术前活动度对人工全膝关节置换术后功能影响的观察

目的回顾性分析患者手术前的活动度对人工全膝关节置换(TKA)术后功能的影响。方法随访2000年1月—2003年12月在我科行TKA的患者65例(97膝),年龄64．8±9．9岁(35～85岁)。其中骨性关节炎55例(81膝),类风湿关节炎10例(16膝)。单膝置换33例,双膝同时置换32例。所有患者按术前膝关节活动度数(ROM)分成两组,≤90°(5°～90°)49膝,>90°(95°～140°)48膝。对两组患者进行疗效(最大屈膝度、活动度、KSS评分及功能评分)对比。所有患者均采用Scorpio后稳定型骨水泥固定的假体,均为初期置换,全部手术由同一组医师完成。术后3 d在同一康复师指导下行患肢CPM及主动功能锻炼至出院。结果平均随访时间29个月(10～44个月)。所有膝关节的活动度从术前的平均84．2°(5°～140°)提高到术后的平均101．6°(40°～140°) (P=0．000);而最大屈膝度数术前的平均103．5°(25°～140°)与术后的平均101．6°(40°～140°)无显著差异(P=0．439);KSS膝关节评分从术前平均19．5分(-24～62分)提高到术后平均78．8分(50～95分)(P=0．000)。所有患者的总满意度为93．8％(61／65)。两个分组比较,ROM≤90°的膝关节ROM及最大屈膝度术后均较术前有提高,而ROM>90°的膝关节平均最大屈膝度术后反而下降。没有翻修及深部感染。结论(1)在影响TKA术后膝关节功能的多种因素中,手术技术是关键因素。(2)在其他因素相同的情况下,术前膝关节的活动度对TKA术后的功能也有很大的影响,术前活动度大的膝关节比那些术前活动度小的膝关节术后能获得更好的功能。     

Total knee arthroplasty in bony ankylosis in gross flexion

Between June 1993 and December 1994, we performed total knee arthroplasty (TKA) on 27 knees in 24 patients with spontaneous bony ankylosis in severe flexion. The mean age at operation was 43.5 years (30 to 60). No patient had preoperative pain. Three were unable to walk and 21 could manage less than five blocks. The mean duration of the ankylosis was 18.7 years (13 to 25) and its mean position was 105 degree flexion (75 to 135). The preoperative Hospital for Special Surgery Knee Score of 60 points was improved to 87 at the final follow-up three to five years later. All knees were free from pain. The mean range of active flexion in 24 knees was 97 degrees (78 to 115) and the mean arc of movement 91 degrees (78 to 98). The mean fixed flexion deformity was 6 degrees (0 to 25) and the extension lag 8 degrees (0 to 25). Angular deformity was corrected to between 0 degrees and 10 degrees of valgus. Four patients were able to walk one block and 20 five to seven blocks. Thirteen knees (48%) showed some necrosis at the skin edge; one knee required arthrodesis and another resection arthroplasty. One had a recurrence of tuberculous infection requiring arthrodesis. One patient had a rupture of the quadriceps tendon. To date no prosthesis has required revision for loosening. Radiolucency of 1 mm or less about the tibial prosthesis was observed at follow-up in four of the 24 knees. Our results have shown that one-stage TKA and skeletal traction after operation can achieve correction of severe flexion deformity of the knee with marked improvement in the function and quality of life.     

高屈曲度人工全膝关节置换术的临床疗效

目的 探讨影响人工全膝关节置换术患者术后屈膝的因素,以及获得相对最大屈曲度的技术.方法 自2002年3月至2007年3月,85例患者102膝行高屈曲度人工全膝关节置换术(LPS-Flex knee arthroplasty,LF-KA),男16例17膝,女69例85膝;年龄35～79岁,平均64.9岁.膝关节骨关节炎94膝,类风湿关节炎8膝.膝内翻畸形82膝(平均12.8°±3.1°),膝外翻畸形7膝(平均5.1°±2.4°),屈曲畸形31膝(平均15.6°±4.9°).骨缺损5膝.膝关节骨关节炎患者术前活动度为61°～135°,平均110.5°;类风湿关节炎患者为41°～120.,平均85.5°.手术均采用NexGen,LPS-Flex假体.临床疗效以HSS评分为标准,根据影像学资料评估膝关节假体位置、下肢力线以及骨缺损修复情况.结果 66例81膝随访24～60个月,平均39个月.术前HSS平均(69.6±7.4)分,术后平均(90.9±4.8)分.优64膝,良11膝,中4膝,差2膝,优良率为92.6%.膝关节活动度由术前平均100.5°,改善至术中平均136.8°,终末随访时平均127.5°.结论 膝关节活动度的改善对满足患者的日常生活需要尤为重要.患者术前活动度、手术技术、特殊的假体设计以及积极的术后锻炼都是实现全膝关节置换术后最大屈曲度的重要因素.但肥胖、有膝关节手术史、强直性脊柱炎等患者,人工全膝关节置换术后的活动度都会受到一定的限制.     

Influence of hip position on knee flexion angle in patients undergoing total knee arthroplasty

The influence of hip position on knee flexion angle before total knee arthroplasty (TKA) and that after TKA were investigated and compared. Sixty-six patients (70 knees) with osteoarthritis who were undergoing TKA were examined using lateral radiographs of maximum knee flexion angle with the hip joint at 0 degrees extension and 90 degrees flexion. The postoperative rate of decrease in knee flexion angle caused by hip extension was significantly larger compared with the value before surgery. The preoperative rate of decrease in knee flexion angle caused by hip extension showed strong inverse correlation with the preoperative and postoperative knee flexion angle ratio. In conclusion, tightness of the extensor mechanism is present in all knees undergoing TKA and especially has a strong influence on the postoperative flexion angle of the knee.     

增加胫骨平台后倾角度、后交叉韧带部分松解对全膝关节置换术后膝关节运动影响的实验研究

目的通过增加胫骨平台后倾角度或后交叉韧带（PCL）部分松解对全膝关节置换术（TKA）中屈曲间隙过紧进行处理,分析这两种方法对TKA术后膝关节运动学的影响。方法测量6例新鲜尸体膝关节标本在完整状态下、正常TKA、屈曲间隙过紧、增加胫骨平台后倾角以及PCL部分松解TKA术后膝关节屈曲0°、30°、60°、90°、120°时的前后松弛度、内外翻松弛度、旋转松弛度及最大屈曲度。结果屈曲过紧TKA与正常TKA相比,在屈曲30°、60°、90°和120°时前后松弛度、内外翻松弛度及旋转松弛度均显著较小（P〈0．05）。与屈曲过紧TKA相比,增加胫骨后倾角后,在屈曲30°、60°、90°和120°时前后松弛度、内外翻松弛度和旋转松弛度均明显增大（P〈0．05）。PCL部分松解与屈曲过紧TKA相比,在屈曲30°、60°、90°和120°时前后松弛度明显增加（P〈0．05）;旋转松弛度在屈曲30°、60°、90°时明显增加（P〈0．05）。与PCL部分松解相比,增加胫骨后倾角的内外翻松弛度在屈曲30°、60°、90°时明显较大（P〈0．05）;旋转松弛度在屈曲0°、30°、60°和90°时明显较大（P〈0．05）。屈曲过紧TKA的最大屈曲度（120．4°）与正常TKA（130．3°）及增加胫骨后倾角（131．1°）相比明显较小（P〈0．05）。增加后倾角与PCL部分松解（124．0°）相比,最大屈曲度较大,但差异无统计学意义（P=0．0816）。结论屈曲间隙过紧TKA术后膝关节的前后松弛度、内外翻松弛度、旋转松弛度和最大屈曲度均减小;增加胫骨平台后倾角后,前后松弛度、内外翻松弛度、旋转松弛度和最大屈曲度均明显增大;PCL部分松解仅能明显增大前后松弛度。因此对于TKA术中屈曲紧张的膝关节,增加胫骨平台后倾角比PCL部分松解能更好地改善膝关节的运动学。     

膝关节类风湿关节炎伴重度屈曲畸形患者关节置换术后的中长期随访

目的分析膝关节类风湿关节炎(RA)伴重度屈曲畸形行全膝关节置换术(TKA)中长期随访结果,探讨其关键的手术技术和康复措施。方法 1998年1月至2005年12月,18例RA伴重度屈曲畸形患者32膝行TKA,平均年龄38.8岁。RA病程14.2年,畸形时间6.5年;术前畸形67.5°,活动度20.3°,合并内翻畸形3例,外翻11例;术前股四头肌肌力3级7例,4级11例;HSS评分21.1分。术前锻炼股四头肌肌力,术中软组织松解及增加截骨,术后伸直支具及伸膝锻炼。术后1、2、3、6、12个月及以后每年随访,评价关节活动度、生存率、HSS评分等。结果 16例患者获得随访,5～10年随访10例18膝,10年以上6例11膝。最后一次随访,膝关节屈曲畸形3.7°,活动度103.2°,HSS评分为81.4分,与术前相比差异有统计学意义(P<0.05)。2膝翻修,假体生存率93.1%。无感染及侧副韧带损伤。结论通过加强术前术后股四头肌功能训练,术中软组织松解及增加股骨远端截骨,膝关节RA伴重度屈曲畸形患者TKA术后中长期随访效果满意。     

Factors affecting flexion gap tightness in cruciate-retaining total knee arthroplasty

With the exception of flexion gap tightness, which is common in cruciate-retaining (CR) total knee arthroplasty (TKA), the risk factors of flexion gap tightness have not been described. This retrospective study characterized factors that are associated with flexion gap tightness in CR TKA. Data on 203 consecutive knees that underwent CR TKA were reviewed. The prevalence rate of flexion gap tightness was 21.1%. By logistic regression analysis after adjusting for age, preoperative flexion contracture, and referencing method used for femoral sizing, insufficient tibial slope remained a significant independent risk factor of flexion gap tightness. Although excessive tibial slope should be avoided, the findings of the present study demonstrate that the risk of flexion gap tightness can be reduced by increasing the tibial slope in CR TKA.     

In vivo kinematic comparison of posterior cruciate ligament retention or sacrifice with a mobile bearing total knee arthroplasty

Video fluoroscopy and computer photogrammetry was used to evaluate 20 knees with posterior cruciate ligament (PCL) retaining and 19 knees with PCL sacrificing total knee arthroplasties (TKAs) with a mobile bearing total condylar prosthesis compared with 10 normal patients. In extension, femorotibial contact was posterior for TKA patients (P<.05) and demonstrated anterior translation from 60 degrees-90 degrees flexion. However, posterior rollback with limited translation was seen from 0 degrees-40 degrees, which may reflect the high congruity of this prosthesis. Fifty percent of meniscal bearing implants demonstrated bearing translation. Kinematics and weight-bearing range of motion were similar with PCL retention or sacrifice.     

不同程度屈膝挛缩畸形人工全膝关节置换的早期疗效比较

目的探讨不同程度屈膝挛缩畸形行人工全膝关节置换术(totalkneearthroplasty,TKA)后的早期疗效。方法回顾性分析2000年1月～2003年12月行TKA的65例97膝屈膝挛缩畸形患者资料。其中骨关节炎51例74膝,类风湿关节炎14例23膝。单膝置换33例33膝,双膝同时置换32例64膝。按屈膝挛缩畸形程度不同将患者分成A、B两组,A组屈曲挛缩<20°(0～15°)32例49膝,B组屈曲挛缩≥20°(20～60°)33例48膝。A、B两组膝关节术前屈曲挛缩度数、活动度(rangeofmotion,ROM)、KSS(kneesocietyscore)评分及功能评分分别为10.7±8.0°、104.6±20.0°、29.1±18.0、32.6±20.7和28.2±7.8°、60.8±26.6°、12.1±13.2、26.8±18.1,各指标组间比较差异均有统计学意义(P<0.05)。术中均采用Scorpio后稳定型骨水泥固定假体,行初期置换。术后3～4d在同一康复师指导下行CPM及主动功能锻炼。结果患者获随访8个月～3年6个月,平均2年7个月。A、B组术后膝关节屈曲挛缩度数、ROM、KSS评分和功能评分分别为0.4±2.1°、108.6±19.0°、82.1±13.8、72.3±29.1和1.3±3.2°、98.6±16.4°、75.9±8.2、81.4±26.9,组间比较差异均无统计学意义(P>0.05)。术后患者总满意度为94.6%,无深部感染及再翻修者。结论膝关节屈膝挛缩畸形严重与否对TKA的早期疗效无明显影响;TKA后ROM有“趋中”现象;术后早期行膝关节功能锻炼也是获得功能改善的重要环节之一。     

Tibiofemoral force following total knee arthroplasty: comparison of four prosthesis designs in vitro.

Despite ongoing evolution in total knee arthroplasty (TKA) prosthesis design, restricted flexion continues to be common postoperatively. Compressive tibiofemoral force during flexion is generated through the interaction between soft tissues and prosthesis geometry. In this study, we compared the compressive tibiofemoral force in vitro of four commonly used prostheses: fixed-bearing PCL (posterior cruciate ligament)-retaining (PFC), mobile-bearing posterior-stabilized (PS), posterior-stabilized with a High Flex femoral component (HF), and mobile-bearing PCL-sacrificing (LCS). Fourteen fresh-frozen cadaver knee joints were tested in a passive motion rig, and tibiofemoral force measured using a modified tibial baseplate instrumented with six load cells. The implants without posterior stabilization displayed an exponential increase in force after 90 degrees of flexion, while PS implants maintained low force throughout the range of motion. The fixed-bearing PFC prosthesis displayed the highest peak force (214 +/- 68 N at 150 degrees flexion). Sacrifice of the PCL decreased the peak force to a level comparable with the LCS implant. The use of a PCL-substituting post and cam system reduced the peak force up to 78%, irrespective of whether it was a high-flex or a standard PS knee. However, other factors such as preoperative range of motion, knee joint kinematics, soft tissue impingement, and implantation technique play a role in postoperative knee function. The present study suggests that a posterior-stabilized TKA design might be advantageous in reducing soft tissue tension in deep flexion. Further research is necessary to fully understand all factors affecting knee flexion after TKA.     

Posterior condylar offset and flexion in posterior cruciate-retaining and posterior stabilized TKA

Background Anterior tibial translation associated with posterior impingement has been reported to be one of the factors limiting flexion after posterior cruciate-retaining (CR) total knee arthroplasty (TKA), especially when posterior condylar offset is decreased postoperatively. On the other hand, its effect on postoperative motion in posterior-stabilized (PS) TKA remains unknown. It has been demonstrated that PS TKA exhibits a consistent posterior femoral rollback during flexion. Thus, we hypothesized that the problem of posterior impingement can be avoided by use of PS TKA. In this study, we examined the relationship between postoperative posterior condylar offset and knee flexion in CR and PS TKAs. Methods In this study, analysis was performed for 20 subjects who underwent bilateral TKAs (one CR and one PS TKA) as well as another group of 50 PS TKAs. All patients could be tracked for a minimum of 2 years. The range of flexion was measured before operation and at follow-up. Preoperative and postoperative posterior condylar offset was evaluated on true lateral radiographs. Results At the follow-up examination, the mean flexion angle was 123° in the CR knees and 131° in the PS knees with a significantly greater improvement observed for the latter group. In the roentgenographic measurement of the posterior condylar offset, no significant difference was observed between the preoperative and postoperative values both in the CR and PS knees. We divided the patients into two groups according to the change of posterior condylar offset. The first group (Group I) showed a decrease in the posterior condylar offset after surgery and the second group (Group II) showed no change or an increase. Subsequently, postoperative change in flexion was compared between Groups I and II for the CR and PS knees. A significant difference between Groups I and II was observed in the CR knees, while no difference was observed in the PS knees. The magnitude of postoperative posterior condylar offset did not correlate with an improvement in maximum flexion angle in the 50 PS knees. Conclusions It was shown that the magnitude of posterior condylar offset correlated with a postoperative change in flexion angle in CR knees, while no such correlation was observed in PS knees.     

全膝关节置换术中股骨假体屈曲对髌股关节生物力学影响的实验研究

[目的]探讨全膝置换术中股骨假体矢状位上屈曲对髌股关节生物力学的影响,为临床指导人工膝关节置换的手术技术提供实验依据,以减少术后髌股关节的并发症。[方法]取正常国人新鲜冷冻尸体的5个膝关节作为研究对象,模拟膝关节自站立位屈膝下蹲的动作,设计制作膝关节实验架,与生物力学测试仪共同搭建实验平台。人工膝关节采用DePuy PFC假体全膝系统,手术由同一位有经验的术者实施以控制实验误差,置换髌骨。比较股骨假体相对于按下肢力线位、前屈5°、10°及后屈5°、10°、15°位置时的髌股关节的生物力学指标。选择屈膝30°、60°、90°、120°为观察角度,采用美国Tecscan公司生产的感测片测定髌股关节接触压峰值,最后软件处理得到数字化的结果。[结果]除了在膝关节屈曲30°、60°、90°,股骨假体前屈5°时,髌股关节内侧间隙接触压峰值与下肢力线位相比较无显著性差异(P>0.05),其余各种屈膝角度下,股骨假体不同屈曲角度所致髌股关节内外侧间隙接触压峰值与下肢力线位比较有显著性差异(P<0.05)。股骨假体后屈角度越大,峰值的升高越明显。[结论]全膝关节置换术中,股骨假体在矢状位上争取按下肢力线位置入,以降低术后并发症的发生。     

晚期类风湿关节炎患者的假体选择疗效对比

目的探讨晚期膝关节类风湿关节炎(RA)伴重度内翻屈曲畸形和严重骨质疏松患者行全膝关节置换术(TKA)假体选择及临床效果。 方法对2010年1月至2015年12月采用全膝关节置换治疗的晚期RA伴重度内翻屈曲畸形患者21例(27膝)进行回顾性分析。13例17膝采用后稳定型假体,8例10膝采用限制型假体。纳入标准：类风湿性关节炎合并膝关节重度内翻畸形;类风湿性关节炎合并膝关节患者骨密度T-Score<－2.8;无严重心肺疾病。排除标准：合并关节原发性或继发性活动期感染;合并关节外畸形通过单纯截骨无法矫正的患者。采用SPSS 16. 0统计软件分析,术前、术后屈曲挛缩度数、关节活动度及胫骨角均值比较采用配对样本t检验。 结果本组21例27膝均获得随访,病例随访时间2.0～5.3年,平均(3.8±1.1)年。后稳定组膝关节屈曲挛缩由术前(55. 5±12. 5)°(65.0°～85.0°)减少到末次随访时(5. 5±3. 5)°(0°～10.0°)(t ＝28.868,P < 0.01),关节活动度由(32. 5±6. 5)°(0°～40.0°)提高到末次随访时(105. 5±10. 5)°(85.0°～130.0°)(t ＝94.83,P < 0.01);股胫角由术前(31.0±3.5)°(23.0°～45.0°)修正为末次随访时(8.5±2.5)°(0°～12.0°)(t ＝116.913,P <0.01)。限制型假体组膝关节屈曲挛缩由术前(56.5±15.5)°(65.5°～80.0°)减少到末次随访时(6.0±5.0)°(5.0°～15.0°)(t＝25.486,P < 0.01),关节活动度由(32. 0±8.0)° ( 0°～40.0°)提高到末次随访时(100.0±5.5)°(85.0°～120.0°)(t ＝141.335,P < 0.01);股胫角由术前(31.5±5.5)°(22.0°～45.0°)修正为末次随访时(8.0±4.5)°(0°～12.0°)(t＝122.11,P < 0.01),均较术前明显改善,手术前后差异有统计学意义。两组之间术前及末次随访比较各指标得知,限制型假体组显著低于后稳定组关节活动度(t ＝5.716,P <0.01),差异具有统计学意义。 结论对晚期RA伴膝关节重度内翻屈曲畸形和严重骨质疏松患者在假体选择方面,后稳定型假体活动度更好,但在纠正内翻屈曲畸形和股胫角疗效比较方面,未见显著差异,所有患者近期疗效满意。     

The natural history of flexion contracture in total knee arthroplasty. A prospective study

A prospective study was carried out to document the natural history of flexion contractures of the knee after total knee arthroplasty (TKA). Thirty-five knees in 33 patients with TKA were followed for a mean duration of 55 weeks. In no case did the surgical procedure include excessive bony resection in order to correct a flexion contracture. Standard goniometric measurements were used to determine the knee flexion contractures preoperatively and postoperatively while the patient was anesthetized and at each successive follow-up visit. All preoperative and postoperative flexion contractures were less than 30 degrees. The mean fixed flexion deformity of the entire group preoperatively was 12.9 degrees; immediately postoperatively, 14.8 degrees; and at final follow-up, 2.9 degrees. No difference was found in the amount of flexion contracture present at final follow-up evaluation with respect to age or gender. The impression that fixed flexion contractures must be corrected at the time of arthroplasty has led to the intraoperative removal of excess bone from the distal femur and/or proximal tibia. The present findings indicate that knee flexion contractures can significantly improve after TKA. There appears to be little, if any indication for excessive removal of bone in an attempt to achieve intraoperative correction.     

膝关节内翻屈曲畸形全膝关节置换的软组织平衡

目的探索对膝关节内翻屈曲畸形患者施行的全膝关节置换（total knee arthroplasty,TKA）软组织平衡技术。方法2001年1月～2005年12月,对实施的86例104膝骨性关节炎（osteoarthritis,OA）行TKA的膝内翻屈曲畸形患者进行回顾性研究,对术中的软组织平衡问题进行讨论。其中男19例23膝,女67例81膝;年龄57岁～78岁,平均66岁。行单侧TKA术68例,双侧18例。均为初次行TKA的OA患者。术前内翻角为6～34°,平均12.3°;其中软组织性内翻占总内翻角的56.7%,骨性内翻占43.3%。术前膝关节屈曲挛缩畸形10°以下21膝,10～19°45膝,20～29°22膝,30°以上16膝,平均18.9°。结果患者术前膝关节平均屈曲挛缩18.9°,术中除4例残留5°屈曲挛缩外,其余患者术中膝关节均能达到完全伸直。术后随访6～72个月,平均37个月,6例残留5～10°屈曲挛缩,余膝关节可达到完全伸直。术前内翻角6～34°,平均12.3°;术后测量股胫角170.3～175.6°,平均174.7°,其中2例残留内翻角〉3°。术中、术后发生并发症6例,其中内侧副韧带股骨起点损伤2例;髌骨弹响2例;脑栓塞及腔隙性脑梗塞各1例,经内科治疗后未遗留神经症状。均无皮肤坏死、切口感染及深部感染发生。结论软组织平衡是矫正膝关节内翻屈曲挛缩畸形的主要手段,良好合理的软组织平衡可使高度畸形的膝关节在TKA术后获得明显的功能恢复和畸形矫正。     

人工全膝关节置换术治疗终末期膝关节病变合并膝外翻畸形的手术技巧及临床疗效评价

目的探讨对终末期膝关节病变合并膝外翻畸形患者行经髌旁内侧入路人工全膝关节置换(total kneearthroplasty,TKA)时膝外翻畸形矫正方法及临床疗效。方法 1998年11月-2010年10月,收治64例72膝合并膝外翻畸形的终末期膝关节病变患者。男18例,女46例;年龄23～82岁,平均62.5岁。骨关节炎44例49膝,类风湿性关节炎17例20膝,血友病性关节炎2例2膝,创伤性关节炎1例1膝。双膝8例,单膝56例。膝关节屈伸活动度为(82.2±28.7)°,X线片测量股胫角为(18.0±5.8)°。膝关节学会评分系统(KSS)临床评分为(31.2±10.1)分,功能评分(37.3±9.0)分。根据Krackow膝外翻分型标准:Ⅰ型65膝,Ⅱ型7膝。手术经髌旁内侧入路,采用常规方法行股骨及胫骨截骨,Ranawat技术进行软组织松解。6例7膝采用保留后交叉韧带型假体,54例60膝采用后稳定型假体,4例5膝采用髁限制型假体。结果术后患者切口均Ⅰ期愈合。1例血友病性关节炎合并严重膝外翻畸形(股胫角41°)、屈曲挛缩20°的患者术后出现腓总神经麻痹,经保守治疗1年后神经功能恢复。1例术后2年发生深部感染,行二期翻修术后治愈。患者术后均获随访,随访时间1～13年,平均4.9年。末次随访时X线片示股胫角为(7.0±2.5)°,与术前比较差异有统计学意义(t=15.502,P=0.000)。KSS临床评分为(83.0±6.6)分,功能评分(85.1±10.5)分,膝关节屈伸活动度为(106.1±17.0)°,与术前比较差异均有统计学意义(P0.05)。5例遗留12～15°膝外翻畸形,但患膝关节功能良好。结论通过恰当的术中截骨和软组织平衡,采用经髌旁内侧入路TKA治疗合并膝外翻畸形的终末期膝关节病变可有效改善膝外翻畸形和恢复关节功能,临床疗效满意。     

Total knee arthroplasty in hemophilic arthropathy

Total knee arthroplasty (TKA) is very effective in relieving pain and improving function in patients with advanced hemophilic arthropathy. Because of intra-articular fibrosis and extra-articular muscle contracture, the gain in motion after TKA has been unsatisfactory. The purpose of this study is to report the results of TKA in patients with hemophilia using posterior cruciate ligament (PCL)-sacrificing prostheses. From April 1987 to May 1998, 9 patients underwent 14 PCL-sacrificing TKAs for advanced hemophilic arthropathy. The average length of follow-up evaluation in surviving patients (13 knees) was 77 months (range, 25-159). A statistically significant difference was found between the preoperative and postoperative values with respect to pain score (5 vs 48), functional score (42 vs 78), flexion deformity (17 degrees vs 5 degrees ), and flexion range (56 degrees vs 81 degrees ). Nine complications occurred in 6 knees. One patient died from HIV-related complications, and none of the patients seroconverted to HIV during the follow-up period.     

The Use of Navigation to Obtain Rectangular Flexion and Extension Gaps During Primary Total Knee Arthroplasty and Midterm Clinical Results

The authors evaluated 112 knees treated by total knee arthroplasty (TKA) using a navigation-assisted modified gap balancing technique. Initial mediolateral gap differences in extension and in 90° of flexion were measured after proximal tibia bone cutting. Final flexion and extension gaps were measured by checking distances under equal tension before prosthesis insertion. Amount of femoral bone cutting and external rotations of femoral components were found to depend on initial gaps. Patients with a final rectangular gap had greater knee flexion angles preoperatively and at 1 year after TKA. However, no differences were observed between the clinical and radiologic outcomes of knees with rectangular and nonrectangular gaps at 1 or 4 years after TKA. The study shows that the navigation-assisted modified gap balancing technique provides an effective means of achieving rectangular flexion and extension gaps during TKA.     

髌骨合理设计在全膝关节置换中的临床效果

目的探讨髌骨合理设计后重塑在全膝关节置换(TKA)中的临床效果。方法根据股骨假体滑动轨迹及所需置换髌骨的形态,对56例TKA患者(72膝)术中进行髌骨合理设计并重塑,观察患者术后的关节活动度及疼痛情况,用KSS膝关节评分系统评定治疗效果。结果 56例均获得随访,时间6~18个月。仅1例患者膝关节活动度70°,活动较差,但疼痛明显减轻;其余患者屈曲活动度在0°~110°。KSS评分:优69膝,良2膝,中1膝,优良率达到98.6%。结论术中根据股骨假体滑动轨迹对髌骨合理设计并重塑,可以使未进行髌骨置换的TKA患者取得满意的治疗效果。     

Association of increased knee flexion and patella clunk syndrome after mini-subvastus total knee arthroplasty

This study reviewed 747 consecutive posterior stabilized total knee arthroplasty (TKA) to explain the increased incidence of patella clunk syndrome that occurred when the surgeon switched from a medial parapatellar arthrotomy to a mini-subvastus (MIS) TKA technique. The incidence of patella clunk syndrome increased with increased postoperative knee flexion. Six weeks after surgery, knees that developed patella clunk had a mean flexion of 124 degrees vs 117 degrees for knees that did not develop this syndrome (P = .016). As the MIS approach resulted in increased knee flexion, this approach was indirectly associated with the increased incidence of patella clunk. Knee flexion at 6 weeks postoperatively was 117 degrees for the MIS knees vs 108 degrees for traditional medial parapatellar arthrotomy knees (P < .001). The effect of increased knee flexion achieved with the MIS approach, which resulted in an increase in patella clunk, was mitigated by using a new posterior stabilized femoral component designed to minimize soft tissue entrapment.