102 lumbar pedicle subtraction osteotomies: one surgeon's learning curve.

PURPOSE: Pedicle Subtraction Osteotomy (PSO) is an effective surgical technique for the correction of fixed sagittal malalignment of the spine. It is a demanding technique that requires a long learning curve. The aim of this study is to analyze a surgeon's learning curve for lumbar PSO in relation to the preoperative, perioperative, and postoperative management, with assessment of the global outcome.

MATERIALS AND METHODS: 102 patients operated over an 8-year period were included, distributed in 3 groups over the time, and retrospectively analyzed. The following data were collected: demographic characteristics, preoperative and postoperative radiological parameters, operative technical details, and complications. Multiple regression analysis was performed, and while the number of cases was the predictor, other variables such as demographic, radiographical, and surgical variables were considered as a covariate in the final model.

RESULTS: When comparing the first group and the last group of patients, the mean surgical time had decreased by 50 min, the estimated blood loss was decreased by 655 ml, and a significant decrease in dural tear occurrence was noticed. In addition, we found a significant decrease in the hospital stay length. Multivariate linear regression analysis showed that when the surgeon's experience doubles, the operative time decreases by 29 min, the blood loss by 281 ml, and the odds of hospital stay ≥ 21 days decrease by 0.66 times.

CONCLUSION: PSO technique has a relatively long learning curve. This study showed that accumulating the experience over the years, while performing cases on a regular basis, is definitely the key in mastering this complex and risky technique, with significant improvements in the perioperative parameters that directly impact the recovery and global outcome. These slides can be retrieved under Electronic Supplementary Material.