Prosthesis loosening is the leading cause of postoperative revision in unicompartmental knee arthroplasty (UKA). The deviation of medial and lateral translational installation of the prosthesis during surgery is a common clinical phenomenon and an important factor in increasing the risk of prosthesis loosening. This study established a UKA finite element model and a bone-prosthesis fixation interface micromotion prediction model. The predicted medial contact force and joint motion of the knee joint from a patient-specific lower extremity musculoskeletal multibody dynamics model of UKA were used as boundary conditions. The effects of 9 femoral component medial and lateral translational installation deviations on the Von Mises stress of the proximal tibia, the contact stress, and the micro-motion of the bone prosthesis fixation interface were quantitatively studied. It was found that compared with the neutral position (a/A of 0.492), the lateral translational deviation of the femoral component significantly increased the tibial Von Mises stress and the bone-prosthesis fixation interface contact stress. The maximum Von Mises stress and the maximum contact stress of the fixation interface increased by 14.08% and 143.15%, respectively, when a/A was 0.361. The medial translational deviation of the femoral component significantly increased the bone-prosthesis fixation interface micro-motion. The maximum value of micromotion under the conditions of femoral neutral and medial translation deviation was in the range of 20-50 μm, which is suitable for osseointegration. Therefore, based on considerations such as the micromotion range suitable for osseointegration reported in the literature, the risk of reducing prosthesis loosening, and factors that may induce pain, it is recommended that clinicians control the mounting position of the femoral component during surgery within the safe range of 0-4 mm medial translation deviation.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Finite Element Analysis ; Biomechanical Phenomena ; Knee Prosthesis ; Tibia/surgery* ; Femur/surgery* ; Stress, Mechanical ; Prosthesis Failure ; Knee Joint/surgery* ; Prosthesis Design

OBJECTIVE To evaluate the short-term efficacy of single-session microwave ablation for benign thyroid nodule.METHODS Patients with benign thyroid nodules treated by microwave ablation between June 2019 and December 2022 at the Department of Otolaryngology Head and Neck Surgery,the First Affiliated Hospital of Xi'an Jiaotong University,were included for analysis.Thyroid function was tested 1 month after treatment,and ultrasound and thyroid function were performed 3 months,6 months and 1 year after treatment.Volume reduction rates(VRR)of nodules were calculated.Data of the last follow-up within 1 year were included for analysis.Variables including gender,age,whether Hashimoto's thyroiditis was present,longitudinal diameter of nodules,solid volume of nodules were included for univariate and multivariate analysis.RESULTS A total of 151 patients with 163 nodules were included.The perioperative complication rate was 1.99%(3/151).The VRR at half year after treatment was(79.58±17.70)%,and the success rate at half year after treatment was 93.43%(128/137).The VRR of at 1year after treatment was(81.24±24.29)%.The 1-year treatment success rate was 92.77%(77/83).Univariate and multivariate analysis showed that nodular solid volume and age were independent factors affecting VRR after ablation.Regression coefficient of age and solid volume was 0.34(P<0.05)and-0.47(P<0.05),respectively.For every 1 cm3 increase in solid volume,1-year VRR(%)decreased by 0.47.Regression equation:1-year VRR=68.92+0.34×age-0.47×solid volume.Serum FT4 gradually decreased and the thyroid stimulating hormone(TSH)gradually increased within 6 months after ablation,and the differences were statistically significant(P<0.05).After 6 months,serum FT4 gradually recovered to the normal level and TSH gradually recovered.However,TSH still did not reach the preoperative level one year after ablation.FT3 decreased gradually after treatment,but there was no significant difference between the values at each time point(P=0.40).After the ablation of thyroid nodule,the mean value of thyroid function index fluctuated,but all of them were within the normal reference range.CONCLUSION Microwave ablation is a safe and effective treatment method for benign thyroid nodules,with an overall success rate of over 90%.Solid nodule volume and age are independent factors affecting the microwave ablation effect of benign thyroid nodules.

Objective To observe the effect of Zhongtong'an Capsules combined with rivaroxaban tablets on deep venous thrombosis (DVT) of lower extremities after total knee arthroplasty. Methods A total of 82 patients were randomly divided into control group and experimental group, with 41 cases in each group. The control group was treated with rivaroxaban tablets after surgery, while the experimental group was treated with oral administration of Zhongtong'an Capsules on the basis of the control group. The main outcome indicators (occurrence of DVT of lower extremities), secondary outcome indicators[circumference of lower extremities, blood flow velocity of femoral deep vein, whole blood high shear viscosity, whole blood low shear viscosity, hematocrit, plasma viscosity index, serum prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), and plasma D-dimer (D-D)], and therapeutic effects[the Visual Analogue Scale (VAS) score for pain, score of American Hospital for Special Surgery (HSS) forknee function]were compared between the two groups. Results After 14 days of treatment, the incidence of DVT of lower extremities in the experimental group was 9.76% (4/41), which was significantly lower than 31.71%(13/41) in the control group (χ²=6.011, P < 0.05). Compared with the control group, the experimental group had faster venous blood flow velocity and reduced circumference of lower extremities after 7 and 14 days of treatment (P < 0.05). After 7 and 14 days of treatment, all the hemorheological-related indicators in the experimental group were significantly lower than those in the control group (P < 0.05). After 7 and 14 days of treatment, the PT and APTT in the experimental group were significantly longer than those in the control group, while the FIB and D-D levels were significantly lower than those in the control group (P < 0.05). After 7 and 14 days of treatment, the VAS scores decreased and the HSS scores increased significantly in both groups, and the VAS scores in the experimental group were significantly lower than those in the control group, while the HSS scores were significantly higher than those in the control group (P < 0.05). Conclusion Zhongtong'an Capsules combined with rivaroxaban tablets can effectively improve the hypercoagulable state of patients after knee arthroplasty and reduce the formation of postoperative DVT.

Male ; Humans ; Immunohistochemistry ; Testicular Neoplasms/diagnosis* ; Tomography, X-Ray Computed

Objective To study the stability of plate-assisted intramedullary nailing for fixing proximal third tibiafractures, compare and observe biomechanical characteristics of anterolateral or posteromedial plate-assisted intramedullary nailing after fixation of proximal third tibia fractures. Methods Eight artificial tibia of 4th-generation sawbones were divided into two groups based on location of the assisted plate, namely, anterolateral plate group and posteromedial plate group, with 4 specimens in each group. Each two locking bolts were fixed to theintramedullary nail proximally and distally, and each three bicortical screws were fixed to the plate proximally and distally. The specimens were osteotomized with a 10-mm defect which located 0. 5 cm to the proximal locking bolt of intramedullary nail or 5-6 cm distally to the knee joint line, in order to simulate an AO/ OTA 41-A2 type proximal third tibia fracture after fixation of intramedullary nail. After osteotomy was finished, axial compression test, three point bending test, cyclic loading and overstress test were conducted by mechanical testing machine. The results of axial stiffness and three-point stiffness between two groups were compared and analyzed. Results Axial compression test showed that the average axial stiffness in posteromedial plate group was lower than that in anterolateral plate group, but no significantly statistical differences were found between the two groups. Three point bending test showed that the average bending stiffness in posteromedial plate group was significantly higher than that in anterolateral plate group when stimulating either varus stress (plate located at pressure side of the fracture, t = 3. 679, P<0. 05) or valgus stress (plate located at tension side of the fracture, t = 8. 975, P<0. 05). Conclusions Plate-assisted intramedullary nailing for fixation of proximal third tibia fractures can minimize the angulation malalignment, improve the stability of nailed proximal tibial fragment and allow the early weight bearing. Both anterolateral and posteromedial plate-assisted intramedullary nail can provide satisfactory axial stability for proximal third tibia fractures, while posteromedial plate-assisted intramedullary nail shows better bending stability than anterolateral plate in countering varus or valgus stress deformity. This study provides an essential basis for clinical decision making about plate-assisted intramedullary nailing for fixing proximal third tibia fractures.

Objective To analyze the plantar pressure distribution of knee osteoarthritis ( KOA) patients after medial opening wedge high tibial osteotomy ( MOWHTO), so as to provide biomechanical references for the surgical treatment and rehabilitation of patients. Methods A total of 31 patients with medial single compartmental KOA after unilateral MOWHTO treatment were selected as the experimental group, and 35 healthy subjects at same age were selected as the control group. The Pedomedic 40 􀅺 pressure measuring system was used to test dynamic plantar pressure. By comparing the maximum pressure ( pmax ), force-time integral ( FTI) and contact area (CA) of different plantar zones between the experimental group (operative side and unoperated side) and the control group during walking, the changes of plantar pressure in patients with medial single compartmental KOA after MOWHTO were evaluated. Results Compared with the unoperated side and the control group, the CA and FTI of the 1st metatarsal head (MH1) were higher (P<0. 05), the CA of the 4th metatarsal head (MH4)was smaller (P<0. 001), the pmax and FTI of the 5th metatarsal head (MH5) were smaller (P<0. 05), the CA of the lateral middle foot (MF-L) was smaller (P<0. 001), and the CA of the medial rear foot (RF-M) was larger (P<0. 05). Compared with the control group, the pmax of MH1 and MH2 was smaller (P<0. 05), the CA and FTI of MH5 were larger (P<0. 05), the pmax of MF-L was larger (P<0. 001), and the FTI of lateral rear foot (RF-L) was larger (P<0. 05). Conclusions Compared with healthy people, patients with medial single compartmental KOA have abnormal plantar pressure residual after MOWHTO. In clinical practice, targeted intensive rehabilitation therapy is necessary to restore the normal plantar distributions of patients.

Objective:To explore the risk factors for death within 1 year after hip fracture surgery in the elderly.Methods:A case control study was made on the clinical data of 551 elderly patients with hip fracture treated in Second Affiliated Hospital of Soochow University from January 2019 to December 2020, including 182 males and 369 females; aged 65-100 years [80(73,86)years]. Joint replacement, cannulated screw fixation or proximal femoral nail fixation were performed. The patients were divided into survival group ( n=494) and death group ( n=57) based on the death within 1 year after surgery recorded at postoperative telephone follow-up. The gender, age, hypertension, diabetes, cardiovascular diseases, chronic respiratory diseases, neurological diseases, chronic renal failure, anemia on admission, fracture types, American anesthesiologist Association (ASA) classification, operative methods, preoperative waiting time, duration of operation and perioperative blood transfusion were recorded in two groups. Univariate Cox regression was used to analyze the correlation between the above indexes and death within 1 year after surgery. All indexes with P<0.2 in the univariate analysis were included in multivariate Cox regression analysis to clarify the independent risk factors for death within 1 year after surgery. Results:Univariate Cox regression analysis showed that death within 1 year after surgery correlated with gender, age chronic respiratory diseases, chronic renal failure and anemia on admission (all P<0.01), but not with hypertension, diabetes, cardiovascular diseases, neurological diseases, fracture types, ASA classification, operative methods, preoperative waiting time, duration of operation or perioperative blood transfusion (all P>0.05). Multivariate Cox regression analysis showed that male ( HR=2.08, 95% CI 1.20, 3.61, P<0.01), age ≥ 80 years ( HR=2.22, 95% CI 1.15, 4.28, P<0.05), chronic respiratory diseases ( HR=2.54, 95% CI 1.19, 5.40, P<0.05), chronic renal failure ( HR=4.57, 95% CI 1.27, 16.44, P<0.05), anemia on admission ( HR=2.82, 95% CI 1.38, 5.76, P<0.01) were significantly associated with death within 1 year after surgery. Conclusion:Male age≥ 80 years, chronic respiratory disease, chronic renal failure and anemia on admission are independent risk factors for death within 1 year after hip fracture surgery in the elderly.

OBJECTIVE: To analyze the clinical effect of decompression and bone grafting on osteonecrosis of the femoral head(ONFH) at different sites of necrotic lesions. METHODS: A total of 105 patients with ARCOⅡstage ONFH admitted from January 2017 to December 2018 were retrospectively analyzed. There were 71 males and 34 females, with an average age of (55.20±10.98) years old. The mean course of all patients was(15.91±9.85) months. According to Japanese Inveatigation Committee (JIC) classification, all patients were divided into 4 types:17 cases of type A, 26 cases of type B, 33 cases of type C1 and 29 cases of type C2. All four groups were treated with decompression of the pulp core and bone grafting. Visual analogue scale(VAS) and Harris hip joint score were used before and at 3, 6, 12, and 24 months after the operation, and the collapse of the femoral head was observed by X-ray examination within 2 years. RESULTS: All 105 patients were successful on operation without complications, and the mean follow-up duration was (24.45±2.75) months. Harris score showed that there was no statistical difference among four groups before surgery and 3, 6 months after surgery (P>0.05);at 12 and 24 months after surgery, there were significant differences among all groups (P<0.01). There were significant differences in intragroup Harris scores at preoperative and postoperative time points among four groups (P<0.01). VAS showed that there was no statistical difference among four groups before and 3, 6 months after surgery (P>0.05);at 12 and 24 months after surgery, there were significant differences among all groups (P<0.01). There were significant differences in VAS at preoperative and postoperative time points among four groups (P<0.01). None of the patients in four groups had femoral head collapse before and 3, 6 months after surgery. At 12 months after operation, there were 3 cases of femoral head collapse in group C and 4 cases in group C2(P>0.05);At 24 months after operation, 1 case of femoral head collapse occurred in group B, 6 cases in group C1 and 8 cases in group C2(P<0.05). CONCLUSION Core decompression and bone grafting can improve the effect of ONFH and hip preservation. The effect of hip preservation for ONFH is closely related to the location of the osteonecrosis lesion, so the influence of the location of lesion on the effect of hip preservation should be considered in clinical treatment, so as to make better preoperative hip preservation plan.
Male ; Female ; Humans ; Adult ; Middle Aged ; Aged ; Retrospective Studies ; Femur Head Necrosis/diagnosis* ; Femur Head/surgery* ; Treatment Outcome ; Decompression, Surgical ; Bone Transplantation

OBJECTIVE: To compare clinical effect of robot-assisted core decompression and conventional core decompression in treating ARCO Ⅰ stage necrosis of femoral head. METHODS: A retrospective analysis was performed on 60(unilateral operation) patients who underwent core decompression for femoral head necrosis from February 2018 to February 2020. Among them, 30 patients(30 hips) were underwent robot-assisted core decompression (RCD group), including 19 males and 11 females, aged from 17 to 58 years old with an average of(38.50±10.61) years old;30 patients(30 hips) were underwent traditional core decompression surgery (CCD group), including 20 males and 10 females, aged from 20 to 55 years old with an average of (40.63±10.63) years old. Intraoperative fluoroscopy times, intraoperative blood loss and operation time between two groups, and Harris score, visual analogue scale (VAS) before opertaion and 24 months after operation were compared. RESULTS: All patients were followed up, RCD group followed up from 21 to 26 months with an average of(23.40±1.65) months, CCD group followed up from 21 to 26 months with an average of (23.30±1.66) months, and had no difference between two groups(P>0.05). The number of intraoperative X-ray fluoroscopy, intraoperative blood loss and operative time in RCD group were (9.43±1.14) times, (153.80±22.04) ml, (33.40±1.87) min, respectively;while(19.67±1.32) times, (165.04±20.41) ml and (54.75±3.46) min in CCD group respectively;and there were statistical difference between two groups(P<0.05). In addition, there were no statistical difference between two groups in Harris score and VAS at 24 months after operation(P>0.05). CONCLUSION Compared with conventional core decompression, robot-assisted core decompression could reduce the number of intraoperative fluoroscopy, shorten operation time, and reduce risk of surgery.
Male ; Female ; Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Case-Control Studies ; Retrospective Studies ; Femur Head Necrosis/surgery* ; Treatment Outcome ; Blood Loss, Surgical ; Robotics ; Bone Transplantation ; Decompression, Surgical ; Femur Head/surgery*