股骨干骨折髓内钉远端徒手锁钉技术及应用解剖学研究

Study of interlocking intramedullary nail locked with the free-hand technique in femoral shaft fractures and the applied anatomy

目的:探讨股骨干骨折髓内钉固定时远端徒手锁钉的可行性。方法:选取成人不成对股骨防腐标本22根,对12根标本远端锁钉横截面的周径、外侧边边长及外侧上下角进行测量。选最大截面运用平面几何与三角函数来计算探针通过截面外侧边上探测孔的最大摆动角并确定探测孔的最佳定位点。用直径1mm的克氏针经过直径4mm的探测孔来探测直径为9mm的髓内钉,并通过10根股骨干骨折模型及15例临床股骨干骨折病例对徒手锁钉法加以验证。结果:股骨干远端锁钉横截面即股骨远端骨骺线上3cm处的横截面,其外周径为(153.00±7.45)mm,外侧边长为(36.30±2.65)mm,外上角为102.42±5.85°,外下角为81.00±3.25°,外侧边髓腔厚度(1.96±0.04)mm。在最大的横截面处当探查孔直径为4mm时,在外侧两边角区存在盲区(即髓内钉位于其间但通过探查孔的探针不能探到的区间)。但当髓内钉通过约10cm的髓腔狭窄段时,髓内钉不会到达盲区。探针向上、向下的最大摆动角均为44°,当探查孔定位于外侧边中点时,如髓内钉通过的10cm的髓腔狭窄段,骨折复位满意时是可以被探针探及的。应用此法在10根标本及14例利用定位器远端锁钉失败的临床病例中获得成功。结论:通过股骨外侧4mm的探查孔用直径1mm的细克氏针滑移来寻找髓内钉徒手锁钉的方法是可行的。

Objective：To discuss the feasibility of the interlocking intramedullary nail distally locked with free-hand technique in femoral shaft fractures. Methods：Twenty-two femoral speciments of native adults were used in the study. Twelve speciments were selected to measure the circumference,the length of lateral border,superlor lateral and inferior lateral angle of the transverse section on which distal locking screws were implanted. A hole was drailed in the lateral side of the biggest transverse section. The biggest moving angle of the kirschner wire through the detective hole, and the most correct orientation point were defected by using plane geometry and the triangular function mathematics methods. Then the locking method was confirmed in 10 different femoral fracture speciments and 15 patients with femoral shaft fracture. Results：The transverse section of distal locking screw was just the transverse section of 3 cm upper from distal femoral epiphyseal line. The measure results were as follows ：the average circumference was （ 153 ± 7.45 ） mm, the average length of the lateral border was （ 36. 3 ± 2.65 ） mm, the average outer-superior angle and the outer-lower angle were 102.42 ± 5.85° and 81.00± 3.25° respectively, the thickness of the medullary cavity at the biggest transverse section was （ 1.96±0. 04） mm. The above numbers were used to figure out that when the diameter of the detective hole was 4 mm, there was a blind zone in the lateral part, to which the exploring needle could not touch. But when the intramedullary nail went through about 10 cm length narrow part of the medullary cavity, the intramedullary nail could not reach the blind zone. The biggest upward and downward moving angle of the Kirschner wire were 44°. If the orientation point located in the middle point of the outer side and the reduction was satisfactory, the intramedullary nail through about 10cm length narrow part of the medullary cavity could be found. This method successfully used in 10 specimens and 14 patients in which locator was failure to treat fracture. Conclusion：The intramedullary interlocking nail locked by free hand through the 4 mm diameter detective hole is actable.