Presence of manubrium–sternum joint does not assure sufficient elevation of sternum in Nuss procedure for pectus excavatum patients

The manubrium and body of the sternum are connected by the manubrium–sternum joint (MSJ). In performing the Nuss procedure for pectus excavatum patients, the body of the sternum is elevated as the operator flips correction bars upside down. Theoretically, the presence of the MSJ should allow elevation of the sternum body. However, does the MSJ secure sufficient elevation of the sternum? This study aims to elucidate this clinical question.

Seventy-four adult pectus excavatum patients with moderate to serious deformity (with Haller Index being equal to or greater than 5) were included in the study. The MSJ was open in all patients. For 29 patients, the sternum was elevated by only bar flipping (Non-Separation Group); for 45 patients, the sternum was horizontally separated after bar flipping (Separation Group). Whether or not additional elevation for Separation Group patients results from the division was observed, and the degree of the additional elevation was evaluated. Furthermore, 74 patients subjectively evaluated postoperative pain and gave scores with a Visual Analog Scale ranging from 0 (no pain) to 10 (intolerable pain). The VAS scores were compared between the two groups.

In the Separation Group, the sternums of all patients achieved additional elevation from sternum separation. The pain scores were lower for the Separation Group than for the Non-Separation Group.

Even when the MSJ is present, horizontal separation enhances the elevation of the sternum. Furthermore, horizontal separation of the sternum reduces postoperative pain.