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the included studies. the RevMan 5.3 software was used to perform a meta-analysis of the general factors, injuries and surgical-related factors affecting the healing of defective bony nonunion.Results:Included in this Meta analysis were 17 studies with 1,236 patients. The NOS score of the included studies was from 5 to 8. The meta-analysis showed the following: age ( MD=-4.27, 95% CI: -8.29 to 2.91, P < 0.01), smoking ( OR=3.56, 95% CI: 2.81 to 6.32, P < 0.01), soft tissue defect ( OR=3.54, 95% CI: 2.21 to 5.69, P < 0.01), combined ipsilateral fibular fracture ( OR=4.18, 95% CI: 1.24 to 14.03, P=0.02), venous thrombosis ( OR=4.27, 95% CI: 1.05 to 17.44, P=0.04), and postoperative infection ( OR=2.96, 95% CI: 1.97 to 4.47, P < 0.01) were significant risk factors for the healing of defective bone nonunion. Minor bone defect ( SMD=-0.67, 95% CI: -1.25 to -0.10, P=0.02), proximal to distal bone transport ( OR=-0.42, 95% CI: 0.22 to 0.77, P < 0.01), short-term external fixation ( MD=-3.92, 95% CI: -7.10 to -0.73, P=0.02), and autologous bone grafting ( OR=0.39, 95% CI: 0.16 to 0.95, P=0.04) were protective factors for the healing of defective bony nonunion. Conclusions:High age (senility), smoking, soft tissue defect, ipsilateral fibular fracture, venous thrombosis, and postoperative infection are risk factors affecting the healing of defective bony nonunion. Minor bone defect, proximal to distal bone transport, short-term external fixation, and autologous bone grafting are protective factors affecting the healing of defective bony nonunion. Surgeons can predict early the prognosis of patients with defective bony nonunion based on the above factors.

Objective:To provide an effective protection method for reducing the ankle injury during airborne force landing by investigating the protective effect of a protective ankle brace (PAB).Methods:Airborne soldiers were selected as subjects and they were asked to jump from 1.5 m and 2 m high training platform with and without PAB protection. They maintained a standard bending and knee-bending posture as they touched the buffer surface of the training ground. Each subject completed 4 simulated landing trials: from 1.5 m with PAB (1.5 m PAB group), from 2 m with PAB (2 m PAB group), from 1.5 m without PAB (1.5 m control group), and from 2 m without PAB (2 m control group). The muscle electrical signals of bilateral tibialis anterior, peroneal longus and brevis and gastrocnemius were recorded by surface electromyography, and the percentage of maximal voluntary electrical activation (MVE%) was calculated and analyzed.Results:Sixty-one subjects were included. At the same height with different ankle protection status, the MVE% values of bilateral tibialis anterior and gastrocnemius in the 1.5 m PAB group were lower than those in the 1.5 m control group, and the differences were significant ( t=2.45, 2.74, 2.35, P=0.017, 0.008, 0.022). The MVE% values of bilateral peroneus longus and brevis in the 1.5 m PAB group were higher than those in the 1.5 m control group, and the differences were significant ( t=5.28, 4.56, both P<0.001). The MVE% values of left tibialis anterior and left gastrocnemius in the 2 m PAB group were lower than those in the 2 m control group, and the differences were significant ( t=2.21, 0.53, 4.35, P=0.031, 0.598, <0.001). The MVE% values of bilateral peroneus longus and brevis in the 2 m PAB group were higher than those in the 2 m control group, and the differences were significant ( t=4.92, 6.31, both P<0.001). With the ankle protection the MVE% values of bilateral tibialis anterior, gastrocnemius, peroneus longus and brevis in the 1.5 m PAB group were lower than those in the 2 m PAB group, and the differences were significant ( t=3.56-4.94, all P≤0.001). The MVE% values of bilateral tibialis anterior, gastrocnemius, peroneus longus and brevis in the 1.5 m control group were lower than those in the 2 m PAB group, and the differences were significant ( t=2.30-5.85, all P<0.05). Conclusions:PAB can reduce the ankle injury during airborne force landing and provide good protection.

Objective:To provide an effective protection method for reducing the ankle injury during airborne force landing by investigating the protective effect of a protective ankle brace (PAB).Methods:Airborne soldiers were selected as subjects and they were asked to jump from 1.5 m and 2 m high training platform with and without PAB protection. They maintained a standard bending and knee-bending posture as they touched the buffer surface of the training ground. Each subject completed 4 simulated landing trials: from 1.5 m with PAB (1.5 m PAB group), from 2 m with PAB (2 m PAB group), from 1.5 m without PAB (1.5 m control group), and from 2 m without PAB (2 m control group). The muscle electrical signals of bilateral tibialis anterior, peroneal longus and brevis and gastrocnemius were recorded by surface electromyography, and the percentage of maximal voluntary electrical activation (MVE%) was calculated and analyzed.Results:Sixty-one subjects were included. At the same height with different ankle protection status, the MVE% values of bilateral tibialis anterior and gastrocnemius in the 1.5 m PAB group were lower than those in the 1.5 m control group, and the differences were significant ( t=2.45, 2.74, 2.35, P=0.017, 0.008, 0.022). The MVE% values of bilateral peroneus longus and brevis in the 1.5 m PAB group were higher than those in the 1.5 m control group, and the differences were significant ( t=5.28, 4.56, both P<0.001). The MVE% values of left tibialis anterior and left gastrocnemius in the 2 m PAB group were lower than those in the 2 m control group, and the differences were significant ( t=2.21, 0.53, 4.35, P=0.031, 0.598, <0.001). The MVE% values of bilateral peroneus longus and brevis in the 2 m PAB group were higher than those in the 2 m control group, and the differences were significant ( t=4.92, 6.31, both P<0.001). With the ankle protection the MVE% values of bilateral tibialis anterior, gastrocnemius, peroneus longus and brevis in the 1.5 m PAB group were lower than those in the 2 m PAB group, and the differences were significant ( t=3.56-4.94, all P≤0.001). The MVE% values of bilateral tibialis anterior, gastrocnemius, peroneus longus and brevis in the 1.5 m control group were lower than those in the 2 m PAB group, and the differences were significant ( t=2.30-5.85, all P<0.05). Conclusions:PAB can reduce the ankle injury during airborne force landing and provide good protection.

Objective To know the safety situation of home environment in retired cadres, and provide references for reducing the accident rates of the elderly at home and construction of barrier-free environment at home.Methods Totally 69 retired cadres who were admitted in one tertiary hospital in shanghai from May 2012 to December 2015 and their hospitalization time was less than 30 days, were investigated with general information questionnaires and observation schedule of home environment. Results The investigation showed that, the potential hazardous factors of the elderly′home were:walking barriers in living room (71.01%);slip rug in living room ( 57. 97%); no emergency alarm in bed room ( 55. 07%); walking barriers in dining aisle (53.62%);improper position of lamp switches in bed room (52.17%);some obstacles in taking oral medicine by themselves ( 50. 72%) and indoor walking barriers ( 44. 93%) . Conclusions There are certain potential hazards in retired cadres′ home. Therefore, the elderly should be trained with the related safety environment program, so to improve the safety environment of their home, enhance their identification abilities to potential hazards at home and strengthen the construction of barrier-free environment at home.

Objective To investigate the preparation method of hydroxyapatite by amino acids induced hydrothermal technique.Methods The hydroxyapatite nanorods were obtained using alanine and glycine as templates by hydrothermal method.The samples were characterized by X-ray diffraction (XRD),Fourier infrared spectroscopy (FTIR),transmission electron microscopy (TEM).Results The results showed that amino acids induced the formation of hydroxyapatite.Amino acids could affect crystallinity and dispersion of the formed hydroxyapatite.In addition,the substituent content of carbonate ions in hydroxyapatite was reduced by changing the ratio of amino acids.Conclusion Hydroxyapatite with high crystallinity and low carbonate ions can be prepared by hydrothermal method in the presence of amino acids.