A review of the trunk surface metrics used as Scoliosis and other deformities evaluation indices

Abstract

BackgroundAlthough scoliosis is characterized by lateral deviation of the spine, a 3D deformation actually is responsible for geometric and morphologic changes in the trunk and rib cage. In a vast related medical literature, one can find quite a few scoliosis evaluation indices, which are based on back surface data and are generally measured along three planes. Regardless the large number of such indices, the literature is lacking a coherent presentation of the underlying metrics, the involved anatomic surface landmarks, the definition of planes and the definition of the related body axes. In addition, the long list of proposed scoliotic indices is rarely presented in cross-reference to each other. This creates a possibility of misunderstandings and sometimes irrational or even wrong use of these indices by the medical society.Materials and methodsIt is hoped that the current work contributes in clearing up the issue and gives rise to innovative ideas on how to assess the surface metrics in scoliosis. In particular, this paper presents a thorough study on the scoliosis evaluation indices, proposed by the medical society.ResultsMore specifically, the referred indices are classified, according to the type of asymmetry they measure, according to the plane they refer to, according to the importance, and relevance or the level of scientific consensus they enjoy.ConclusionsSurface metrics have very little correlation to Cobb angle measurements. Indices measured on different planes do not correlate to each other. Different indices exhibit quite diverging characteristics in terms of observer-induced errors, accuracy, sensitivity and specificity. Complicated positioning of the patient and ambiguous anatomical landmarks are the major error sources, which cause observer variations. Principles that should be followed when an index is proposed are presented.

Posture and low back pain during pregnancy — 3D study

“…No palpation examination of the subject's body was necessary. Based on the positions of landmarks, the automatic calculation was performed to obtain well-known and commonly used parameters for back surface evaluation [24]: Posterior Trunk Symmetry Index (POTSI) [25][26][27], Deformity in the Axial Plane Index (DAPI) [24][25][26], surface kyphosis and lordosis angles and sagittal trunk inclination. The example result of the postural assessment is presented in Figure 1.…”

Evaluation of Scoliosis Deviation with Clinical Measurements during Physical Therapy

“…Our way of measuring is based on some before researches that convexity of lumbal spine is with correlation of pelvis fall, by thoracic lumbar scoliosis, and the upper arm and scapula asymmetry is with correlation of scoliosis deviation [33][34][35]. Our TS measurement is only for existing asymmetry of Lorence's triangle and pelvis tilting in thoracic lumbar scoliosis.…”

Automatic recognition of surface landmarks of anatomical structures of back and posture

“…The most of them are marker-dependent or markerless optical systems, based mainly on the moiré technique, laser and structured light illumination (SLI), incorporating assessment methods which analyze mutual position of certain anatomical structures. [21][22][23][24][25][26][27][28][29][30][31][32] Back shape indices calculated using mentioned systems were proven to be useful and reliable in clinical settings. 25,33 The conformity of the parameters with the gold standard used in radiography, the Cobb angle measurement, is quite high, e.g., the r-Pearson correlation coefficient was estimated to 0.801 for the Quantec Q-angle parameter 34 and to 0.668 and 0.706 for the posterior trunk symmetry index (POTSI) and deformity in the axial plane index (DAPI).…”

“…22 The approach used in creating these parameters is approximately equivalent to the physical examination, where the physician mainly evaluates the broadly understood symmetry of the back. The vast majority of diagnostic systems are based on manual indication of anatomical back surface landmarks 28,[35][36][37] by operator's palpation. Palpated landmarks are often considered as a principle for quantitative evaluation of deformation, however, landmarks pointed by inspection are accepted and reliable.…”

“…Palpated landmarks are often considered as a principle for quantitative evaluation of deformation, however, landmarks pointed by inspection are accepted and reliable. 28,38 The aim of the presented algorithm is to provide a more reliable way of anatomical back shape landmarks localization by automatic markerless analysis of the back shape surface. The algorithm was developed as a straightforward generalization of the existing manual deformation assessment methods used in clinical conditions.…”