TRACE (Trunk Aesthetic Clinical Evaluation), a routine clinical tool to evaluate aesthetics in scoliosis patients: development from the Aesthetic Index (AI) and repeatability

Abstract

Background: Aesthetic appearance is of primary importance in the treatment of adolescent idiopathic scoliosis (AIS), but to date tools for routine clinical practice have not become available. The aim of the present study is to develop such a tool and to verify its repeatability.

Instrumentation: At first we developed the Aesthetic Index (AI), based on a three-point scale for asymmetry of the shoulders, scapulae and waist that we tested for 5 years. From this experience we developed another tool we called TRACE, the acronym of Trunk Aesthetic Clinical Evaluation; TRACE is a 12-point scale based on four sub-scales, shoulders (0-3), scapulae (0-2), hemi-thorax (0-2) and waist (0-4).

Population: Posterior-anterior (PA) photographs of one hundred-sixty AIS patients.

Procedures: Each photograph was scored in two independent tests by four observers using AI, and subsequently TRACE.

Data analysis: Kappa statistical analysis and 95% level of agreement were used; we also identified the minimum significant change (95% confidence level).

Results: We found the intra- and inter-raters repeatability of AI to be fair. Three points out of seven was the minimum significant change between two different evaluations. For TRACE, intra-rater repeatability was fair and inter-raters poor; but the minimum significant change was three (intra-rater), or four (inter-raters) out of twelve points.

Conclusion: Widening the scale from 7 (AI) to 12 points (TRACE) increased the clinical sensitivity to changes of the aesthetic scale, even if TRACE has only a fair repeatability. TRACE is a no-cost tool for routine clinical practice in AIS patients. Due to the absence of other comparable validated tools, once the inherent measurement error is known and understood, its routine clinical use by physicians is advised.

Figure 1

Shoulder asymmetry, as evaluated in TRACE, ranges from 0 to 3. For the shoulders it is easy to detect some intermediate values, so we defined asymmetry (from the top) slight (1), moderate (2) and important (3).

Figure 2

Hemi-thorax asymmetry as evaluated in TRACE: This item was created as a complement of the scapulae, since we noted that occasionally there is an evident prominence of the last ribs on the back even when there is no real asymmetry in the scapulae. From the left: slight (1) and important (2) asymmetry.

Figure 3

Scapulae asymmetry as evaluated in TRACE: (from the left) slight (1) and important (2).

Figure 4

Waist asymmetry as evaluated in TRACE: it was quite easy to define a total asymmetry (a score of 4) when one flank was straight or when there was a lateral decompensation of the trunk. It was easy as well to define a very slight (a score of 1) and an important but not complete (a score of 3) asymmetry; between these points we defined a mild asymmetry (a score of 2). In the figure, from the top: slight (1), mild (2), moderate (3) and important (4) asymmetry.