Intramedullary needle fixation

Intramedullary needle internal fixation is mostly used for long bone fractures (such as femur, humerus, ulna, tibia, radius, etc.). Its advantages are: the intramedullary needle itself is relatively solid and reliable, and it can be used with little or no external fixation after surgery, which is conducive to the early exercise of the injured limb; the skin incision is small, the periosteal strip is limited, and the injury is small; There are different shapes of edges and corners, embedded in the medullary cavity, can achieve a reliable internal fixation, can avoid the occurrence of rotation, side shift and angular displacement. Its disadvantages are: it requires certain equipment and its operation is more complicated. Intramedullary needles are used to fix long bone fractures, as if using a shaft to pass through two bamboo tubes. If the outer diameter of the intramedullary needle is equal to the inner diameter of the long bone, the fixing effect is good, and the alignment and alignment can be stably maintained. Fractures occur in the narrowest sections of long tubular bones (such as the ulna, middle radius, upper, middle 1/3 of femur, humerus, and tibia), and intramedullary needles of corresponding width can be directly tightly embedded in the cortex around the medullary cavity On the inner layer of bone, the cross-section of the needle can have a good elastic fixation effect, and both ends of the needle can be fixed in the cancellous bone or the cortical bone at the entrance of the needle to prevent various displacements, which is ideal. Internally fixed. When the fracture occurs in the non-narrow section of the long tube bone, although the direct elastic fixation of the intramedullary needle cannot be relied on, the stability of the fracture can be achieved by the fixation of the upper, middle, and lower points [Figure 1]. The types of intramedullary needles are plum-shaped, v-shaped, diamond-shaped, triangular and round. Straight intramedullary needles are used for the femur, humerus, and ulna, and curved intramedullary needles are used for the tibia and radius [Figure 2]. The advantages of plum-shaped and v-shaped intramedullary needles are less damage to the medullary cavity, little increase in intramedullary pressure during insertion, and few complications of fat embolism; at the same time, the cross-section of these two needles has strong elastic fixation and can be tight Embedded in the medullary cavity, it effectively prevents the fracture from rotating, so it is more commonly used clinically, especially the plum blossom shape. Round needles are only used for short tubular bones, such as metacarpals, patellas, etc. Solid intramedullary nails have been discarded due to severe bone marrow damage.