ScapuloThoracic Arthrodesis for Facio-Scapulo-Humeral Dystrophy: Outcomes at mean 7.3 years [3.5-13] follow-up. CT measurement of the fixation position of the arthrodesis and radioclinical correlations

Abstract

Introduction: Scapulothoracic arthrodesis may be proposed to patients having facio-scapulohumeral dystrophy to achieve gains in shoulder motion and pain relief. This study aimed to assess shoulder motion, pain and functional scores at last follow-up and to present a method of computed tomography measurements of the position of the scapulothoracic arthrodesis and study their correlations with shoulder motion.

Patients and methods: Seven patients (11 arthrodesis) were included. Shoulder motion, pain, respiratory function and deltoid strength were compared with preoperative values and Constant, Brooke and Vignos scores were assessed at last follow-up. The elevation/depression and upward/downward position of the scapula were measured by performing postoperative 3D CT reconstruction. The protraction/retraction position was measured with 2D CT reconstructions on axial view. Correlations between these measurements and shoulder flexion and abduction were analysed. All complications were searched.

Results: We found a significant improvement in mean VAS (from 3±2 to 1±1, p=0,008) shoulder flexion (64°± 11 to 113°±20, p=0,003) and abduction (from 63°±9 to 92°±13°, p=0,004). Postoperative external rotation wasn't significantly different (from 49°±19 to 43°±10, p=0,112) and on internal rotation, the hand reached on average the 9th thoracic vertebra (S1-T2). Scapulothoracic arthrodesis was mainly positioned in regard to the 1^st and the 6^th rib. The mean protraction/retraction position was 38,5°±8° and the mean scapular upward/downward rotation position was 92°±15°. No correlations were found between the scapular position and shoulder flexion and abduction.

Conclusions: Scapulothoracic arthrodesis for facioscapulohumeral dystrophy improved pain, shoulder flexion and abduction and provided good functional outcomes at 3,5 to 13 years of follow up. A method of CT assessment of the position of the arthrodesis is presented to analyse precisely the position of the scapula but no correlations with shoulder motions were found. Preoperative evaluation of deltoid function and scapular winging seemed to be the most important predictors of shoulder motions gains after this procedure.

Level of evidence: III, Retrospective cohort study.

Keywords: Facio-scapulo-humeral dystrophy; Scapula alata; Scapulothoracic arthrodesis; Shoulder motion.