Abstract Details

Presented By:Baschuk, Christopher
Affiliated with:University of Utah, Orthopaedics
Authors:Chris Baschuk, Trevor Shelton, Roy Bloebaum, Kent Bachus
From:Orthopaedic Research Laboratory University of Utah Orthopaedic Center, Bone & Joint Research Lab DVA SLC Health Care System, University of Utah Department of Bioengineering
Title
Variance of Femoral Bow in the Sagittal Plane Based on Age, Gender and Ethnicity for Percutaneous, Osseointegrated Implants
Abstract

Percutaneous osseointegrated implants as a docking technology for exoprosthetic limbs are being considered worldwide as an alternative to sockets. No data are currently available to quantify the variance of femoral bow based on age, gender and ethnicity (AGE). These data are critical for establishing implant design parameters that are required to assure endosteal attachment of these percutaneous osseointegrated implants.

To determine variance based on AGE the femoral canal of cadaveric femurs of varying AGE were modeled as two straight lines subtended by an angle of incidence based on the center of area data from CT scans of the region from 35-80% of the biomechanical length (BML) (N=178). The acute angle between the defined lines and its location were taken to represent the angle of incidence of the femoral bow and its break point respectively. Statistical significance between AGE was defined as a p-value of less than 0.05 from a multivariable mixed-effects linear regression model.

The average angle of incidence of the femoral bow was found to be 7.08 ± 0.19º. The break point of the femoral bow was found to be at 59.3 ± 0.37% of the BML.

Statistically significant difference was found in the break point data based on ethnicity. This suggests that ethnicity may be a more important variable to consider in the design and development of femoral intramedullary implants than are age and gender.

Modeling the femoral canal as two line segments subtended by a small angle of incidence simplifies the design of intramedullary implants. Only at the break point of the femur would the implant need to be curved instead of straight. Only in the region surrounding the break point would it be important to know the bow angle.