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

Abstract

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.

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Funding

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the contents of this study.

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Authors

Contributions

YHP: lead investigator and first author, performing study intervention, writing manuscript. WK: performing study intervention and data analysis. KSJ: performing study intervention and data analysis. THL: performing study intervention and data analysis. EDY: outcome assessment and data analysis. GWC: outcome assessment and manuscript review. HJK: corresponding author and study coordinator, manuscript review.

Corresponding author

Correspondence to Hak Jun Kim.

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Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

This study was approved by the local Ethics Committee (IRB No. 2021GR0048, 2021AS0021, and BOHUN202101036). This study was approved by the institutional review boards of three facilities.

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Park, Y.H., Kim, W., Jang, K.S. et al. Learning curve of the Krackow suture technique for the repair of Achilles tendon rupture. Arch Orthop Trauma Surg (2021). https://doi.org/10.1007/s00402-021-04213-3

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Keywords

  • Linear models
  • Operative time
  • Suture techniques
  • Tendon repair