The Learning Curves of Adelaide- and Gan-Modified Lim-Tsai Flexor Tendon Repair Techniques.

Abstract

Purpose: Surgical performance that improves with experience is often depicted as representing a "learning curve." Although numerous studies examine the tensile properties of various flexor tendon repairs, few compare the associated learning curves. This study aims to address this gap by comparing the learning curves of Adelaide- and Gan-modified Lim-Tsai repairs. Emphasizing the difference in learning curves is crucial because it highlights the tension between achieving biomechanically superior repairs, which may be challenging to many surgeons, and opting for possibly incrementally less strong but more feasible techniques.

Methods: We organized a workshop attended by 20 medical students whose experience in surgery was limited to a few suturing exercises. Each participant repaired five porcine tendons in situ either with Adelaide- or Gan-modified Lim-Tsai, followed by a peripheral suture. We tested all tendons with linear static testing to measure ultimate and yield loads. In addition, repair times were recorded for each repair. We used a linear mixed model to compare learning between the techniques.

Results: Ultimate loads increased with experience and were higher in Adelaide technique during the first two repairs, compared with Gan-modified Lim-Tsai (80 N vs 63 N and 79 N vs 66 N, respectively). Yield loads also increased with experience but did not differ between the repair techniques at any time point. Mean repair times decreased from 44 to 28 minutes and from 46 to 25 minutes with Adelaide- and Gan-modified Lim-Tsai repairs, respectively.

Conclusions: The Adelaide core suture had a higher initial ultimate load capacity despite fewer suture strands, possibly indicating better tension consistency. The ultimate load of the Gan-modified Lim-Tsai repair increased between the first and fifth repair, and repeats were needed to achieve comparable results with the Adelaide repair.

Clinical relevance: The results of this study suggest that both repair methods are suitable for novice surgeons, but Adelaide tends to result in higher strength from the first repair. Generalizability to other repairs should be made with caution.