Humans ; Tranexamic Acid/therapeutic use* ; Arthroplasty, Replacement, Knee ; Antifibrinolytic Agents/therapeutic use* ; Blood Loss, Surgical ; Postoperative Hemorrhage

With enhanced recovery after surgery (ERAS), research and application of knee revision protheses and customized components or prostheses in the past decade, revision of total knee arthroplasty (TKA) is developing rapidly. However, periprosthetic joint infection (PJI) has always been a major clinical challenge. A comprehensive preoperative examination to find any potential infection sites should be conducted. The overall condition of the patients should be improved. Surgeons should evaluate the classification and degree of soft tissue and bone defects comprehensively and carefully select appropriate surgical approaches, bone reconstruction strategies, and revision prostheses to ultimately restore the alignment, stability, and the range of motion of the knee joint. In the future, efforts should be made to build a team of experts for the support of revisions of TKAs, including preoperative planning, 3D printing, surgical techniques, and ERAS. Nevertheless, primary TKAs protocols should always be firmly sticked to, which are a key to a low rate of revision surgeries. Prevention of PJIs and periprosthetic fractures, as well as establishing a high-quality follow-up system are of the same importance.

Objective:To analyze the clinical efficacy of internal fixation and prosthesis revision in the treatment of periprosthesis fracture after total knee arthroplasty.Methods:A total of 35 patients (35 knees) with periprosthetic fractures after total knee arthroplasty were retrospectively analyzed from January 2008 to January 2022 in the Department of Orthopaedics, West China Hospital, Sichuan University, including 13 males and 22 females, aged 71.4±4.1 years (range, 62-81 years). Left knee 19 cases, right knee 16 cases. There were 20 cases of Rorabeck type II and 15 cases of Rorabeck type III. The initial replacement was performed using a fixed platform post-stabilized knee prosthesis, which was fixed with bone cement. Patients with Rorabeck type II were treated with internal fixation alone (internal fixation group) and patients with Rorabeck type III underwent revision with replacement prosthesis (revision group). The Hospital for Special Surgery (HSS) score, range of motion (ROM) of knee joint, alignment of lower extremity and incidence of postoperative complications were compared between the two groups.Results:All patients successfully completed the operation and were followed up for 5.2±3.6 years (range, 1-12 years). Intraoperative blood loss was 680±102 ml (range, 420-1100 ml). The operative time in the internal fixation group was 105±17 min, which was less than 140±21 min in the revision group, and the difference was statistically significant ( t=-5.450, P<0.001). There was no complication of nerve or blood vessel injury during the operation. Five cases in the internal fixation group had unsatisfactory lower extremity force lines (>3° deviation from normal) after surgery, and all lower extremity force lines in the revision group were satisfied, and the difference in the satisfaction rate of lower extremity force lines between the two groups was not statistically significant ( P=0.057). The fracture healing time, knee ROM and HSS scores at the last follow-up were 5.1±1.3 months, 86°±5° and 84±5 in the internal fixation group and 4.8±1.5 months, 83°±6° and 82±4 in the revision group. One case in the revision group was diagnosed postoperatively with periprosthetic infection with pathogen culture suggestive of Candida albicans, recurrent anterior knee sinus tracts and patellar ectasia, which progressed to osteomyelitis, and mid-thigh amputation was performed 1 year after revision. Conclusion:The stability of prosthesis is an important reference for the treatment of periprosthetic fractures after total knee arthroplasty. Strong internal fixation in patients with unloosened prosthesis and revision with replacement of prosthesis in patients with loose prosthesis can achieve good knee joint function.

Humans ; Tranexamic Acid ; Atrial Fibrillation ; Antifibrinolytic Agents ; Arthroplasty ; Blood Loss, Surgical ; Arthroplasty, Replacement, Hip

Revision total hip arthroplasty is becoming more common due to an increasing number of primary total hip arthroplasty procedures being performed annually. Chronic pelvic discontinuity is an important and difficult complication after primary total hip arthroplasty. It is estimated that chronic pelvic discontinuity account for 1%-5% of all acetabular revisions. Pelvic discontinuity occurs mostly in female patients or patients with a history of prior pelvic radiation or rheumatoid arthritis. There are three following crucial factors in regards to achieving satisfied outcomes in treating pelvic discontinuity, the amount of bone stock remaining, biologic in-growth potential and the healing potential of the discontinuity. Treatment approaches include cage reconstruction with bulk acetabular allograft, custom triflange acetabular component, a cup-cage construct, jumbo acetabular cup with porous metal augments, and acetabular distraction with a porous tantalum shell with or without modular porous augments. The present course reported the classification, evaluation, reconstruction options and outcomes of chronic pelvic discontinuity.

Objective: To investigate the influence of displacement of femoral and tibial components on the biomechanics of femoral or tibial bone in coronal view. Methods: A series of CT and MRI of the left knee joint of a Han male volunteer was taken and a three-dimensional finite element model of the healthy knee joint was established. The femoral component and the tibial component were designed with varus 6°, varus 3°, 0°, valgus 3°, and valgus 6°, and were combined into 25 three-dimensional finite element model (FEM) of medial unicompartmental knee arthroplasty. A 1 000 N load was applied along the femoral mechanical axis. The von Mises cloud stress distribution was observed. Moreover, the lateral compartment load ratio, the high contact stress of cancellous bone and medial cortical bone below the tibial component, the upper surface of the polyethylene liner, and the femoral cartilage in the lateral compartment was measured. The statistically significant indicators compared with the neutral position (0° varus or valgus of the tibia and the femoral prosthesis, and 5° posterior slope of tibia prosthesis) were identified by scatter plots to find the dense and sparse areas of point items. The optimal position of the femoral component and the tibial component was determined by the number of items with statistical significance in the sparse area. Results: When the femoral component was placed at 0° position, there was no significant difference in the high contact stress of cancellous bone below the tibial component in the five groups. When the femoral component was placed at 0° position, the tibial component was 6° varus or 6° valgus and the stress was increased by 9.21±3.38 MPa and 9.08±4.13 MPa (P<0.05), respectively. With the changes of femoral and tibial components from 6° varus to 6° valgus, the high contact stress of the medial cortical bone below the tibia was gradually decreased (P<0.05). When the femoral component was placed at 0°, the tibial component changes from 6° varus to 6° valgus without significant difference in the high contact stress on the upper surface of each group of polyethylene gasket. Compared with the neutral position group, the high contact stress of the 6° varus or 6° valgus group were increased by 2.88±2.53 MPa and 3.47±2.86 MPa, respective ly (P<0.05). The lateral compartment load ratio and the high contact stress of lateral compartment femoral cartilage was gradually decreased (P<0.05), when the femoral and tibial components changed from 6° varus to 6° valgus. The number (2.8%, 1/36) of indicators in the sparse area (the combination of all combinations of femur or tibia from 3° varus to 3° valgus) was less than that (57.8%, 37/64) in the dense area (set of all combinations except sparse area), and the difference was significant (χ²=29.61, P<0.001). Conclusion It is suggested that the position of the femoral component and the tibial component in fixed medial unicompartmental arthroplasty should not exceed 3° varus or valgus in patients with standard lower limb alignment.

Periprosthetic femoral fracture (PFF) is one of severe complications after total hip arthroplasty (THA). As the number of patients receiving THA increased recently, the incidence of PFFs also increased dramatically. There are a number of risk factors for PFFs, such as age, sex, falling and prosthesis loosening. The Vancouver classification system is the most commonly used classification method for PFFs. According to the fracture location, PFFs can be divided into type A intertrochanteric fracture, type B fracture around the stem and type C fracture beyond the stem. The Vancouver type B PFF is further subdivided into type B1 with a well-fixed prosthesis, type B2 with a loose prosthesis but with adequate bone stock, and type B3 with a loose prosthesis and poor proximal bone stock simultaneously. Currently, there are some controversies in treating PFFs, mainly including whether the stem is fixed or not, whether the prosthesis needs to be revised, the selection of the stem, the reconstruction of bone defects, and the methods of fracture fixation. We searched literatures related to PFFs after THA. The incidence, risk factors, classification methods, treatment principles and strategies of PFFs were summarized in the present study. Based on our long-term clinical experience, we evaluated the advantages and disadvantages of each treatment method and provided considerations for the clinical research and selection in treating PFFs.

OBJECTIVETo observe the effect of electromyography (EMG) guided point injection at Renying (ST 9) for post-stroke dysphagia caused by bulbar paralysis, and explore effective treatments for improving swallowing function on the basis of conventional medicine and rehabilitation training.

METHODSA total of 60 patients were randomly divided into an observation group and a control group, 30 cases in each one. The conventional drugs combined with rehabilitation training were given in the control group, the treatment was given once every day. Based on the treatment in the control group, the EMG guided point injection at Renying (ST 9) was added in the observation group, three times a week. All the treatment was given for 2 weeks. drinking test score and Toshima Ichiro swallow test score were observed before and after treatment in the two groups, and the effects were assessed.

RESULTSToshima Ichiro swallow test score increased after treatment in both groups compared with that before treatment, and drinking test score decreased compared with that before treatment (all <0.05), and the change rate in the observation group was significantly better than that in the control group (both <0.05). The total effective rate of swallowing efficacy in the observation group was 93.3% (28/30), and the cured rate was 46.7% (14/30), which were better than 26.7% (8/30) and 3.3% (1/30) in the control group (both <0.05).

CONCLUSIONOn the basis of conventional drugs and rehabilitation training, the EMG guided point injection at Renying (ST 9) can effectively increase the swallowing function of patients with post-stroke dysphagia caused by bulbar paralysis .

Objective To explore the effects of multiple intravenous tranexamic acid (Ⅳ-TXA) administrations after total knee arthroplasty (TKA) on fibrinolytic activity and inflammatory response in an enhanced recovery after surgery (ERAS) program and to assess the efficacy and safety of Ⅳ-TXA.Methods One hundred and forty-one severe knee osteoarthritis patients following primary unilateral TKA from January 2016 to April 2017 were investigated retrospectively.The patients were divided into following three groups based on the dosage of Ⅳ-TXA after surgery:40 patients received ≤3 g Ⅳ-TXA after surgery (group T1),50 patients received 4 g (group T2) and the other 51 patients received ≥5 g Ⅳ-TXA (group T3).The total blood loss (TBL),hidden blood loss (HBL),transfusion rate,maximum hemoglobin (Hb) drop,the incidence of intramuscular venous thrombosis,deep vein thrombosis (DVT) and pulmonary embolism (PE),fibrinolysis parameters [fibrin(-ogeu) degradation products (FDP),D-dimer],and inflammation markers [C-reactive protein (CRP),interleukin-6 (IL-6)] during perioperative period were evaluated.In addition,correlation analyses between the dosage of Ⅳ-TXA and fibrinolysis parameters and inflammation markers were conducted.Results The mean TBL,HBL and maximum Hb drop in group T2 (537.16±270.43 ml,431.36±271.99 ml,19.68± 10.68 g/L) and T3 (541.31±290.00 ml,439.94±290.71 ml,20.24±8.48 g/L) were lower than those in group T1 (748.22±394.34 ml,P=0.012,0.013;636.47±388.14 ml,P=0.011,0.015;25.88± 11.77 g/L,P=0.005,0.010,respectively).No patient needed transfusion in all groups.There was no statistically difference in the incidence of intramuscular venous thrombosis of lower limbs among three groups (P＞ 0.05).No episode of DVT or PE occurred in any group in two weeks after surgery.There were negative correlation between the dosage of Ⅳ-TXA and FDP at postoperative day 1 and day 3 (r=-0.191,P=0.025;r=-0.291,P=0.001) and D-dimer on postoperative day 3 (r=-0.176,P=0.048).Moreover,the CRP (r=-0.184,P=0.036) and IL-6 (r=-0.269,P=0.002) level in serum on postoperatire day 1 also showed a negative relationship with the dosage of Ⅳ-TXA after surgery.Conclusion The multiple Ⅳ-TXA (≥4 g) after surgery can further reduce the TBL,HBL and maximum Hb drop following primary TKA in ERAS program without increasing the risk of thrombotic events.Most importantly,the effect of anti-fibrinolysis will be enhanced and may have an anti-inflammatory effect with the dosage of Ⅳ-TXA increased.

Objective To investigate biomechanical effects of different joint line height on unicompartmental knee arthroplasty (UKA) and to provide biomechanical evidence for surgical decision during UKA using finite element analysis (FEA).Methods On the basis of knee joint CT data from a healthy volunteer (male,30 years old,165 cm and 60 kg) and UKA prosthesis 3D scanned data,the 3D models of normal knee and UKA were constructed.Subject-specific finite element models with inhomogeneous material property assignment were constructed for normal knee and UKA with 3 different height of joint line (-3 mm,0 mm and +3 mm).Starting from the tibial articular surface,5 sections were extracted with 2 mm interval.30 nodes were selected in medial and lateral area,respectively on each section.The mean stress value of nodes was defined as the stress level of subchondral bone.Results Mean values of stress on polyethylene upper surface of 0,-3 and+3 mm joint line position were 14.84,26.81and 20.86 MPa,and the difference was statistical significant (t0vs-3=4.896,P0vs-3=0.000;t0vs+3=3.455,P0v+3=0.008;t-3vs+3=2.579,P-3vs+3=0.020).Mean values of stress on tibial prosthesis upper surface of 0,-3 and +3 mm joint line position were 29.69,50.49 and 39.99MPa,respectively,and the difference was statistical significant(t0vs-3=5.675,P0vs-3=0.000;t0vs+3=4.755,P0v+3=0.001;t-3vs+3=4.783,P-3vs+3=0.000).When joint line was in 0 mm height,stress level of subchondral bone was similar to that of normal knee.When joint line was in-3 mm height,significantly increased stress was found on polyethylene (increased 81％) and tibial component (increased 70％) surface compared with that of 0 mm height,while stress on trabecular bone under lateral tibial articular surface also increased by 8.7％.When joint line was in +3 mm height,increased stress on polyethylene (increased 41％) and tibial component (increased by 35％) surface were less than that of-3 mm height.Stress on trabecular bone under lateral articular surface decreased by 55.6％ compared with 0 mm height.Conclusion During UKA,ensuring a normal height of joint line is benefit to keep the stress path of the medial and lateral tibia similar with normal knee and decrease the risk of premature polyethylene wear,tibial component subsidence and periprosthetic fracture.