Abstract Objective Previous studies have shown that knee arthritis is a disease influenced by environmental and genetic factors. In this paper, we mainly investigate the association between SNPs in the DVWA gene region and the susceptibility to KOA in north Chinese Han people. Methods We performed two-center cross-sectional observational study that included 103 Chinese Han patients with KOA and 128 healthy Chinese Han volunteers. We investigated four SNPs (rs11718863, rs7639618, rs7651842 and rs7639807) in the DVWA gene region and extracted the genes using QIAamp DNA Mini Kit. We amplified the target gene fragment and sequenced the genotype.The corresponding frequency were counted and the counting results were statistically analyzed. Results The patient group was significantly older than the control group, and the difference was statistically significant(P < 0.001). There were no statistically significance between-group differences in gender, height, weight, or BMI (P > 0.05, respectively). The chi-square test was used to analyze the four SNPs of DVWA gene, and rs11718863 and rs7639618 polymorphism was statistically different between the two groups(P = 0.04, P = 0.04, respectively). The rs11718863 and rs7639618 was consistent with Hardy-Weinberg equilibrium. Logistic regression analysis showed that KOA risk was significantly increased in the rs11718863 TT genotype (3.31, 95%CI 1.32, 8.34, P = 0.011) and the rs7639618 TT genotype (OR 2.86 ,95% CI 1.16, 7.04, P = 0.023). After age adjustment, the same result was observed in the rs11718863 SNP(OR 2.79, 95% CI 1.04, 7.43, P = 0.041), and the risk of KOA disappeared in the rs7639618 SNP (OR 1.50, 95% CI 0.79, 2.86, P = 0.217). The rs7651842 and rs7639807SNP were monomorphic for the T and C allele respectively. Conclusions We found that the rs11718863 SNP was associated with KOA. The TT genotype and T allele were the highest risk factors for the development of KOA in the north Chinese Han population.

上个世纪七八十年代，人工全膝关节置换术(total knee arthroplasty，TKA)的发展经历了"辉煌10年"[1]。此后，各种新型设计假体、更精准的植入工具等不断涌现，这些革新致力于改善TKA的临床结果，提高患者术后的满意率。遗憾的是，除了加速康复外科(enhanced recovery after surgery，ERAS)以外，还没有一项里程碑式的革新能显著改善TKA术后效果。在手术技术方面，运动学对线(kinematic alignment，KA)技术因为获得了不劣于机械对线(mechanical alignment，MA)技术的临床结果和中期假体生存率[2,3,4]，使之受到广泛关注。

Objective:To explore and compare the early clinical results between kinematic alignment using special tools and mechanical alignment in total knee arthroplasty.Methods:A retrospective analysis was performed on patients who underwent unilateral total knee arthroplasty due to knee osteoarthritis with a follow-up time of more than three months and complete follow-up data.in Beijing Chaoyang Hospital, Capital Medical University from March 2019 to March 2021. The patients with inflammatory arthropathy such as rheumatoid arthritis, severe misalignment of patellofemoral joint, and previous knee collateral ligament or posterior cruciate ligament injury were excluded. According to alignment method, patients were divided into special tools kinematically aligned total knee arthroplasty (KA-TKA) group and mechanically aligned total knee arthroplasty (MA-TKA) group. The hip-knee-ankle (HKA) angle before and after the surgery, the knee joint clinical score (KS-C), the knee joint functional score (KS-F) before and three months after the surgery were recorded, as well as the postoperative forgotten joint score (FJS). Independent sample t test was used to compare the data.Results:A total of 162 patients were enrolled, including 82 in the KA-TKA group and 80 in the MA-TKA group. There was no statistically significant difference in the postoperative HKA angle between the two groups (P>0.05). Three months after the surgery, the KS-C score (t=2.259), KS-F score (t=1.994) and FJS score (t=2.945) in the KA-TKA group were higher than those in the MA-TKA group, the differences between the two groups were statistically significant (all P<0.05).Conclusion:KA-TKA has similar postoperative lower limb alignment, better clinical performance and higher knee function, and a higher FJS compared with MA-TKA.

Precise bone resection is mandatory for kinematically aligned total knee arthroplasty (KA-TKA). This study is to investigate whether surgeon-dominated design can alter the accuracy of patient-specific instrumentation (PSI) in KA-TKA compared with the engineer design. A total of 24 patients (24 knees) who underwent KA-TKA in our institution were assigned to an engineer design group (10 knees) and surgeon design group (14 knees) chronologically. A novel portable medical-engineer interactive application can greatly enhance the surgeon's participation in PSI design. The bone resection discrepancies were used to evaluate the accuracy of PSI in bone resection. The overall discrepancy of bone resection was reduced by surgeon-designed PSI compared to engineer-designed PSI by 0.33 mm. Surgeon-designed PSI seems to reduce the outliers in terms of relative discrepancies in bone resection as well, but it does not reach statistical significance. Moreover, surgeon-designed PSI could significantly improve the accuracy of PSI in the restoration of the joint line in terms of medial proximal tibial angle and mechanical lateral distal femoral angle. This study indicates that the dominance of surgeons in both PSI design and subsequent surgical operation should be emphasized in efforts to improve the accuracy of PSI.

This study aimed to investigate the influence of tibial malrotation on knee kinematics after total knee arthroplasty (TKA). A symmetric fixed-bearing posterior-stabilized prosthesis was implanted in the validated knee model with different rotational alignments of the tibial component (neutral, 3° external rotation, 5° external rotation, 3° internal rotation, and 5° internal rotation). Computational kinematic simulations were used to evaluate the postoperative kinematics of the knee joint including anteroposterior translation femoral condyles and axial rotation of tibial component during 0°–135° knee flexion. The results revealed that the neutral position of the tibial component was not the closest kinematics to the intact knee, the model with 5° external rotation of the tibial component showed the closest lateral condyle translation and tibial axial rotation, and moderate external rotation could improve the kinematics after TKA.

目的 评价后交叉韧带保留型膝关节置换术(CR TKA)术中完整保留后交叉韧带(PCL)的临床疗效.方法 回顾性分析北京朝阳医院骨科2016年6月至2018年12月收治的386例符合纳入标准并行单侧C R T K A患者的临床资料,其中男124例,女262例.患者在术前均行影像学检查并排除关节外畸形.术中进行等量截骨及常规软组织松解技术,PCL的两个束支完整保留.选择术前,术后3个月、6个月以及12个月对患者进行临床评价,观察指标包括膝关节活动度、膝关节临床评分系统(包括临床评分以及功能评分)以及屈膝90°位时膝关节前后向最大位移距离,并记录患者术后并发症情况及影像学检查结果.采用单因素方差分析对手术前后指标进行统计学分析.结果 由于各种原因共失访患者98例,最终纳入研究合计288例,年龄53～86岁,平均(64.8±8.7)岁,随访时间持续14～31个月,平均(21.2±4.3)个月.患者术后3个月、6个月以及12个月的膝关节活动度、膝关节临床评分系统较术前均有较大提高,差异有统计学意义(P<0.01);而术后6个月与12个月观察点屈膝90°位时膝关节前后向最大位移距离变化不大,差异无统计学意义(P>0.05).4例患者术后切口持续渗出、1例患者出现切口裂开,均早期清创处理后治愈,未发现切口皮肤坏死、下肢深静脉血栓形成、术后感染等并发症,影像学检查未见假体松动、垫片过度磨损、脱位病例.结论 CR TKA术中完整保留PCL不会影像假体的放置及关节活动,反而会增加膝关节的稳定性,早期恢复关节功能.

Background A mismatch between the femoral component and trochlear resection surface is observed in kinematically aligned total knee arthroplasty (KA-TKA) when conventional prostheses are employed. This mismatch is mainly manifested in the undercoverage of the lateral trochlear resection surface. The aim of the present study was to assess the relationship between the mismatch and the alignment parameters of the tibiofemoral joint. Methods Forty-five patients (52 knees) who underwent KA-TKA in our hospital were included. Patient-specific instrumentation was used in 16 patients (16 knees), and conventional instruments with calipers and other special tools were employed in the other 29 patients (36 knees). The widths of the exposed resection bone surface at the middle (MIDexposure) and distal (DISexposure) levels on the lateral trochlea were measured as dependent variables, whereas the hip-knee-ankle angle (HKAA), mechanical lateral distal femoral angle (mLDFA), joint line convergence angle (JLCA), medial proximal tibial angle (MPTA) and transepicondylar axis angle (TEAA) were measured as independent variables. Correlation analysis and subsequent linear regression were conducted among the dependent variables and various alignment parameters of the tibiofemoral joint. Results The incidence of undercoverage of the lateral trochlear resection surface was 86.5 % with MIDexposure and DISexposure values of 2.3 (0–6 mm) and 2.0 (0–5 mm), respectively. The widths of the two levels of exposed bone resection were significantly correlated with mLDFA and HKAA but were not related to TEAA. Conclusions The undercoverage of the trochlear resection surface in KA-TKA is mainly correlated with the degree of valgus of the distal femoral joint line. The current study suggests that this correlation should be considered in the development of KA-specific prostheses.

Kinematically aligned total knee replacements have been shown to better restore physiological kinematics than mechanical alignment and also offer good postoperative satisfaction. The purpose of this study is to evaluate the extent to which an inclined joint line in a kinematically aligned knee can alter the postoperative kinematics. A multi-body dynamic simulation was used to identify kinematic changes in the joint. To accurately compare mechanical alignment, kinematic alignment and a natural knee, a “standard” patient with neutral alignment of the lower extremities was selected for modeling from a joint database. The arthroplasty models in this study were implanted with a single conventional cruciate-retaining prosthesis. Each model was subjected to a flexion movement and the anteroposterior translation of the femoral condyles was collected for kinematic analysis. The results showed that the mechanical alignment model underwent typical paradoxical anterior translation of the femoral condyles. Incorporating an inclined joint line in the model did not prevent the paradoxical anterior translation, but a 3° varus joint line in the kinematic alignment model could reduce the peak value of this motion by about 1 mm. Moreover, the inclined joint line did not restore the motion curve back to within the range of the kinematic curve of the natural knee. The results of this study suggest that an inclined joint line, as in the kinematic alignment model, can slightly suppress paradoxical anterior translation of the femoral condyles, but cannot restore kinematic motions similar to the physiological knee. This finding implies that prostheses intended to be used for kinematic alignment should be designed to optimize knee kinematics with the intention of restoring a physiological motion curve.

Objective:This study aimed to explore the correlation between the insufficient coverage of lateral trochlear bone resection and the various alignment parameters of the lower extremities in kinematically aligned total knee arthroplasty(KA-TKA).Methods:Forty-eight patients (54 knees) who underwent KA-TKA surgery at Beijing Chaoyang Hospital from May 2018 to July 2020 were retrospectively investigated. The patients comprised 12 males and 36 females who were aged 69±6.7 years (range: 57-85 years). Twenty-three patients (23 knees) underwent surgery using patient-specific instruments, and conventional instruments with caliper and other special tools were used in 25 patients (31 knees). The hip-knee-ankle (HKA) angle, the mechanical distal femoral lateral angle (mLDFA), the joint line convergence angle (JLCA), the medial proximal tibial angle (MPTA), and the transepicondylar axis angle (TEAA) were obtained through full-length weight-bearing X-ray, CT, or intraoperative measurement and used as independent variables. The exposed resection bone surface data at the middle (MIDcover) and inferior (INFcover) levels of the patients' lateral femoral trochlear were recorded through CT or intraoperative caliper measurements and used as dependent variables. Spearman correlation and linear regression analyses were conducted.Results:Among the 54 knees, 37 (87%) had varying degrees of lateral trochlear resection coverage insufficiency, with MIDcover and INFcover being 2.8 mm (2.6 mm) and 2.3 mm (2.5 mm) [ M( QR)], respectively. MIDcover and INFcover had a significant negative correlation with mLDFA, and the correlation coefficients were -0.839 and -0.691 (all P values<0.05), respectively; they were also significantly negatively correlated with HKA, and the correlation coefficients were -0.574 and -0.585 (all P values<0.05), respectively. The insufficient coverages were not significantly correlated to TEAA and MPTA. Linear regression analysis showed that MPTA had a great impact on MIDcover and INFcover, with regression coefficients of -0.703 ( R2=0.708) and -0.473 ( R2=0.489), respectively. Conclusions:When performing KA-TKA using conventional prostheses, insufficient coverage of the lateral trochlear resection surface is common. The greater the valgus of the distal femoral joint line is, the more insufficient the coverage of the lateral trochlear bone resection is.

背景:假体周围感染(PJI)是人工髋膝关节置换术(THA/TKA)后一种少见但是灾难性的并发症,在中国大陆,关于HI翻修负担的流行病学数据缺乏.目的:本研究旨在回顾性分析北京地区9家医院3年间的感染翻修病例资料并计算翻修负担.方法:回顾性收集2014年1月至2016年12月北京市9家三甲医院关节置换总数及PJI患者的病例资料,分析患者一般资料、感染类型、主要诊断、术前合并疾病、手术方式,计算PJI翻修负担,并描述PJI处理方式及并发症发生情况.结果:此期间共实施髋膝关节置换术38319例次,髋膝关节翻修手术1222例次(总翻修负担3.1％),因PJI翻修366例次(翻修负担0.96％),且总体翻修负担呈逐年下降趋势(1.09％,0.96％,0.84％).9家医院PJI翻修负担分别为0.78％、0.77％、0.52％、0.77％、0.55％、0.63％、1.24％、0.78％、1.71％.髋关节总体翻修负担为5.60％,其中PJI翻修负担为1.14％,PJI是髋关节翻修的第三大原因;膝关节总体翻修负担为1.77％,其中膝关节PJI翻修负担为0.85％,PJI是膝关节翻修的最常见原因;髋/膝关节PJI患者的手术治疗方式中,二期翻修术分别占75.2％(髋,121/161)和69.8％(膝,143/205),一期翻修术占19.9％(髋,32/161)和6.3％(膝,13/205)、开放清创术占4.3％(髋,7/161)和22.0％(膝,45/205).结论:2014～ 2016年北京市9家医院总体髋膝关节翻修负担为3.1％,髋膝关节PJI翻修负担为0.96％;二期翻修术是主要的外科治疗手段.由于随访时间短和病例流失等因素,真正PJI翻修负担可能更高.

Objective: To examine the clinical effects of the treatment of knee osteoarthritis patients with kinematic alignment technique of total knee replacement (KA-TKA) assisted by patient-specific instrumentation (PSI). Methods: The clinical data of 14 patients with knee osteoarthritis treated with unilateral KA-TKA assisted by PSI at Department of Orthopaedic Surgery, Beijing Chaoyang Hospital Affiliated to Capital Medical University from May 2018 to August 2019 were analyzed retrospectively. There were 6 males and 8 females, aged 66.6 years (range: 56 to 79 years), 9 left knees and 5 right knees. The operation time, soft tissue release and extra varus or valgus osteotomy were recorded. The data of osteotomy blocks were measured and compared with the corresponding position of the prostheses. The hip knee ankle angle (HKA), the mechanical distal femoral lateral angle (mLDFA) and the proximal tibial medial angle (MPTA) were measured before and 3 months after the operation. The knee joint functional score (KS-F) , knee joint clinical score (KS-C) and the Western Ontario McMaster (WOMAC) Osteoarthritis Index were recorded and compared by paired t test or Wilcoxon non-parametric test. Results: The operation time was (81.8±16.9) minutes (range: 60 to 115 minutes), 2 cases were manually increased varus osteotomy by 2 mm and 1 patient received lateral retinaculum release. There was no extra medial or lateral soft tissue release. Intraoperative measurement of the resection showed that the femoral side mismatch was within 2 mm. The medial and lateral condyle, the medial and lateral posterior condyles were relatively overcut by 0.50 mm, 0.21 mm, 0.93 mm, and 0.71 mm, respectively. The tibial side mismatch was within 1.5 mm, the medial and lateral plateau were relatively undercut by 0.43 mm and 0.32 mm. HKA was corrected from (8.8±5.6) ° to (1.6±4.3) ° (t=20.723, P=0.000) .KS-C improved from 28.21±13.47 preoperative to 78.07±8.01 postoperative (t=-16.570, P=0.000); KS-F improved from 41.00±15.25 preoperative to 84.93±10.85 postoperative (t=-14.675, P=0.000).WOMAC Osteoarthritis Index decreased from 53.5 (25.75) (M(Q(R))) preoperative to 5.5 (5.25) postoperative (Z=-3.297, P=0.001) .No statistically significant difference was found in mLDFA and MPTA before and after surgery. No significant patellofemoral complication was recorded during follow-up time. Conclusions: PSI assisted TKA resection has high accuracy. KA-TKA aims to restore the native anatomy of the knee joint, only corrects the malalignment of lower extremities caused by articular cartilage wear, with less interference to soft tissues, easy to obtain satisfactory knee joint laxity and has a promising early clinical effect.

Objective:This work aims to explore the relationship between leg length discrepancy (LLD) and the onset and imaging features of primary knee osteoarthritis (KOA) to provide a theoretical basis for the prevention and treatment of this disease.Methods:Clinical and imaging data of 141 patients with primary KOA who underwent total knee arthroplasty (TKA) were analyzed retrospectively from June 2017 to August 2019 in Beijing Bo'ai Hospital. Among these patients, 19 were males and 122 were females with an average age of(67.8±9.4)years and body mass index (BMI) of (26.8±2.9) kg/m 2. Prior to the operation, the whole legs were examined by CT, and bilateral leg length, anatomical femoral-tibial angle (AFTA), and pelvic tilt angle (PTA) were measured by Webviewer software. The K-L grade of KOA severity was evaluated using weight-bearing X-ray. The patients were categorized into LLD (LLD>5 mm) and control groups (LLD<5 mm) according to the magnitude of LLD. The LLD group was further divided into long and short leg sides according to lower limb length. The incidence of LLD in patients with KOA was evaluated, and the differences in sex, age, BMI, and PTA were compared between the two groups. In the LLD group, the association of LLD with age, BMI, and PTA was evaluated by Spearman correlation analysis, and the differences of AFTA, K-L grade, and TKA operation location (long or short leg side) were compared. Results:Among the 141 patients with KOA, 68 patients presented as LLD with incidence rate of 48.2%. The PTA (3.93°±3.13°) of LLD group was higher than that of control group (2.31°±2.06°), and the difference was statistically significant ( t=3.654, P<0.05). In the LLD group, the AFTA of the short leg side (4.74°±7.02°) was larger than that of the long leg side (2.0°±5.69°), and the difference was statistically significant (χ 2=2.554, P<0.05). The operation rate of TKA in the short leg side was 89.7% (61/68), which was significantly higher than that in the long leg side at 57.4% (39/68), and the difference was statistically significant (χ 2=16.753, P<0.05). No statistically significant difference in K-L grade was observed between the short and long leg sides ( P>0.05). In the LLD group, Spearman correlation analysis showed that LLD was positively correlated with PTA, and the difference was statistically significant ( r s=0.547, P<0.01). No correlation was observed among LLD, BMI, and age ( r s=0.082, 0.075, all P values>0.05). Conclusions:LLD has high incidence in patients with primary KOA and usually occurs on the short leg side and may lead to pelvic tilt. When the magnitude of LLD is high, the deformity becomes severe. Early active intervention may be important in the prevention of KOA.

目的 回顾性研究初次全膝关节置换(total knee arthroplasty,TKA)术中内侧副韧带(medial collateral ligament,MCL)损伤患者的处理方法以及随访结果.方法 选取2013年1月至2016年1月,在首都医科大学附属北京朝阳医院行初次全膝关节置换患者共612例(798膝),术中出现MCL损伤的患者共10例(10膝).其中体部损伤患者7例,除1例采取同种异体肌腱加强固定以外,其余患者均采用了断端直接缝合的方法;股骨侧止点撕脱2例,采用双排锚钉桥样缝合进行止点重建;胫骨侧止点撕脱1例,采用单排带线锚钉重建止点的方法.所有MCL损伤的患者均未使用限制性假体,术后康复过程中佩戴下肢膝关节保护支具,出院后定期门诊随访,检查患者侧方应力情况,并记录手术前及最后一次随访时的美国膝关节协会评分(Knee Society Score,KSS)以及膝关节的活动度.结果 患者术中出现MCL损伤的总发生率为1.2％(10/798,95％CI:0.5％ ～2.0％),10例MCL损伤的患者中无失访病例,随访时间25～62个月(中位随访时间46.5个月);门诊检查伸直位外翻应力均未见松弛,屈膝30°位有3例患者出现轻度松弛(+);患者KSS由术前的74.5分(52～96分)改善为术后的149.8分(124～172分);患者的膝关节活动度由术前的平均78.5°(65°～95°)改善为术后的105.5°(95°～120°),差异均有统计学意义(P<0.05);至最后一次随访无患者因为内侧松弛而进行膝关节翻修手术.结论 对TKA术中出现MCL的损伤应该积极地进行修复,采用牢靠的固定方法可以避免术中更换限制性假体,降低术后因为内侧松弛而进行膝关节翻修的发生率.

Background: Discrepancies in bone resection between the medial and lateral compartments is very common in total knee replacement (TKA) when mechanical alignment (MA) is used. The purpose of this study was to explore whether and how joint line orientation affects the gross amount of bone resected in mechanically aligned TKA. Methods: A total of 112 patients (137 knees) diagnosed with osteoarthritis (OA) were included. Bone resection simulations were conducted in the coronal view using full-length weight-bearing radiographs per the technical parameters of MA, and the feasibility of simulated osteotomy was verified via intraoperative caliper measurement. Correlation and regression analyses were conducted comparing the amount of bone resected and various parameters, including hip-knee-ankle (HKA) angle, mechanical lateral distal femoral angle (mLDFA), joint line congruency angle (JLCA), and medial proximal tibial angle (MPTA). Moreover, any intraoperative bone resection adjustments that were made were retrospectively collected using a medical record query system. Results: All knees in the current case series could be artificially divided into 4 subgroups: 84 varus knees (61.3%) with valgus femurs in subgroup 1, 32 varus knees (23.4%) with varus femurs in subgroup 2, 14 valgus knees (10.2%) with varus tibias in subgroup 3, and 7 valgus knees (5.1%) with valgus tibias in subgroup 4. Simulated bone resection thickness was highly consistent with intraoperative measurements. MPTA and mLDFA were positively correlated with the amount of bone resected in subgroup 1. The regression equation was: Maximum resection thickness (mm) = 0.556*mLDFA (deg.) + 0.098*MPTA (deg.) -39.74; R 2 =0.808. Similarly, intraoperative bone resection adjustments also showed a correlation with mLDFA in subgroup 1. Conclusions: Deformities in knee OA can be divided into 4 subgroups based on the alignment of extremities and the joint line orientation. When TKA is performed in varus knees with valgus femurs using conventional instruments and mechanical alignment techniques, the amount of bone resected in the coronal plane demonstrates a linear relationship with the patient’s mLDFA.

OBJECTIVETo identify differentially expressed serum proteins that could serve as sensitive biomarkers of heterotopic ossification in patients with traumatic brain injury.METHODSFrom August 2014 to December 2015, 18 patients with traumatic brain injury were enrolled in the study, and blood samples were collected. Patients with traumatic brain injury were divided based on the presence (n=9 patients, heterotopic ossification group) or absence (n=9 patients, traumatic brain injury group or control group) of heterotopic ossification. Protein expression profiles were compared using 2-dimensional electrophoresis. Differentially expressed proteins were examined using matrix-assisted laser desorption/ionization and time-of-flight tandem mass spectrometry (MALDI-TOF/TOF). The differentially expressed proteins identified were further confirmed by Western blotting.RESULTSSeven protein spots were differentially expressed between heterotopic ossification and traumatic brain injury groups in 2-dimensional electrophoresis analysis. Vitamin D binding protein (Gc protein), retinol binding protein 4 (RBP4) and haptoglobin expression decreased significantly in the heterotopic ossification group compared with the control group (p < 0.05), and this was further confirmed by Western blotting.CONCLUSIONLower levels of expression of Gc protein, RBP4 and haptoglobin may be closely related to heterotopic ossification after traumatic brain injury. These proteins may be potential biomarkers of heterotopic ossification secondary to traumatic brain injury.

BACKGROUND:Periprosthetic joint infection (PJI) is a rare but devastating complication after total joint arthroplasty. There is a paucity of data on the incidence and prevalence of periprosthetic infection in mainland China. This study aimed to analyze the rates of surgical revision after arthroplasty due to PJI and the procedures followed in Beijing, China.METHODS:The study involved a retrospective multicenter cross-sectional survey of patients undergoing revisions for periprosthetic infection after hip/knee arthroplasty at nine hospitals in Beijing from 2014 to 2016. Age, gender, body mass index, primary diagnosis, comorbidity, primary surgery, treatment methods, and post-revision complications were analyzed.RESULTS:A total of 38,319 hip/knee arthroplasties and 366 (0.96%) revisions for PJI were identified. Of these, 161 (161/14,110; 1.14%) revisions involved hip arthroplasty, whereas 205 (205/24,209; 0.85%) revisions were due to knee arthroplasty. Procedures for revisions of infected hip included 7 (4.3%) cases of open debridement and prosthesis retention, 32 (19.9%) cases of one-stage exchange, 121 (75.2%) cases of two-stage exchange, and 1 (0.007%) case of hip dissection. As for the infected knee, the procedures included 45 (22.0%) cases of open debridement and prosthesis retention, 13 (6.3%) cases of one-stage exchange, 143 (69.8%) cases of two-stage exchange, and 4 (0.02%) cases of knee fusion.CONCLUSIONS:The study found the rates of revision due to PJI to be low. Nonetheless, the incidence of PJI in mainland China could be higher and calls for more elaborate studies in geographically and socioeconomically diverse health institutions.

Objective: To investigate the microbiological test, antibiotic sensitivity and surgical treatment of periprosthetic joint infection(PJI) cases in post total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients. Methods: A retrospective cross-sectional survey was conducted on 318 patients who underwent THA or TKA in 9 clinical centers in Beijing from January 2014 to December 2016.The data of microbiology, antibiotic sensitivity and surgical treatment were collected.The average age of patients was (62.3±13.1) years old (range: 21-86 years old), including 145 males and 173 females.The body mass index was (25.6±3.8) kg/m (2) (range: 15.6-38.1 kg/m(2)). Results: In total, 318 patients had microorganisms detected by periprosthetic tissue culture or synovial fluid culture, 209 cases (65.7%) had Gram-positive bacteria, 29 cases (9.1%) had Gram-negative bacteria, 10 cases (3.1%) had fungi, 3 cases (0.9%) had non-tuberculous mycobacteria, 72 cases (22.6%) were negative, 69 cases (21.7%) had methicillin-resistant bacteria. The antibiotic sensitivity results showed that the overall resistance rate of penicillin, cefuroxime, amoxicillin+clavulanic acid was 79.9%, 69.9%, and 68.1%, respectively; meropenem, vancomycin, and linezolid resistance rate was 0. For the treatment methods of hip and knee PJI, two-stage revision surgery acounted for 72.9% (108/148) and 64.1% (109/170), respectively. One-stage revision surgery accounted for 21.6% (32/148) and 7.6% (13/170), and open debridement surgery accounted for 4.7%(7/148) and 26.4% (45/170). Conclusions: Gram-positive bacteria was still the main pathogen of PJI.The methicillin-resistant bacteria and rare bacteria should be payed attention to. The Majority of hip and knee PJI cases were treated by two-stage revision surgery.

Rotational malalignment between the femoral and tibial components in total knee arthroplasty (TKA) can affect clinical outcomes, but there is no consensus on how to best determine tibia tray orientation. The posterolateral corner-locked (PLCL) technique may be a new method. This study aims to assess the applicability of this technique in a Chinese population. Forty normal Chinese volunteers were recruited and underwent computed tomography (CT) of the lower limbs. Knee model reconstructions and simulated standard tibial osteotomy were conducted digitally. The transepicondylar axis (TEA), the Akagi line, and the line connecting the medial third of the tibial tubercle with the midpoint of the posterior cruciate ligament (PCL) were projected to the tibial cross-section and marked. The PLCL technique was applied using either symmetrical or asymmetrical tibial tray templates, and the anteroposterior (AP) axis of the tibial tray was marked. The angles between the TEA and these lines were calculated, and the statistical differences were analyzed. The angle between the TEA and the Akagi line and between the TEA and the line connecting the medial third of the tibial tubercle with the midpoint of the PCL were 96.90 +/- 5.57 and 107.31 +/- 5.95 degrees, respectively. The angles between the TEA and the AP axis of the symmetrical and the asymmetrical design tibial trays were 94.01 +/- 4.21 and 96.65 +/- 4.70 degrees, respectively. Except for the Akagi line and AP axis of the asymmetrical tibial tray, statistical differences were found between all lines ( p < 0.05). The PLCL technique is principally suitable for Chinese patients requiring TKA when using the tibial component referred to in this study, although it may result in slight external rotation.

Objective: To observe the clinical effects of continuous femoral nerve block combined with flur-biprofen axetil injection in postoperative analgesia of total knee arthroplasty.Methods:From March 2014 to March 2016, 126 patients who undertook the single side primary total knee arthroplasty in the Department of Orthopedics, Beijing Chao-yang Hospital were selected, and randomly divided into three groups according to different pain relief protocols: Intravenous group A (42 Knees), Block group B (42 Knees) and combined group C (42 Knees). Patients in the Intravenous group were injected the pain solutions of Sulfentanyl, flurbiprofen ax-etil, ondansetron hydrochloride and saline via PCA. Patients in the block group accepted the continuous femoral nerve block with 0.2％ ropivacaine. Patients in combined group were administrated with femoral nerve block and flurbiprofen axetil injection together. The intensity of pain was assessed by visual analog scale (VAS) at thetime of 6, 12, 24, 48 and 72 h after operation at the resting and active states. The knee range of motion (ROM) at the time of 48h and 72 h after operation was evaluated. Side effects such as nausea, vomiting, urinary retention, catheter-related problems were also investigated.Results:The VAS scores at rest in the Block group were lower than those in the Intravenous group at the time of 12, 24 and 48 hours after operation but higher than combined group (P < 0.05). The VAS scores of motion pain in the Block group were significantly lower than those in the Intravenous group at 48 h and 72 h after operation but significantly higher than those in combined group (P < 0.01). The ROM in the Block group was significantly higher than that in the Intravenous group at the time of 48 h and 72 h after operation but lower than that in combined group (P < 0.05). On the contrary, the side effects were more evident in Intravenous group compared with the other two groups (P < 0.05). Conclusions:Continuous femoral nerve block combined with flurbiprofen axetil injection could provide remarkable postoper-ative analgesia of total knee arthroplasty.