Objective:To compare the impacts of external fixation of different durations on rehabilitation outcomes after open repair of acute Achilles tendon rupture.Methods:A prospective cohort study was conducted to analyze the clinical data of patients with unilateral acute closed Achilles tendon rupture admitted to Peking University Third Hospital from August 2020 to August 2023. Patients were divided into Group A ( n=96), Group B ( n=347), Group C ( n=346), and Group D ( n=105) based on different postoperative immobilization durations (0, 2, 4 and 6 weeks, respectively). After all the patients received identical open repair procedure, Group A was rehabilitated immediately but the other groups were rehabilitated with the same protocol after removal of the external fixation. Four groups were compared in terms of recovery time of one-leg heel-rise height (OHRH), recovery time of light exercise (LE) in brisk walking and jogging and recovery time of range of motion (ROM). Visual analogue scale (VAS) scores were also compared at 2, 4, 6 and 8 weeks postoperatively. Achilles tendon total rupture score (ATRS) and American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores were evaluated at 6, 8, 10, 12, 14 and 16 weeks postoperatively. Complications were recorded. Results:A total of 894 patients including 869 males and 25 females were included, aged 18-60 years [(35.0±6.3)years]. All the patients were followed up for 14-25 months [(19.0±3.0)months]. The recovery time of OHRH in Group A and B was 12.0(12.0, 12.0)weeks and 12.0(10.0, 12.0)weeks, shorter than those in Group C [14.0(14.0, 16.0)weeks] and D [14.0(14.0, 14.0)weeks] ( P<0.05), with no significant difference between Group A and B ( P>0.05) and between Group C and D ( P>0.05). The recovery time of LE in Group A and B was 18.0(18.0, 18.0)weeks and 18.0(16.0, 18.0)weeks, shorter than those in Group C [20.0(20.0, 20.0)weeks] and D [20.0(20.0, 20.0)weeks] ( P<0.05), with no significant difference between Group A and B ( P>0.05) and between Group C and D ( P>0.05). The recovery time of ROM in Group A and B was 6.0(6.0, 6.0)weeks and 6.0(6.0, 6.0)weeks, shorter than those in Group C [8.0(8.0, 10.0)weeks] and D [10.0(10.0, 10.0)weeks)] ( P<0.05), with no significant difference between Group A and B, and between Group C and D ( P>0.05). At 2 weeks postoperatively, the VAS scores were 2.0(1.0, 2.0)points, 2.0(1.0, 2.0)points, and 2.0(1.5, 2.0)points in Group B, C and D, lower than 5.0(5.0, 5.0)points in Group A ( P<0.05), with no significant difference among Group B, C, and D ( P>0.05). At 4 weeks postoperatively, the VAS scores were 1.0(0, 1.0)points, 1.0(0, 1.0)points, and 1.0(0.5, 1.0)points in Group B, C and D, lower than 2.0(1.0, 2.0)points in Group A ( P<0.05), with no significant difference among Group B, C, and D ( P>0.05). At 6 weeks postoperatively, the VAS score was 0(0, 0)points in all the 4 groups, with no significant difference among them ( P>0.05). At 8 weeks postoperatively, the VAS score was 0(0, 0)points, with lower scores in Group A and B than those in Group C and D ( P<0.05) but with no significant difference between Group A and B and between Group C and D ( P>0.05). At 6 weeks postoperatively, the ATRS scores were 52.0(52.0, 53.8)points and 52.0(50.0, 53.0)points in Group A and B, higher than 41.0(38.0, 43.0)points and 19.0(18.0, 20.0)points in Group C and D ( P<0.05), with a higher score in Group C than that in Group D ( P<0.05) but with no significant difference between Group A and B ( P>0.05). At 8 weeks postoperatively, the ATRS scores were 66.0(66.0, 68.0)points in Group A, higher than 63.0(62.0, 64.0)points, 52.0(50.0, 53.0)points, and 39.0(37.0, 40.0)points in Group B, C and D ( P<0.05), with a higher score in Group B than those in Group C and D ( P<0.05) and a higher score in Group C than that in Group D ( P<0.05). At 10 weeks postoperatively, the ATRS score was 75.0(74.0, 76.0)points in Group B, higher than 69.0(69.0, 70.0)points, 72.0(66.0, 74.0)points, and 62.0(58.5, 63.0)points in Group A, C and D ( P<0.05), with higher scores in Group A and C than that in Group D ( P<0.05) but with no significant difference between Group A and C ( P>0.05). At 12 weeks postoperatively, the ATRS score was 84.0(82.0, 85.0)points in Group B, higher than 75.0(75.0, 77.0)points, 79.0(72.0, 81.0)points, and 72.0(71.0, 73.0)points in Group A, C and D ( P<0.05), with higher scores in Group A and C than that in Group D ( P<0.05) but with no significant difference between Group A and C ( P>0.05). At 14 weeks postoperatively, the ATRS score was 87.0(86.0, 87.0)points in Group B, higher than 82.0(82.0, 84.0)points, 83.0(80.0, 85.0)points, and 79.0(77.5, 80.0)points in Group A, C and D ( P<0.05), with higher scores in Group A and C than that in Group D ( P<0.05) but with no significant difference between Group A and C ( P>0.05). At 16 weeks postoperatively, the ATRS scores were 87.0(87.0, 88.0)points and 88.0(87.0, 88.0)points in Group A and B, higher than 86.0(85.0, 87.0)points and 84.0(83.0, 85.0)points in Group C and D ( P<0.05), with a higher score in Group C than that in Group D ( P<0.05) but with no significant difference between Group A and B ( P>0.05). At 6 weeks postoperatively, the AOFAS ankle-hindfoot scores were 94.0(94.0, 95.0)points and 95.0(94.0, 96.0)points in Group A and B, higher than 85.0(83.0, 86.0)points and 74.0(72.0, 75.0)points in Group C and D ( P<0.05), with a higher score in Group C than that in Group D ( P<0.05) but with no significant difference between Group A and B ( P>0.05). At 8 weeks postoperatively, the AOFAS ankle-hindfoot scores were 100.0(99.0, 100.0)points in Group B, higher than 94.0(94.0, 95.0)points, 92.0(90.0, 93.0)points, and 83.0(82.0, 84.0)points in Group A, C and D ( P<0.05), with a higher score in Group A than those in Group C and D ( P<0.05) and a higher score in Group C than that in Group D ( P<0.05). At 10 weeks postoperatively, the AOFAS ankle-hindfoot score was 100.0(100.0, 100.0)points in Group B, higher than 98.0(98.0, 98.0)points, 98.0(96.8, 99.0)points, and 96.0(95.0, 97.0)points in Group A, C and D, with higher scores in Group A and C than that in Group D ( P<0.05) but with no significant difference between Group A and C ( P>0.05). At 12 weeks postoperatively, the AOFAS ankle-hindfoot score was 100.0(100.0, 100.0)points in both Group A and B, with no significant difference between them ( P>0.05), which was higher than 100.0(98.0, 100.0)points and 99.0(98.0, 99.0)points in Group C and D ( P<0.05), with a higher score in Group C than that in Group D ( P<0.05). At 14 and 16 weeks postoperatively, AOFAS ankle-hindfoot score was 100.0(100.0, 100.0)points, with no significant difference among all the groups ( P>0.05). Superficial wound infection occurred in 12 patients [5.2%(5/96) in Group A, 0.6%(2/347) in Group B, 0.6%(2/346) in Group C and 2.9%(3/105) in Group D] ( P<0.01) while rerupture occurred in 16 [9.4%(9/96) in Group A, 1.2% (4/347) in Group B, 0.9%(3/105) in Group C, and 0 patient in Group D] ( P<0.01). Conclusion:For patients with unilateral acute Achilles tendon rupture, two weeks of postoperative external fixation after open repair can shorten the time of returning sports, alleviate pain, and promote functional recovery, without increasing the risk of complications.

Objective:To investigate the effect of triply periodic minimal surfaces (TPMS) structure and ceramic volume fraction on the mechanical properties of polymer-infiltrated ceramic network (PICN) composite and reveal its strengthening and toughening mechanism.Methods:In this study, TPMS structures with gyroid (G), primitive (P), diamond (D), and ceramic volume fraction (40%, 55%, 70%, 85%) were designed. Porous zirconia scaffolds were prepared using stereolithography technology, and resin was infiltrated into the scaffolds through a vacuum. Then, the PICN composites were obtained after curing. The bending strength, elastic modulus and fracture toughness of PICN were tested using an electronic universal testing machine, with commercial PICN as the control group. The micromorphology of PICN was observed through stereomicroscope and scanning electron microscope. The cytocompatibility of PICN was verified by using cell counting kit, live/dead cell staining and phalloidin staining.Results:The bending strength values of PICN with different ceramic volume fractions ranged from 82.0 MPa to 376.0 MPa, and they gradually increased as the ceramic volume fraction rised. The elastic modulus values of PICN with different ceramic volume fractions ranged from 12.1 GPa to 56.1 GPa. The fracture toughness values of PICN with different ceramic volume fractions ranged from 1.7 MPa·m 1/2 to 6.5 MPa·m 1/2. The bending strength of 85G PICN reached 306.0 MPa, and it had the highest fracture toughness (6.5 MPa·m 1/2) and an appropriate elastic modulus between that of the control group and that of enamel. Under scanning electron microscopy, it could be observed that the cracks branch and deflect at the interface and eventually terminate within the resin phase. After co-culture with PICN, the survival rate of mouse fibroblasts exceeded 80%, indicating that PICN had no cytotoxicity. Conclusions:The PICN composite with TPMS structure can satisfy the mechanical properties and cytocompatibility of dental prosthesis.

Objective:To investigate the effect of triply periodic minimal surfaces (TPMS) structure and ceramic volume fraction on the mechanical properties of polymer-infiltrated ceramic network (PICN) composite and reveal its strengthening and toughening mechanism.Methods:In this study, TPMS structures with gyroid (G), primitive (P), diamond (D), and ceramic volume fraction (40%, 55%, 70%, 85%) were designed. Porous zirconia scaffolds were prepared using stereolithography technology, and resin was infiltrated into the scaffolds through a vacuum. Then, the PICN composites were obtained after curing. The bending strength, elastic modulus and fracture toughness of PICN were tested using an electronic universal testing machine, with commercial PICN as the control group. The micromorphology of PICN was observed through stereomicroscope and scanning electron microscope. The cytocompatibility of PICN was verified by using cell counting kit, live/dead cell staining and phalloidin staining.Results:The bending strength values of PICN with different ceramic volume fractions ranged from 82.0 MPa to 376.0 MPa, and they gradually increased as the ceramic volume fraction rised. The elastic modulus values of PICN with different ceramic volume fractions ranged from 12.1 GPa to 56.1 GPa. The fracture toughness values of PICN with different ceramic volume fractions ranged from 1.7 MPa·m 1/2 to 6.5 MPa·m 1/2. The bending strength of 85G PICN reached 306.0 MPa, and it had the highest fracture toughness (6.5 MPa·m 1/2) and an appropriate elastic modulus between that of the control group and that of enamel. Under scanning electron microscopy, it could be observed that the cracks branch and deflect at the interface and eventually terminate within the resin phase. After co-culture with PICN, the survival rate of mouse fibroblasts exceeded 80%, indicating that PICN had no cytotoxicity. Conclusions:The PICN composite with TPMS structure can satisfy the mechanical properties and cytocompatibility of dental prosthesis.

Objective:To compare the impacts of external fixation of different durations on rehabilitation outcomes after open repair of acute Achilles tendon rupture.Methods:A prospective cohort study was conducted to analyze the clinical data of patients with unilateral acute closed Achilles tendon rupture admitted to Peking University Third Hospital from August 2020 to August 2023. Patients were divided into Group A ( n=96), Group B ( n=347), Group C ( n=346), and Group D ( n=105) based on different postoperative immobilization durations (0, 2, 4 and 6 weeks, respectively). After all the patients received identical open repair procedure, Group A was rehabilitated immediately but the other groups were rehabilitated with the same protocol after removal of the external fixation. Four groups were compared in terms of recovery time of one-leg heel-rise height (OHRH), recovery time of light exercise (LE) in brisk walking and jogging and recovery time of range of motion (ROM). Visual analogue scale (VAS) scores were also compared at 2, 4, 6 and 8 weeks postoperatively. Achilles tendon total rupture score (ATRS) and American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores were evaluated at 6, 8, 10, 12, 14 and 16 weeks postoperatively. Complications were recorded. Results:A total of 894 patients including 869 males and 25 females were included, aged 18-60 years [(35.0±6.3)years]. All the patients were followed up for 14-25 months [(19.0±3.0)months]. The recovery time of OHRH in Group A and B was 12.0(12.0, 12.0)weeks and 12.0(10.0, 12.0)weeks, shorter than those in Group C [14.0(14.0, 16.0)weeks] and D [14.0(14.0, 14.0)weeks] ( P<0.05), with no significant difference between Group A and B ( P>0.05) and between Group C and D ( P>0.05). The recovery time of LE in Group A and B was 18.0(18.0, 18.0)weeks and 18.0(16.0, 18.0)weeks, shorter than those in Group C [20.0(20.0, 20.0)weeks] and D [20.0(20.0, 20.0)weeks] ( P<0.05), with no significant difference between Group A and B ( P>0.05) and between Group C and D ( P>0.05). The recovery time of ROM in Group A and B was 6.0(6.0, 6.0)weeks and 6.0(6.0, 6.0)weeks, shorter than those in Group C [8.0(8.0, 10.0)weeks] and D [10.0(10.0, 10.0)weeks)] ( P<0.05), with no significant difference between Group A and B, and between Group C and D ( P>0.05). At 2 weeks postoperatively, the VAS scores were 2.0(1.0, 2.0)points, 2.0(1.0, 2.0)points, and 2.0(1.5, 2.0)points in Group B, C and D, lower than 5.0(5.0, 5.0)points in Group A ( P<0.05), with no significant difference among Group B, C, and D ( P>0.05). At 4 weeks postoperatively, the VAS scores were 1.0(0, 1.0)points, 1.0(0, 1.0)points, and 1.0(0.5, 1.0)points in Group B, C and D, lower than 2.0(1.0, 2.0)points in Group A ( P<0.05), with no significant difference among Group B, C, and D ( P>0.05). At 6 weeks postoperatively, the VAS score was 0(0, 0)points in all the 4 groups, with no significant difference among them ( P>0.05). At 8 weeks postoperatively, the VAS score was 0(0, 0)points, with lower scores in Group A and B than those in Group C and D ( P<0.05) but with no significant difference between Group A and B and between Group C and D ( P>0.05). At 6 weeks postoperatively, the ATRS scores were 52.0(52.0, 53.8)points and 52.0(50.0, 53.0)points in Group A and B, higher than 41.0(38.0, 43.0)points and 19.0(18.0, 20.0)points in Group C and D ( P<0.05), with a higher score in Group C than that in Group D ( P<0.05) but with no significant difference between Group A and B ( P>0.05). At 8 weeks postoperatively, the ATRS scores were 66.0(66.0, 68.0)points in Group A, higher than 63.0(62.0, 64.0)points, 52.0(50.0, 53.0)points, and 39.0(37.0, 40.0)points in Group B, C and D ( P<0.05), with a higher score in Group B than those in Group C and D ( P<0.05) and a higher score in Group C than that in Group D ( P<0.05). At 10 weeks postoperatively, the ATRS score was 75.0(74.0, 76.0)points in Group B, higher than 69.0(69.0, 70.0)points, 72.0(66.0, 74.0)points, and 62.0(58.5, 63.0)points in Group A, C and D ( P<0.05), with higher scores in Group A and C than that in Group D ( P<0.05) but with no significant difference between Group A and C ( P>0.05). At 12 weeks postoperatively, the ATRS score was 84.0(82.0, 85.0)points in Group B, higher than 75.0(75.0, 77.0)points, 79.0(72.0, 81.0)points, and 72.0(71.0, 73.0)points in Group A, C and D ( P<0.05), with higher scores in Group A and C than that in Group D ( P<0.05) but with no significant difference between Group A and C ( P>0.05). At 14 weeks postoperatively, the ATRS score was 87.0(86.0, 87.0)points in Group B, higher than 82.0(82.0, 84.0)points, 83.0(80.0, 85.0)points, and 79.0(77.5, 80.0)points in Group A, C and D ( P<0.05), with higher scores in Group A and C than that in Group D ( P<0.05) but with no significant difference between Group A and C ( P>0.05). At 16 weeks postoperatively, the ATRS scores were 87.0(87.0, 88.0)points and 88.0(87.0, 88.0)points in Group A and B, higher than 86.0(85.0, 87.0)points and 84.0(83.0, 85.0)points in Group C and D ( P<0.05), with a higher score in Group C than that in Group D ( P<0.05) but with no significant difference between Group A and B ( P>0.05). At 6 weeks postoperatively, the AOFAS ankle-hindfoot scores were 94.0(94.0, 95.0)points and 95.0(94.0, 96.0)points in Group A and B, higher than 85.0(83.0, 86.0)points and 74.0(72.0, 75.0)points in Group C and D ( P<0.05), with a higher score in Group C than that in Group D ( P<0.05) but with no significant difference between Group A and B ( P>0.05). At 8 weeks postoperatively, the AOFAS ankle-hindfoot scores were 100.0(99.0, 100.0)points in Group B, higher than 94.0(94.0, 95.0)points, 92.0(90.0, 93.0)points, and 83.0(82.0, 84.0)points in Group A, C and D ( P<0.05), with a higher score in Group A than those in Group C and D ( P<0.05) and a higher score in Group C than that in Group D ( P<0.05). At 10 weeks postoperatively, the AOFAS ankle-hindfoot score was 100.0(100.0, 100.0)points in Group B, higher than 98.0(98.0, 98.0)points, 98.0(96.8, 99.0)points, and 96.0(95.0, 97.0)points in Group A, C and D, with higher scores in Group A and C than that in Group D ( P<0.05) but with no significant difference between Group A and C ( P>0.05). At 12 weeks postoperatively, the AOFAS ankle-hindfoot score was 100.0(100.0, 100.0)points in both Group A and B, with no significant difference between them ( P>0.05), which was higher than 100.0(98.0, 100.0)points and 99.0(98.0, 99.0)points in Group C and D ( P<0.05), with a higher score in Group C than that in Group D ( P<0.05). At 14 and 16 weeks postoperatively, AOFAS ankle-hindfoot score was 100.0(100.0, 100.0)points, with no significant difference among all the groups ( P>0.05). Superficial wound infection occurred in 12 patients [5.2%(5/96) in Group A, 0.6%(2/347) in Group B, 0.6%(2/346) in Group C and 2.9%(3/105) in Group D] ( P<0.01) while rerupture occurred in 16 [9.4%(9/96) in Group A, 1.2% (4/347) in Group B, 0.9%(3/105) in Group C, and 0 patient in Group D] ( P<0.01). Conclusion:For patients with unilateral acute Achilles tendon rupture, two weeks of postoperative external fixation after open repair can shorten the time of returning sports, alleviate pain, and promote functional recovery, without increasing the risk of complications.

Objective To explore the role of serum inflammatory factors in prediction of infection following internal fixation of closed fractures and its significance for surgical timing and infection prophylaxis.Methods A retrospective study was conducted of the 100 patients who had been treated by internal fixation for closed fracture from January 2014 through July 2016.They were 52 men and 48 women,aged from 24 to 76 years (average,45 years).There were 14 femoral fractures,19 tibial plateau fractures,25 patella fractures,8 pilon fractures,22 tibiofibular shaft fractures,and 12 calcaneal fractures.Of them,21 were inflicted by wound infection.The preoperative and postoperative infection indexes,CRP,ESR,PCT and leukocyte count,were recorded.Logistic regression analysis was conducted to test the correlation between the infection indexes and postoperative infection.The optimal cut-off value was determined by the receiver operating characteristic curve.Results CRP showed a significant correlation with postoperative infection while other indexes did not.The optimal cut-off value was 25 mg/L at one day before operation.Conclusions Preoperative determination of CRP may predict the risk of postoperative infection.CRP ＞ 25 mg/L at one day before operation may indicate the following day is not suitable for surgery and active infection prophylaxis should be conducted after surgery.

Objective To explore the effect of topical application of sodium hyaluronate on preventing perivascular adhesion of the vein grafts in rabbits. Methods Thirty-six male New Zealand white rabbits, aged 5 months, were randomly and equally divided into 2 groups: groups A and B. Arterial defect model was established by cutting about 1cm artery from the middle part of the dissected left common carotid artery. A section about 3cm was cut from the right external jugular vein, and the harvested vein was inverted and anastomosed end-to-end to the artery defect. After the anastomosis, the adventitia and two anastomoses of the grafted veins in group A were coated locally with 0.2ml sodium hyaluronate. The grafted veins were obtained 1, 2 and 4 weeks after the operation, with the perivascular adhesion of the vein grafts being examined macroscopically before the resection. HE staining and Masson staining were preformed for histological changes of grafted vein wall and the perivascular adhesion of the vein grafts. At 2, 4 weeks postoperation, the perivascular adhesions of the vein grafts were graded by the grading criteria of adhesion in macroscopic evaluation and histological evaluation. Result At 1, 2 and 4 weeks postoperatively, the macroscopic and histological observation found that the perivascular adhesions in group A were looser than those in group B. The macroscopic grade and histological grade were lower in group A than in group B, there was a significant difference between the two groups at 2 and 4 weeks postoperation (P<0.05). Conclusion Topical application of sodium hyaluronate can reduce the perivascular adhesion and is an ideal treatment strategy for preventing perivascular adhesion of vein grafts.

Objective To analyze the correlation of vertebral osteophyte and lumbar disc degeneration in the elderly people and explore the possible mechanism of osteophyte formation. Methods X-ray and MRI data of 120 elderly people with backache or leg pain were retrospectively analyzed. Osteophyte was classified into four grades by X-ray according to the method proposed by Nathan. Discs with osteophyte were defined as occurring when osteophyte of grade II or greater were present. Lumbar disc degeneration was classified into five grades by MRI according to the method proposed by Pfirrmann. The obtained parameters were statistically treated and analyzed. Results Osteophyte and age were positively correlated at every lumbar disc level (P < 0.05). The proportion of osteophyte in L3/4 (76.7%) and L4/5 (70.08%) were more severe than that in L1/2 (31.7%) and L2/3 (46.7%). Osteophyte and lumbar disc degeneration were positively correlated at every lumbar disc level (P < 0.01). Conclusion Osteophyte becomes more severe with the increasing of lumbar disc degeneration. The vertebral stress after lumbar disc degeneration may be the main cause of osteophyte.

ObjectiveTo study the efficacy of adjuvant percutaneous transhepatic portal vein chemoembolization (PVCE) in the prevention of tumor recurrence after partial hepatectomy for hepatocellular carcinoma.MethodsThe clinical data of 89 patients who received liver resection for hepatocellular carcinoma in our hospital from January 2007 to January 2010 were studied retrospectively.41patients received PVCE (the treatment group) while 48 patients received no PVCE (the control group).Postoperative recurrence and cumulative disease free survivals were compared using the Kaplan-Meier method.ResultsOn follow-up which ranged from 6-42 months,the 1- and 2-year disease free survivals were 76.5％ and 48.0％ in the treatment group,and 53.8％ and 25.8％ respectively in the control group (P＜0.05).The mean disease free survivals were 19.91 (95％ CI,16.09-23.73)and 13.8 months (95 ％ CI,10.95-16.65),respectively.The cumulative disease free survivals in the PVCE group were significantly higher than the control group (P=0.01).Cox multivariate analysis showed that adjuvant PVCE,tumor size,portal vein thrombosis,and postoperative transcatheter arterial chemoembolization (TACE) were independent factors of disease free survival.ConclusionAdjuvant PVCE was effective in preventing postoperative recurrence of hepatocellular carcinoma after partial hepatectomy.