The learning curve associated with thoracoscopic spinal instrumentation

Study Design. Consecutive case prospective radiographic and medical record review. Objective. To define the learning curve associated with thoracoscopic spinal instrumentation by evaluating operative data and early outcomes of 1 surgeon's ( B. L.) cases. Summary of Background Data. Thoracoscopic spinal instrumentation for the treatment of thoracic adolescent idiopathic scoliosis has emerged as an alternative to open anterior and posterior techniques. The technique is technically demanding and has been perceived as having a prohibitive learning curve. Methods. The operative reports, charts, and surgeon's database were used to evaluate operating time, estimated blood loss, levels fused, complication rate, blood transfusions, and curve correction, among other variables. For purposes of analysis, the entire cohort was divided into 2 groups of 28 and 29 patients, respectively, and then 4 groups of 14 patients ( the last group with 15) were used for comparison. Results. The records of 57 patients were evaluated. No significant difference in estimated blood loss or number of levels fused was noted for either comparison ( P = 0.46 and P = 0.66, respectively). There was no significant difference in blood transfusion requirements, with 7% in group 1 and 18% in group 2 ( P = 0.35). Operating time was significantly less after 28 patients were operated on 6.2 +/- 1.3 hours versus 5.3 +/- 1.2 hours ( P = 0.011). Percent curve correction was significantly better after 28 cases were performed, 54.4 +/- 17.9 in the former groups versus 65.7 +/- 10.4 in the latter half of cases ( P = 0.005). Complications were evenly distributed throughout the series. No significant differences were observed between the 2 groups in terms of rate of complication ( P = 0.50). No major complications, such as neurologic deficit or significant hemorrhage, were observed. Conclusions. The learning curve associated with thoracoscopic spinal instrumentation appears to be acceptable. Significant differences were noted in operating time and percent curve correction after 28 cases. The complication rates remained stable throughout the surgeon's experience.