Objective To identify the key determinants that enhance the scientific innovation capabilities of leading dis-ciplines in tertiary hospitals and to construct a predictive model for scientific research outputs,providing a scientific basis for the integrated development of hospital disciplines.Methods This study focused on the orthopedics,endocrinology and metabolism,otolaryngology head and neck surgery,and nephrology departments at the Shanghai Sixth People's Hospital affiliated with Shang-hai Jiao Tong University School of Medicine.Research data from 2013 to 2022 were analyzed.Significant independent variables were identified through univariate analysis,and the LASSO regression model was applied to address multicollinearity issues,in-corporating the time lag effect of research output to construct a predictive model.Results The number of senior professional title holders and the number of enrolled master's and doctoral students emerged as key factors for scientific research outputs.Factors affecting the quality and quantity of article output included the number of senior professionals,the enrollment of master's,doctor-al,and postdoctoral students,and funding for provincial,ministerial,school,bureau,and hospital-level projects.Key factors in-fluencing project-based outputs included the number of senior professionals,doctoral supervisors,the number of enrolled master' s and doctoral students,and funding for school and bureau-level projects.The prediction model based on LASSO regression dem-onstrated a good fit for various research output indicators.Conclusion This study used LASSO regression to identify key factors in scientific research outputs for top disciplines.The predictive model built in the study offers a scientific basis for discipline de-velopment.It helps optimize resource allocation,strengthen interdisciplinary collaboration,and drive high-quality hospital devel-opment.

Objective:To explore the clinical effect on the treatment of radiation induced deep ulcers in the inguinal region with ipsilateral anterolateral thigh chimeric perforator flap.Methods:From March 2020 to March 2024, retrospective analysis of 8 patients with radiation induced deep ulcers in the inguinal region were treated with ipsilateral anterolateral thigh chimeric perforator flap in the Medical Centre of Burn Plastic and Wound Repair, the First Affiliated Hospital of Nanchang University. All ulcers induced by radiation were caused by postoperative radiotherapy in the inguinal region, of which 4 were of vulvar or penile cancer, 2 of urinary tract tumour, 1 of inguinal protuberant dermatofibrosarcoma and 1 of myofibroblastic sarcoma in lower abdominal wall. The course of the radiation induced ulcer was 0.5-11.0 years, with an average of 2.9 years. The sizes of the ulcerative wound were 2.5 cm × 3.0 cm - 5.5 cm × 7.5 cm. Preoperative biopsies of the tissues around wound and pelvic CT scans were performed to preliminarily exclude a tumour recurrence or an ulcerative malignancy, as well as to confirm the depth of radiation ulcer. The wound size after debridement was 4.5 cm × 6.0 cm-13.5 cm × 19.0 cm, with a depth of 2.0-4.0 cm. An ipsilateral anterolateral thigh chimeric perforator flap was transferred to reconstruct the wound, after the wound edges were cleared from tumour through intraoperative frozen section examinations. The flaps were 5.5 cm × 7.0 cm - 14.0 cm × 20.0 cm in size, with the volumes of muscle flap at 7.0 cm × 4.0 cm × 3.0 cm - 14.0 cm × 7.0 cm × 3.0 cm. After having the deep defect at the base of wound filled with a muscle flap, the wound surface was covered by the flap. Four patients had direct suture of the donor sites and 4 received a thick skin graft of head or contralateral thigh grafting. Survival of the anterolateral thigh chimeric perforator flaps and the healing of donor sites were observed after surgery through scheduled postoperative follow-up by the visits of outpatient clinic and distant interviews via telephone, WeChat or the internet hospital.Results:One of the ipsilateral anterolateral thigh chimeric perforator flaps had venous occlusion within 24 hours after surgery. Emergency surgical exploration revealed that it was caused by a haematoma compression due to haemorrhage in the muscle flap. Further debridement, haemostasis and suture were performed, then the wound healed. The rest of 7 flaps all survived. All donor sites healed primarily. The postoperative follow-up lasted for 5-17 months with all of the 8 patients, at 8.4 months in average. Both the donor and recipient sites healed well without recurrence of radiation ulcer in the affected sites. The appearance and texture of the flaps were good, and there was no obvious functional impairment at the donor sites.Conclusion:The treatment of radiation induced deep ulcer in the inguinal region with an ipsilateral anterolateral thigh chimeric perforator flap has shown good results, without recurrence of ulcer after surgery. The appearance and texture of the affected sites are good, and there is no secondary functional impairment at the donor site.

Objective:To explore the application strategies and clinical effects of superior gluteal artery perforator tissue flaps in repairing stage Ⅳ pressure ulcers in the sacrococcygeal region.Methods:This study was a retrospective observational study. From July 2019 to April 2024, 89 patients with stage Ⅳ pressure ulcers in the sacrococcygeal region who met the inclusion criteria were admitted to the First Affiliated Hospital of Nanchang University, including 59 males and 30 females, aged 21 to 84 years. There were 89 sacrococcygeal pressure ulcers, with an area of 5.0 cm×4.0 cm-21.0 cm×21.0 cm after debridement. According to the shape, size, and depth of the wounds after debridement, combined with the elasticity and texture of the skin around the wounds, and the principle of minimizing damage to the donor area, the appropriate forms of superior gluteal artery perforator tissue flaps were cut for wound repair in the following three conditions. (1) For wounds with a round shape, an area of 5.0 cm×5.0 cm-21.0 cm×21.0 cm, and a depth of 1.0-3.5 cm, the superior gluteal artery perforator propeller flap or myocutaneous flap, bilobed superior gluteal artery perforator relay flap, and bilateral superior gluteal artery perforator rotational flap were used. (2) For wounds with an oval shape, an area of 5.0 cm×4.0 cm-18.5 cm×10.5 cm, and a depth of 1.0-3.0 cm, the superior gluteal artery perforator propeller flap or myocutaneous flap, unilateral superior gluteal artery perforator propeller flap combined with contralateral superior gluteal artery perforator V-Y advanced flap or keystone flap were used. (3) For wounds with a fusiformis shape, an area of 7.0 cm×4.0 cm-17.5 cm×6.0 cm, and a depth of 1.5-5.0 cm, the unilateral or bilateral superior gluteal artery perforator V-Y advanced flap, superior gluteal artery perforator keystone flap, or superior gluteal artery perforator keystone flap combined with gluteus maximus muscle flap were used. In this group of patients, a total of 40 superior gluteal artery perforator propeller flaps (with an resection area of 11.0 cm×6.0 cm-17.0 cm×11.0 cm), 22 superior gluteal artery perforator propeller myocutaneous flaps (with an resection area of 10.0 cm×5.0 cm-14.0 cm×8.0 cm), 7 bilobed superior gluteal artery perforator relay flaps (with a main flap resection area of 5.5 cm×5.5 cm-18.0 cm×11.5 cm and a side flap resection area of 4.5 cm×3.0 cm-11.0 cm×6.5 cm), 5 bilateral superior gluteal artery perforator rotational flaps (with a total resection area of 20.0 cm×16.0 cm-26.0 cm×21.0 cm on both sides), 14 superior gluteal artery perforator V-Y advanced flaps (with an resection area of 12.0 cm×10.0 cm-18.0 cm×18.0 cm), 13 superior gluteal artery perforator keystone flaps (with an resection area of 13.0 cm×6.5 cm-19.0 cm×18.0 cm), and 3 gluteus maximus muscle flaps (with an resection area of 8.0 cm×3.0 cm-15.0 cm×4.5 cm). The donor area wounds were all directly sutured. The survival of tissue flaps was observed and the incidence rate of delayed wound healing in the reception area was calculated, and wound healing in the donor area was observed. The appearance and texture of tissue flaps and recurrence of pressure ulcers were followed up.Results:After surgery, all bilateral superior gluteal artery perforator rotational flaps, superior gluteal artery perforator V-Y advanced flaps, superior gluteal artery perforator keystone flaps, and gluteus maximus muscle flaps survived well. There were 6 cases of delayed wound healing in the reception area after surgery, with an incidence rate of 6.7% (6/89). Two patients had incision dehiscence in the donor area wounds due to postoperative bleeding, the wounds healed after debridement, vacuum sealing drainage, and dressing change. The wounds in the donor area of the remaining patients healed well. Six patients were lost to follow-up. Eighty-three patients were followed up for 3-48 months, of whom 4 patients died. Among the remaining 79 patients, 3 cases had pressure ulcers recur due to improper nursing, while the rest of the patients had tissue flaps with good appearance and soft texture and no recurrence of pressure ulcers.Conclusions:Based on the characteristics of wound shape, size, and depth after debridement of stage Ⅳ pressure ulcers in the sacrococcygeal region, individualized selection of flap, myocutaneous flap, or a combination of flap and gluteus maximus muscle flap based on the perforating branch of the superior gluteal artery perforator can achieve good clinical repair results. The postoperative tissue flap survived well, with a good appearance, soft texture, and less recurrence of pressure ulcers.

Objective To identify the key determinants that enhance the scientific innovation capabilities of leading dis-ciplines in tertiary hospitals and to construct a predictive model for scientific research outputs,providing a scientific basis for the integrated development of hospital disciplines.Methods This study focused on the orthopedics,endocrinology and metabolism,otolaryngology head and neck surgery,and nephrology departments at the Shanghai Sixth People's Hospital affiliated with Shang-hai Jiao Tong University School of Medicine.Research data from 2013 to 2022 were analyzed.Significant independent variables were identified through univariate analysis,and the LASSO regression model was applied to address multicollinearity issues,in-corporating the time lag effect of research output to construct a predictive model.Results The number of senior professional title holders and the number of enrolled master's and doctoral students emerged as key factors for scientific research outputs.Factors affecting the quality and quantity of article output included the number of senior professionals,the enrollment of master's,doctor-al,and postdoctoral students,and funding for provincial,ministerial,school,bureau,and hospital-level projects.Key factors in-fluencing project-based outputs included the number of senior professionals,doctoral supervisors,the number of enrolled master' s and doctoral students,and funding for school and bureau-level projects.The prediction model based on LASSO regression dem-onstrated a good fit for various research output indicators.Conclusion This study used LASSO regression to identify key factors in scientific research outputs for top disciplines.The predictive model built in the study offers a scientific basis for discipline de-velopment.It helps optimize resource allocation,strengthen interdisciplinary collaboration,and drive high-quality hospital devel-opment.

Objective:To explore the clinical effect on the treatment of radiation induced deep ulcers in the inguinal region with ipsilateral anterolateral thigh chimeric perforator flap.Methods:From March 2020 to March 2024, retrospective analysis of 8 patients with radiation induced deep ulcers in the inguinal region were treated with ipsilateral anterolateral thigh chimeric perforator flap in the Medical Centre of Burn Plastic and Wound Repair, the First Affiliated Hospital of Nanchang University. All ulcers induced by radiation were caused by postoperative radiotherapy in the inguinal region, of which 4 were of vulvar or penile cancer, 2 of urinary tract tumour, 1 of inguinal protuberant dermatofibrosarcoma and 1 of myofibroblastic sarcoma in lower abdominal wall. The course of the radiation induced ulcer was 0.5-11.0 years, with an average of 2.9 years. The sizes of the ulcerative wound were 2.5 cm × 3.0 cm - 5.5 cm × 7.5 cm. Preoperative biopsies of the tissues around wound and pelvic CT scans were performed to preliminarily exclude a tumour recurrence or an ulcerative malignancy, as well as to confirm the depth of radiation ulcer. The wound size after debridement was 4.5 cm × 6.0 cm-13.5 cm × 19.0 cm, with a depth of 2.0-4.0 cm. An ipsilateral anterolateral thigh chimeric perforator flap was transferred to reconstruct the wound, after the wound edges were cleared from tumour through intraoperative frozen section examinations. The flaps were 5.5 cm × 7.0 cm - 14.0 cm × 20.0 cm in size, with the volumes of muscle flap at 7.0 cm × 4.0 cm × 3.0 cm - 14.0 cm × 7.0 cm × 3.0 cm. After having the deep defect at the base of wound filled with a muscle flap, the wound surface was covered by the flap. Four patients had direct suture of the donor sites and 4 received a thick skin graft of head or contralateral thigh grafting. Survival of the anterolateral thigh chimeric perforator flaps and the healing of donor sites were observed after surgery through scheduled postoperative follow-up by the visits of outpatient clinic and distant interviews via telephone, WeChat or the internet hospital.Results:One of the ipsilateral anterolateral thigh chimeric perforator flaps had venous occlusion within 24 hours after surgery. Emergency surgical exploration revealed that it was caused by a haematoma compression due to haemorrhage in the muscle flap. Further debridement, haemostasis and suture were performed, then the wound healed. The rest of 7 flaps all survived. All donor sites healed primarily. The postoperative follow-up lasted for 5-17 months with all of the 8 patients, at 8.4 months in average. Both the donor and recipient sites healed well without recurrence of radiation ulcer in the affected sites. The appearance and texture of the flaps were good, and there was no obvious functional impairment at the donor sites.Conclusion:The treatment of radiation induced deep ulcer in the inguinal region with an ipsilateral anterolateral thigh chimeric perforator flap has shown good results, without recurrence of ulcer after surgery. The appearance and texture of the affected sites are good, and there is no secondary functional impairment at the donor site.

Objective:To explore the application strategies and clinical effects of superior gluteal artery perforator tissue flaps in repairing stage Ⅳ pressure ulcers in the sacrococcygeal region.Methods:This study was a retrospective observational study. From July 2019 to April 2024, 89 patients with stage Ⅳ pressure ulcers in the sacrococcygeal region who met the inclusion criteria were admitted to the First Affiliated Hospital of Nanchang University, including 59 males and 30 females, aged 21 to 84 years. There were 89 sacrococcygeal pressure ulcers, with an area of 5.0 cm×4.0 cm-21.0 cm×21.0 cm after debridement. According to the shape, size, and depth of the wounds after debridement, combined with the elasticity and texture of the skin around the wounds, and the principle of minimizing damage to the donor area, the appropriate forms of superior gluteal artery perforator tissue flaps were cut for wound repair in the following three conditions. (1) For wounds with a round shape, an area of 5.0 cm×5.0 cm-21.0 cm×21.0 cm, and a depth of 1.0-3.5 cm, the superior gluteal artery perforator propeller flap or myocutaneous flap, bilobed superior gluteal artery perforator relay flap, and bilateral superior gluteal artery perforator rotational flap were used. (2) For wounds with an oval shape, an area of 5.0 cm×4.0 cm-18.5 cm×10.5 cm, and a depth of 1.0-3.0 cm, the superior gluteal artery perforator propeller flap or myocutaneous flap, unilateral superior gluteal artery perforator propeller flap combined with contralateral superior gluteal artery perforator V-Y advanced flap or keystone flap were used. (3) For wounds with a fusiformis shape, an area of 7.0 cm×4.0 cm-17.5 cm×6.0 cm, and a depth of 1.5-5.0 cm, the unilateral or bilateral superior gluteal artery perforator V-Y advanced flap, superior gluteal artery perforator keystone flap, or superior gluteal artery perforator keystone flap combined with gluteus maximus muscle flap were used. In this group of patients, a total of 40 superior gluteal artery perforator propeller flaps (with an resection area of 11.0 cm×6.0 cm-17.0 cm×11.0 cm), 22 superior gluteal artery perforator propeller myocutaneous flaps (with an resection area of 10.0 cm×5.0 cm-14.0 cm×8.0 cm), 7 bilobed superior gluteal artery perforator relay flaps (with a main flap resection area of 5.5 cm×5.5 cm-18.0 cm×11.5 cm and a side flap resection area of 4.5 cm×3.0 cm-11.0 cm×6.5 cm), 5 bilateral superior gluteal artery perforator rotational flaps (with a total resection area of 20.0 cm×16.0 cm-26.0 cm×21.0 cm on both sides), 14 superior gluteal artery perforator V-Y advanced flaps (with an resection area of 12.0 cm×10.0 cm-18.0 cm×18.0 cm), 13 superior gluteal artery perforator keystone flaps (with an resection area of 13.0 cm×6.5 cm-19.0 cm×18.0 cm), and 3 gluteus maximus muscle flaps (with an resection area of 8.0 cm×3.0 cm-15.0 cm×4.5 cm). The donor area wounds were all directly sutured. The survival of tissue flaps was observed and the incidence rate of delayed wound healing in the reception area was calculated, and wound healing in the donor area was observed. The appearance and texture of tissue flaps and recurrence of pressure ulcers were followed up.Results:After surgery, all bilateral superior gluteal artery perforator rotational flaps, superior gluteal artery perforator V-Y advanced flaps, superior gluteal artery perforator keystone flaps, and gluteus maximus muscle flaps survived well. There were 6 cases of delayed wound healing in the reception area after surgery, with an incidence rate of 6.7% (6/89). Two patients had incision dehiscence in the donor area wounds due to postoperative bleeding, the wounds healed after debridement, vacuum sealing drainage, and dressing change. The wounds in the donor area of the remaining patients healed well. Six patients were lost to follow-up. Eighty-three patients were followed up for 3-48 months, of whom 4 patients died. Among the remaining 79 patients, 3 cases had pressure ulcers recur due to improper nursing, while the rest of the patients had tissue flaps with good appearance and soft texture and no recurrence of pressure ulcers.Conclusions:Based on the characteristics of wound shape, size, and depth after debridement of stage Ⅳ pressure ulcers in the sacrococcygeal region, individualized selection of flap, myocutaneous flap, or a combination of flap and gluteus maximus muscle flap based on the perforating branch of the superior gluteal artery perforator can achieve good clinical repair results. The postoperative tissue flap survived well, with a good appearance, soft texture, and less recurrence of pressure ulcers.

Objective:To explore the clinical efficacy of posterior femoral cutaneous nerve nutrient vessel adipofascial flaps plus free-style gluteal perforator flaps in repairing stage IV sciatic tuberosity pressure ulcers.Methods:A retrospective case series study was conducted to analyze the clinical data of 16 patients (16 wounds) with stage IV sciatic tuberosity pressure ulcers admitted to First Affiliated Hospital of Nanchang University from May 2021 to February 2024, including 10 males and 6 females, aged 21-84 years [(58.5±16.5)years]. Among them, 8 patients were complicated with chronic osteomyelitis of the ischium at 8 sites. The wound area before debridement ranged from 2.0 cm×1.5 cm to 9.0 cm×7.0 cm. All the patients underwent staged surgery. In phase I surgery, the scar tissue at the wound margin, necrotic tissue, bursa, and chronic osteomyelitic lesions were removed in the ischium. After debridement, the wound area ranged from 4.0 cm×3.0 cm to 12.0 cm×8.0 cm. Negative pressure closure drainage (VSD) was performed and wound bed preparation was completed. In phase II surgery, the posterior femoral cutaneous nerve nutrient vessel adipofascial flaps were flipped, filled into the wound cavity, and then used to repair the wound by advancing and rotating in combination with free-style gluteal perforator flap. The area of posterior femoral cutaneous nerve nutrient vessel adipofascial flaps ranged from 9.0 cm×3.5 cm to 19.0 cm×10.0 cm and the area of the free-style gluteal perforator flaps ranged from 5.0 cm×4.0 cm to 13.0 cm×8.5 cm. The amount of bleeding in phase II surgery was recorded. The survival and wound healing of the posterior femoral cutaneous nerve nutrient vessel adipofascial flaps and free-style gluteal perforator flaps were observed. At the last follow-up, recurrence of pressure ulcers and osteomyelitis, external appearance of the wound, and secondary functional impairment and deformity in the donor sites were observed.Results:All the patients were followed up for 6-15 months [(9.4±3.1)months]. The intraoperative bleeding volume in phase II surgery was 80-300 ml [(162.9±60.6)ml]. All the posterior femoral cutaneous nerve nutrient vessel adipofascial flaps survived well after surgery. A small area of bruising was observed at the distal end of the freestyle gluteal perforator flap in 1 patient at 1 day after surgery, which was relieved after removing some of the sutures. Torn suture of the incision was found as a result of postoperative subcutaneous hematoma in the donor site of the posterior femoral cutaneous nerve nutrient vessel adipofascial flap in 1 patient at 1 day after surgery, which healed at 22 days after bedside debridement and dressing change. All other incisions healed well. At the last follow-up, there was no recurrence of pressure ulcers or osteomyelitis and the wound was mildly pigmented and soft. There were no secondary functional impairments or deformities in the posterior femoral or gluteal donor sites.Conclusion:Posterior femoral cutaneous nerve nutrient vessel adipofascial flaps plus freestyle gluteal perforator flaps can be used in the repair of stage IV sciatic tuberosity pressure ulcer wounds, with the advantages of less intraoperative bleeding, high tissue flap survival rate, good wound healing, no recurrence of pressure ulcers or osteomyelitis after surgery, good wound appearance and texture, and no secondary functional impairment or deformity in the donor sites.

Objective:To explore the clinical efficacy of posterior femoral cutaneous nerve nutrient vessel adipofascial flaps plus free-style gluteal perforator flaps in repairing stage IV sciatic tuberosity pressure ulcers.Methods:A retrospective case series study was conducted to analyze the clinical data of 16 patients (16 wounds) with stage IV sciatic tuberosity pressure ulcers admitted to First Affiliated Hospital of Nanchang University from May 2021 to February 2024, including 10 males and 6 females, aged 21-84 years [(58.5±16.5)years]. Among them, 8 patients were complicated with chronic osteomyelitis of the ischium at 8 sites. The wound area before debridement ranged from 2.0 cm×1.5 cm to 9.0 cm×7.0 cm. All the patients underwent staged surgery. In phase I surgery, the scar tissue at the wound margin, necrotic tissue, bursa, and chronic osteomyelitic lesions were removed in the ischium. After debridement, the wound area ranged from 4.0 cm×3.0 cm to 12.0 cm×8.0 cm. Negative pressure closure drainage (VSD) was performed and wound bed preparation was completed. In phase II surgery, the posterior femoral cutaneous nerve nutrient vessel adipofascial flaps were flipped, filled into the wound cavity, and then used to repair the wound by advancing and rotating in combination with free-style gluteal perforator flap. The area of posterior femoral cutaneous nerve nutrient vessel adipofascial flaps ranged from 9.0 cm×3.5 cm to 19.0 cm×10.0 cm and the area of the free-style gluteal perforator flaps ranged from 5.0 cm×4.0 cm to 13.0 cm×8.5 cm. The amount of bleeding in phase II surgery was recorded. The survival and wound healing of the posterior femoral cutaneous nerve nutrient vessel adipofascial flaps and free-style gluteal perforator flaps were observed. At the last follow-up, recurrence of pressure ulcers and osteomyelitis, external appearance of the wound, and secondary functional impairment and deformity in the donor sites were observed.Results:All the patients were followed up for 6-15 months [(9.4±3.1)months]. The intraoperative bleeding volume in phase II surgery was 80-300 ml [(162.9±60.6)ml]. All the posterior femoral cutaneous nerve nutrient vessel adipofascial flaps survived well after surgery. A small area of bruising was observed at the distal end of the freestyle gluteal perforator flap in 1 patient at 1 day after surgery, which was relieved after removing some of the sutures. Torn suture of the incision was found as a result of postoperative subcutaneous hematoma in the donor site of the posterior femoral cutaneous nerve nutrient vessel adipofascial flap in 1 patient at 1 day after surgery, which healed at 22 days after bedside debridement and dressing change. All other incisions healed well. At the last follow-up, there was no recurrence of pressure ulcers or osteomyelitis and the wound was mildly pigmented and soft. There were no secondary functional impairments or deformities in the posterior femoral or gluteal donor sites.Conclusion:Posterior femoral cutaneous nerve nutrient vessel adipofascial flaps plus freestyle gluteal perforator flaps can be used in the repair of stage IV sciatic tuberosity pressure ulcer wounds, with the advantages of less intraoperative bleeding, high tissue flap survival rate, good wound healing, no recurrence of pressure ulcers or osteomyelitis after surgery, good wound appearance and texture, and no secondary functional impairment or deformity in the donor sites.

Objective:To study the morphologic features of the fusion site of proximal tibial epiphysis in normal adults and analyze its potential clinical value based on Mimics three-dimensional (3D) reconstruction.Methods:CT images of knee joint of 68 patients without obvious abnormalities of lower limbs were retrospectively analyzed in electronic database of our hospital from June 2020 to June 2021, including 41 males and 27 females. The mean age of the patients was 38.7±8.4 years (range, 25-55 years), and the mean body mass index (BMI) was 25.3±4.0 kg/m 2 (range, 18.75-41.8 kg/m 2). Mimics 3D reconstruction technique was used to reconstruct the 3D model of the proximal tibia and epiphyseal fusion site. The relationship between the surface area of epiphyseal fusion site and age and BMI was studied, and the changes of cortical thickness and density at epiphyseal fusion site were also explored. Results:The fusion site of adult epiphyseal reconstructed by Mimics 3D reconstruction is a complex wavy surface structure in 3D space. The surface area of the epiphyseal fusion site was 2,994.7±645.3 mm 2 (range, 1,704.0-4,650.0 mm 2) obtained by 3-Matic Research 12.0. The fusing area of male epiphysis was 3 269.3±533.9 mm 2 than that of female 2,577.6±578.7 mm 2, the difference was statistically significant ( t=5.06, P<0.001). However, there was no significant correlation between the epiphyseal fusion site surface area and age ( R2=0.02, P=0.268) and BMI ( R2=0.04, P=0.125). Mimics software was used to obtain the CT values of bone cortex at the epiphysis line and the distal end of the epiphysis line at 10 mm and 20 mm levels as 451.059±74.953 Hu, 1,018.412±125.732 Hu and 1,414.162±107.848 Hu, respectively. The thickness of bone cortex was 1.814±0.090 mm, 2.511±0.089 mm and 3.189±0.185 mm at 10 mm and 20 mm layers of epiphysis line and distal epiphysis line, respectively. Conclusion:In this study, Mimics 3D reconstruction technique was used to visualize the fusion site of the proximal tibial epiphysis in normal adults. The epiphyseal fusion site of adult is a undulating plate-like structure, and the cortical bone density of epiphyseal fusion site is low and thin, theoretically, it is easy to fracture under indirect violence.

Postzygotic mutations are acquired in normal tissues throughout an individual's lifetime and hold clues for identifying mutagenic factors.Here,we investigated postzygotic mutation spectra of healthy individuals using optimized ultra-deep exome sequencing of the time-series samples from the same volunteer as well as the samples from different individuals.In blood,sperm,and muscle cells,we resolved three common types of mutational signatures.Signatures A and B represent clock-like mutational processes,and the polymorphisms of epigenetic regulation genes influence the pro-portion of signature B in mutation profiles.Notably,signature C,characterized by C＞T transitions at GpCpN sites,tends to be a feature of diverse normal tissues.Mutations of this type are likely to occur early during embryonic development,supported by their relatively high allelic frequencies,presence in multiple tissues,and decrease in occurrence with age.Almost none of the public datasets for tumors feature this signature,except for 19.6％of samples of clear cell renal cell carcinoma with increased activation of the hypoxia-inducible factor 1(HIF-1)signaling pathway.Moreover,the accumulation of signature C in the mutation profile was accelerated in a human embryonic stem cell line with drug-induced activation of HIF-1α.Thus,embryonic hypoxia may explain this novel signature across multiple normal tissues.Our study suggests that hypoxic condition in an early stage of embryonic development is a crucial factor inducing C＞T transitions at GpCpN sites;and indi-viduals'genetic background may also influence their postzygotic mutation profiles.