Monitoring Osseointegration Process Using Vibration Analysis

Area of Science:

• Biomedical Engineering
• Orthopedic Surgery
• Rehabilitation Medicine

Background:

• Osseointegration implants offer improved comfort and control for transfemoral amputees over traditional socket devices.
• A significant challenge is the lengthy rehabilitation required to achieve sufficient femur-implant stability for full weight-bearing.
• A reliable method to assess osseointegration progress is crucial for reducing recovery time and ensuring prosthesis readiness.

Purpose of the Study:

• To investigate the efficacy of a vibration-related index (E-index) in quantifying the degree of simulated osseointegration.
• To evaluate the E-index's performance across different residual femur lengths (152, 190, and 228 mm).
• To determine if the E-index can provide a quantitative measure of osseointegration independent of residual femur geometry.

Main Methods:

• Simulated osseointegration was modeled using epoxy at the femur-implant interface to mimic stiffness changes.
• Vibrational analysis, including cross-spectrum and colormap of normalized magnitude, was performed.
• The proposed E-index was calculated and correlated with the epoxy's cure time (representing osseointegration progression).

Main Results:

• Significant changes in cross-spectrum and colormap were observed during the epoxy curing process.
• The E-index demonstrated a consistent upward trend, increasing by an average of 53% over the cure time.
• This trend was consistent across all tested residual femur lengths, indicating robustness.

Conclusions:

• The E-index effectively quantifies the degree of simulated osseointegration.
• This vibration-based method offers a promising, geometry-independent approach for assessing implant stability.
• The E-index has the potential to optimize rehabilitation protocols for transfemoral amputees undergoing osseointegration therapy.