New Design of Plate Implant for Bone Healing Assessment Using Frequency Measurement: A Biomechanical Cadaveric Study

Abstract This study is a biomechanical cadaveric investigation to assess bone healing by measuring frequency changes using a new plate design called bone union detection with wire’s natural frequency (BUDWF). This plate produces sound to detect the wire's frequency. Based on natural frequency and strain theory, in bone fracture conditions, the plate experiences higher strain under axial load and generates higher frequency, compared to the bone union condition where strain is lower and frequency is lower. If frequency changes can be detected, they can be used to determine the bone healing status. Eight human cadaveric tibia bones were used in the experiment. Bone union and fracture with a 10 mm gap, fixed by the BUDWF plate, were tested under various axial loads (0 N, 100 N, 200 N, 300 N, and 400 N) using the Instron Electropuls e10000. The sound generated by the wire on the BUDWF plate was recorded with a condenser microphone and analyzed the frequency across both groups at each axial load condition. We found that the frequency did not change with any axial loads in bone healing, which is different from the bone fracture where the frequency was higher under high axial load. When comparing the two bone conditions, there were significant differences in frequency change under axial loads of 300 and 400 N (p 0.01 and <0.001). From the result, The BUDWF plate with frequency measurement can assess bone healing by comparing the frequency changes from the bone fracture and the bone union condition under an axial load of 400 N. The BUDWF plate with frequency measurement can assess bone healing by comparing the frequency changes from the bone fracture and the bone union condition under an axial load of 400 N. The author suggests monitoring bone healing by tracking the decrease in frequency under an axial load of 400 N as it approaches the unloaded condition (axial load of 0 N). This can assist in determining the healing of the bone union. Although this study is a biomechanical cadaveric study and experiment in only two bone conditions without a real, gradual bone healing process, we trust this plate will be the prototype for developing the device to help bone healing detection in the future. Level of Evidence: Experimental study level V