Optimizing Pedicle Subtraction Osteotomy Techniques: A New Reduction Plier to Increase Technical Safety and Angular Reduction Efficiency

BACKGROUND Pedicle subtraction osteotomy (PSO) is a technically demanding surgery. There is room for development of osteotomy reduction instruments like the one we present in this study, to better guide angular correction and closure of the osteotomy line. OBJECTIVE To present a new surgical instrument that optimizes PSOs of the thoracolumbar spine. METHODS Seventeen consecutive patients have been treated at 3 different European University Hospitals. All underwent a PSO of the lumbar spine to treat major sagittal imbalance. The amount of vertebral angular correction needed was calculated using the full balance integrated (FBI) method. A special plier, which allows to safely control the angular correction, was used intraoperatively. Preoperative and early postoperative global sagittal balance parameters were compared. RESULTS The mean preoperative calculated correction angle (FBI) was 33.8 degrees; the mean postoperative correction obtained was 32.1 degrees. Lumbar lordosis was statistically greater than preoperatively (55.8 degrees vs 19.4 degrees, P<.0001). The global sagittal balance was improved, as shown by the increase of the spino-sacral angle from 122 degrees preoperatively to 128 degrees postoperatively (P=.0547). None of the patients had an intraoperative or early postoperative neurologic complication. There were no mechanical intraoperative complications during correction nor at the first postoperative follow-up. CONCLUSION The advantages of the instrument are safe, precise, and efficient reduction, by a rotation of the pedicle screws close to the osteotomy line, thus avoiding collapse and lack of correction, complications usually seen with the conventional technique. Further prospective studies are needed to confirm these results.