软组织平衡对全膝关节置换时膝外翻畸形的矫正作用观察

目前认为,膝关节周围软组织不平衡是影响全膝关节置换术后远期效果的主要因素之一,可使金属假体与聚乙烯内衬之间应力集中,加速内衬磨损,也可由于膝关节不稳定而导致假体松动。因此,保证全膝关节置换术中软组织平衡极为重要。膝外翻畸形患者行人工全膝关节置换术难度较大,争议颇多,我科2006-2010年行膝关节置换矫正外翻畸形23例,术中应用软组织平衡技术,取得了较好疗效,现报告如下。     

人工全膝置换手术6例

人工关节置换是治疗膝关节疼痛和功能丧失的可靠方法。由于人工膝关节材料的不断完善、手术器械固定方法的改进以及手术技术的提高，近10年人工全膝置换术日渐增多。我院200l-09～2003-04实施了9例11个关节，近期疗效满意，报告如下。     

人工假体置换在膝周恶性骨肿瘤中的临床应用

目的探讨人工假体在膝关节周围恶性骨肿瘤保肢术中的临床效果。方法 28例膝关节周围恶性骨肿瘤瘤段广泛切除后,采用人工膝关节假体置换重建。结果 28例患者术后根据Ennek ing评分标准评定疗效优18例,良6例,可4例,优良率85%。随访4~48个月,其中20例患者无局部复发或远处转移,8例复发或转移。结论人工假体置换重建膝关节周围骨肿瘤手术可改善膝部恶性骨肿瘤患者的早期生活质量,减少致残率,严重并发症少,患者术后关节功能、效果较满意。     

创伤性膝关节炎的全膝关节置换

目的评价膝关节骨折后创伤性膝关节炎全膝关节置换的疗效。方法对1997～2002年间膝关节骨折后创伤性关节炎行全膝关节置换的11例患者进行回顾性研究。男10例,女1例;年龄31～76岁,平均59岁。骨折至全膝置换手术的间隔时间2～27年,平均8.7年。有7例患者曾进行手术内固定治疗。全膝置换手术同时拆除内固定4例,分期手术拆除内固定后行全膝关节置换3例。手术时有2例股骨骨折畸形愈合,全膝置换时行外侧支持带松解4例,伸膝装置重建1例,侧副韧带重建2例。结果平均随访时间36个月(12～72个月)。无失访病例。膝关节协会评分从术前的平均37分(10～69分)提高到随访时的85分(10～100分),功能评分从术前的42分(0～60分)提高到随访时的75分(20～100分)。膝活动度从术前的83°增加到随访时的93°。术后由于膝关节活动度差而进行麻醉下手法松解4例。未发现需要进行翻修的假体无菌性松动。有1膝发生切口浅表感染行清创术,假体保留而愈合。结论先前骨折所造成的创伤性关节炎,采用全膝置换可明显改善功能,缓解疼痛。术中恢复肢体的良好对线,确保假体置入正确,达到软组织平衡可促进全膝置换的效果。     

膝关节置换矫正外翻畸形时个性化截骨与统一6°外翻截骨的中期疗效比较

目的探讨膝关节置换矫正外翻畸形时个性化截骨与统一6°外翻截骨中期疗效。方法将2008年1月至2014年1月在我科行膝关节置换矫正外翻畸形患者32例,随机分为观察组和对照组,各16例。观察组患者给予个性化截骨膝关节置换术;对照组给予统一6°外翻截骨膝关节置换术。根据X线片比较术前和术后膝外翻角度,应用HSS膝关节评分系统进行中期疗效评价。结果术后随访6个月,两组患者切口均一期愈合,无感染、无腓总神经麻痹发生。两组患者术后膝外翻角度、膝关节HSS评分、膝关节活动度较手术前明显好转,差异具有统计学意义(P<0.05)。观察组患者平均手术时间、下床活动时间、术后平均引流量明显低于对照组患者,差异有统计学意义(P<0.01)。结论个性化截骨技术保证每位患者都有适合自己的截骨模具,从而达到理想的手术效果。     

延长的胫骨结节截骨在翻修全膝置换中的应用

目的探讨延长的胫骨结节截骨在全膝置换术中的应用。方法对1998年5月至2002年10月间12例采用延长的胫骨结节截骨的患者进行回顾性研究。结果所有截骨在术后6个月临床和X线片评估均愈合,关节活动度平均从79°增加到95°,平均膝关节评分从60改善至85。结论延长的胫骨结节截骨在翻修全膝关节置换术中能改善手术显露和关节功能。     

全膝关节置换假体的生物力学分析

目的：通过有限元分析方法,探究全膝关节置换（TKA）后膝关节假体在不同角度屈膝过程中的应力变化。方法：通过计算机模拟手术截骨,并装配后稳定型（PS）和后交叉韧带替代型（CS）两种膝关节假体。根据步态过程中屈膝角度和轴向载荷间的变化,选择0°、10°、20°和30°四个角度进行有限元分析。观察股骨假体、胫骨假体和衬垫上的Mises应力分布和接触面积,探究术后膝关节的生物力学行为变化。结果：在同一角度下PS型衬垫的应力峰值大于CS型衬垫,屈膝20°和30°时衬垫上出现Mises应力峰值最大值。PS型衬垫内侧的应力峰值大于外侧,而CS型则相反。衬垫的接触面积在多数情况下,外侧大于内侧。PS型衬垫内、外侧的接触面积相对平衡,但CS型衬垫则相差较多,且在屈膝10°时内侧的接触面积最小,这可能会引起衬垫磨损。金属假体的应力峰值位置多出现在与骨组织的连接部位。结论：随着屈膝角度的增加,衬垫内、外侧的Mises应力峰值表现出相应增大的趋势,应尽量减少大角度的屈膝行为,并配合适量的康复运动。同时,注意日常行走的步伐,避免内、外翻带来的假体单侧应力过大。     

人工全膝关节置换术中髌骨置换的临床研究

目的探讨人工全膝关节置换术中髌骨置换之后的临床疗效,为临床上是否要进行髌骨置换提供参考依据。方法选择2009年12月—2012年2月于我院急诊科、骨科就诊并拟行人工全膝关节置换术的骨关节炎患者84例,按随机数字随机将所有入选患者分为对照组42例和研究组42例,研究组患者在关节置换术中接受髌骨置换的治疗,对照组则不进行髌骨置换,治疗后所有患者接受为期1年的随访,对两组疗效进行比较。结果两组术后2、3个月的美国膝关节协会评分系统(KSS)临床评分差异均无统计学意义(P>0.05),术后6、12个月KSS临床评分差异有统计学意义(P<0.05);两组术后2、3、6个月的Feller髌骨评分差异均无统计学意义(P>0.05),术后12个月Feller髌骨评分差异有统计学意义(P<0.05)。结论人工全膝关节置换术中行髌骨置换能在一定程度上改善膝关节功能评分和髌骨评分。     

拉网式松解技术在人工膝关节置换术治疗重度外翻膝中临床应用

目的探讨拉网式松解技术在人工膝关节置换术治疗外翻膝中的安全性及疗效。方法回顾性分析2014年10月至2015年5月北京积水潭医院矫形骨科采用人工膝关节置换术治疗的膝关节外翻畸形患者20例(23膝)的临床资料。所有患者均进行膝关节置换手术治疗,在术后1、3、6个月及1年进行随访,拍摄膝关节负重位X线影像、下肢全长X线影像,观察有无腓总神经损伤的症状,并进行美国膝关节协会(KSS)评分。结果本组20例患者,18例使用后稳定型假体,2例使用限制性假体。全部患者膝关节置换术中行外侧软组织的拉网式松解,松解深度≤5 mm。平均手术时间(79±12)min,平均出血量(150±30)ml,术中及术后无输异体血,术后伤口平均引流量(190±70)ml。术后第1天患者可以扶拐杖下地活动。术后和随访过程中均未发现腓总神经损伤的并发症。KSS评分从术前的(39±10)分提高至术后的(91±6)分,术前、术后KSS评分比较,差异有统计学意义(P<0.05)。结论拉网式松解技术是人工膝关节置换术治疗膝关节外翻畸形的有效方法,松解深度≤5 mm安全、有效,可以得到满意的软组织平衡。     

Knee biomechanics and contralateral knee osteoarthritis progression after total knee arthroplasty

BackgroundDespite the success rate of Total Knee Arthroplasty (TKA), many patients undergo contralateral TKA. It is possible that altered gait mechanics after unilateral TKA play a role in the progression of contralateral OA progression.Research questionThe purpose of this study was to identify biomechanical predictors of radiographic OA progression in the contralateral (non-surgical) knee after unilateral (primary/initial) TKA. In addition, this study quantified for patients who had contralateral OA progression.MethodsBiomechanical outcomes were collected 6–24 months after unilateral primary TKA and were used to predict changes in contralateral OA severity at follow-up. Participants were divided into “Progressor” and “Non-Progressor” groups based on changes in Kellgren-Lawrence (KL) OA grade and Joint Space Width (JSW) between baseline and follow-up testing sessions. Biomechanical factors during walking were peak knee adduction moment, knee flexion/extension excursions, knee angle at initial foot contact, and peak knee flexion/extension. Multiple independent t-tests were used to examine the magnitude of differences in biomechanical variables between the groups. Logistic regression was used to examine the association between the biomechanical predictors and change in KL scores and JSW.ResultsThe mean time between surgery and follow-up x-rays was 8.8 (2.4) years. Of 40 participants, 62.5–78% had contralateral radiographic knee OA progression by follow-up. There were no significant differences in the biomechanical variables between groups. For the regression analysis, none of the biomechanical variables were found to be predictors for contralateral OA progression.SignificanceAlthough abnormal biomechanics are known risk factors for primary knee OA, it is possible that the mechanisms that result in OA progression of the contralateral limb are different than primary knee OA progression. Future work should evaluate other objective measures of OA progression and determine if cumulative measures of joint loading are related to OA worsening.     

加速康复外科理念在膝关节置换术围术期应用

目的评价加速康复(ERAS)外科理念在膝关节置换术围术期的应用疗效。方法收集2015年1月至2016年1月收治的因膝关节骨性关节炎行膝关节置换术的82例患者,随机分为ERAS组(n=40)和常规组(n=42),比较两组围手术期疗效。结果患者82例随访1个月。所有患者切口均一期愈合,术后12 d拆线。ERAS组术中出血量、输血量均明显少于常规组,差异有统计学意义(P<0.05)。两组手术时间比较,差异无统计学意义(P>0.05)。ERAS组术后住院(8.0±3.4)d,明显低于常规组的(11.5±3.6)d,两组平均住院日比较,差异有统计学意义(P<0.05)。两组均未发生切口并发症。两组深静脉血栓、泌尿系统感染并发症发生率比较,差异无统计学意义(P>0.05)。比较术后12 d和术后1个月的膝关节KSS评分,ERAS组膝关节KSS评分优于常规组,差异有统计学意义(P<0.05)。结论 ERAS外科理论在膝关节置换围术期的应用能明显缩短术后住院时间和住院费用,可以促进患者膝关节功能的康复,值得推广和应用。     

人工全膝关节置换术治疗严重畸形膝关节临床研究

目的：探讨人工全膝关节置换术（total knee arthroplasty, TKA）治疗严重畸形膝关节的手术方法和临床疗效。方法对人工全膝关节置换术916例（1031膝）,严重畸形膝关节置换术80例,其中56例（70膝）成功随访。严重内翻畸形19例（23膝）、严重外翻畸形21例（27膝）、严重屈曲畸形16例（20膝）。术后平均随访时间60个月（6个月～10年）。对膝关节屈伸活动度、HSS、KSS膝关节评分系统对手术前后进行回顾性研究。结果膝关节屈伸活动度由术前平均80°（伸直0°～屈曲120°）提高到术后115°（伸直0°～屈曲130°）,膝关节评分系统 HSS、KSS术前及随访时比较差异有统计学意义（P＜0．05）,KSS评分：临床评分由术前平均33分（10～68分）提高到术后平均81分（70～100分）,HSS临床评分由术前平均43分（27～68分）提高到术后平均86分（72～100分）。膝内外翻、屈曲挛缩畸形得到较好矫正。结论严重畸形膝关节通过关节置换术同样能恢复正常的关节功能,提高了患者生活质量,获得满意的临床疗效。     

Lower extremity gait kinematics outcomes after knee replacement demonstrate arthroplasty-specific differences between unicondylar and total knee arthroplasty: A pilot study

BackgroundThe aim of the present study is to compare sagittal gait kinematics of ankle, knee and hip joints between subjects with unicondylar and total knee arthroplasty and age matched healthy controls. Since unicondylar knee replacement is a less invasive procedure, which more closely preserves knee joint anatomy, we hypothesized that one year post unicondylar knee arthroplasty patients would demonstrate more normal gait patterns than patients with total knee arthroplasty.Research questionDo unicondylar and total knee arthroplasty patients display similar gait kinematics one year after surgery?MethodsFourteen subjects (8 posterior stabilized and 6 medial unicondylar knee replacements) that were one year post surgery, and 6 healthy control subjects underwent a 3D gait analysis and a physical examination (range of motion, muscle strength). Statistical parametric mapping was used to compare gait kinematics of the lower limbs between groups. Additionally, differences in peak angles and clinical outcomes were assessed using a one-way ANOVA between subjects analysis.ResultsBoth knee replacement groups showed reduced knee flexion range of motion and reduced muscle strength at the operated leg compared to the control group. Subjects with TKA demonstrated reduced knee flexion at loading response and midstance of the gait cycle. Both UKA and TKA demonstrated significantly less knee flexion during swing.SignificanceThe results of this study demonstrate arthroplasty-specific differences in muscle strength, range of motion and gait kinematics of the lower limb one year after knee surgery. Future planning of post-surgery follow-up should addresses these arthroplasty-specific weaknesses and gait deviations.     

Co-contraction in RA patients with a mobile bearing total knee prosthesis during a step-up task

It was hypothesized that rheumatoid arthritis (RA) patients with a total knee prosthesis that allows axial rotation of the bearing (MB) will show more co-contraction to stabilize the knee joint during a step-up task than RA patients with a fixed bearing total knee prosthesis (FB) where this rotational freedom is absent while having the same articular geometry. Surface EMG, kinematics and kinetics about the knee were recorded during a step-up task of a MB group (n = 5), a FB group (n = 4) and a control group (n = 8). Surface EMG levels of thigh muscles were calibrated to either knee flexion or extension moments by means of isokinetic contractions on a dynamometer. During the step-up task co-contraction indices were determined from an EMG-force model. Controls showed a higher active ROM during the step-up task than the patient group, 96° versus 88° (P = 0.007). In the control group higher average muscle extension, flexion and net moments during single limb support phase were observed than in the patient group. During the 20–60% interval of the single limb support, MB patients showed a significant higher level of flexor activity, resulting in a lower net joint moment, however co-contraction levels were not different. Compared to the control group arthroplasty patients showed a 40% higher level of co-contraction during this interval (P = 0.009). Control subjects used higher extension moments, resulting in a higher net joint moment. Visual analysis revealed a timing difference between the MB and FB group. The FB group seems to co-contract approximately 20% later compared to the MB group. RA patients after total knee arthroplasty show a lower net knee joint moment and a higher co-contraction than controls indicating avoidance of net joint load and an active stabilization of the knee joint. MB and FB patients showed no difference in co-contraction levels, although timing in FB is closer to controls than MB subjects. Since visual analysis revealed a timing difference between the MB and FB group, this may express compensation by coordination. Rehabilitation programs for RA patients should include besides muscle strength training, elements of muscle-coordination training.     

Improved accuracy of component alignment with the implementation of image-free navigation in total knee arthroplasty

Accuracy of implant positioning and reconstruction of the mechanical leg axis are major requirements for achieving good long-term results in total knee arthroplasty (TKA). The purpose of the present study was to determine whether image-free computer navigation technology has the potential to improve the accuracy of component alignment in TKA cohorts of experienced surgeons immediately and constantly. One hundred patients with primary arthritis of the knee underwent the unilateral total knee arthroplasty. The cohort of 50 TKAs implanted with conventional instrumentation was directly followed by the cohort of the very first 50 computer-assisted TKAs. All surgeries were performed by two senior surgeons. All patients received the Zimmer NexGen? total knee prosthesis (Zimmer Inc., Warsaw, IN, USA). There was no variability regarding surgeons or surgical technique, except for the use of the navigation system (StealthStation^® Treon plus^®, Medtronic Inc., Minnesota, MI, USA). Accuracy of implant positioning was measured on postoperative long-leg standing radiographs and standard lateral X-rays with regard to the valgus angle and the coronal and sagittal component angles. In addition, preoperative deformities of the mechanical leg axis, tourniquet time, age, and gender were correlated. Statistical analyses were performed using the SPSS 15.0 (SPSS Inc., Chicago, IL, USA) software package. Independent t-tests were used, with significance set at P < 0.05 (two-tailed) to compare differences in mean angular values and frontal mechanical alignment between the two cohorts. To compute the rate of optimally implanted prostheses between the two groups we used the χ² test. The average postoperative radiological frontal mechanical alignment was 1.88° of varus (range 6.1° of valgus–10.1° of varus; SD 3.68°) in the conventional cohort and 0.28° of varus (range 3.7°–6.0° of varus; SD 1.97°) in the navigated cohort. Including all criteria for optimal implant alignment, 16 cases (32%) in the conventional cohort and 31 cases (62%) in the navigated cohort have been implanted optimally. The average difference in tourniquet time was modest with additional 12.9 min in the navigated cohort compared to the conventional cohort. Our findings suggest that the experienced knee surgeons can improve immediately and constantly the accuracy of component orientation using an image-free computer-assisted navigation system in TKA. The computer-assisted technology has shown to be easy to use, safe, and efficient in routine knee replacement surgery. We believe that navigation is a key technology for various current and future surgical alignment topics and minimal-invasive lower limb surgery.     

Effects of total knee arthroplasty for primary knee osteoarthritis on postural balance: A systematic review

BackgroundKnee osteoarthritis is often related to physical function impairment. Although total knee arthroplasty is considered effective for advanced cases of knee osteoarthritis, its effects on postural balance is a topic of debate.Research questionWhat are the effects of total knee arthroplasty for primary knee osteoarthritis on postural balance compared to preoperative status and/or to healthy controls?.MethodsLongitudinal studies (with more than 1-month follow-up) assessing postural balance measures (either clinical-based such as balance scales or laboratory-based such as postural sway) were considered eligible and selected in a 2-phase process. Six main electronic databases were searched, complemented by 3 grey literature sources. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Tools.ResultsA total of 19 studies were included for qualitative synthesis, of which 14 had low and 5 had a moderate risk of bias. The follow-up period ranged from 1–24 months. Most studies (n = 11) presented comparisons to preoperative status only. From these, 7 studies reported relevant improvements in postural balance, 2 reported partial improvements, and 2 no improvements. The remaining studies (n = 8) presented comparisons to healthy controls and, although improvements following total knee arthroplasty were consistently observed, only one study reported postural balance measures comparable to that of controls.ConclusionsThe majority of studies reported relevant improvements (especially in clinical-based measures) compared to preoperative evaluations, although inconsistencies were found possibly due to variability in studies' populations, assessment tools, and follow-up times. Despite this, persistent deficits in postural balance were commonly observed when compared to healthy controls.SignificanceThis evidence synthesis could better inform clinicians and researchers about the therapeutic effects and limitations of total knee arthroplasty concerning postural balance. Standardization of assessment tools is recommended to strengthen the certainty of cumulative evidence.     

Arthrodesis of the knee after failed infected total knee arthroplasty

Infection after total knee arthroplasty (TKA) can be a challenging and difficult problem to treat. In selected patients, knee arthrodesis is a well-recognized salvage procedure after infected TKA. The authors retrospectively reviewed their experience with this treatment option, presenting 20 patients (8 women, 12 men), performed between 1990 and 2002. The average age was 67 years (range: 47–81 years) and the mean number of previous surgical procedures was 6 (range: 4–11 procedures). There were multiple indications for knee arthrodesis, including extensive bone or soft tissue loss, poor bone stock, and recurring infections. One-stage fusion was done in 7 knees while, on the other 13, arthrodesis was performed as two-stage fusions. The average clinical follow-up was 4.5 years (range: 2–11 years). 18 of the 20 patients were interviewed and graded using the Visual Analogue Scale (VAS) for pain, the Short Form-36 Health Survey (SF-36), and the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire that has knee-related quality of life items. According to the VAS, the mean intensity was 3.4 points. 6 (33%) of the patients had no difficulty with the knee and 9 (50%) of them had mild or moderate difficulty. The SF-36 scores were similar to those for normative data for patients after TKA, with only the social functioning, role emotional, and physical functioning scores being lower and the role physical and social functioning scores being higher. Three of 20 fusions failed, whereas two knees became non-infected non-unions. In one, the knee infection persisted and required above-knee amputation. The two-stage arthrodesis gave the most predictable rate of fusion. Persistent infection and extensive bone stock losses led to failure even under the best circumstances. In our opinion, arthrodesis of the knee is a satisfactory salvage procedure following a failed TKA, and can provide reliable expectation for a stable, painless extremity for high-functioning patients who are able to walk.     

Patients’ perspective on controversial issues in total knee arthroplasty

We investigated the level of patient knowledge and preferences over the currently controversial issues in TKA. One hundred patients who had decided to undergo TKA for advanced osteoarthritis were asked to complete a questionnaire inquiring their knowledge and preferences over three controversial issues: (1) computer assisted surgery (CAS), (2) minimal invasive surgery (MIS), and (3) ceramic femoral component. The patient preferences over the three issues were questioned again after they had been informed of advantages and disadvantages of each option using an explanatory document. Most (more than 75%) of the patients did not have sufficient knowledge and their knowledge was based on non-professional sources (more than 85%). Before the information was given, most (more than 80%) of the patients preferred a new option. After the information was provided, more patients preferred a standard option in the issues of CAS (60%) and MIS (88%). This study prompts health care providers to become more active in providing accurate information and to consider patients perspective in making decisions which will influence the benefits and risk of the patients.