[目的]探讨前参考系统全膝关节置换术(total knee arthroplasty,TKA)前侧皮质切割发生的相关因素.[方法]回顾性分析2015年10月-2020年12月在本院因原发性膝关节骨关节炎行前参考系统TKA的86例患者(105膝)连续病例资料.根据术后膝关节侧位X线片是否有前皮质切割表现,将患者分为切割组和未切割组.采用单因素分析和多因素逻辑回归分析前皮质切割发生的相关因素.[结果]105膝中,术后影像显示共28膝发生前皮质切割,占26.7％;77例未发生前皮质切割,占73.3％.前侧皮质切割者按Tayside分级,Ⅰ级13膝(12.4％),Ⅱ级10膝(9.5％),Ⅲ级5膝(4.8％),无Ⅳ级发生.单项因素比较,两组年龄、BMI、性别、侧别、前髁厚度、LDFA、MAD、前皮质屈曲角、髁间窝形态、前髁骨赘量、开髓点位置、股骨远端截骨量、后髁截骨量、通髁线辨认情况的差异均无统计学意义(P＞0.05).但是切割组术前后髁厚度显著大于未切割组(P＜0.05);切割组股骨假体选择偏小的比率显著高于未切割组(P＜0.05).多因素逻辑回归分析显示,术前影像测量后髁厚度大(OR=1.124;P＜0.05)是前皮质切割的危险因素,术中股骨假体选择偏大(OR=0.375;P＜0.05)是前皮质切割保护因素.[结论]在前参考系统TKA中,较大术前测量后髁厚度是前皮质切割的危险因素,而术中偏大的股骨假体选择是前皮质切割保护因素.

Objective To find out the causes of anterior femoral notching in 3D printed patient-specific patient-specific instrumentation (PSI) assisted total knee arthroplasty (TKA). Methods A retrospective analysis was carried out on the consecutive cases undergoing PSI assisted TKA in the Peking University International Hospital from January 2019 to September 2021. The clinical data of those having anterior femoral notching were collected. 3D CT scanning was performed on the knee joint after intraoperative osteotomy and the intraoperative bone fragments. Rapidform software (Version 2006) was used to reconstruct 3D images and to perform image registration and comparison analysis with the preoperatively planned 3D models. The anterior femoral notching depth was measured, and the differences in the thickness of bone fragments between preoperatively planned and intraoperative bone cutting in order to analyze the causes of the anterior femoral notching. Results A total of 86 consecutive cases (94 knees) were included and 17 cases (18/94, 19.1%) of them had anterior femoral notching. The causes of anterior femoral notching were summarized into 3 categories: abnormal position of the PSI (10 cases, 83.3%), intraoperative reduction of the femoral prosthesis size (2 cases, 16.7%), and overextension of the femoral prosthesis (1 case, 8.3%). Conclusion Abnormal femoral PSI position, intraoperative reduction of femoral prosthesis size, and preoperative femoral prosthesis overextension design are the main causes of anterior femoral notching after PSI assisted knee arthroplasty.

Objective To explore the prediction accuracy of prosthesis size of the modified 3D printed patient-specific instrumentation (PSI)-assisted total knee arthroplasty (TKA) by comparing the difference between intraoperative prosthesis size and preoperative planned prosthesis size. Methods We optimized and improved the workflow, design scheme, shape of guide, operation technology and verification method of the traditional PSI-assisted TKA. A total of 126 patients (137 knees) who received 3D printed PSI-assisted TKA based on preoperative CT images in our center were recruited in this study. The differences between the actual prosthesis size and the preoperative planned size were compared and analyzed. Results All patients completed the surgery successfully, and no serious complications occurred. For the femoral side, the difference between the actual used size and the doctor's planned size was observed in 7 cases, and the difference between the actual used size and the engineer's planned size was in 25 cases (P < 0.01), and the engineer's planned size adjusted by doctors was 19 cases (P < 0.01). For the tibial side, the actual used size and the doctor's planned size was 39 cases, the difference between the actual used size and the engineer's planned size was 44 cases, and the engineer's planned size adjusted by doctors was 5 cases. Conclusion The planned prosthesis size in Our modified 3D printed PSI-assisted TKA is consistent with the intraoperative prosthesis size, and the plan will be more consistent after adjustment by the doctors. [Key words]Objective To explore the prediction accuracy of prosthesis size of the modified 3D printed patient-specific instrumentation (PSI)-assisted total knee arthroplasty (TKA) by comparing the difference between intraoperative prosthesis size and preoperative planned prosthesis size. Methods We optimized and improved the workflow, design scheme, shape of guide, operation technology and verification method of the traditional PSI-assisted TKA. A total of 126 patients (137 knees) who received 3D printed PSI-assisted TKA based on preoperative CT images in our center were recruited in this study. The differences between the actual prosthesis size and the preoperative planned size were compared and analyzed. Results All patients completed the surgery successfully, and no serious complications occurred. For the femoral side, the difference between the actual used size and the doctor's planned size was observed in 7 cases, and the difference between the actual used size and the engineer's planned size was in 25 cases (P < 0.01), and the engineer's planned size adjusted by doctors was 19 cases (P < 0.01). For the tibial side, the actual used size and the doctor's planned size was 39 cases, the difference between the actual used size and the engineer's planned size was 44 cases, and the engineer's planned size adjusted by doctors was 5 cases. Conclusion The planned prosthesis size in Our modified 3D printed PSI-assisted TKA is consistent with the intraoperative prosthesis size, and the plan will be more consistent after adjustment by the doctors.

Objective To compare the effect of 3D printed patient-specific instrumentation (PSI) and conventional instrumentation (CI) on the patellar height and joint line position in total knee arthroplasty (TKA). Methods A retrospective case-control study was carried out on 58 patients, who underwent primary TKA in our hospital from January 2021 to October 2021. According to the osteotomy tools selected in TKA, the patients were divided into CI-TKA group and PSI-TKA group. The Insall-Salvati index, modified Caton-Deschamps (mCD) index and relative height of joint line before and after TKA were recorded and compared between the 2 groups. Results In terms of the Insall-Salvati index, the absolute difference between preoperative and postoperative score was 0.11 (0.07, 0.15) in the CI-TKA group, and 0.06 (0.03, 0.12) in the PSI-TKA group, and statistical difference was seen in the postoperative index between the 2 groups (P < 0.05). Similarly, the absolute difference between preoperative and postoperative mCD index was 0.16±0.09 in the CI-TKA group and 0.08±0.05 in the PSI-TKA group, and obvious difference was also seen in the postoperative difference between them (P < 0.01). However, the absolute difference between preoperative and postoperative joint line height was 2.53 (1.64, 4.40) mm in the CI-TKA group and 2.27 (1.53, 5.32) mm in the PSI-TKA group. There was no notable difference in postoperative joint line position between the 2 groups, but the position after TKA were significantly higher in both groups than that before TKA (P < 0.05). Conclusion The use of 3D printed PSI can help reduce the impact of TKA on the patella height, but there is no obvious advantage in maintaining the joint line position compared with conventional instrumentation.

[目的]介绍三维术前规划在全髋关节置换术(total hip arthroplasty,THA)中的应用方法和临床效果.[方法]2019年5月—2020年6月采用三维术前规划辅助人工全髋关节置换术8例.术前行双髋关节三维CT薄层扫描,建立三维立体模型,三维图像上确定解剖标志点,分析原始解剖形态及病理改变,实施模拟手术操作和假体置入.根据术前规划实施真实THA.[结果]术后髋臼杯外展角(41.63±4.63)°、前倾角(19.13±5.57)°;术后股骨前倾角(14.38±6.35)°;肢体长度改变为(-0.40±1.06)mm.三维术前规划髋臼侧假体型号6例与术前规划相同,1例相差1号,1例相差2号;股骨侧假体型号3例同术前规划,3例相差1号,2例相差2号.[结论]三维术前规划可以较精准的预估假体型号、安放假体位置..

Objective To evaluate the mid-term clinical efficacy of total hip replacement using a standardized 3D printed porous trabecular titanium acetabular cup. Methods Clinical data of 23 consecutive patients undergoing total hip replacement with a standardized 3D printed porous trabecular titanium acetabular cup (25 arthroplasties) between February 2016 and August 2018 were collected and retrospectively analyzed in this study. All patients were followed up for 39~69 (51.7±10.7) months. Efficacy evaluation indicators included incidence of postoperative complications and survival rate of prosthesis, as well as visual analog scale (VAS) score, Harris score, acetabular side imaging evaluation and cup survival rate at 6 months after operation and last follow-up. Results No complications were observed in all 25 hip replacements, and the survival rate of cup was 100% during the whole follow-up. The VAS scores were decreased significantly at 6 months postoperatively (1.44±0.82) and last follow-up (0.08±0.27) when compared with the scores preoperatively (7.48±0.96, P < 0.05). The Harris scores were increased significantly at 6 months postoperatively (86.88±3.52) and last follow-up (95.04±1.86) than the pre-operative scores (45.64±4.55, P < 0.05). There were no significant differences in postoperative VAS score and Harris score between the patients with and without periprosthetic radiolucent zone. Conclusion Standardized 3D printed porous trabecular titanium acetabular cup shows its favorable mid-term outcome in total hip arthroplasty, provides high acetabular survival rate, and has certain advantages in reducing aseptic loosening of the prosthesis.

OBJECTIVES:To explore the anatomical parameters proximal femoral cavity and developmental dysplasia of the hip.METHODS:The retrospective study was conducted at Peking University Third Hospital, Beijing, China, and comprised data of adult patients of either gender who underwent total hip arthroplasty from January 2009 to August 2015. Paients with a diagnosis of primary osteoarthrosis or aseptic necrosis of the femoral head were taken as the control group A, while patients with developmental dysplasia of the hip in group B were graded into subgroups I-IV using the Crowe classification. For each patient, the inner diameter of the proximal femoral medullary cavity was measured on preoperative radiographs using Noble's technique. Data was analysed using SPSS 20.RESULTS:Of the 835 hips, 571(68.4%) were in group A and 264(31.6%) in group B. The mean age of the patients at the time of surgery was 58.3 ± 12.3 years. Overall, there were 404(48.4%) hips of male patients; 59(22.3%) in group B. There were 431(51.6%) hips of female patients; 205(77.7%) in group B. In group B, 186(70.5%) hips were graded I, 38(14.4%) grade II, 22(8.3%)grade III, and 18(6.8%) hips were graded IV. There were significant differences in femoral offset, height of the femoral head, and canal flare index of the metaphysis between groups A and B (p<0.05). There was no significant difference in the morphology of the marrow cavity between subgroups II and III. The femoral offset, height of the femoral head, canal flare index of the metaphysis and medullary cavity isthmus were significantly smaller in the subgrop IV than group B (p<0.05). There was significantly greater stenosis in the diaphysis in subgroup IV than in the remaining subgroups (p<0.05).CONCLUSIONS:The morphology of the marrow cavity was significantly different between patients with proximal femoral cavity and those with developmental dysplasia of the hip. Patients with developmental dysplasia grade IV had a narrower metaphyseal and diaphyseal cavity.

Objective:To investigate the accuracy of bony resection and component size planning of total knee arthroplasty (TKA) assisted with a novel designed patient-specific instrumentation (PSI).Methods:Thirty-eight TKAs assisted with a novel designed PSI of thirty-five patients from March 2018 to April 2019 were retrospectively analyzed. There were 11 males (10 knees) and 27 females (25 knees), aged 67.7±6.9 years (range 49-81 years). Intraoperative bone resection thicknesses at medial distal femur (MDF), lateral distal femur (LDF), medial posterior femur (MPF), lateral posterior femur (LPF), anterior femur (AF), medial tibial (MT), lateral tibial (LT) were measured with vernier caliper and compared with the preoperative planned bone resections as a primary outcome. The femur and tribal component sizes used intraoperatively were recorded and compared the preoperative planning.Results:The difference of thickness was -0.1±1.6 mm at MDF, -0.5±1.6 mm at LDF, 0.8±1.7 mm at MPF, 0.0±1.7 mm at LPF, 0.0±1.4 mm at AF, -0.3±1.4 mm at MT and 0.3±1.5 mm at LT. The ratio of differences <2 mm and <3mm were 87.8% and 93.94% at MDF, 87.8% and 93.94% at LDF, 71.3% and 85.71% at MPF, 77.14% and 91.43% at LPF, 88.46% and 100% at AF, 85.29% and 97.06% at MT, 83.78% and 94.59% at LT. 89.47% of femoral components were the same size with preoperative planning, 10.53% femoral components were within 0.5 size compared to the preoperative planning, no femoral components were over 0.5 size compared to the preoperative planning; 36.84% of tibial components were the same size with preoperative planning, 60.53% tibial components were within 0.5 size compared to the preoperative planning, 2.63% tibial components were within 1 size compared to the preoperative planning, notibial components were over 1 size compared to the preoperative planning.Conclusion:TKA assisted with a novel designed PSI shows good accuracy with bone resection and component size planning. The procedure of TKA could be simplified with this technique.

背景:在正常解剖结构破坏的情况下,利用健侧肢体解剖参数重建患侧是目前的常用方法.然而,这种方法依赖于双侧髋关节解剖参数一致,其是否可行尚缺乏可靠依据.目的:通过对比双侧髋关节解剖参数,研究双侧髋关节对称性及解剖形态变异范围,并测量双髋关节置换术后解剖参数一致性.方法:选取我院2012年1月至2017年12月诊断为骨关节炎、股骨头无菌性坏死行双侧初次全髋关节置换术患者119例(238髋),其中男64例,女55例,年龄55～75岁,平均(59.3±5.3)岁,同期手术61例,分期手术58例,病历资料完整.根据Noble测量方法测量术前股骨近端髓腔解剖参数;测量髋臼外展角及大粗隆高度.测量术后偏心距恢复及双下肢长度差异.结果:除股骨近端峡部宽度双侧对比存在差异外,其余股骨髓腔近端及髋臼外展角等解剖形态差异无统计学意义(P>0.05).Pearson相关性分析发现,随着体重的增加,双侧颈干角、髓腔闪烁指数(CFI)及大粗隆高度差值逐渐增加;股骨小粗隆中点(T)、T+20 mm及T-20 mm的髓腔宽度存在相关性.分期手术较同期手术更易出现双侧假体柄型号不一致,且双髋置换术后有近1/3的患者存在双下肢不等长.结论:应用健侧形态重建患肢结构是可行的.即使双侧形态一致,术后仍难以达到100％解剖对称.髋关节髓腔形态差异是由多个相邻层面相互协同影响.

Purpose: In total hip arthroplasty (THA), optimal stability and fixation is achieved via tight adaptation of the prosthesis to the bone. This study aimed to analyze the proximal femoral medullary cavity morphology of Chinese subjects on three-dimensional reconstructed imagery to explore the factors influencing these parameters.Methods: CT was performed on 63 healthy subjects from northern China (94 hips; 31 men, 63 women). Three-dimensional CT reconstruction of the proximal femoral medullary cavity was performed using Mimics 22.0 software. The anatomical parameters related to THA were measured to examine the relationships between sex, age, and femoral length. These parameters were compared with previously published data.Results: The internal and external coronal diameters of the femoral medullary cavity, and the anterior and posterior sagittal diameters had different contracting trends. There were correlations between the femoral length, femoral head diameter, and coronal diameter, and between the sagittal diameter and cross-sectional area of the medullary cavity. Age was negatively correlated with the CFI(canal flare index). Sex was correlated with the cross-sectional coronal/sagittal diameters, but not with the canal flare index. The proximal end of the medullary cavity was similar to that reported in Caucasians, but the Asian medullary cavity was narrower distal to the level of the lesser trochanteric line.Conclusions: THA-related anatomy was affected by sex, age, and subpopulation. Compared with sex, age had a greater effect on the fit of the stem to the femoral canal. Each patient must be treated individually, as the anatomical structure varied between individuals.

OBJECTIVETo analyze the association of preoperative C-reactive protein (CRP) level with postoperative complications in elderly patients undergoing surgeries for femoral neck fracture.METHODSWe retrospectively analyzed the data of 147 elderly patients (median age 80 years; 73.5% of the patients were female) undergoing surgeries for femoral neck fracture. According to preoperative CRP level, the patients were divided into normal CRP (< 10 mg/L) group (31 patients), mild elevation group (CRP level of 10-40 mg/L; 51 patients), and severe elevation group (CRP ≥40 mg/L; 65 patients). The association of preoperative CRP levels with postoperative complications was analyzed.RESULTSPreoperative CRP level was significantly correlated with the occurrence of postoperative complications (P=0.003). Compared with that in normal CRP group, the unadjusted ORs in mild and severe elevation groups were 0.97 (95%CI: 0.29-3.27) and 3.04 (95%CI: 1.03-8.98) with the adjusted ORs of 1.13 (95%CI: 0.33-3.90) and 4.89 (95%CI: 1.47-16.26), respectively.CONCLUSIONSPreoperative CRP level has a dose-response relationship with complications in elderly patients following arthroplasty for femoral neck fracture, and the patients with a preoperative CRP level ≥40 mg/L are exposed to a significantly increased risk for postoperative complications by 3.89 folds compared with the patients with a normal CRP level.

Tinnitus, characterized by an auditory perception in the absence of actual sound, is one of the most common encountered difficulties to manage otological problems, in which, lidocaine has been shown to provide temporary relief from subjective tinnitus. However, the pathophysiological mechanism of lidocaine treatment remains to be understood. The study demonstrates the first observation on that lidocaine well suppresses the decrease in the level magnesium (Mg2+) in inferior colliculus (IC) of guinea pigs following salicylate-induced tinnitus with an online electrochemical system (OECS) for continuously monitoring of microdialysate of Mg2+. The OECS was established by efficiently coupling a selective electrochemical detector with invivo microdialysis to monitor Mg2+ in the microdialysate continuously sampled from animal brain. The selective detection of Mg2+ over other coexisting neurochemicals was successfully achieved through a mechanism with divalent metal cations (e.g., Mg2+, Ca2+) enhanced catalytic current of organic dyes (i.e., polymerized film of toluidine blue O, p-TBO) toward the oxidation of nicotinamide adenine dinucleotide (NADH) and with ethyleneglcol-bis (2-aminoethylether) tetraacetic acid (EGTA) as selective masking agents for Ca2+. Tinnitus was induced by intraperitoneal injection of sodium salicylate (350mg/kg body weight). For the lidocaine group, using the microdialysis probe, 1% lidocaine was perfused into IC of guinea pigs at 2L/min for 20min. With the OECS, we found that the perfusion of lidocaine could recover the decrease of the Mg2+ level caused by salicylate-induced tinnitus. The basal level of microdialysate Mg2+ in IC of guinea pigs was previously determined to be 1.29 +/- 0.44mM, which was decreased significantly following salicylate-induced tinnitus. The lidocaine perfusion significantly recovers the Mg2+ level by 37.7 +/- 14.8%. This observation suggests that Mg2+ plays an important role in the pathological mechanism of tinnitus.

Objective To demonstrate the advantages of 3D printing as a teaching tool in total knee arthroplasty and the effectiveness of improving the understanding on anatomy and operative skills of young trainee surgeons.Methods 3D printing in TKA provides 3D printing models which could assisted preoperative training of design and provided surgical rehearsals,3D printing cutting block which could guided intra-operative osteotomy,and 3D printing software which could reviewed the patient-specific implants results.Results The 3D printing model can show the real anatomical structure to young trainee surgeons more intuitively,and the surgical rehearsal on the model provide the opportunities to operate real cases for the trainees.With the intra-operative usage of cutting block,young trainee surgeons are going to have exercise whilst ensuring there is no detriment to patient safety.At last,3D printing software will help young trainee surgeons understand the complex cases and the patient-specific implants,as well as used for distance education.Conclusions 3D printing has a valuable role as a training tool to improve young trainee surgeons skills for it have tremendous teaching advantages in total knee arthroplasty.

Background: The aim of this study was to assess the level of concern and expectations of patients and their families of total knee arthroplasty (TKA), peri-operative procedures, postoperative rehabilitation, and outcome in a Chinese population. Material/Methods: The study recruited 133 patients with osteoarthritis, scheduled to undergo primary elective TKA. Before surgery, the surgeon completed the Hospital for Special Surgery (HSS) Knee Score questionnaire on pain, function, range of motion (ROM), and muscle strength. There were 128 patients and 127 family members (spouses, sons, or daughters) who completed the 24-item Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questionnaire on pain, stiffness, and physical function, and also a 61-item questionnaire that included direct questions on their concerns and expectations on TKA and its outcome, using scores of: 1, not concerned; 2, somewhat concerned; 3, very concerned; and 4, extremely concerned. Results: The five greatest pre-operative concerns for patients included the degree of postoperative mobility; the experience and expertise of their surgeon; the risk of failure of TKA; the duration of the joint implant; and their expected degree of postoperative independence. Scores for Chinese patients indicated a higher level of concern compared with Western patients. Family members were significantly more concerned than patients regarding the postoperative restoration of knee function and alleviation of pain (p=0.001), the ability to squat (p=0.049) and to kneel (p=0.039). Conclusions: Communicating pre-operative information on TKA might result in realistic expectations for patients and their families, alleviate concerns, and improve relationships between doctors and patients.

Immune thrombocytopenia (ITP) is a common acquired autoimmune disease, and thrombopoietin (TPO) is an important cytokine that regulates the production of megakaryocytes and platelets. We have identified a biologically active component, icaritin, from a Chinese herba epimedii extract. Icaritin promotes platelet production and regulates T cell polarization, but its mechanism is not clear. In this study, the BALB/c mouse model of ITP was established by injection of an antiplatelet antibody every other day for seven total times. The antiplatelet sera were derived from guinea pigs immunized with the platelets of BALB/c mice. Mice with ITP were treated with icaritin at low, moderate, or high doses of 4.73, 9.45, and 18.90 mg/kg, respectively, for fourteen consecutive days. The present study shows that icaritin can significantly increase peripheral blood platelet counts and thrombocytocrit, increase the TPO level in serum, attenuate splenomegaly, and reduce the abnormal proliferation of megakaryocytes in the spleen and bone marrow. Icaritin can also downregulate the expression of bone marrow TPO, myeloproliferative leukemia virus oncogene (MPL), and p-Stat3. Our results suggest that icaritin can significantly improve the health of mice with ITP via possible downregulation of p-Stat3 expression in the JAK2/Stat3 phosphorylation signaling pathway and regulation of bone marrow TPO/MPL metabolism.

Vertigo is a common clinical symptom; however, the chemical and electrophysiological processes involved in the pathological mechanism of vertigo remain to be fully understood. In this study, we used an online electrochemical system (OECS) and electrophysiological system to record the dynamics of ascorbate and the change in the neural excitability in medial vestibular nucleus (MVN) and hippocampus of rats following vertigo induced by vestibular ice water stimulation. The OECS employed for recording the dynamics of ascorbate consists of invivo microdialysis and online selective electrochemical detection. We observed that the level of ascorbate in MVN increased to 155 +/- 14% of the basal level after ice water vestibular stimulation. Whereas, the level of ascorbate in hippocampus decreased to 55 +/- 12% of the basal level after ice water vestibular stimulation. To explore the neural excitability of MVN and hippocampus, we used an electrophysiological recording system and analyzed spontaneous firing rate (SFR) of the neuronal discharges in both nucleus. We found that, in MVN, the neural excitability began to increase during vestibular ice stimulation, remained to be elevated until 1 hour after stimulation. Whereas, in hippocampus, the neural excitability decreased soon after vestibular ice stimulation and recovered 1 hour after stimulation. Dynamics of ascorbate recorded with the OECS correlate with the change in the neural excitability, which may suggest the function of ascorbate as an antioxidant and possibly as a neuromodulator for glutamate-mediated neurotransmission. The involvement of MVN and hippocampus for the dynamics of ascorbate observed here may be related to the vestibular compensation of vertigo.

Arterial complications following total knee arthroplasty are rare but carry a high risk of significant morbidity and mortality. Herein, the authors report a case of pseudoaneurysm in a branch of a high-division anterior tibial artery caused by laceration by the retractor following primary total knee arthroplasty in a 72-year-old woman. The patient presented with an unexplained hematoma and an enlarging swelling, with pallor and acute hemorrhage on the first postoperative day. The diagnosis was confirmed by arteriography and the patient was successfully treated using endovascular embolization without long-term complications. Because of the high risk of progression to a potentially limb- or life-threatening condition, it is important to discuss the risk factors for this complication, as well as its early diagnosis and treatment methods.

Background: Many implant designs have been modified to a high-flex version for increasing range of motion (ROM) after total knee arthroplasty (TKA). However, its clinical benefits remain unconfirmed. Objective:To investigate the effect of"high-flex"versus"standard"polyethylene tibial inserts on long-term ROM and clinical outcomes after TKA. Meth-ods:A total of 150 patients who underwent TKA by one surgeon from February 2009 to October 2010 were enrolled into a pro-spective, blinded, randomized clinical trial. Of them, 75 patients received a high-flex insert and the other 75 received a stan-dard insert. There were no differences in the baseline information between two groups (P>0.05). All patients received the iden-tical operation, pain management and rehabilitation protocol. With minimum 5-year follow-up, the ROM, maximum flexion angle, and HSS, WOMAC, anterior knee pain VAS scores were recorded and compared between two groups. Results:Eventu-ally, 56 patients in high-flex group and 54 patients in standard group were followed for 63.1 and 62.7 months on average, re-spectively. There was no significant difference in any outcome measures (ROM, maximum flexion angle, HSS, WOMAC, an-terior knee pain VAS scores) before operation or at the last follow-up between the two groups (P>0.05). Conclusions:The high-flex insert can not increase long-term ROM or maximum flexion angle after TKA as compared with a standard insert.

Objective To study value of MRI 3D MERGE for quasi dynamic 3D knee trajectories simulations.Methods Twelve healthy volunteers (seven females,five males,mean age 29.9 ± 0.74years) were involved.3D MERGE sequence was used in five intervallic knee flexion angles-hyperextension on Sagittal GE 3.0T Discovery MR750 with an 8-channel US TORSOPA.After bone and cartilage segmentation,3D-reconstruction and 3D-registration,quasi-dynamic 3D knee trajectories were simulated with spline interpolation algorithm.Results All knee MRIs were acquired with this technique,12 quasi dynamic 3D knee trajectories were simulated.Conclusion 3D MERGE sequence can be used on MRI scan of knee flexion angles,which can meet demand for quasi dynamic 3D knee trajectories simulation.

[Objective] To explore the anatomic characteristics of proximal femoral cavity and its morphological parameters in the Chinese population,and provide anatomic basis for the design of prosthesis.[Method] A total of 502 patients diagnosed with osteoarthritis or aseptic necrosis of femoral head,and already treated by total hip arthroplasty (572 surgeries) in our hospital from January 2009 to August 2015,were selected in this research.Based on anterior-posterior X-ray photograph of affected extremity's hip joint,the proximal femur anatomic parameters were measured using the picture archiving and communication systems (PACS).The data were compared with western people's proximal femur anatomic parameters.Furthermore,the gender,age,height,weight,and drinking were screened for influence factors to the anatomic structure of femoral proximal medullary cavity by using multiple linear regression method.[Results] The anatomic parameters of proximal femoral cavity in this series showed significant differences with those measured by Noble for the American and European population.Age and chronic alcohol consumption had statistically significant influences on anatomic characteristics.[Conclusions] A database of proximal femur anatomic parameters for Chinese population is necessary and important.Meanwhile,the relevant influence factors such as race,age,chronic alcohol consumption should be considered for the design of prosthesis.