###### Abstract
The primary goal of limb lengthening is to correct leg length discrepancies, thereby achieving bodily balance and preventing issues in the back, hips, and knees that can result from walking with legs of different lengths [4]. Motorized intramedullary lengthening nails have been used for three decades, marking a significant improvement over external fixators by reducing the risk of pin site infections and enhancing patient comfort during the limb lengthening process. Moreover, internal nails allow patients to engage in weight-bearing activities earlier in their treatment. In a review of 377 patients who underwent limb lengthening, 40 devices experienced mechanical failures, with over half requiring additional corrective surgeries. Specifically, 16 devices failed during the lengthening phase [5]. Given this failure rate, further studies are necessary to investigate the mechanical characteristics and the pros and cons of intramedullary lengthening nails. One common method for inserting the lengthening nail involves entering through the upper part of the femur, near the hip, in a procedure known as antegrade insertion. This process includes making skin incisions and possibly cutting the bone at the osteotomy site for lengthening [6]. Once inserted, the lengthening process begins and can extend up to a maximum of 80 mm, depending on the patient's requirements. The lengthening duration correlates with the length requirement, the greater the required length, the longer the process. During weight-bearing activities such as standing, walking, and physical exercise, mechanical loading occurs on the bones, stimulating bone cells called osteoblasts responsible for bone formation. Controlled stress or load increases bone density and strength, making weight-bearing exercises essential for maintaining strong bones. In limb lengthening, all weight loading is borne by the intramedullary lengthening nails. The global average adult human mass is approximately 136.7 pounds (62.14 kg) [7]. Understanding average human mass is crucial in the design and use of limb lengthening devices, as it affects the mechanical load the limbs must bear during lengthening. These devices work by gradually separating the bone at the desired length and allowing new bone and soft tissue to form in the gap. Body weight and mass distribution significantly influence the stresses on the lengthened limb, making it essential to consider factors such as the patient's mass, the location of the lengthening, and the rate of distraction. Maintaining a healthy body weight is important for both patients and healthcare providers to ensure successful limb lengthening outcomes. Materials used for medical implants must meet stringent requirements for their safe integration into the human body, including biocompatibility, corrosion resistance, mechanical strength, inertness, and radiopacity. The selection of materials for orthopedic implants and surgical instruments is meticulous, with titanium and stainless steel being preferred due to their exceptional properties. Stainless steel is ideal for its strength, corrosion resistance, and biocompatibility, ensuring durability and minimizing adverse reactions in the challenging environments that these devices encounter. Titanium and its alloys are also highly regarded for their biocompatibility, low density, and robustness, making them excellent choices for orthopedic and dental implants. The careful selection of these materials prioritizes patient well-being and advances healthcare outcomes by ensuring their successful integration within the human body [8].