全髋关节置换术直接前入路改良切口与股外侧皮神经损伤的解剖学研究

目的 探讨全髋关节置换术直接前方入路(DAA)改良切口和经典切口的解剖特点,为术中避免股外侧皮神经(LFCN)损伤提供解剖学依据。方法 由蚌埠医学院解剖教研室提供成年国人尸体髋关节及股骨标本6具6侧,其中男2具2侧、女4具4侧,年龄48~72(61.7±8.2)岁。通过解剖标志定位的方式做DAA手术切口,切口起点均为髂前上棘最高点向下向外3 cm;DAA经典切口延长方向指向腓骨小头;改良切口将切口延长方向向经典切口外后方偏移,偏移角度为髂前上棘最高点分别与腓骨小头、股骨大粗隆顶点连线夹角的1/2。解剖显露LFCN以及所有分支:(1)观察LFCN走行及其与DAA经典切口、DAA改良切口的关系;(2)对LFCN进行分型;(3)测量DAA经典切口和改良切口与LFCN最短距离,判断LFCN与DAA经典切口和改良切口的解剖关系。结果 (1)LFCN由髂前上棘内侧0.8 cm经腹股沟韧带下方走向股骨前方,LFCN走行向前、向外近乎平行于髂前上棘最高点与腓骨小头连线。DAA经典切口远端与LFCN有交叉,有直接损伤LFCN可能,延长DAA经典切口会增加损伤LFCN概率;而DAA改良切口与LFCN无交叉。(2)6侧标本LFCN分型:缝匠肌型3侧,后向型2侧,扇形型1侧。(3)LFCN与DAA改良切口最短距离为1.2~2.4(2.0±0.40)cm,与经典切口最短距离为0~1.4(0.98±0.55)cm。缝匠肌型和后向型LFCN主干及分支与DAA改良切口的最短距离均＞2.0 cm;与DAA经典切口无交叉,且LFCN所有分支与DAA改良切口最短距离均＞0.7 cm。扇形型LFCN与DAA经典切口有交叉,而与DAA改良切口无交叉,最短距离为1.2 cm。结论 在解剖关系上,DAA改良切口比DAA经典切口距离LFCN更远,DAA全髋关节置换术中更不易发生LFCN损伤。

Anatomical study of modified incision and lateral femoral cutaneous nerve injury with direct anterior approach in total hip arthroplasty

Objective To investigate the anatomical characteristics of modified and classical incisions through the direct anterior approach (DAA) in total hip arthroplasty and to provide an anatomical basis for avoiding the intraoperative injury of the lateral femoral cutaneous nerve (LFCN).Methods The Department of Anatomy of Bengbu Medical College provided six specimens of the hip joint and femur of adult Chinese cadavers, which included two males with two sides and four females with four sides and were aged 48-72(61.7±8.2) years old. The DAA incision was performed via anatomical marker localization, and the starting point of the incision was all downward and outward 3 cm from the highest point of the anterior superior iliac spine. The classical incision in DAA was directed toward the prolongation of the fibular head. The extension direction of the modified incision was shifted outward and backward to the classical incision, and the offset angle was 1/2 of the angle between the highest point of the anterior superior iliac spine and the vertex of the fibula head and the greater trochanter of the femur. The LFCN and all its branches were revealed by anatomy (1) to observe the morphology of the LFCN and its relationship with the classical and modified DAA incisions; (2) to classify the LFCN; and (3) to measure the shortest distance between the classical and modified incisions in DAA and the LFCN to determine the anatomical relationship between the LFCN and the classical and modified incisions in DAA.Results (1) The LFCN moved from the medial 0.8 cm of the anterior superior iliac spine to the anterior femur through the lower part of the inguinal ligament. The LFCN moved forward and outward almost parallel to the connection between the highest point of the anterior superior iliac spine and the fibula microcephalus. The classical DAA incision crossed the LFCN distally; such an approach might directly damage the LFCN. Extending the classical DAA incision will increase the probability of LFCN injury. No crossover occurred between the modified DAA incision and the LFCN. (2) The LFCN classifications of the six specimens were as follows: three sartorius types, two backward types, and one fan type. (3) The shortest distance between the modified incision of the LFCN and DAA was 1.2-2.4 (2.0±0.40) cm, and the shortest distance between the LFCN and the classical incision was 0-1.4 (0.98±0.55) cm. The shortest distance between the trunk and branch of the sartorius type and backward types of LFCN and the modified incision of in DAA was＞2.0 cm. The sartorius and backward types of LFCN had no crossover with the classical DAA incision, and the shortest distance between all LFCN branches and the modified DAA incision was ＞0.7 cm. The fan-shaped LFCN intersected with the classical DAA incision. No crossover was observed between the modified DAA incision and the LFCN, and the shortest distance was 1.2 cm.Conclusions In terms of anatomical relationship, the modified DAA incision is farther from the LFCN than the classical DAA incision, and the LFCN is less prone to injury in DAA in total hip arthroplasty.