跟腱断裂修复术后康复治疗观察

目的 :探讨跟腱断裂修复术后康复治疗与自然恢复对疗效的影响。方法 :对80例采用手术治疗的跟腱断裂中的62例临床资料进行分析和平均18年随访。结果 :按尹庆水等疗效评定 :康复治疗组的优良率为91% (33/36) ,自然恢复组的优良率为73%(19/26) ;康复组 (36例 )术后感染2例 ,再断裂1例 ,自然恢复组 (26例 )术后感染4例 ,再断裂5例。结论 :跟腱断裂修复术后的康复治疗是提高疗效和减少并发症的有效措施之一。     

软骨修复组织蛋白多糖代谢与一氧化氮合酶抑制剂的影响

目的:应用一氧化氮合酶抑制剂可改善骨性关节炎和风湿性关节炎软骨的代谢,作者前期的实验也证明一氧化氮合酶抑制剂能提高软骨修复组织的质量。实验进一步观察一氧化氮合酶抑制剂对软骨修复组织蛋白多糖代谢的影响。方法:实验于1999-06/2002-02在南方医科大学完成。①实验分组:取雄性新西兰兔24只,8月龄,体质量(2.5±0.2)kg。随机抽签法分为对照组、骨形态发生蛋白组和S-甲基异硫脲组,每组8只。②实验方法:将大白兔双侧股骨髁间关节面造成全层软骨缺损,对照组:软骨缺损不充填任何物质;骨形态发生蛋白组:缺损用骨形态发生蛋白纤维蛋白凝胶复合物充填;S-甲基异硫脲组:缺损应用胶原复合骨形态发生蛋白充填,术后按5mg/(kg·12h)皮下注射S-甲基异硫脲。术后1年麻醉后处死动物。③实验评估:应用组织切片番红O-快绿染色和图像分析技术,按照染色百分率、平均灰度(平均染色程度)和染色厚度(软骨厚度)指标来检测糖胺聚糖含量;应用Na235SO4掺入法检测软骨修复组织蛋白多糖合成。结果:纳入新西兰兔24只,均进入结果分析。①术后1年,对照组几乎无红色染色区域;骨形态发生蛋白组可见到少量的不均匀红色区域;S-甲基异硫脲组可见到较多均匀一致的红色染色区域。②S-甲基异硫脲组软骨修复组织番红O染色百分率为89.28%,明显高于骨形态发生蛋白组36.54%和对照组13.4%,S-甲基异硫脲组修复组织番红O-快绿染色平均灰度值134.5,分别为骨形态发生蛋白组平均灰度值56.8的2.5倍,为对照组26.4的7倍。软骨平均厚度S-甲基异硫脲组1.75cm分别为骨形态发生蛋白组0.76cm和对照组0.25cm的2倍和6倍。③Na235SO4掺入法结果显示,S-甲基异硫脲组[35S]摄入量明显高于骨形态发生蛋白组和对照组(P<0.01)。结论:诱导型一氧化氮合酶抑制剂S-甲基异硫脲的应用能明显增加软骨修复组织糖胺聚糖含量和蛋白多糖合成,对于软骨修复质量的提高有积极意义。     

间歇性红外线加热对人成纤维细胞三维立体培养的影响

目的　观察红外线加热对人成纤维细胞三维立体培养的影响。方法　在人成纤维三维立体培养模型基础上 ,用红外线加热装置间歇性加热 ,共设 42℃组 (A组 )、3 8℃组 (B组 )和 3 3℃组对照组 (C组 ) ,观察第 0、2、3、5和 7d凝胶收缩状况及纤维细胞计数。结果　第 3天 ,A组的胶原凝胶收缩 (5 4.7% )明显大于B组 (4 8.5 % )和C组 (3 4.8% ) (P <0 .0 0 1)。第 7天 ,A、B、C三组的胶原凝胶收缩分别为 67%、5 5 .8%和49 .47% (P <0 .0 0 1) ,同时发现 ,各组间成纤维细胞生长状况与胶原凝胶收缩呈正相关关系。结论　间歇性红外线加热可通过促进成纤维细胞增殖而使胶原凝胶收缩 ,对慢性伤口的愈合可能有促进作用     

异体肌腱在陈旧性跟腱断裂修复中的应用

目的探讨异体肌腱修复陈旧性跟腱断裂的疗效和并发症,并与传统方法比较。方法选择2016年3月至2019年3月收治的41例陈旧性跟腱断裂患者,均为闭合性运动损伤,按照随机数字表法将41例患者分为甲组(21例)和乙组(20例),所有患者均采用跟腱旁内侧入路进行手术,甲组使用异体肌腱桥接结合编织缝合的方法进行修复,乙组使用传统的腓肠肌腱膜翻转术修复跟腱,术后评估踝关节活动度,并通过美国足踝外科协会(AOFAS)踝-后足评分标准进行功能评估。结果 41例患者术后均获随访,随访时间13～40个月,平均25个月。甲组除有1例皮肤延迟愈合外,其余伤口均Ⅰ期愈合,乙组有2例术后伤口渗出,经换药后愈合,两组患者均无皮肤坏死、感染、皮肤感觉异常及下肢深静脉血栓形成。甲组患者术后12周可以恢复日常活动,乙组患者术后16周恢复日常活动,末次随访时踝关节活动度甲组为(55.2±7.1)°,乙组为(54.6±5.8)°,两组差异无统计学意义(P0.05)。甲组AOFAS评分平均为(91.8±8.5)分,乙组AOFAS评分平均为(90.5±8.1)分,两组差异无统计学意义(P0.05)。甲组治疗效果为优16例、良4例、可1例,乙组治疗效果为优14例、良4例、可2例,两组治疗效果差异无统计学意义(P0.05)。结论采用异体肌腱桥接结合编织缝合修复陈旧性跟腱断裂,操作简单,效果确切可靠、并发症少,可以早期进行功能锻炼,使患者早日恢复日常活动,但最终治疗效果与传统方法无差别。     

血管内皮生长因子对免跟腱内源性愈合作用的量效关系

背景:多种生长因子在肌腱愈合过程中参与调控细胞的增生和基质合成,血管内皮生长因子在组织愈合和再生中发挥重要作用.目前对于血管内皮生长因子在肌腱内源性愈合方面的研究尚不多.目的:观察兔跟腱局部硅胶管阻隔后,应用血管内皮生长因子对跟腱内源性愈合作用的量效关系.设计、时间及地点:随机对照动物实验,于2007-11/2008-04在中南大学湘雅二医院中心实验室完成.材料:健康家兔48只,体质量2.5～3.0 kg,随机均分成空白组、血管内皮生长因子100,50,10 ng组,每组12只,用于建立跟腱损伤模型.方法:切开家兔右侧跟腱表面皮肤、皮下组织,钝性分离跟腱的腓肠肌束支和比目鱼肌束支,于跟骨止点上方约2 cm处横行切断跟腱腓肠肌束支,将2 cm长硅胶管套入一侧断端,5-0缝合线改良Kessler法缝合跟腱,缝合后将硅胶管覆盖跟腱缝合处,空白组硅胶管内不加药,其他3组于手术当日及术后第7,14,21天往硅胶管内加入血管内皮生长因子100,50,10 ng.主要观察指标:术后2,4,6周,每组各取4只家兔行大体标本肉眼观察及组织学观测.结果:术后6周,各组硅胶管外与周围组织粘连较2,4周时减轻,需钝性或用手术刀分离一面,各组肌腱粘连程度分级差异均无显著性意义(P>0.05),管内跟腱断端完全被牢固的新生跟腱纤维组织所连接,各组均愈合良好,血管内皮生长因子100,50,10 ng组较空白组愈合质量好(P<0.05).术后2,4,6周,血管内皮生长因子100,50 ng组成纤维细胞数较血管内皮生长因10 ng组多(P<0.05),血管内皮生长因子100,50 ng组成纤维细胞计数差异无显著性意义(P>0.05),3组胶原水平无差异,血管内皮生长因子100,50,10 ng组成纤维细胞计数及胶原水平均高于空白组(P<0.05).结论:不同剂量外源性血管内皮生长因子均能促进成纤维细胞的增殖和成熟,增加胶原的分泌,促进胶原纤维的成熟,从而促进跟腱的内源性愈合.100,50 ng血管内皮生长因子对促进跟腱愈合效果要优于应用1 0 ng,100 ng与50 ng之间无明显差异.     

伞式经跟骨缝合法修复跟腱断裂的实验研究与临床应用

目的:将伞式经跟骨缝合法作临床实验,并与其他不同缝合组合作应力分析,从而为临床提供术后无须石膏固定修复技术的科学依据。方法:临床实验于2001-05/2006-08在新疆医科大学第一附属医院骨科完成。对急性跟腱断裂患者7例、陈旧性跟腱断裂患者4例,共11例,进行前瞻性手术治疗,端对端运用伞式经跟骨缝合法采用0-0普迪斯缝线、腱周采用交叉缝合法采用3-0无创缝线,术后随访平均36个月。应力实验于2002-11/2003-05在上海大学生物力学工程研究所完成。按L(1465)正交实验设计,对32只健康新西兰白兔跟腱断裂模型,以4种不同端对端缝合方法(伞式经跟骨缝合法、改良Kirschmayer缝合法、Motta缝合法、Kakiuchi缝合法)、4种不同缝合材料(0-0薇乔线、2-0慕丝线、3-0薇乔线、0-0攀状尼仑线)、4种不同腱周缝合方法(连续缝合法、城垛样缝合法、交叉缝合法、间断缝合法),在局部麻醉下组合修复、修复后分笼喂养,术后4种不同愈合时间(0,7,14,21d)对离体跟腱进行应力分析,正常对照组为16只同种单侧跟腱。结果:临床实验:11例患者术后均获得随访,按Arner-Lindholm法评定优良率100%,10例跟腱断裂患者切口均I/甲愈合。应力实验:32条跟腱模型均进入结果分析。①伞式经骨缝合法的极限强度平均为(3.09±0.35)N/mm2,Kirschmayer法,Motta法,Kakiuchi法平均分别为(1.61±15.5)N/mm2,(1.54±0.13)N/mm2,(1.31±0.11)N/mm2,前者分别比后者平均高48%,50%,58%。②伞式经骨缝合法刚度平均达(282.47±18.31)N/mm,Kirschmayer法,Motta法,Kakiuchi法平均分别为(229.38±17.41)N/mm,(238.98±15.27)N/mm,(225.81±22.07)N/mm,分别相差19%,15%,20%。③伞式经骨缝合法的比能平均为(0.92±0.06)J/mm3,Kirschmayer法为(0.66±0.04)J/mm3,Kakiuchi法和Motta法平均为(0.36±0.03)J/mm3,与前者相差60%,28%。④伞式经骨缝合法的最大拉伸载荷平均为(159.38±16.00)N,Kirschmayer法,Motta法,Kakiuchi法平均分别为(138.13±14.00)N,(109.38±8.20)N,(98.13±15.00)N,高于后3者13%,31%,38%,平均高于27.3%。但与正常组相比(367.14N),两者相差50%以上。⑤伞式经骨缝合法载荷-应力强度增长速率比其他缝合方法快。以上所有指标差别均具有统计学意义(P<0.05)。结论:临床应用伞式经跟骨缝合方法术后无须石膏固定,且有利于术后早期功能锻炼。实验中伞式经跟骨缝合方法生物力学明显优于其他3种方法。为进一步研究在运动状态下跟腱愈合的方向打下了基础。     

微创吻合器小切口跟腱吻合修复急性跟腱断裂

背景:切开手术治疗急性跟腱断裂对跟腱的血运和腱周组织造成较大的破坏,容易发生跟腱粘连,延缓跟腱愈合.目的:观察跟腱微创吻合器吻合修复急性跟腱断裂的效果.方法:对2008-02/2009-08采用跟腱微创吻合器治疗的急性跟腱断裂并获得随访的22例患者,进行早期功能操练,并按照美国骨科协会足踝外科分会的标准评价踝关节功能,评价跟腱微创吻合器的治疗效果.结果与结论:22例均获得随访,随访期为7～14个月(平均11.4个月),所有患者伤口愈合良好,未发生跟腱再断裂,无腓肠神经支配区的感觉缺失,吻合后3个月AOFAS标准评分为95分,吻合后6个月为98分.说明跟腱微创吻合器能微创治疗急性跟腱断裂并获得良好效果.     

一氧化氮合酶抑制剂对软骨修复组织蛋白多糖代谢和胶原表达的影响

目的研究诱导型一氧化氮合酶（iNOS）抑制剂对软骨修复组织蛋白多糖代谢和胶原表达的影响。方法双侧股骨髁间关节面全层软骨缺损新西兰大白兔24只,随机均分为对照组、骨形态发生蛋白（BMP）组和iNOS抑制剂S-甲基异硫脲（SMT）组。术后1年处死动物。应用组织切片番红O-快绿染色检测蛋白多糖,苦味酸-天狼猩红染色检测胶原的分布情况,利用图像分析技术检测糖胺聚糖含量和胶原的表达以及软骨厚度。结果术后1年,SMT组软骨修复组织番红O-快绿染色百分率（89．28％）明显高于BMP组（36．54％）和对照组（13．4％）,SMT组软骨修复组织番红O-快绿染色平均灰度值（134．5）分别为BMP组（56．8）和对照组（26．4）的2．5倍和7倍。修复组织软骨平均厚度,SMT组（1．75cm）分别为BMP组（0．76cm）和对照组（0．25cm）的2倍和7倍。SMT组修复组织Ⅰ型胶原表达量为65．9％,明显少于BMP组（88．5％）和对照组（94．6％）;Ⅱ型胶原表达量（30．7％）多于BMP组（10．8％）和对照组（4．5％）。结论iNOS抑制剂SMT的应用能明显增加软骨修复组织中糖胺聚糖含量,并能明显增加Ⅱ型胶原表达,对于维持软骨表型和提高软骨修复质量有积极意义。     

重组人碱性成纤维细胞生长因子复合胶原海绵的制备及其在齿槽外科的应用

目的观察重组人碱性成纤维细胞生长因子复合胶原海绵对牙科创面止血及伤口修复愈合的影响。方法实验于2003-01/2004-03在暨南大学医学院附属广州市红十字会医院创伤研究所和口腔科完成。首先用Ⅰ型胶原蛋白、碱性成纤维细胞生长因子与壳聚糖配制成混合物,冷冻干燥成复合胶原海绵备用。收治60例错牙合畸型患者需行牙齿对称减数进行正畸治疗,共计对称拔除双尖牙212颗、磨牙14颗。左侧为实验组牙槽窝置入复合胶原海绵,右侧为对照组置入医用明胶海绵。记录拔牙创面止血时间,观察术后2,7d拔牙面创愈合情况。结果60例236颗牙拔除后的止血时间,实验组(45.9±12.8)s,对照组(89.0±16.4)s。实验组2d拔牙创面愈合78例(66%)、7d拔牙创面愈合117例(98%);对照组2d拔牙创面愈合25例(21%)、7d拔牙创面愈合95例(79%)。实验组创面愈合均好于对照组。结论重组人碱性成纤维细胞生长因子复合胶原海绵的止血效果和促进创面愈合作用明显优于明胶海绵。     

非止点性跟腱病患者的肌骨超声显像特征

  目的  分析非止点性跟腱病患者肌骨超声显像特征。  方法  收集2020年11月~2022年4月共60例患者82足跟腱超声结果,将其分为健康对照组(A组,15例30足)和非止点性跟腱病组(B组,45例52足),应用肌骨超声和彩色多普勒血流显像观察并分析比较各组:(1)跟骨后结节上2 cm处跟腱厚度; (2)跟腱止点上2 cm处跟腱横截面积; (3)跟骨上缘上1 cm处Kager脂肪垫前后径; (4)跟骨后滑囊积液检出率; (5)跟腱内血流信号检出率。总结归纳非止点性跟腱病的超声显像特征。  结果  (1) 跟骨后结节上2 cm处跟腱厚度:A组小于B组(0.43±0.06 cm vs 0.55±0.17 cm,P < 0.05);(2)跟腱止点上2 cm处跟腱横截面积:A组小于B组(0.52±0.11 cm2 vs 0.74±0.23 cm2,P < 0.05);(3)跟骨上缘上1 cm处Kager脂肪垫前后径:A组小于B组(1.01±0.21 cm vs1.49±0.26 cm,P < 0.05);(4)跟骨后滑囊积液检出率:A组未检出,B组38.46%,差异有统计学意义(P < 0.05);(5)跟腱内血流信号检出率:A组未检出,B组51.92%,差异有统计学意义(P < 0.05)。  结论  非止点性跟腱病超声显像特征为跟腱厚度增厚,跟腱横截面积增大,跟腱前Kager脂肪垫前后径增宽,跟骨后滑囊积液产生或增加,以及跟腱内部血管增生。      

Effects of intermittent tendon pressure on alpha motoneuron excitability

The purpose of this study was to test the effectiveness of intermittent tendon pressure on the depression of alpha motoneuron excitability. The excitability changes of the motoneurons were assessed by measuring changes in H-reflex amplitudes before, during, and after intermittent tendon pressure application. Twenty-six of 28 subjects with no known neurological deficit displayed an immediate decrease in H-reflex amplitudes during tendon pressure (X = 73% of control values), which reached a maximum depression (45% of controls) within 20 to 30 seconds of application. The analysis of variance revealed significant differences (p less than .05), and post-hoc t tests indicated that these differences were between control values (prepressure and postpressure) and those values obtained at times 0, 5, 10, 20, and 30 seconds of pressure application. These results suggest that a maintained reduction in muscle tone might be induced through intermittent tendon pressure. Because we found no carry-over effects after pressure application, the usefulness of this technique is limited to the time during which the stimulus is presented.     

Effects of tendon pressure on alpha motoneuron excitability in patients with stroke

The purpose of this study was to evaluate the effects of two intensities (5 and 10 kg) of continuous and intermittent Achilles tendon pressure on the H-reflex in eight hemiparetic subjects. A decrease in the H-reflex was interpreted as a depression in motoneuron excitability, a condition conducive for reducing muscle tone. The H-reflex measurements were obtained before, during, immediately after, and 2.5 minutes after tendon pressure application. Piecewise linear regression equations were used to evaluate the effects of four pressure conditions. The mean of the midpoints of the lines for each pressure condition was compared with prepressure baseline values by t tests and with the other pressure conditions by an analysis of variance. All four pressure conditions demonstrated H-reflexes less than prepressure baseline values, with three of the four conditions (5 and 10 kg of intermittent pressure and 5 kg of continuous pressure) being significantly less than prepressure baseline values (p less than .05). The analysis of variance revealed a significant difference among pressure conditions. Scheffé post hoc contrast comparisons revealed significant differences between intermittent and continuous pressure but not between 5 and 10 kg of pressure. The results of this study indicate that in these hemiparetic subjects, the H-reflex was depressed during both continuous and intermittent tendon pressure. Intermittent pressure was more effective then continuous, but 10 kg of pressure had no greater effect than 5 kg of pressure. The effects of pressure lasted only as long as the stimulus was present.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intermittent sonographic guidance in air enemas for reduction of childhood intussusception.

OBJECTIVE: The purpose of this study was to prospectively assess the value of intermittent sonographic guidance in nonsurgical air reduction of childhood intussusception. METHODS: The study group included 86 consecutive childhood intussusceptions confirmed on sonography for which we designed an air enema. With intermittent sonographic guidance of our own method, air was gradually injected to the initial intracolonic pressure of 60 mm Hg, which we attempted for 30 seconds on the initial attempt. If the air enema reduction attempts were not successful at a given pressure setting, we repeated the technique at each pressure setting upgraded by increments of 20 mm Hg up to 120 mm Hg. Surgery was performed when even repeated reduction attempts at the maximum intracolonic pressure of 120 mm Hg were unsuccessful. We calculated the successful reduction rate for the intussusceptions at each pressure setting. RESULTS: The overall success rate of sonographically guided air enema reductions was 95% (82/86). The success rates of air enema reductions at 60, 80, 100, and 120 mm Hg showed progressive increases of 53% (42/86), 67% (58/86), 78% (67/86), and 95% (82/86), respectively, with no immediate recurrence and no gross perforation. CONCLUSIONS: The use of intermittent sonographic guidance in air enemas is thought to help safely increase successful reductions of childhood intussusception even with sufficient air enema attempts.     

间歇性负压干预前交叉韧带重建后的腱一骨愈合

背景;间歇性负压被证实可以促进软组织修复及骨愈合,但其对交叉韧带重建后腱一骨愈合的影响尚未见报道。目的：观察间歇性负压对兔前交叉韧带重建后腱一骨愈合及肌腱移植物生物力学的影响。方法：取24只新西兰大白兔制各自体半腱肌前交叉韧带重建模型,随机取一侧后腿作为负压侧,负压侧关节通过引流管接微型负压吸引器,并维持低强度、间歇性负压;对侧后腿作为对照,接普通引流管。5d后两侧同时拔除吸引管。造模后6周,取关节液检测白细胞介素113的表达水平;取股骨一韧带一胫骨复合体行肌腱移植物拉力测定和腱一骨界面组织学观察。结果与结论：1只兔关节感染,最终23只兔进入结果分析。拉力测定结果显示,负压组完全断裂所需拉力显著大于对照组（P〈0．05）。组织学观察结果发现,负压组成骨细胞数目显著多于对照组,差异有显著性意义（P〈0．01）。关节液检测结果提示负压组关节滑液中自细胞介素113含量低于对照组,差异有显著性意义（P〈0．01）。提示间歇性负压可能在前交叉韧带重建后腱一骨愈合、肌腱移植物的塑性过程中扮演着积极作用。     

Caprini评估联合间歇性气压治疗对ICU患者下肢深静脉血栓发生率的影响

目的探讨Caprini评估联合间歇性气压治疗对ICU患者下肢深静脉血栓发生率的影响。方法选取我院2015年8月至2018年7月收治的ICU患者358例为研究对象,按照随机数字表法等分为对照组与观察组,对照组实施Caprini评估联合常规护理,观察组在对照组基础上联合间歇性气压治疗仪进行物理预防。比较两组患者下肢深静脉血栓发生率。结果观察组下肢深静脉血栓发生率为1.68%,明显低于对照组的8.38%,差异有统计学意义(P<0.05)。结论Caprini评估联合间歇性气压治疗可有效降低ICU住院患者下肢深静脉血栓的发生,保证患者安全,值得临床应用和推广。     

Design and effectiveness of a membrane-pump-driven ventilator for mice.

To perform mechanical ventilation of mice in the absence of highly expensive commercially available devices, we developed a membrane-pump-driven respirator and studied its practicability. The continuous airflow generated by the membrane pump was changed into an intermittent flow by using a multifunction timer. Tidal volume was adjusted by a rotary dimmer regulating the electric power onto the pump. The expiration air left the circuit through openings at the tube connection. Mice were ventilated with room air for 5 h with a tidal volume of approximately 200 muL. In group 1 (n = 6), ventilation was performed with a frequency of 110 min-1, in group 2 (n = 6) with a frequency of 150 min-1. Spontaneously breathing anesthetized mice (n = 6) served as controls. In addition we performed single-lung open-chest ventilation for 1 h in two animals. The parameters of arterial blood gas analyses were within the normal range except for moderate hyperventilation in group 2. Single-lung ventilation led to a significant decline (P < 0.05) of pO2 and SO2, whereas the pCO2 remained within the normal range. Respiratory rate, tidal volume and pressure limitation can be adjusted for optimal ventilation. In addition, the device provides a minimalized dead space and impedes potential alveolar damage caused by negative pressure generated by spontaneous inspiration during positive-pressure ventilation.     

人组织工程化肌腱构建的实验研究

INTRODUCTIONInjuryoftendonisacommondifficultprobleminclinicandthemostknottyproblemisthelargedefectoftendoncomplicated．Inclinictransplantationoftendon，artificialsuccedaneumwereadoptedtore－pairtendondefect，butlimitedsourceofauto－tendon，rejectreactiontoartificialsuccedaneum，badmechanics，etallimiteddevelopoftendonsurgery[１]．Fromthelateeighties，rapiddevelopoftissueengineeringbroughtupanewmethodforrepairoftendondefect[２－４]．Inthisex－periment，absorptivepolyglycolicacidisusedasnet…     

An experimental study on tissue engineered tendon with human tenocytes

AIM:To investigate the technique of tissue engineered tendon with human tenocytes.METHODS:Human tenocytes in vitro,then the tenocytes were mixed with Polyglycolic Acid (PGA)to form cell-polymer constructs and cul-tured in vitro.After one week,the constructs were surgicallly implanted sub-cutaneously into athymic mice.Specimens were harvested at 6 weeks for gross,histologic examinations and immuno-histological analysis .RESULTS:The engineered tendon resembled natural tendon grossly in both color and tex-ture.Histologically,most tenocytes and collagen bundles were aligned along the longitudinal axis of engineered tendon.CONCLUSION:Human tenocytes be used as seed cell,engineered tendon can be generated in the nude mice by means of tissue engineering technique.     

The effect of posterior tibialis tendon dysfunction on the plantar pressure characteristics and the kinematics of the arch and the hindfoot

OBJECTIVE: To study posterior tibialis tendon dysfunction using an in vitro model of the foot and ankle during the heel-off instant of gait. BACKGROUND: Previous studies have concentrated primarily on the effect of posterior tibialis tendon dysfunction on the kinematics of the hindfoot and the arch. METHODS: The specimens were loaded using a custom designed axial and tendon loading system and the location of the center of pressure was used to validate heel-off. Arch position, hindfoot position and plantar pressure data were recorded before and after the posterior tibialis tendon was unloaded. These data were recorded with the ligaments intact and after creating a flatfoot deformity. RESULTS: Unloading the posterior tibialis tendon caused significant posterior movement in the center of pressure for the intact and flatfoot conditions. This also resulted in a medial shift in the force acting on the forefoot. The forefoot loads shifted medially after a flatfoot was created even when the posterior tibialis tendon remained loaded. The spatial relationships of the bones of the arch and the bones of the hindfoot also changed significantly for the intact specimen, and to a lesser extent after a flatfoot. CONCLUSIONS: The posterior tibialis tendon plays a fundamental role in shifting the center of pressure anteriorly at heel-off. Posterior tibialis tendon dysfunction causes posterior shift in the center of pressure and abnormal loading of the foot's medial structures. This may be the reason that posterior tibialis tendon dysfunction leads to an acquired flatfoot deformity. Conversely, flatfoot deformity may be a predisposing factor in the onset of posterior tibialis tendon dysfunction. This tendon also acts to lock the bones of the arch and the hindfoot in a stable configuration at heel-off, but a flatfoot deformity compromises this ability.     

Removal of the lateral or medial third of patellar tendon alters the patellofemoral contact pressure and area: an in vitro experimental study in dogs

OBJECTIVES: To compare patellofemoral contact pressure and areas after immediate removal of the lateral, central, or medial third of patellar tendon. DESIGN: In vitro experiment in 12 dogs. BACKGROUND: Alteration of the vector sum of the quadriceps muscle contraction after removal of partial patellar tendon might result in changes of patellar tracking in the trochlea. METHODS: Patellofemoral contact pressure and areas were recorded using Fuji pressure-sensitive film at 45 degrees, 60 degrees, and 90 degrees of knee flexion under an isometric quadriceps force of 100% body weight. The patellofemoral contact imprint from the intact knees were obtained as control, and the lateral (n=4), central (n=4), and medial (n=4) third of the patellar tendon were subsequently removed and the patellofemoral contact imprint was recorded. RESULTS: The patellofemoral contact area was found to increase with increasing knee flexion angles. No change in patellofemoral contact pressure and areas was found after removal of the central third patellar tendon. However, after removal of either lateral or medial third of patellar tendon, the patellofemoral contact was rotated with increasing knee flexion angles. This was due to the altered vector sum of the quadriceps force, resulting in significantly decreased patellofemoral contact areas and simultaneously a significantly increased contact pressure, characterized with concentration of patellofemoral contact pressure on both lateral and medial facets of the patellofemoral joint. CONCLUSIONS: The results suggest that removal of the central third of patellar tendon may not alter the patellofemoral contact pressure and areas as compared with removal of either lateral or medial third of patellar tendon that may result in an altered postoperative tracking mechanism of the patellofemoral joint immediately after operation. RELEVANCE: Findings of this in vitro animal study supports the use of central third of patellar tendon as autograft for anterior cruciate ligament reconstruction. However, further experimental studies are needed to investigate how the postoperative healing of the host patellar tendon will influence the findings obtained from this in vitro study.