Aetna considers the use of the Metrecom skeletal analysis system or other computerized, biomechanical, or digital skeletal analysis systems experimental and investigational because the value of this analysis in improving clinical outcomes is unproven. Individual components of these analyses are also considered experimental and investigational.
The Metrecom skeletal analysis system is a non-invasive, computerized electrogoniometer designed for postural evaluation, spinal analysis, and measurements of joint range of motion (ROM) and the Cobb angle. It is designed to measure the entire expanse of the human body, in particular the osseous spatial arrangement of the spine, pelvis, upper and lower limb segments, in an X-Y-Z coordinate system.
This instrument consists mainly of a touch probe, a linkage arm with 6 angular displacement transducers, collectively known as a digitizer, and an IBM-compatible computer with a software package. The system is actually a 3-dimensional (3-D) digitizer incorporating an electromechanical linkage arm having 3 joints comprised of 6 angular displacement transducers. The arrangement of the 6 rotatory transducers allows the stylus point at the end of the linkage arm to move with 6 degrees of freedom; thus, it is able to reach any point in space within the range of the linkage arm. The touch probe is placed on various palpated landmarks of the body, and readings of these landmarks, orientations, and positions are accomplished by means of a foot switch. The computer then processes all this information and creates a 3-D image in its memory. This image is then manipulated through various mathematical and engineering procedures to provide projections of various long bones on the 3 planes of the body. The software creates a computer plumb line by which all the landmarks are referenced. Both relative and absolute deviations from the plumb line are recorded for various clinically important landmarks and structures.
There is still considerable controversy regarding whether the Metrecom skeletal analysis system or other computerized/biomechanical/digital skeletal analysis systems provide accurate and reliable postural and vertebral analyses and measurements of ROM and the Cobb angle. Further investigation is needed to ascertain the usefulness of these systems in the evaluation of musculoskeletal dysfunction, especially the rating of a disability or the grading of a recognized musculoskeletal disorder, as well as their contribution to treatment effectiveness and final health outcomes.