Normative 3D opto-electronic stereo-photogrammetric sagittal alignment parameters in a young healthy adult population

Abstract

This paper describes and presents a stable and reliable set of stereo-photogrammetric normative data for global and spino-pelvic sagittal alignment, as a proven reference system for evaluating/measuring a fully unconstrained natural upright neutral standing attitude in a young healthy adult population. The methodological features described in this article will enable future studies to replicate and/or directly compare a wide range of different postural tests and/or sagittal alignment assessment procedures including the study of sagittal spine shape variations occurring during gait performance. To date, the quantitative evaluation of adult spinal deformity (ASD) has been mainly confined to the X-ray imaging approach and, more recently, to 3D X-ray reconstruction. Within the existing evaluation framework an opportunity exists for an additional approach: a quantitative evaluation procedure which is easy, accurate, relatively speedy and non-ionising, in order to monitor and track the progress of patients in the areas of both surgical and non-surgical treatment. The resources and methodology described in this paper have been proven to meet all these criteria. They have enabled full 3D posture (including 3D spine shape and sagittal alignment of the skeleton) to be consistently and successfully measured in adult volunteers. All the measurement/evaluation procedures and outcomes carried out were based entirely on the new non-ionising 3D opto-electronic stereo-photogrammetric approach described in this article. The protocol for this methodology was based on a standard set of 27 pre-selected anatomical “landmarks” on the human body, providing standard reference points for observation and measurement. A total of 124 healthy subjects were successfully assessed and, for each subject, 27 individual markers were applied to the corresponding locations on his/her body. Statistical tests to investigate gender differences were also carried out. Descriptive statistics are provided for all 15 of the spino-pelvic parameters under consideration. Results indicated significant differences between genders in five sets of parameters: Kyphosis tilt, Head tilt, Pelvic tilt, Spino-pelvic angle and T1-pelvic angle. The data also demonstrate a high degree of congruity with results obtained using the X-ray method, as evidenced by the existing literature in the field. In summary, the current study presents a new stereo-photogrammetric opto-electronic technology which can be used successfully for ASD evaluation and introduces a comprehensive set of normative data analogous to those proposed in X-ray analysis for sagittal spino-pelvic and total body alignment.

3D Quantitative Evaluation of Posture and Spine Proprioceptive Perception Through Instinctive Self-Correction Maneuver in Adolescent Idiopathic Scoliosis

“…Such data demonstrated a high agreement with results obtained via other methods as presented in the existing literature. There is firm consistency with the results, especially concerning the spine, obtained via x-ray measurements which at this time are the "gold standard" (D'Amico et al, 2017b;Kinel et al, 2018). Other nonionizing approaches, such as the rasterstereographic back-surface measurement technique or the recently introduced ultrasound measurement, were excluded because they raise concerns and questions that need further clarification about measurement accuracy and/or the need for the patient to keep a constrained position during the scanning measurement (Kotwicki et al, 2007;Frerich et al, 2012;Takács et al, 2014;Bassani et al, 2019;Wanke-Jellinek et al, 2019;Wu et al, 2020).…”

“…The research presented here is a cross-sectional observational study. We have used a validated, innovative stereophotogrammetric method of 3D quantitative evaluation of the entire skeleton posture and spine shape utilizing an evidence-based medicine approach (D'Amico et al, 2017b(D'Amico et al, , 2018aKinel et al, 2018). The Ethics Committee of the University of Medical Sciences in Poznan, Poland, approved this study.…”

“…As it happens for the curve identified in the frontal plane, also the kyphosis and lordosis in the sagittal plane are appropriately identified according to the actual spine curvature spatial changes at the limit-vertebrae, i.e., they are no longer restricted to specific thoracic or lumbar anatomical regions (D'Amico et al, 1995(D'Amico et al, , 2017b(D'Amico et al, , 2018aKinel et al, 2018). We decided to consider the Cobb angle value of the two major curves (CA1, CA2, Table 2) for statistical analysis regarding the spinal deformities in the frontal plane.…”

“…• Sagittal Plane parameters: in this case [except for pelvis torsion (|PT|) that should be zero], there are no theoretical optimal reference values, so we decided to consider the normative data determined in previous studies in healthy young adults, for IO and ISCO, as reference values to be approached (D'Amico et al, 2017b(D'Amico et al, , 2018aKinel et al, 2018). • | UL| (i.e., the difference of underfoot load between the feet):…”

Quantitative Evaluation of Upright Posture by X-Ray and 3D Stereophotogrammetry With an Original Marker Placement Protocol in Late Onset Pompe Disease.

“…Other studies [24] analysed sagittal spine parameters introducing a larger number of markers placed on the spine than standard protocols, but no correlation study was performed between stereophotogrammetric and radiological sagittal angles. Instead, in our study a strong correlation was found (Table 4), highlighting a high reliability of DBTotal protocol in matching markers to spinous processes of the reference vertebrae and in detection of dorsal angles; a lower correlation was found in lumbar angles probably due to the higher thickness of the adipose tissue present in this area.…”