不同程度膝内翻患者初次全膝关节置换术后下肢力线分布与近期临床疗效的关系

目的:探讨不同程度膝内翻畸形患者行初次全膝关节置换术后下肢力线分布与近期临床疗效之间的关系。方法:自2016年12月至2018年3月行初次全膝关节置换术治疗的膝骨性关节炎患者87例(101膝),男21例(25膝),女66例(76膝);年龄51～85(67.6±7.0)岁。根据患者全膝关节置换术后下肢髋膝踝角(hip knee ankle angle,HKA)不同分为4组:中立位组(A组),-3°≤HKA≤3°,50膝;轻度内翻组(B组),3°HKA6°,20膝;严重内翻组(C组),HKA≥6°,20膝;外翻组(D组),HKA-3°,11膝。比较4组患者术前性别、年龄、体质量指数、手术侧别、术前及术后膝关节活动度,美国特种外科医院膝关节评分(Hospital for Special Surgery Knee Score,HSS),美国膝关节协会评分(Knee Social Score,KSS),并分别比较术后股骨、胫骨假体力线分布与近期临床疗效的关系。结果:所有病例获得随访,时间(18.4±4.0)个月。4组患者术后末次随访膝关节活动度、HSS、KSS评分均较术前提高(P0.001)。4组患者术后末次随访HSS、KSS评分组间比较差异具有统计学意义(P0.05);A组评分优于C、D两组(P0.05),B组评分优于C、D两组(P0.05),A、B两组间以及C、D两组间比较差异无统计学意义(P0.05);4组患者术后膝关节活动度组间比较差异无统计学意义。股骨假体力线在±3°以内组评分优于3°以外组(P0.05),胫骨假体力线在±3°以内组评分较3°以外组差异无统计学意义(P0.05)。结论:膝内翻型骨关节炎患者初次全膝关节置换术后近期临床疗效与下肢力线分布有关,力线轻度内翻位分布可获得与中立位相似的近期临床疗效,股骨假体力线分布与初次膝关节置换术后近期临床疗效有关。     

胫骨内翻畸形对全膝关节置换术胫骨假体对线影响的临床研究

目的胫骨内翻畸形(tibia vara)是膝关节关节外畸形的一种特殊类型。胫骨内翻畸形会给全膝关节置换术中胫骨假体的正确对线和安装带来困难。本研究的目的在于:a)测量国人内翻膝关节骨关节炎患者的胫骨平台内翻角(tibial varus angle,TVA),分析胫骨内翻畸形在内翻膝关节骨关节炎患者中所占的比例;b)探讨胫骨内翻畸形对全膝关节置换术术后胫骨假体对线和临床功能的影响。方法本研究回顾了我科从2015年8月至2015年12月收治的连续60例女性内翻膝关节骨关节炎的全膝关节置换患者资料,将患者分为正常组和胫骨内翻畸形组两组,术前下肢全长X线片中测量髋膝踝角(hip knee ankle angle,HKA)、TVA,术前所有患者的膝关节功能评分采用美国膝关节协会(knee society score,KSS)评分和西大略湖麦克马斯特大学(Western Ontario McMaster Universities,WOMAC)评分系统,术后下肢全长X线片中测量HKA以及胫骨假体近端内侧角(medial proximal tibial angle,MPTA),采用KSS评分和WOMAC评分系统评价膝关节功能。结果正常组TVA为(0.69±0.44)°,胫骨内翻畸形组TVA为(2.53±0.56)°,两组差异具有统计学意义。60例患者平均TVA为(1.12±0.52)°。正常组中TVA为0°的患者9例,占正常组病例数的20%。胫骨内翻畸形组中TVA大于等于2°的患者14例,占胫骨内翻畸形组的100%,即TVA大于等于2°为胫骨内翻畸形,胫骨内翻组患者占总病例数的23.3%。术后正常组HKA为(178.8±1.5)°,大于术后胫骨内翻畸形组HKA(177±2.0)°。术后正常组HKA异常值(Outlier值)有2例,占正常组病例的4.3%;术后胫骨内翻畸形组HKA Outlier值有3例,占胫骨内翻畸形组病例的21.4%。术后正常组活动度(range of motion,ROM)为(112.0±11.5)°,大于胫骨内翻畸形组ROM(105±8.0)°,两组比较差异有统计学意义。正常组术后WOMAC评分为(15.6±3.2)分,胫骨内翻畸形组WOMAC评分为(16.8±4.0)分。正常组术后KSS功能评分为(92.5±3.5)分,胫骨内翻畸形组术后KSS功能评分为(94.0±2.4)分。结论本研究中有23.3%的女性内翻膝骨关节炎患者合并胫骨内翻畸形(TVA大于等于2°),女性内翻膝关节骨关节炎患者平均TVA为(1.12±0.52)°。术前TVA大于等于2°的患者行全膝关节置换术发生术后对线不良的风险显著增加,手术时须注意胫骨近端正确截骨以及胫骨假体偏外安装,以避免术后对线不良的发生。     

严重膝关节类风湿关节炎患者下肢力线的测量分析

目的：测量终末期膝关节受累类风湿关节炎（RA）患者下肢力线及膝关节解剖参数并分析畸形来源,为获取全膝关节置换术（TKA）术后理想的下肢力线提供参考。方法：纳入2013年1月至2020年5月因膝RA行TKA患者210例,术前均拍摄负重位双下肢全长X线片,根据下肢力线分为内翻组、中立组、外翻组。测量髋膝踝角（HKA）、机械轴股骨远端外侧角（mLDFA）、机械轴胫骨近端内侧角（mMPTA）及关节线相交角（JLCA）,比较各组间上述参数的差异,并进一步分析畸形来源。结果：严重RA外翻力线占比40.5%(85/210),其次为中立力线占比32.9%(69/210),内翻力线占比26.6%(56/210)。内翻组、中立组、外翻组HKA,mLDFA,mMPTA,JLCA组间比较,差异均有统计学意义。内翻组mMPTA、JLCA及外翻组mLDFA、mMPTA均偏离正常参考范围。结论：严重RA下肢力线分布以外翻膝为主,不同力线分布的膝关节下肢解剖不同。内翻组畸形主要来自于胫骨侧及关节间隙;外翻组畸形主要来自于股骨侧及胫骨侧,充分了解RA患者上述解剖特点有助于精确截骨并获取良好的术后力线。     

中国西南地区单纯半月板损伤患者下肢力线测量及临床意义

目的测量中国西南地区未合并软骨病变的早期单纯半月板损伤患者的下肢力线角度,分析这一人群的下肢力线特点,为该地区全膝关节置换(TKA)术中截骨提供参考依据。方法将2015年1月至2018年3月陆军军医大学第一附属医院收治的200例中国西南地区早期单纯半月板损伤患者纳入研究,男女各100例,均未合并软骨病变。在患者下肢全长负重位X线片上测量髋-膝-踝角(HKA)、胫骨平台内翻角及股骨外翻角,比较不同性别下肢力线的差异,同时与北美正常人群的下肢力线进行对比。结果中国西南地区单纯半月板损伤患者男性HKA、胫骨平台内翻角、股骨外翻角分别为(176.2±0.6)°、(5.1±0.9)°、(5.7±0.2)°,均大于女性[(175.6±0.6)°,(3.1±0.7)°、(5.7±0.1)°],且HKA及股骨外翻角小于北美正常人群,但胫骨平台内翻角较大(P 0.05)。结论中国西南地区早期单纯半月板损伤患者较北美正常人群的下肢力线内翻趋势明显,且女性下肢力线内翻趋势大于男性;该地区人群TKA术中截骨以股骨远端外翻6.0°,女性后髁外旋3.0°、男性后髁外旋5.0°为宜,但具体截骨角度应根据术前个体化测量结果及术中实际情况决定。     

膝内翻畸形程度对全膝关节置换术的影响

[目的]探讨膝内翻畸形程度对全膝关节置换术（total knee arthroplasty, TKA）疗效的影响。[方法]回顾性分析2020年4月—2022年4月86例在本院行TKA的膝骨关节炎患者的临床资料。根据术前髋-膝-踝角（hip-knee-ankle angle,HKAA）,54例为轻度内翻（≤10°）,32例为中度内翻畸形（10°～20°）。分析下肢力线与临床评分的相关性。[结果]两组均顺利手术,无严重并发症,两组间围手术期指标的差异均无统计学意义（P>0.05）。随时间推移,两组术后VAS评分、WOMAC评分、膝伸-屈ROM及HSS评分均显著改善（P<0.05）。术前及术后3个月轻度组VAS、HSS、WOMAC及膝伸-屈ROM均显著优于中度组（P<0.05）。影像方面,轻度组术前股胫角（femorotibial angle, FTA）[(190.4±5.6)°vs (196.3±6.1)°, P<0.001]、胫骨近端内侧角（medial proximal tibial angle, MPTA）[(73.4±3.8)°vs (67.2±3.1)°,...     

Mako机器人辅助全膝关节置换术在膝骨性关节炎的早期应用

目的：探讨Mako机器人辅助人工全膝关节置换术（total knee arthroplasty,TKA）治疗膝骨性关节炎（knee osteoarthritis,KOA）早期疗效,总结初步应用经验。方法：回顾分析2021年6月至2021年12月,采用Mako机器人辅助TKA治疗73例KOA患者。男16例,女57例,年龄54～81(67.8±6.6)岁。记录分析患者术前术后髋膝踝角（hip knee ankle,HKA）、股骨远端外侧角（lateral distal femoral angle,LDFA）、胫骨近端内侧角（medial proximal tibial angle,MPTA）,矢状位股骨角（lateral femoral component angle,LFCA）、矢状位胫骨角（lateral tibial component angle,LTCA）。采用Western Ontario McMater大学骨性关节炎指数（Western Ontario McMaster Universities osteoarthritis index,WOMAC）评分和美国膝关节协会评分（...     

计算机导航辅助与传统手术行人工膝关节置换的疗效比较

目的比较计算机导航辅助与传统方法行人工膝关节置换术(TKA)的近期疗效,探讨计算机导航辅助应用于TKA的优势。方法将186例行TKA的骨关节炎患者(186膝)分为导航组(110膝)和非导航组(76膝)。比较两组的手术时间、切口长度、术后总引流量、术后下肢力线、术后KSS关节功能评分以及WOMAC评分。结果 186例患者均获得随访,时间12个月。与非导航组相比,导航组手术时间平均延长9 min,手术切口平均长了2 cm,但术后引流量更少,下肢力线偏离≥3°更少,胫骨平台后倾更接近预设值0°;以上各项指标两组比较差异均有统计学意义(P 0. 05)。术后KSS关节功能评分和WOMAC评分导航组均优于非导航组(P 0. 05)。结论计算机导航辅助TKA能提高下肢力线的精准度,提高膝关节假体安放的准确性,近期临床效果较传统手术更有优势。     

3D打印导板辅助人工全膝关节置换术后患者步态分析

目的探讨3D打印导板辅助人工全膝关节置换术(total knee arthroplasty,TKA)后患者步态特点。方法选择2017年2月—2018年2月接受3D打印导板辅助TKA治疗的20例(20膝)膝关节骨关节炎女性患者为研究对象(手术组)。患者年龄50～69岁,平均57.2岁。病程4～7年,平均5.6年。骨关节炎分级:Kellgren-LawrenceⅢ级5例,Ⅳ级15例。术前髋-膝-踝角(hip-knee-ankle angle,HKA)为(170.8±5.6)°,内翻畸形。按照年龄及侧别进行配比,选择20名健康女性志愿者为对照组。年龄51～70岁,平均56.7岁;HKA为(178.8±0.6)°。两组HKA比较差异有统计学意义(t=6.352,P=0.000)。比较手术组手术前后HKA、美国西部Ontario与McMaster大学骨关节炎指数评分(WOMAC)及疼痛视觉模拟评分(VAS)。术后6个月使用Vicon三维步态捕捉系统进行步态分析,比较手术组与对照组运动学参数,包括步速、步频、步长以及支撑相膝关节最大屈曲角度、支撑相膝关节最小屈曲角度、摆动相膝关节最大屈曲角度、支撑相平均髋关节旋转角度、支撑相平均踝关节旋转角度。结果手术组患者术后切口均Ⅰ期愈合,无手术相关并发症发生。患者均获随访,随访时间7～12个月,平均9.0个月。术后6个月WOMAC评分及VAS评分均优于术前(P0.05)。影像学复查示,术后4周HKA为(178.8±0.8)°,与术前比较差异有统计学意义(t=39.203,P=0.000);假体位置良好,股骨后髁截骨线、外科通髁线及髌骨横轴平行,内翻畸形均矫正,下肢力线恢复至中立位。术后6个月步态分析显示两组运动学参数比较,差异均有统计学意义(P0.05)。结论与健康人群相比,3D打印导板辅助TKA术后早期患者步态主要表现为步速、步频及步长减小,膝关节屈曲范围减小,代偿性髋关节及踝关节旋转范围增大的特点。     

内侧开放楔形胫骨高位截骨术治疗膝关节内翻畸形的临床应用

目的比较内侧开放楔形胫骨高位截骨术(OWHTO)与人工全膝关节置换术(TKA)治疗膝关节内翻畸形的手术和术后下肢力线的疗效。方法原发性膝内侧骨关节炎伴内翻畸形病人28例,根据病人意愿分成两组,HTO组16例,行OWHTO术;TKA组12例,行TKA术。记录两组手术时间、术中出血量、切口长度、住院费用。使用目测类比法评分(VAS)、膝关节活动度(ROM)和美国特种外科医院(HSS)评价术后疗效,下肢全长X线片测量股胫角(FTA)和髋-膝-踝角(HKA)评估下肢力线。结果 HTO组手术时间(92.10±7.58)分钟、术中出血量(394.40±54.03)ml、切口长度(7.20±1.80)cm、住院费用(30893.10±1177.70)元,TKA组分别为(104.30±7.20)分钟、(505.80±70.51)ml、(10.40±2.19)cm和(45801.90±1097.18)元,两组比较差异有统计学意义(P0.05)。两组病人术前及术后6个月VAS评分、ROM测量和HSS评分比较,差异无统计学意义(P0.05)。HTO组术后1个月VAS(4.30±0.93)分、ROM(109.30±3.61)°、HSS(71.90±5.09)分,TKA组分别为(5.30±1.07)分、(105.10±2.75)°、HSS(67.50±4.27)分,两组比较差异有统计学意义(P0.05)。两组FTA和HKA结果比较差异无统计学意义(P0.05)。HTO组术后FTA(173.80±2.18)°、HKA(185.00±1.41)°,与术前FTA(183.10±4.25)°、HKA(171.40±3.50)°比较,TKA组术后FTA(174.00±1.65)°、HKA(184.30±1.66)°,与术前FTA(181.40±4.21)°、HKA(169.50±3.42)°比较,差异均具有统计学意义(P0.05)。结论 OWHTO技术简单,创伤小,畸形矫正较精确,恢复快,花费少。     

人工全膝关节置换术中联合股骨外髁滑移截骨术矫正股骨外弓畸形的疗效分析

目的探讨人工全膝关节置换术(total knee arthroplasty,TKA)中采用股骨外髁滑移截骨术(lateral condyle sliding osteotomy,LCSO)矫正股骨外弓畸形的疗效。方法回顾分析2018年7月—2020年7月TKA中采用LCSO治疗的17例伴股骨外弓畸形的骨关节炎患者临床资料。男3例,女14例;年龄58~68岁,平均63.2岁。股骨外弓畸形病因:股骨发育畸形12例,股骨骨折畸形愈合5例。膝关节骨关节炎KellgrenLawrence分级:Ⅲ级4例,Ⅳ级13例。术前生理外翻角为9.5°~12.5°,平均10.94°。病程3~25年,平均15.1年。术前及末次随访时测量股骨远端机械外侧角(mechanical lateral distal femur angle,mLDFA)、髋-膝-踝角(hip-knee-ankle angle,HKA)、机械轴偏向(mechanical axis deviation,MAD),评估关节外畸形在关节内矫正及下肢机械力线恢复情况;采用膝关节学会评分系统(KSS)膝评分和功能评分、疼痛视觉模拟评分(VAS)、膝关节活动度(range of motion,ROM)评估疗效;行膝内、外翻应力试验,X线片复查截骨片愈合情况,评估关节稳定性及LCSO的安全性。结果术后患者切口均Ⅰ期愈合,无切口感染、下肢深静脉血栓形成等术后早期并发症发生。17例患者均获随访,随访时间12~36个月,平均23.9个月。截骨片均达骨性愈合,愈合时间2~5个月,平均3.1个月。术后膝内、外翻应力试验均为阴性,未发生外侧副韧带松弛、断裂,膝关节不稳,假体松动、翻修、感染等情况。末次随访时mLDFA、HKA、MAD及膝关节ROM、VAS评分、KSS膝评分和功能评分均较术前显著改善,差异有统计学意义(P<0.05)。结论在伴有股骨外弓畸形TKA中应用LCSO疗效确切且安全,关节外畸形在关节内矫正,一次手术可同时恢复下肢机械力线和关节平衡。     

Varus Gonarthrosis Predisposes to Varus Malalignment in TKA

Postoperative alignment is a predictor for long-term survival of total knee arthroplasty (TKA). The purpose of this study was to evaluate whether or not preoperative deformities predispose to intraoperative malposition of TKA components. A retrospective radiographic analysis of 53 primary TKA cases was performed. Preoperative AP hip to ankle and lateral knee radiographs were compared with postoperative views to evaluate component positioning. The following angles were measured: the hip–knee–ankle (HKA) angle expressing the mechanical axis of the leg, the mechanical lateral distal femur angle (mLDFA), the medial proximal tibia angle (MPTA), the posterior distal femur angle (PDFA), and the posterior proximal tibia angle (PPTA). Postoperative measurement of the HKA revealed 34.0% of the cases had a deviation of >±3° from neutral alignment. Sixteen knees (30.2%) were in varus and, with one exception, all presented with severe varus gonarthrosis prior to surgery with a mean tibiofemoral angle of 12.4° compared with 1.0° of valgus in the optimally aligned group. Patients (93.3%) with preoperative valgus malalignment showed optimal postoperative HKA. Odds ratios for malalignment of TKA for varus knees in comparison with valgus knees were 7.1 for HKA, 2.4 for MPTA, 4.9 for PDFA, and 1.7 for PPTA. The overall number of outliers in the presented data corresponds well with reports from other authors using different implants and guide systems. The presented data indicate that patients with preoperative varus alignment have a higher risk of postoperative implant malposition than patients with valgus alignment. The data supports that preoperative varus deformity predisposes to varus malposition of TKA. The risk for intraoperative malposition is significantly lower in valgus knees.     

Femoral Lateral Bowing and Varus Condylar Orientation Are Prevalent and Affect Axial Alignment of TKA in Koreans

Background

Coronal alignment is considered key to the function and longevity of a TKA. However, most studies do not consider femoral and tibial anatomical features such as lateral femoral bowing and the effects of these features and subsequent alignment on function after TKA are unclear.

Questions/purposes

We therefore determined (1) the prevalence of lateral femoral bowing, varus femoral condylar orientation, and severe tibia plateau inclination in female Koreans undergoing TKA; (2) whether postoperative alignments are affected by these anatomical features and improved by the use of navigation; and (3) whether postoperative coronal alignments are associated with function.

Methods

We measured alignment in 367 knees that underwent TKA and 60 sex- and age-matched normal knees (control group). We determined patterns and degrees of femoral bowing angle, femoral condylar orientation, and tibial plateau inclination on preoperative full-limb radiographs. Postoperatively, coronal alignment of limbs and of femoral and tibial components was measured. We compared American Knee Society scores, WOMAC scores, and SF-36 scores in aligned knees and outliers (beyond ± 3° or ± 2°) at 1 year.

Results

The prevalence of lateral femoral bowing was 88% in the TKA group and 77% in the control group. Mean femoral condylar orientation angle was varus 2.6° in the TKA group and valgus 1.1° in the control group, and mean tibial plateau inclination was varus 8.3° in the TKA group and varus 5.4° in the control group. Femoral lateral bowing and varus femoral condylar orientation were associated with postoperative alignments. Several clinical outcome scales were inferior in the outliers in mechanical tibiofemoral angle, anatomical tibiofemoral angle, and tibial coronal alignment but not in femoral coronal alignment outliers.

Conclusions

Lateral femoral bowing, varus condylar orientation, and severe varus inclination of the tibia plateau should be considered when performing TKA in Korean patients or patients with otherwise similar anatomical features.     

Influence of limb alignment and prosthetic orientation on patient-reported clinical outcomes in total knee arthroplasty

BackgroundThe relationship between postoperative limb alignment and clinical outcomes in primary total knee arthroplasty (TKA) is well reported, but the instruments used to evaluate clinical outcomes of TKA are mainly scoring systems from the physician's viewpoint, not patient-reported outcomes. The purpose of this study was to investigate retrospectively the relationship between postoperative limb alignment and patient-reported clinical outcomes using the 2011 Knee Society Knee Scoring System (2011 KSS).MethodsThe present study included 155 knees of patients (median age, 74 years) who underwent primary TKA for varus osteoarthritis, with a mean follow-up period of 46 months. The subjects were divided into three groups based on postoperative limb alignment and femoral and tibial component positioning angle (varus, neutral, and valgus). The 2011 KSS scores were compared among the groups.ResultsFor limb alignment, the postoperative objective knee indicator score was significantly lower in the valgus group than in the varus and neutral groups, whereas no significant differences were observed in any subjective categories of the 2011 KSS. However, for the femoral component angle, functional activity scores were significantly lower in the valgus group than in the varus and neutral groups.ConclusionsThe subjective patient-reported score was not affected by the postoperative limb alignment. However, the valgus femoral component angle resulted in lower subjective functional scores. For clinical relevance, postoperative valgus positioning of femoral component should be avoided from patient-reported functional aspects during TKA.     

全膝关节置换术中股骨内髁滑移截骨治疗伴有关节外畸形的膝内翻

目的：探讨股骨内髁滑移截骨术（medial condyle sliding osteotomy, MCSO）在全膝关节置换术中纠正患者内翻膝关节外畸形的临床疗效。方法通过回顾性研究2013年1月至2015年12月在第三军医大学附属西南医院关节外科中心于全膝关节置换术中采用MCSO在关节内纠正股骨侧的关节外内翻畸形的12例患者,统计该组患者手术前后的股骨远端外侧力线角（mechanical lateral distal femoral angle, mLDFA）、髋-膝-踝（hip?knee?ankle, HKA）角、疼痛视觉模拟量表（visual analogue scale, VAS）评分及美国膝关节协会（American Knee Society, AKS）综合评分系统中的膝评分和功能评分等,评价MCSO纠正关节外的内翻畸形的效果。结果本组患者随访6~40个月,无感染、骨折、假体松动、截骨不愈合等并发症发生。本组患者手术前后的mLDFA分别为117.4°±4.7°、91.6°±1.4°;手术前后的HKA角分别为167.2°±9.8°、179.6°±1.6°;手术前后的VAS评分分别为（6.4±1.1）分、（1.8±1.5）分;手术前后的AKS膝评分分别为（60.2±17.6）分、（92.6±9.4）分;手术前后的AKS功能评分分别为（69.4±21.3）分、（87.6±14.9）分。手术前后以上指标的差异均有统计学意义（均P＜0.05）。结论在合并关节外畸形的内翻膝的关节置换手术中,采用MCSO技术可以正确纠正内翻力线,更容易实现伸屈间隙平衡,达到满意的手术疗效。能有效避免对膝关节后内侧和内侧组织结构的过度松解,从而避免单纯依赖软组织松解而导致的屈曲位内侧间隙松弛及髌股关节对位不良等问题。     

Accuracy of Image-Free Computer Navigated Total Knee Arthroplasty Is Not Compromised in Severely Deformed Varus Knees

In severe varus knee deformity, image-free computer navigated total knee arthroplasty (TKA) may result in a malaligned knee. The aim of this study was to compare the results of 17 severe varus knees (≥ 20°) and 81 varus knees (< 20°) that underwent image-free computer navigated TKA and analyze postoperative malalignment. Computer navigated TKA was performed according to standard protocol, and component angles and mechanical axes were evaluated postoperatively with weight bearing full-length standing radiographs. All severe varus knees were corrected to within 3° of neutral lower limb alignment despite having a mean preoperative varus deformities of 22.4°. Neutral alignment was obtained in 88.9% of the varus group (mean preoperative varus deformity of 11.7°), without significant difference between the two groups. No significant difference was found in either the femoral or tibial component angles, or in the frequency of complications. Severity of varus deformity did not affect the accuracy of image-free computer navigated TKA.     

Femoral Bow Predicts Postoperative Malalignment in Revision Total Knee Arthroplasty

Diaphyseal bowing may compromise axial alignment in revision total knee arthroplasty (TKA). 277 patients undergoing revision TKA were evaluated for coronal bowing and hip–knee–ankle (HKA) axis. The mean femoral bow was 1.52° ± 0.18° varus (− 10.1° to + 8.4°). The mean tibial bow was 1.25° ± 0.13° valgus (− 5.9° to + 10°). HKA axis averaged 3.08° ± 0.35° varus preoperatively compared to 0.86° ± 0.25° varus postoperatively. Inter-rater and intra-rater reliability was high. Femoral bow greater than 4° significantly correlated with postoperative HKA axis malalignment (r = 0.402, P = 0.008). 39.7% of patients deviated 3° or greater from a neutral mechanical axis with a significant difference in femoral bow (0.94° ± 0.31°, P = 0.003). Diaphyseal bowing clearly has an important effect on postoperative limb alignment in revision TKA.     

Risk factors of post-operative malalignment in fixed-bearing medial unicompartmental knee arthroplasty

Purpose

The purpose of this study was to identify risk factors of post-operative malalignment in medial unicompartmental knee arthroplasty (UKA) using multivariate logistic regression.

Methods

We retrospectively enrolled 92 patients who had 127 medial UKAs. According to post-operative limb mechanical axis (hip-knee-ankle [HKA] angle), 127 enrolled knees were sorted into acceptable alignment with HKA angle within the conventional?±?3 degree range from a neutral alignment (n?=?73) and outlier with HKA angle outside?±?3 degree range (n?=?54) groups. Multivariate logistic regression was used to analyse risk factors including age, gender, body mass index, thickness of polyethylene tibial insert, pre-operative HKA angle, distal femoral varus angle (DFVA), femoral bowing angle (FBA), tibial bone varus angle (TBVA), mechanical distal femoral and proximal tibial angles, varus and valgus stress angles, size of femoral and tibial osteophytes, and femoral and tibial component alignment angles.

Results

Pre-operative DFVA, TBVA and valgus stress angle were identified as significant risk factors. As DFVA increased by one degree, malalignment was about 45 times probable (adjusted OR 44.871, 95 % CI 2.608–771.904). Shift of TBVA and valgus stress angle to a more varus direction were also significant risk factors (adjusted OR 13.001, 95 % CI 1.754–96.376 and adjusted OR 2.669, 95 % CI 1.054–6.760).

Conclusions

Attention should be given to the possibility of post-operative malalignment during medial UKA in patients with a greater varus angle in pre-operative DFVA, TBVA and valgus stress angle, especially with a greater varus DFVA, which was the strongest predictor for malalignment.

     

Does the Preoperative Varus Deformity Influence the Survival of Postoperative Neutral-Aligned TKAs? An Analysis With a Minimum 5-Year Follow-Up

Background

Postoperative neutral alignment may be an important factor for longevity of total knee arthroplasty (TKA). In knees with severe varus deformity, greater soft tissue release and bone resection were required to achieve neutral alignment. We investigated the relationship between the severity of preoperative varus deformity and longevity of neutral-aligned TKAs.

胫骨后倾截骨对后十字韧带保留型全膝关节置换术疗效的影响

目的 探讨胫骨后倾截骨对后十字韧带保留型全膝关节置换术后临床疗效的影响.方法 2008年1月至2009年3月应用胫骨后倾5°截骨(后倾组)进行后十字韧带保留型全膝关节置换治疗骨关节炎患者27例(27膝),男7例7膝,女20例20膝;平均年龄69.5岁.同期应用胫骨后倾0°截骨(非后倾组)57例57膝,男15例15膝,女42例42膝;平均年龄67.4岁.两组患者术前一般资料、膝关节最大伸直角度、最大屈曲角度和美国膝关节协会评分(knee society score,KSS评分)差异均无统计学意义.比较术后两组胫骨后倾角、关节最大伸直角度、最大屈曲角度和KSS评分的差异.结果 所有患者均获随访12～24个月,平均(15.7±4.3)个月.未发生腓总神经损伤、伤口感染、假体脱位、假体松动等并发症.后倾组术后胫骨后倾角5.7°±2.1°,非后倾组0.9°±0.6°.后倾组术后关节最大伸直角度0.8°±0.3°,非后倾组1.2°±0.4°,差异无统计学意义.后倾组术后关节最大屈曲角度115.7°±4.8°,非后倾组101.1°±5.6°,差异有统计学意义.后倾组术后KSS评分(87.6±5.9)分,非后倾组(83.3±7.2)分,差异无统计学意义.结论 在后十字韧带保留型全膝关节置换术中胫骨后倾截骨可以增加术后关节最大屈曲角度,但对最大伸直角度和KSS评分无明显影响.