Accuracy of a new innovative automatic sensor system (ADEPTH^®) for measuring drill hole depth in orthopedic surgery

The purpose of this study was to compare the accuracy, precision and the rate of correct screw size selection of the ADEPTH^® automatic sensor to that of a manual depth gauge (DG) when measuring drill hole depths on human cadaveric bones.

The depths of holes, drilled in the femur, tibia and bilateral radii of a Thiel embalmed human cadaver, were measured with both the ADEPTH and a DG. Depths measured on a high resolution computed tomography (CT) scan served as a reference for the ADEPTH and the DG measurements. Errors and variances of the errors of the ADEPTH and DG measurements, compared to the CT measurements, were analyzed to assess the accuracy and precision, respectively. Additionally, the proportion of correct screw size selection of both the DG and ADEPTH system were established based on the agreement with the CT measurements.

The ADEPTH showed a smaller mean absolute error (0.72 mm [0.62, 0.83]) compared to the DG measurements (0.88 mm [0.75, 1.02]), yet the difference was not statistically significant (p = 0.098). The ADEPTH showed higher precision compared to the DG measurements. The ADEPTH measurements showed a significantly higher agreement with the CT (68%) as compared to the DG measurements (52%) (p = 0.03).

The ADEPTH automatic sensor system has a comparable accuracy and higher precision than the conventional depth gauge (DG), translating into a higher rate of accurately selected screw sizes. Further clinical studies should be performed to investigate the employability and benefit of the ADEPTH in a clinical setting.