Effects of personalized bone prosthesis applied after knee peripheral bone tumor on lower extremity biomechanics

In recent years, 3D printing technology has been increasingly applied in the medical field. Personalized plaques and prostheses are designed with the help of 3D printing technology for repair and reconstruction of bone defects after tumor resection. Measuring the effects of the applied treatment on body biomechanics is important and necessary to determine the effectiveness of the treatment and to determine what needs to be done for better results. The determined results will also guide the treatment that should be done in order to have a healthier body biomechanics in the recovery after the application. In addition, previous evaluations are important in determining what differences this pathology causes. The aim of the study is to present these differences in data and to present a statistical data to the solution studies to be carried out in line with the results. For this purpose, joint range of motion measurement and gait evaluation were performed before and after surgery. Joint motion measurement was applied to the lower extremity joints with a goniometer. The walking assessment was made by video recording the person's walking on the determined four-meter-long walking track from the front and from the side. In the lower extremity; hip joint movements, knee joint movements and ankle joint movements were evaluated. Goniometric measurements of hip flexion and extension movements, knee flexion and extension movements, ankle dorsiflexion and plantar flexion movements were made. In gait evaluation; walking speed, number of steps, swing and stance phases durations were determined. After surgery, hip flexion, knee extension, ankle plantar flexion, and hip extension angles decreased in the pathological extremity compared to the pre-surgery. An increase in knee flexion has been observed. No change in ankle dorsiflexion was observed. While hip flexion, ankle plantar flexion and knee flexion angles increased after surgery compared to preoperatively, hip extension angles decreased in non-pathological extremities. There was no change in knee extension and ankle dorsiflexion. An increase in the number of steps and a decrease in walking speed were observed. There was an increase in all gait phases after surgery compared to preoperatively. The total swing phase increased more than the stance phase. The pathological limb stance phase increased more than the swing phase. The non-pathological limb swing phase increased more than the stance phase.