股骨颈骨折行人工髋关节置换45例的临床分析(2)
在给老年性股骨颈骨折患者行人工髋关节置换术时,其手术成功的关键是重建股骨偏心距。适宜的股骨偏心距可以使髋关节获得最大的外展功能、最小的关节面间的应力,对股骨柄假体及其与骨交界面间产生最小的轴向力矩和内翻应力,其偏差不应超过±4mm[7]这一标准。临床研究显示[8～9]:股骨偏心距的恢复程度决定了聚乙烯假体磨损的多少。术中如能使股骨偏心距恢复到解剖水平,则术后关节内应力就能达到理想的程度,假体的使用寿命长。而过小的股骨偏心距则会使聚乙烯假体磨损明显增加,如果股骨偏心距偏小,将会出现臀中肌收缩时前负荷减少,导致臀中肌收缩乏力,直接的后果是病人行走时步态异常,加大髋关节假体的磨耗。另一方面,过小的股骨偏心距将会使股骨接近骨盆,这将增加髋关节与骨盆碰撞的几率,减少髋关节活动范围。同时,术后股骨偏心距减小,会使关节周围软组织松弛,将会有髋关节不稳的趋势,增加髋关节脱位的风险。本组2例术后发生髋关节脱位的患者,经X线片测量证实其术后偏心距较术前测量差值减少均>4mm,在术后坐位时屈髋>90°、内收超过15°时出现患髋脱位,予以手法复位后加强保护并行患髋制动6周,未再发生脱位。股骨偏心距增加会使安放的假体有内翻的趋势,而这样会引起大粗隆远端骨水泥壳的厚度不足,这是诱发股骨假体松动的可能因素[10]。本组2例术后遗留髋关节疼痛;1例出现术后假体松动,均经X线片证实其差值>4mm。偏心距的重建与假体位置、大小、保留股骨距的长度、选用假体颈的长度、髋臼杯是否中心化、肢体是否等长有关。一般来说,应选择适宜的颈干角假体系统以利于股骨偏心距的恢复,并有助于提高术后效果;术中应尽量恢复髋关节的旋转中心,这样不但可以增加髋臼杯与骨面的接触面积,增加骨长入的几率,还可增加臀中肌张力,缩短了身体重心的力臂;此外,股骨距的长度、假体颈长度的选用亦有利于偏心距的重建。
, 百拇医药
综上所述,老年性股骨颈骨折行人工髋关节置换术的优势在于术后可以早期下地活动并恢复功能锻炼,术后症状和功能恢复更加确切,再手术率较低,其手术成功的关键是重建股骨偏心距。
参考文献
[1]Gocen Z,Sen A,Unver B,et al.The effect of preoperative physiotherapy and education on the outcome of total hip replacement:a prospective randomized controlled trial[J].Clin Rehabil,2004,18(4):353～358.
[2]董天华,卢世壁,吉士俊.髋关节外科学[M].河南:郑州大学出版社,2005:105～107.
[3]Michelson JD,Myers A,Jinnah R,et a1.Epidemiology of hip fractures among the elderly.Risk factors for fracture type[J].Clin Orthop,1995(311):129～135.
, 百拇医药
[4]Robinson CM,court-Brown CM,McQueen MM,et a1.Hip fractures in adults younger than 50 years of age[J].Clin Orthop,1995(312):238～246.
[5]Radford PJ,Needoff M,Webb JK.A prospective randomized comparison of the dynamic hip screw and the Gamma locking nail[J].J Bone Joint Surg Br,1993,75(5):789～793.
[6]Hardy DC,Descamps PY,Krallis P,et a1.Use of an Intramedullary hip-screw compared with a compression hip-screw with a plate for intertrochanteric femoral fractures.Aprospective,randomized study of one hundred patients[J].J Bone Joint Surg Am,1998,80(5):618～630.
, 百拇医药
[7]Papadakis SA,Segos D.Capsular decompression during internal fixation of intracapsular hip fractures[J].J Orthop Surg (Hong Kong),2008,16(1):132～133.
[8]CharlesMN,Boume RB,Davey JR,et a1.Soft-tissue balancing of the hip:the role of femoral offset restoration[J].Instr Course Lect,2005,54:131～141.
[9]Goldstein WM,GordonA,Branson JJ.Leg lengthinequality in totalhip arthroplasty[J].Orthop,2005,28(9 Suppl):1037～1040.
[10]Enocson A,Tidermark J,Tornkvist H,et a1.Dislocation of hemiarthroplasty after femoral neck fracture:better outcome after the anterolateral approach in a prospective cohort study on 739 consecutive hips [J].Acta Orthop,2008,79(2):211～217.
【收稿日期】 2011-05-09, 百拇医药(金德才 戴和本 杨维民)
, 百拇医药
综上所述,老年性股骨颈骨折行人工髋关节置换术的优势在于术后可以早期下地活动并恢复功能锻炼,术后症状和功能恢复更加确切,再手术率较低,其手术成功的关键是重建股骨偏心距。
参考文献
[1]Gocen Z,Sen A,Unver B,et al.The effect of preoperative physiotherapy and education on the outcome of total hip replacement:a prospective randomized controlled trial[J].Clin Rehabil,2004,18(4):353～358.
[2]董天华,卢世壁,吉士俊.髋关节外科学[M].河南:郑州大学出版社,2005:105～107.
[3]Michelson JD,Myers A,Jinnah R,et a1.Epidemiology of hip fractures among the elderly.Risk factors for fracture type[J].Clin Orthop,1995(311):129～135.
, 百拇医药
[4]Robinson CM,court-Brown CM,McQueen MM,et a1.Hip fractures in adults younger than 50 years of age[J].Clin Orthop,1995(312):238～246.
[5]Radford PJ,Needoff M,Webb JK.A prospective randomized comparison of the dynamic hip screw and the Gamma locking nail[J].J Bone Joint Surg Br,1993,75(5):789～793.
[6]Hardy DC,Descamps PY,Krallis P,et a1.Use of an Intramedullary hip-screw compared with a compression hip-screw with a plate for intertrochanteric femoral fractures.Aprospective,randomized study of one hundred patients[J].J Bone Joint Surg Am,1998,80(5):618～630.
, 百拇医药
[7]Papadakis SA,Segos D.Capsular decompression during internal fixation of intracapsular hip fractures[J].J Orthop Surg (Hong Kong),2008,16(1):132～133.
[8]CharlesMN,Boume RB,Davey JR,et a1.Soft-tissue balancing of the hip:the role of femoral offset restoration[J].Instr Course Lect,2005,54:131～141.
[9]Goldstein WM,GordonA,Branson JJ.Leg lengthinequality in totalhip arthroplasty[J].Orthop,2005,28(9 Suppl):1037～1040.
[10]Enocson A,Tidermark J,Tornkvist H,et a1.Dislocation of hemiarthroplasty after femoral neck fracture:better outcome after the anterolateral approach in a prospective cohort study on 739 consecutive hips [J].Acta Orthop,2008,79(2):211～217.
【收稿日期】 2011-05-09, 百拇医药(金德才 戴和本 杨维民)