## 1 Introduction  
Osteogenesis Imperfecta (IO) stands out from other bone diseases due to its high rarity and clinical severity, typically detected in newborns and child patients. It is characterized by low bone mass, causing several deformations due to body weight. Additionally, long bones like the femur and tibia, among others, become more fragile and susceptible to bone fracture [1]. This has led to treatments that include wearing external elements on the body to decrease possible injuries due to considerable low bone stiffness [2]. Bone-plates, external nails, flexible intramedullary devices, hydromechanics implants, and electromechanical devices treat fractures in fragile bone. In general, all these devices increase bone stiffness by attaching elements directly onto the bone. The main trouble with this solution is due to the fragility of the IO bones. The bones' low density in IO patients decreases the implantation area, causing the implant to slip out of place. In addition, IO children increase in size by almost 2 cm per year and need to replace their implants constantly. For this reason, it is necessary to attach medical devices with minimal invasion and high bone fixation. One practical solution is the use of intramedullary implants. The procedure described for this kind of implant includes putting metallic elements onto the bone's medullary space. State-of-the-art intramedullary implants are mainly classified into three types: rigid implants, flexible implants, and telescopic implants. Rigid implants were first used by [PERSON] [3]. These devices are characterized by plates or rods fixed to the fractured bone using completely steel nails. Their main advantage is the immediate intervention for the patient. Unfortunately, this type of element cannot be placed in patients with severe bone deformities or those with multiple fractures, since their fixation depends on the patient's available bone area. In anticipation of this in the late 1990s, the [PERSON] brothers proposed the use of flexible nails. The main improvement was that these implants are put in pairs inside the medullary cavity, increasing the implant's adaptability to the bone shape [4]. The patient's operation is less invasive and allows for the combination of this technique with other fracture fixation methods, significantly improving the patient's recovery. The trouble with this method is that it prevents bone growth when used on patients too young. In other words, if the implant remains well-fixed to the ends of the bone, the growth in the patient's bone will be limited to the original size of the implant, causing the need for continuous operations to adapt to the bone growth. To solve this inconvenience, intramedullary telescopic nails (ITN) were developed [5]. These devices are mainly characterized by having an element that dynamically increases the original implant's length by dividing the main element's size into two parts by some types of active or passive mechanisms [6]. The most recent models, such as Bailey and Dubow [7], Sheffield [8], or the Fassier-Duval [9], differ in the way in which each one is anchored to the bone. The main disadvantage of using this kind of device in patients with IO is the small area to anchor the device to enable proper functioning. Auxiliary systems could be used to fix this type of device [10; 11]. Another way is using external blocks, although they lack aesthetics and efficiency by remaining for long periods outside the stabilized limb [12]. Thus, reference [13] points out that, until 1999, intramedullary fixation evolution has been lack. The main design parameters have been the cross-transversal section and the locking method to the bone. By combining the previously mentioned models' results a new model of the intramedullary telescopic nail, with minimal external anchorage on the distal section and screw fixation on the proximal section, was developed. In addition, the intramedullary nail is divided into two parts, allowing them to be extended almost 2/3 of their original length.