人工膝关节术后感染的诊断和二期翻修术

目的：对人工膝关节(TKA)术后感染接受二次翻修术的膝关节进行评估。方法：1996年1月～2002年1月实行人工膝关节置换术353膝，其中5个膝关节在术后出现感染，行二期翻修术即一期手术取出原假体，彻底清创，置入抗生素骨水泥间隙垫，术后使用6周以上的敏感抗生素，二期手术作假体翻修术。结果：平均随访2年，无1例翻修的膝关节发生感染或无菌性松动。最近一次随访时平均膝关节功能评分从翻修术前的0分增加到术后的58分(20～100分)，平均膝关节疼痛评分从术前的38分(24～50分)增加到术后的93分(87—100分)。结论：应该尽量采用二期翻修术处理TKA术后感染，以彻底的清除感染灶，使病人获得良好的功能。     

人工膝关节置换术后发热特点及趋势的相关分析

背景：围手术期发热在人工膝关节置换术患者中十分常见,但关节术后感染尤其是假体周围感染可产生灾难性后果,因此骨科医师对其患者术后发热仍难免特别担心。 目的：探讨人工膝关节置换术后发热的相关特点和趋势,以及人工膝关节置换术后发热与感染等因素的潜在关系。 方法：回顾性分析2009年7月至2012年5月行膝关节置换术的700例患者的病历资料。详细记录每例患者术前1 d至术后10 d每天的最高体温,术后血红蛋白丢失量、是否输血、麻醉方式、是否发生感染及感染类型等。 结果：351例（50.1%）人工膝关节置换术患者出现术后发热。在发热患者中,第1次发热症状最常出现在术后第1天（204例,占所有发热病例数的58.1%）,手术当日（55例,15.7%）和术后第2天（62例,17.7%）次之。整个住院期间的最高体温最常出现在术后第1天（168例,47.9%）、第2天（125例,35.6%）。25例（3.6%）患者发生术后感染事件,术后发热与感染事件、输血显著相关;与年龄、性别、血红蛋白丢失、麻醉方式等因素之间没有显著的相关性。在感染事件中,呼吸系感染最易引起术后发热。 结论：人工膝关节置换术患者术后发热与感染事件、输血明显相关,而连续发热、超过39℃的发热尤其需要引起医师对术后感染的警惕。     

感染性人工膝关节翻修术中抗生素的选择

目的:探讨二期翻修术治疗人工膝关节术后感染的抗生素选择原则.方法:1990～2000年本科采用二期翻修术处理11膝人工膝关节术后感染.第1次手术时,彻底清创后膝关节内植入庆大霉素骨水泥间隙垫,之后根据细菌的药物敏感试验结果和医生的经验选择合理的抗生素治疗6周以上(非胃肠道途径).翻修术后平均随访32个月(24～43个月),采用膝关节临床评分系统对这些膝关节进行评估.结果:没有一个翻修的膝关节因为感染或者无菌性松动而接受再次翻修术,所有部件均获得良好固定.最后一次随访时,平均膝关节功能评分从翻修术前的0分增加到术后的63分(20～100分),平均膝关节疼痛评分从术前的42分(24～50分)增加到术后的95分(87～100分).结论:为彻底清除人工膝关节术后感染,临床医生应该尽量明确致病菌,根据药物敏感试验的结果和医生的经验选择有效的抗生素进行系统的治疗,并在膝关节内使用抗生素骨水泥间隙垫.     

An articulated antibiotic spacer used for infected total knee arthroplasty: a comparative in vitro elution study of Simplex and Palacos bone cements.

For the staged management of infected total knee arthroplasty (TKA), antibiotic laden polymethylmethacrylate (PMMA) spacers have been recommended. Antibiotic-impregnated PMMA spacers target drug delivery, achieving high local levels while limiting the potential for host toxicity associated with parenteral antimicrobial therapy. This study examined the elution characteristics of an articulating PMMA TKA spacer that has been useful clinically. Tobramycin and vancomycin are both active against many organisms leading to joint infections. We used various combined antibiotic concentrations (maintaining a relative ratio of 55% tobramycin to 45% vancomycin w/w), and then assayed the elution profile of the TKA spacer in vitro. Additionally, the elution qualities of two brands of bone cement, Simplex and Palacos, were compared. Briefly, three groups of PMMA spacers, impregnated with different antibiotic loads, were fashioned from a mold replicating a femoral TKA component. The entire spacer surface area was immersed in sterile phosphate buffered saline (PBS) in a 1:6 ratio of grams of cement to milliliters of PBS and incubated at 37 degrees C for 24 h. After 24 h, aliquot eluates were taken, the PBS discarded, and replaced with fresh, sterile PBS. PBS was changed daily and an aliquot was taken at least weekly for nine weeks. Eluate samples were stored at -70 degrees C until assayed. Each spacer eluate sample's antibiotic concentration was determined by disc diffusion bioassay against Bacillus subtilis. Mean zone inhibition diameters were extrapolated from the standard curve to yield micrograms per milliliter of antibiotic in PBS. In all groups the Palacos spacers demonstrated higher elution levels, above the MIC for the organism used, for a longer period of time than those made with Simplex. Based on the observed elution profiles, antibiotic-impregnated Palacos bone cement may offer a more effective vehicle for local drug delivery during staged treatment of infected TKA.     

术中自制临时关节型抗生素骨水泥占位器治疗人工膝关节置换术后感染

目的:研究术中自制临时关节型抗生素骨水泥占位器治疗人工膝关节置换术后感染的有效性。方法:使用自制压模器术中制备临时关节型抗生素骨水泥占位器。自2002年3月至2007年3月共使用此占位器治疗22例膝关节置换术后感染患者,男10例10膝,女12例12膝,平均年龄59.6岁(33～75岁)。初次置换到感染症状出现时间间隔平均6.7个月(1～14个月)。临床症状,血象、血沉、C-反应蛋白等血液感染指标及膝关节穿刺涂片和培养用以明确假体周围感染,两期手术后均监测感染指标变化,定期随访复查X线片,功能评价使用HSS评分系统。结果:所有患者获得随访,平均占位器植入间隔时间为4.7个月(3～9个月),Ⅱ期术前感染控制率为100%。Ⅱ期术后平均随访时间29.8个月(10～64个月),无感染复发。Ⅰ期术后膝关节HSS评分由术前的平均40.5±5.9提高到65.8±7.5,Ⅱ期术后最近随访时达平均88.7±5.1。9例对治疗结果满意,12例非常满意。结论:此方法制备的膝关节临时关节型占位器具有治疗期间保留较好关节功能、降低Ⅱ期手术难度、无须长期灌注及可靠的感染控制力等优点,治疗人工膝关节置换术后感染效果可靠。     

带抗生素可活动关节骨水泥间隔在全膝关节置换术后感染中的应用

目的总结带抗生素可活动关节骨水泥间隔治疗全膝关节置换术后感染的早期经验。方法2004年6月至2005年4月,采用二期翻修术治疗5例全膝关节置换术后感染患者。男1例,女4例;年龄57～75岁,平均67岁。一期手术彻底清创,取出假体,置入带抗生素可活动关节骨水泥间隔物。术后患者早期部分负重,关节屈曲活动。术后选用敏感抗生素静脉滴注6周,感染控制后再植入高限制性假体。结果患者中3例基础病因为类风湿关节炎,其中2例长期服用激素;余2例基础病因为骨关节炎,都有糖尿病。所有患者术前都曾出现过窦道,其中2例有窦道封闭现象。所有患者均未发现与骨水泥间隔相关的骨折、脱位及不稳定。两次手术间隔期为12～20周,平均15周。在间隔期,5例患者都能扶拐行走和屈曲膝关节,活动度平均为95°,平均膝关节协会评分(kneesocietyscores,KSS)81分。再植入术后平均随访时间为10个月,目前尚未发现复发和新的感染。结论采用带抗生素可活动关节骨水泥间隔可以成功治疗全膝关节置换术后感染,在间歇期能保留关节活动度,最终可有效处理感染并使再植入手术更加方便。     

Enhancing femoral cement fixation in total knee arthroplasty

Several factors have been shown to be associated with early development of radiolucent lines at the bone-cement interface in total knee arthroplasty (TKA). The posterior condylar surfaces, in particular, seem subject to poor cement technique, which could lead to early loosening. This study compares two cementation techniques in TKA, with respect to depth of cement penetration and radiolucency in the posterior condyles. All penetration depths were greater in group I (injected) versus group II (noninjected). Sixty-seven percent of group I showed penetration depths >1.5 mm compared with 23% of group II. No specimen in group I had gaps in the cement mantle on visual inspection or radiolucency on radiographic evaluation. No statistical differences, however, could be demonstrated between the two groups.     

The effect of cement gun and cement syringe use on the tibial cement mantle in total knee arthroplasty

Evidence suggests that a thicker cement mantle improves fixation strength and resistance to tensile and shear forces in the tibial component of total knee arthroplasty. A low proportion of orthopaedic surgeons currently use techniques to improve cement penetration in the tibial plateau. We demonstrate that the use of a pressurized cement gun or cement syringe provides a highly statistically significant difference (P < .001) to the depth of the tibial cement mantle and reduction in radiolucent lines when compared to cement applied by hand. This ensures a thicker cement mantle and may reduce the possibility of early failure by improving the strength of fixation and the resistance to tensile and shear forces. There is no statistical difference in the cement mantle produced by the cement syringe and the cement gun.     

A comparative study of 5 different antibiotic prophylaxis regimes in 4500 total knee replacements

AimTo compare the incidence of surgical site infection with different antibiotic regimes in elective total knee arthroplasty. We hypothesise that a single high dose of Teicoplanin and Gentamicin is as effective as other regimes.MethodsA retrospective study of prospectively collected data on a total of 4500 elective knee replacements over a 9-year period was conducted in a district general hospital. Data were collected on antibiotic regime, patient characteristics, infection (treatment, infective agents, sensitivities) and complications.ResultsFive different antibiotic regimes that have been used in elective knee arthroplasty were identified in our institution. 40 patients in total were identified who had a deep infection. Rates of deep surgical site infection were not significantly different between the five groups (p = 0.83).ConclusionA single pre-operative dose of Teicoplanin and Gentamicin has similar efficacy of prophylaxis to other regimes for patients undergoing primary elective total knee replacements. We recommend the choice of prophylaxis regimen is made locally based on pathogen virulence, drug resistance and cost.     

Antibiotic-loaded bone cement vs. plain cement as an infection prophylaxis in primary elective shoulder arthroplasty

HypothesisThe use of antibiotic-loaded bone cement (ABC) in the setting of revision arthroplasty for deep infections is a broadly accepted practice. However, its use in the setting of primary arthroplasty continues to be controversial with few studies assessing the efficacy of ABC for primary total shoulder arthroplasty (TSA). The purpose of this study was to determine whether the use of ABC in primary TSA is associated with a difference in the risk of deep infections.MethodsA retrospective cohort study was conducted using data from a United States integrated health-care system’s shoulder arthroplasty registry. Patients aged ≥18 years who underwent primary elective anatomic TSA for osteoarthritis or reverse TSA (RTSA) for rotator cuff arthropathy with implanted cement information were included in the study (2009-2020). We compared patients that received ABC to those who received plain cement and are at risk of revision due to deep infection within 5 years of follow-up using Cox proportional hazard regression weighted with the inverse propensity score, stratified by procedure type.ResultsThe study sample included 6409 TSAs for osteoarthritis and 779 RTSAs for rotator cuff arthropathy performed by 198 surgeons at 58 hospitals. In the TSA group, 20% received ABC; the cumulative infection probability at 5 years of follow-up was 0.5% and 0.6% for the ABC and plain cement groups, respectively. After covariate adjustment, no significant difference in infection risk was found (hazard ratio = 0.72, 95% confidence interval = 0.43-1.21, P = .216). In the RTSA group, 19% received ABC; the cumulative infection probability at 5 years of follow-up was 2.7% and 0.9% for the ABC and plain cement groups, respectively. After covariate adjustment, no significant difference in infection risk was found between the 2 cement groups (hazard ratio = 1.47, 95% confidence interval = 0.66-3.26, P = .341).ConclusionIn this study of more than 7000 primary elective shoulder arthroplasties performed in patients with a standard risk of infection, antibiotic bone cement did not confer any risk-reduction for periprosthetic infection when compared to plain bone cement. Different at-risk pathogen profiles may develop with prolonged use of antibiotic bone cement.     

Antibiotic bone cement and the incidence of deep infection after total knee arthroplasty

We asked if the use of antibiotic-laden bone cement (ALBC) decreased the deep infection rate after primary total knee arthroplasty as compared to plain bone cement. We surveyed 1625 consecutive patients for relevant covariates. Joint pain and function were assessed at baseline and at 1 year of follow-up with the Western Ontario McMaster University Osteoarthritis Index scores. The incidence of deep infection at 1-year follow-up was recorded. There were no differences in baseline covariates between groups (P > .05). We found a deep infection rate of 2.2% in the ALBC group and 3.1% in the plain bone cement group (P = .27). Adjusted analysis showed that ALBC was not predictive of a lower infection rate at 1 year (P = .84). Antibiotic-laden bone cement did not reduce the incidence of deep infection following primary total knee arthroplasty at 1-year follow-up.     

Tibial component in total knee arthroplasty: To cement or not to cement?

Loosening of the tibial component is a major cause of failure in total knee arthroplasty. Implant stability is a key element for achieving long term successful results and relies on the interplay of several factors which include the method of fixation, prosthesis design, surgical technique, bone quality and patient characteristics. The analysis of these aspects may provide some guidelines for the choice of fixation, but an ultimate solution of the problem can not be found in the past experience with total knee replacement. A better understanding of the biological and mechanical changes induced in bone tissue by the joint disease as well as by the prosthesis, will probably allow us to adopt the most appropriate solution for every patient.      

初次全膝关节置换术抗生素骨水泥应用的回顾性队列研究

目的回顾性分析初次全膝关节置换术的合适病例,探讨抗生素骨水泥的应用是否可以降低其术后感染率。方法对1994年至2009年本组所有接受初次全膝关节置换术的患者按是否使用抗生素骨水泥分为两组,分析年龄、性别、BMI、糖尿病、基础疾病、HSS评分、手术时间的差别,对其中的差异项目进行Logistic回归分析以找出影响TKA术后感染的因素,并对感染病例进行感染时问、致病菌、药敏结果等分析。结果抗生素骨水泥组相比于非抗生素骨水泥组,其感染率方面并无统计学差异（8／945vs5／701,x^2=0．0913,P〉0．05）。相关性Logistic回归分析显示抗生素骨水泥应用并不能降低感染率[OR=1．241,95％CI（0．402,3．834）,x^2=0．140,P〉0．05]。13例感染病例分析表明,凝固酶阴性葡萄球菌（CNS）占38％,传统的金黄色葡萄球菌（SA）仅占23％,临床常用的庆大霉素骨水泥无法完全覆盖。结论对抗生素骨水泥的使用仍应保持审慎的态度,避免过度使用造成的医疗资源浪费以及抗生素相关并发症发生率的增加。     

Surgical factors for total knee arthroplasty in younger patients

With improvements in implant modularity and polyethylene, it is important to assess the contemporary performance of cement vs. cementless fixation in total knee arthroplasty (TKA). Aseptic loosening is the most common indication for revision. Registry data indicates that the type of fixation (cemented, cementless, or hybrid) makes little difference in revision rates for younger patients (<55 years old). Regardless of the type of fixation, there is an opportunity for improvement. Attention to surgical factors, such as coronal alignment and cementing technique, can improve the survivorship of TKA.     

全膝关节置换术围手术期镇痛

目的探讨全膝关节置换术(TKA)围手术期镇痛效果,获得最佳的镇痛方案。方法2005年1月至2006年4月的82例单侧TKA手术患者随机分成两组,采用不同的镇痛方案进行围手术期镇痛治疗。对术后疼痛进行评分分析并观察并发症。结果两种镇痛方法均具有明显的镇痛效果,患者满意率及功能康复效果取得明显改善,并发症发生率较低。结论TKA围手术期采用积极的综合镇痛措施,具有重要意义。     

The painful total knee arthroplasty: Keys to diagnosis

As the prevalance of patients living with total knee replacements continues to rise we continue to see a significant portion of patients living with pain following their primary total knee arthroplasty. For some patients, the etiology of their pain following knee replacement is obvious, yet in many cases the cause of pain remains elusive and thus creates a significant burden for the patient and treating physician. In this review article we focus on common sources of pain following knee replacement and discuss keys to diagnosis. We also propose a unique clinical pathway algorithm to guide diagnostic work up and treatment options.     

Intraoperative cutting errors in total knee arthroplasty

Introduction Precise reconstruction of leg alignment offers the best opportunity for achieving good long-term results in total knee arthroplasty (TKA). It was the aim of this study to evaluate the bone-cutting process as a potential source of inaccuracy in TKA.Materials and methods In a consecutive series of 50 computer-assisted TKAs, cutting errors, which were defined as a difference between the cutting block position before sawing and the achieved resection plane afterwards, were measured for the distal femur and proximal tibia resection. Measurements were performed using a CT-based navigation system.Results For the distal femoral cut, there was a mean varus/valgus deviation of 0.6° (SD±0.5°) and a mean flexion/extension deviation of 1.4° (SD±1.3°). For the proximal tibia, varus/valgus alignment showed a mean deviation of 0.5° (SD±0.5°). The mean sagittal variability was 1.0° (SD±0.9°). Differences between the frontal and the sagittal plane were significant.Conclusion To minimize cutting errors, techniques and instruments are needed which enable a more stable fixation of the cutting blocks or even more appropriate preparation instruments. Using a computer-assisted technique, the surgeon is aware of cutting errors occurring at each point of the operation and will therefore be able to correct these errors during surgery, while he is not aware of those errors with the conventional TKA technique.     

Joint position sense in total knee arthroplasty

Seventeen postoperative total knee arthroplasty (TKA) patients were evaluated using two tests of knee joint position sense. Young controls and age-matched controls underwent identical tests. The TKA patients also underwent gait analysis, including foot switch stride analysis, and clinical evaluation using a standard scoring system. Results showed statistically significant decreases in joint position sense from young controls to old controls, and further significant decreases with joint disease; however, no further worsening was noted as a result of TKA. The abnormal gait parameters seen in TKA patients correlated as well with position sense as with clinical score. Strongest correlations were seen when a combined clinical and proprioceptive score was compared with gait parameters. In spite of alleviation of pain and correction of deformity, normal gait and function are not typically achieved after total knee replacement. Irreversible loss of joint proprioceptive function due to the disease process may be a major factor in the discrepancy between clinical and functional outcomes of total joint arthroplasty. Furthermore, loss of proprioception and the resulting abnormal gait patterns may place increased stress on components and contribute to loosening. In addition, an association between degenerative joint disease and decline in proprioception is suggested.     

Wound healing after total knee arthroplasty

Wound healing complications in the early postoperative period can be severely detrimental to clinical outcomes after total knee arthroplasty. Thorough knowledge of preoperative risk factors, meticulous surgical technique and wound closure, along with careful postoperative wound monitoring can prevent wound complications or lead to their resolution without subsequent morbidity. If complications arise in the postoperative period, the wound must be evaluated and treated promptly to avoid periprosthetic infection.     

Anterior knee pain following primary total knee arthroplasty

Despite improvements in technique and technology for total knee arthroplasty (TKA), anterior knee pain impacts patient outcomes and satisfaction. Addressing the prosthetic and surgical technique related causes of pain after TKA, specifically as it relates to anterior knee pain, can aid surgeons in addressing these issues with their patients. Design features of the femoral and patellar components which have been reported as pain generators include: Improper femoral as well as patellar component sizing or designs that result in patellofemoral stuffing; a shortened trochlear groove distance from the flange to the intercondylar box; and then surgical technique related issues resulting in: Lateral patellar facet syndrome; overstuffed patella/flange combination; asymmetric patellar resurfacing, improper transverse plane component rotation resulting in patellar subluxation/tilt. Any design consideration that allows impingement of extensor mechanism anatomical elements has the possibility of impacting outcome by becoming a pain generator. As the number of TKA procedures continues to increase, it is increasingly critical to develop improved, evidence based prostheses that maximize function and patient satisfaction while minimizing pain and other complications.