Objective To investigate the evaluation of femoral neck anteversion using the digital three-dimensional model induced determination method.Methods Ten healthy volunteers,including five men and five women,aged 18-60 years (mean,43 years) were recruited.Bilateral femur CT scan was taken and processed with Mimics 17.0 software to build the three-dimensional model of the femur.Traditional Photoshop and three-dimensional reconstruction techniques were separately applied to determine the femoral neck anteversion.Anteversion angle and measurement time determined with the two methods were compared.Results Anteversion angle was (17.0 ± 4.2) ° based on the Photoshop method and was (17.0 ± 4.2) ° based on the three-dimensional method (P ＞ 0.05).Measuring time was (1,231.5 ± 152.8) sec with the Photoshop method and (590.0 ± 37.2) sec with the three-dimensional method (P ＜ 0.01).Conclusion Both methods provide accurate measuring of the femoral neck anteversion,but three-dimensional measurement spends far less time resulting in improved measure efficiency.

Objective To investigate a special optimization technique for computer aided measure, and provide anatomical basis for screw internal fixation in the cavitas glenoidalis through the coracoid process of scapula. Methods Thirty accurate scapula models were reconstructed from CT data sets. First, special optimization objective function was designed for single screw internal fixation configuration, and the optimal placement of screw was found automatically under constraints. Then, the placements of double screws internal fixation configuration were searched taking advantage of principal component analysis. Finally, statistical measure data were provided according to new anatomical reference landmarks for clinical use. Results For single screw internal fixation configuration, the distance from the optimal screw entry point P to the acromion process point X was (39.15±2.28) mm, to the coracoid process point Y was (28.66±2.68) mm, to the angulus superior point Z was (61.13±6.57) mm;The angle was (81.27±7.15)° between PX and PY, and (133.27±6.84)° between PX and PZ. The mean inclination of the lag screw was (104.08±4.41)° for the angle with line PX, (101.29±3.51)° with line PY, and (76.23±5.03)° with line PZ. For double screws configuration, the distance from the original single screw entry point P to the screw entry point E was (5.12±1.37)mm,to the screw entry point F was (3.88±0.94)mm. The angle between the long axis of coracoid process and line EF was (27.41±3.51)°. Conclusion The automatic optimization technique for computer aided measure is very efficient and has many advantages over the conventional manual dissection methods, and is convenient to design new anatomical reference landmark system for clinical use.

Objective To investigate the clinical efficacy of domestic porous tantalum rod in treatment of early avascular necrosis of femoral head (ANFH).Methods A prospective study was made on 18 cases (19 hips) diagnosed as early ANFH treated by domestic porous tantalum rod from July 2014 to December 2015.There were 14 males and four females, with a mean age of 44.2 years (range, 30-62 years).According to the modified Ficat staging, four cases were identified as stage Ⅱa and 14 stageⅡb.Efficacy of the treatment was evaluated by Harris score, Womac score, radiological images of the hip, complications and bone growth.Results All cases were followed up for 8-24 months (mean, 16 months).No complications such as infection, wound healing problems, immunological rejection, tantalum rod breakage, loosening or displacement were observed at last follow-up.Harris score was (82.7±9.0)points, (84.5±10.8)points and (87.2±10.0)points at postoperative 3, 6 and 12 months respectively, significantly higher than that pre-operation [(75.5±11.9)points] (P<0.05).Harris score was rated excellent in 10 cases, good in three, fair in five and poor in one at the last follow-up, with the excellent and good rate of 68%.Womac score was (17.4±9.4)points, (12.4±7.3)points, and (11.1±8.4)points at postoperative 3, 6 and 12 months respectively, significantly lower than that pre-operation [(28.3±13.1)points] (P<0.05).Seventeen cases (18 hips) showed no obvious deterioration in femoral head necrosis, with femoral head survival rate of 95%.One case underwent total hip arthroplasty after operation because of progressive hip pain and collapsed femoral head.Bone ingrowth was detected in the porous tantalum biomaterial after operation.Conclusion Domestic porous tantalum rod can effectively promote bone ingrowth, relieve pain, prevent the collapse of the femoral head, delay total hip arthroplasty time and finally improve hip function in treatment of early avascular necrosis of femoral head.

Objective:To explore effect of competitive teaching on clinical skill teaching of knee puncture and improve students' clinical skills.Methods:Students participated knee puncture course in September 2020 were randomly divided into experimental group (competitive teaching group) and control group (traditional teaching group). One month after the class, 90 students were randomly selected to participate knee puncture examination, including 39 in experimental group and 51 in control group, and their examination results were recorded and analyzed. The statistical analysis was conducted by t test and chi-square test. Results:The mean scores in experimental group were (84.18±7.21) points, which were statistically higher than these in the control group (80.17±10.51) points, P=0.044. On the other hand, there was no statistical difference between experimental and control group in the aspect of score distribution in each score section. Conclusion:Competitive teaching is beneficial for the improvement of students' overall grades and clinical skills.

OBJECTIVETo investigate the effect of co-expression of bone morphogenetic protein 2 (BMP2) and Sox9 on chondrogenic differentiation of mesenchymal stem cells (MSCs) in vitro and provide experimental evidence for tissue engineering of cartilage.

METHODSMouse embryonic bone marrow MSC C3H10T1/2 cells were infected with recombinant adenovirus expressing BMP2, Sox9 and green fluorescent protein (GFP) for 3-14 days, with cells infected with the adenovirus carrying GFP gene as the control. The mRNA expression of the markers of chondrogenic differentiation, including collagen type II (Col2a1), aggrecan (ACAN), and collagen type X (Col10a1), were determined by real-time PCR. Alcian blue staining was used for quantitative analysis of sulfated glycosaminoglycan in the cellular matrix. The expression of Col2a1 protein was assayed by immunohistochemical staining and Western blot analysis.

RESULTSAdenovirus-mediated BMP2 expression induced chondrogenic differentiation of C3H10T1/2 cells. Overexpression of Sox9 effectively enhanced BMP2-induced expression of the chondrogenic markers Col2a1, aggrecan and Col10a1 mRNAs, and promoted the synthesis of sulfated glycosaminoglycan and Col2a1 protein in C3H10T1/2 cells.

CONCLUSIONCo-expression of BMP2 and Sox9 can promote chondrogenic differentiation of MSCs in vitro, which provides a new strategy for tissue engineering of cartilage.

Animals ; Bone Morphogenetic Protein 2 ; genetics ; metabolism ; Cartilage ; cytology ; Cell Differentiation ; Cells, Cultured ; Chondrocytes ; cytology ; Humans ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Mice ; SOX9 Transcription Factor ; genetics ; metabolism ; Tissue Engineering

Objective:To explore whether deep learning could apply to recognize the recurrent laryngeal nerve in the video of unilateral axillary approach endoscopic thyroidectomy.Methods:Videos of endoscopic thyroidectomy via unilateral axillary approach in Peking Union Medical College Hospital from Jul. 1st, 2020 to May. 1st, 2021 were collected. Videos containing the recurrent laryngeal nerve were selected, and the outline of recurrent laryngeal nerve were marked by two senior thyroid surgeons and staffs. Data were divided into training set and test set in a ratio of 5:1, and classified into high, medium and low recognition group according to difficulty of recognizing the outline of the nerve. The neuron network was based on PSPNet combined with Resnet50. All data were analyzed by R (ver. 4.0.2) .Results:A total of 38 videos including 35,501 frames of pictures were included in this study. 29, 704 frames of 32 videos were in our training set and 5797 frames of 6 videos were in the test set. When the intersection over union (IOU) threshold is 0.1, the sensitivity and precision is 100.0%/92.1%, 95.8%/80.2% and 81.0%/80.6% in high, medium and low recognition group respectively. When the IOU threshold is 0.5, the sensitivity and precision is 92.6%/85.3%, 71.7%/60.5% and 38.1%/37.9% in high, medium and low recognition group respectively, indicating that neuron network could located the outline of recurrent laryngeal nerve in high and medium recognition group. False negatives were often due to small targets and unclear boundaries.Conclusion:Recurrent laryngeal nerve recognition based on deep learning is feasible and has potential application value in endoscopic thyroidectomy, which may help surgeons reduce the risk of accidental injury of recurrent laryngeal nerve and improve the safety of thyroidectomy.

Objective:To investigate the application value of machine learning algorithms for gauze detection in laparoscopic pancreatic surgery.Methods:The retrospective and descriptive study was conducted. The 80 intact laparoscopic pancreatic surgery videos from Peking Union Medical College Hospital of Chinese Academy of Medical Sciences with timing of July 2017 to July 2020 were collected. The training set was used to train the neural network, and the test set was used to test the ability of neural network for gauze detection under different difficulties. Under the supervision of two superior doctors, videos that containing gauze were selected and classified according to recognition difficulty into three difficulty level including easy, normal and hard difficulty, and further divided based on random number method into training set with 61 videos and test set with 19 videos in a ratio of 3:1 roughly. The minimum enclosing rectangle of the gauze were marked frame by frame. All images were input to the neural network model for training after normalization and preprocessing. For every image, the output of neural network is the predicted minimum enclosing rectangle of gauze. The intersection over union >0.5 was identified as positive result. Observation indicators: (1) video annotation and classification; (2) test outcomes of neural network for test set.Count data were represented as absolute numbers or percentages.Results:(1) Video annotation and classification: a total of 26 893 frames of images form 80 videos were annotated, with 61 videos including 22 564 frames of images as the training set and 19 videos including 4 329 frames of images as the test set. Of the training set, 19 videos including 5 791 frames of images were classifed as easy difficulty, 38 videos including 15 771 frames of images were classifed as normal difficulty, 4 videos including 1 002 frames of images were classifed as hard difficulty, respectively. Of the test set, 4 videos including 1 684 frames of images were classifed as easy difficulty, 6 videos including 1 016 frames of images were classifed as normal difficulty, 9 videos including 1 629 frames of images were classifed as hard difficulty, respectively. (2) Test outcomes of neural network for test set: the overall sensitivity and accuracy of gauze detection by neural network in the test set were 78.471%(3 397/4 329) and 69.811%(3 397/4 866), respectively. The sensitivity and accuracy of gauze detection by neural network were 94.478%(1 591/1 684) and 83.168%(1 591/1 913) in easy difficulty test set. The sensitivity and accuracy of gauze detection by neural network were 80.413%(817/1 016) and 70.859%(817/1 153) in normal difficulty test set, 60.712%(989/1 629) and 54.944%(989/1 800)in hard difficulty test set. The frame rate reached more than or equally to 15 fps. The overall false negative rate and false positive rate of gauze detection by neural network in the test set were 21.529%(932/4 329) and 30.189%(1 469/4 866), respectively. The false negative was mainly due to the existence of blurred images, too small gauze exposure or blood immersion of gauze. The false positive was caused by the reflection of connective tissue or body fluids.Conclusion:The machine learning algorithms for gauze detection in laparoscopic pancreatic surgery is feasible, which could help medical staff identify gauze.

Objective:To explore whether deep learning could apply to recognize the recurrent laryngeal nerve (RLN) in videos of endoscopic thyroidectomy (ETE) via breast approach.Methods:Videos of ETE via breast approach in Peking Union Medical College Hospital from Feb. 2020 to Aug. 2021 were collected. Videos containing RLN were selected, and the outline of RLN was marked by two thyroid surgeons. Then data were divided into a training set and a test set in a ratio of 5:1 and classified into the high and low difficulty group according to a senior thyroid surgeon’s opinion. Those pictures were input to D-LinkNet model. Precision, sensitivity and mean dice index was calculated.Results:A total of 46 videos including 153, 520 frames of pictures were included in this study. 131,039 frames of 39 videos were in the training set and 22,481 frames of 7 videos were in the test set. When the intersection over union threshold was 0.1, the sensitivity and precision was 92.9%/72.8% and 47.6%/54.9% in high and low recognition group, respectively. When the intersection over union threshold was 0.5, the sensitivity and precision turned to 85.8%/67.2% and 37.6%/43.5% in high and low difficulty group, respectively. Mean Dice index was 0.781 and 0.663 in high and low difficulty group, respectively.Conclusions:RLN recognition based on deep learning is feasible and has potential application value in ETE, which may help surgeons reduce the risk of accidental injury of RLN and improve the safety of thyroidectomy.

Objective:To summarize the experience and the clinical data of patients with primary hyperparathyroidism undergoing endoscopic parathyroidectomy.Methods:A total of 24 patients who underwent endoscopic parathyroidectomy for primary hyperparathyroidism in Peking Union Medical College Hospital during Feb. 2021 to May. 2022 were concluded in this study (20 cases of parathyroidectomy via axillary approach and 4 cases of parathyroidectomy via thoracic and breast approach) . The operation time, postoperative drainage, length of stay, level of parathyroid hormone and serum calcium of those patients were collected. Postoperative complications and recurrence of hyperparathyroidism were also observed.Results:The postoperative levels of serum parathyroid hormone and serum calcium were significantly reduced (over 50%) compared with preoperative level ( P<0.05) . The average operation time was (96±22) min (64-157 min) . The mean postoperative drainage volume was (47±16) ml on day 1, (46±11) ml on day 2, and (30±9) ml on day 3, respectively. The average length of postoperative hospital stay was (2.8±1.1) days (2-6 days) . In one case of parathyroidectomy via axillary approach, the operation was converted to open surgery because of the low position of lesion. Other cases completed endoscopic surgery and obtained satisfactory cosmetic results. There were no postoperative complications such as bleeding, permanent hoarseness, coughing while drinking water, or surgical site infection. The mean follow-up time was (7.4±4.2) months (1-16 months) . There was no obvious discomfort and no recurrence during follow-up. Conclusion:Endoscopic parathyroidectomy is safe and effective in the treatment of primary hyperparathyroidism, which can be used as a surgical option for patients with cosmetic requirements.

Objective To investigate the effect of co-expression of bone morphogenetic protein 2 (BMP2) and Sox9 on chondrogenic differentiation of mesenchymal stem cells (MSCs) in vitro and provide experimental evidence for tissue engineering of cartilage. Methods Mouse embryonic bone marrow MSC C3H10T1/2 cells were infected with recombinant adenovirus expressing BMP2, Sox9 and green fluorescent protein (GFP) for 3-14 days, with cells infected with the adenovirus carrying GFP gene as the control. The mRNA expression of the markers of chondrogenic differentiation, including collagen type II (Col2a1), aggrecan (ACAN), and collagen type X (Col10a1), were determined by real-time PCR. Alcian blue staining was used for quantitative analysis of sulfated glycosaminoglycan in the cellular matrix. The expression of Col2a1 protein was assayed by immunohistochemical staining and Western blot analysis. Results Adenovirus-mediated BMP2 expression induced chondrogenic differentiation of C3H10T1/2 cells. Overexpression of Sox9 effectively enhanced BMP2-induced expression of the chondrogenic markers Col2a1, aggrecan and Col10a1 mRNAs, and promoted the synthesis of sulfated glycosaminoglycan and Col2a1 protein in C3H10T1/2 cells. Conclusion Co-expression of BMP2 and Sox9 can promote chondrogenic differentiation of MSCs in vitro, which provides a new strategy for tissue engineering of cartilage.