Should Shoulder Balance Determine Proximal Fusion Levels in Patients With Lenke 5 Curves?

Abstract

Multicenter review of prospectively collected data. To identify the frequency of an opposite high shoulder in Lenke 5 patients and evaluate factors that influence preoperative and postoperative shoulder balance. A high left shoulder is an indication to extend the fusion proximally in a right thoracic curve. Some apply a similar rule to high right shoulders in patients with left thoracolumbar/lumbar curves. A prospective multicenter adolescent idiopathic scoliosis database was queried for patients with Lenke 5 curves and minimum 2-year follow-up. Preoperative and postoperative shoulder height differences were recorded and categorized by the opposite shoulder (right shoulder in a left thoracolumbar curve) as high (greater than 1 cm), level (0-1 cm), and low (less than 1 cm). Preoperative and postoperative radiographic variables and Scoliosis Research Society questionnaire scores were evaluated. Of the 104 patients identified, 37% had level shoulders and 53% had a high opposite shoulder. A high shoulder was associated with a greater mean thoracic Cobb (31°) than a level (24°) or low shoulder (26°) (p = .008). Postoperatively, 64% of patients had level shoulders (less than 1 cm); 93% had a shoulder difference less than 2 cm. Preoperative lumbar Cobb was a significant predictor of postoperative shoulder height (p = .051). A slightly greater proportion of preoperative high shoulders (36%) had a nonselective fusion than those with level (27%) or low (9%) shoulders. Among the 29 patients with a preoperative moderate or significant high shoulder (greater than 2 cm), 3 continued to have a high shoulder greater than 2 cm that was not influenced by fusing the thoracic spine. There were no significant differences in preoperative or postoperative Scoliosis Research Society scores based on shoulder height (p > .05). Half of all Lenke 5 curves have a high opposite shoulder that is influenced by the size of the compensatory thoracic curve. Postoperatively, most patients had level shoulders. Inclusion of the thoracic spine did not influence postoperative shoulder balance.