Research

Real time noninvasive assessment of external trunk geometry during surgical correction of adolescent idiopathic scoliosis

Luc Duong¹ , Jean-Marc Mac-Thiong^1,2 and Hubert Labelle^1,2

¹  Research Center, Hôpital Sainte-Justine, 3175 Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada

²  Department of Orthopaedic Surgery, Université de Montréal, PO Box 6128, Station Centre-ville, Montréal, H3C 3J7, Canada

author email corresponding author email

Scoliosis 2009, 4:5doi:10.1186/1748-7161-4-5

Published:	24 February 2009

Abstract

Background

The correction of trunk deformity is crucial in scoliosis surgery, especially for the patient's self-image. However, direct visualization of external scoliotic trunk deformity during surgical correction is difficult due to the covering draping sheets.

Methods

An optoelectronic camera system with 10 passive markers is used to track the trunk geometry of 5 scoliotic patients during corrective surgery. The position of 10 anatomical landmarks and 5 trunk indices computed from the position of the passive markers are compared during and after instrumentation of the spine.

Results

Internal validation of the accuracy of tracking was evaluated at 0.41 +/- 0.05 mm RMS. Intra operative tracking during surgical maneuvers shows improvement of the shoulder balance during and after correction of the spine. Improvement of the overall patient balance is observed. At last, a minor increase of the spinal length can be noticed.

Conclusion

Tracking of the external geometry of the trunk during surgical correction is useful to monitor changes occurring under the sterile draping sheets. Moreover, this technique can used be used to reach the optimal configuration on the operating frame before proceeding to surgery. The current tracking technique was able to detect significant changes in trunk geometry caused by posterior instrumentation of the spine despite significant correction of the spinal curvature. It could therefore become relevant for computer-assisted guidance of surgical maneuvers when performing posterior instrumentation of the scoliotic spine, provide important insights during positioning of patients.