Learning curve of the Krackow suture technique for the repair of Achilles tendon rupture.

Introduction: Knowledge on the learning curve for the repair of Achilles tendon rupture is limited. The aim of this study was to quantify the learning curve for the Krackow suture technique for the repair of Achilles tendon rupture and to identify the correlation between the cumulative volume of cases and clinical outcome measures.

Materials And Methods: A total of 226 cases of Achilles tendon repair using the Krackow suture technique were reviewed. Each surgery was independently performed by four surgeons who started a foot and ankle specialty career after fellowship training. After logarithmic transformation of the operative time and cumulative volume of cases, a linear regression analysis was performed to determine the best-fit linear equations to predict the required time for the Krackow suture technique according to the cumulative volume of cases. The correlation between the cumulative volume of cases and clinical outcome measures was analyzed using Pearson correlation coefficients. Receiver operating characteristic curves were constructed to determine the minimum number of cases with an operative time shorter than the average in the first 30 cases.

Results: In all four surgeons, significant log-linear correlations were observed between the operative time and cumulative volume of cases. The best-fit linear equations showed estimated learning rates of 90%, 87%, 92%, and 86% for each of the four surgeons, indicating that the necessary operative time decreased by 10%, 13%, 8%, and 14%, respectively, when the cumulative volume of cases had doubled. The minimum number of cases with an operative time shorter than the average was 9 (91% sensitivity and 59% specificity). The clinical outcome measures at 6 and 12 months postoperatively were available for one surgeon; however, no correlation was found with the cumulative volume of cases.

Conclusion: The learning rate for the Krackow suture technique for the repair of Achilles tendon rupture was approximately 89%, indicating that the required operative time can decrease by up to 11% when the cumulative volume of cases doubles. Therefore, it is important to rapidly accumulate surgical experience during the early phase of training.