Proximal femoral cross-locking type intramedullary nail

Abstract

The invention discloses a proximal femoral cross-locking type intramedullary nail. The nail comprises a main nail, a first hip screw and a second hip screw; the main nail is provided with a locking nail hole allowing a hip screw to penetrate through, and the locking nail hole is internally provided with an internal thread; the hip screw is provided with an intermediate external thread part cooperating with the internal thread; the distance between the first locking nail hole center and the top of the main nail and the distance between the second locking nail hole center and the top of the mainnail are 26.9 mm and 45 mm respectively; in the positive position direction, extension cords of projections of axes of the first hip screw and the second hip screw intersect at one point, and the included angles of the axes of the first hip screw and the second hip screw and the axis of the main nail are 120 degrees and 130 degrees respectively. According to the proximal femoral cross-locking type intramedullary nail, by setting the positions and angles of the two hip screws, stable fixation of the intramedullary nail is achieved; meanwhile, pressure stress applied to whirlbone can be effectively dispersed, and the bear load of a femur rotor part can be helped to recover early.

Description

technical field [0001] The invention relates to the field of medical devices, and more specifically relates to a proximal femoral cross-locking intramedullary nail for fixing fractures of the femoral trochanter. Background technique [0002] There are many types of internal fixation for trochanteric fractures, which can be roughly divided into two fixation methods: one is the extramedullary fixation system, with dynamic hip screw (dynamic hip screw, DHS) and dynamic condylar screw (dynamic condylar screw, DCS) The other is the intramedullary fixation system, represented by the Gamma nail and the proximal femoral nail (PFN). Stable intertrochanteric fractures (including AO classification 31A1.1 and 31A1.2) can achieve good results with extramedullary or intramedullary fixation systems. [0003] Unstable type A2 fracture is due to the cortical defect of the posteromedial femoral moment, and the compressive stress cannot be transmitted through the femoral moment. The lateral c...

AI Technical Summary

Problems solved by technology

[0006] The problem lies in: the dynamic hip screw and the proximal femoral intramedullary nail in the fixation of the intertrochanteric fracture accompanied by comminuted lateral wall of the greater trochanter, coronal plane fracture, and comminuted fracture from the subtrochanter to the lateral wall of the greater trochanter At the same time, the hip screw of the dynamic hip screw and proximal femoral intramedullary nail is driven in from the fracture of the lateral wall. If the hip screw does not have a good fulcrum on the lateral wall, the probability of postoperative internal fixation failure will increase, and hip screw failure will occur. Complications such as excessive dynamic compression, penetration into the acetabulum, or Z-effect

[0007] In summary, unstable intertrochanteric fractures are usually accompanied by comminution of the posteromedial cortex or comminuted fracture of the lateral wall of the trochanter, and there is a fracture in the posteromedial part of the trochanter, which lacks posteromedial support and increases the stress of the internal fixation; hip screws The fracture of the lateral wall at the entry point weakens the ability of the hip screw to resist the rotation and varus tendency of the femoral head and neck bone fragment, which affects the postoperative rotational stability of the femoral head and neck

For the fracture of the lateral wall of the trochanter, DHS, intramedullary nails, and locking bone plates all have disadvantages. At present, there is no suitable internal fixation to fix the fracture of the lateral wall of the trochanter. New internal fixation needs to be designed to solve the above problems

Images